Fast exchange microcatheters and systems for access to intracranial neurovasculature

Abstract

A fast exchange microcatheter (600) for access to an intracranial neurovasculature. A side opening (604) through the sidewall is located at a first distance proximal to the distal-most tip. A proximal opening (606) proximal to the side opening is a second distance from the distal-most tip. A distal reinforced catheter portion (650) extends between the distal region to a point near the side opening. A proximal reinforced catheter portion (652) extends a distance from a point near the side opening toward the proximal end of the catheter body. The side opening is positioned within a gap (G) between the proximal end of the distal reinforced catheter portion and the distal end of the proximal reinforced catheter portion. A payload (505) of the brain treatment device is housed within the lumen of the proximal end of the side opening. Related apparatus, systems, and methods are disclosed. Methods of accessing the intracranial neurovasculature using the catheter system and fast exchange microcatheter systems for accessing the intracranial neurovasculature are also disclosed.

Description

[0001] This application is a divisional application of the invention patent application with application date of January 19, 2018, application number 201880019743.X, and invention name “Single-operator intracranial medical device delivery system and method of use”; the invention patent application with application date of January 19, 2018, application number 202210564611.3, and invention name “Single-operator intracranial medical device delivery system and method of use” is also a divisional application of the above application.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to co-pending U.S. Provisional Patent Application No. 62 / 448,678, filed on January 20, 2017, and co-pending U.S. Provisional Patent Application No. 62 / 517,005, filed on June 8, 2017. The disclosures of the above provisional applications are hereby incorporated by reference in their entirety. Technical Field

[0004] The present technology generally relates to medical devices and methods, and more particularly, to single-operator intracranial medical device delivery systems and methods of use; and rapid exchange microcatheters, systems and methods for accessing the intracranial neurovasculature. Background Art

[0005] Acute ischemic stroke (AIS) usually occurs when an artery to the brain becomes blocked, which prevents fresh oxygenated blood from being delivered to the brain from the heart and lungs. These blockages are usually caused by a blood clot or embolus that gets stuck in an artery and blocks the artery that supplies an area of ​​brain tissue. If an artery is blocked, post-ischemic damage ensues, and brain cells may stop working. Furthermore, if the artery remains blocked for more than a few minutes, brain cells may die, which leads to permanent neurological deficits or death. Therefore, immediate treatment is critical.

[0006] Two main therapies are used to treat ischemic stroke: thrombolytic therapy and endovascular therapy. The most common treatment for reestablishing flow or reperfusing the stroke area is the use of intravenous (IV) thrombolytic therapy. The time period for thrombolytic therapy is within 3 hours of symptom onset for IV infusion (4.5 hours in selected patients) or within 6 hours for fixed-point intra-arterial infusion. There is no proven benefit in administering therapy at a later time, and the patient may be exposed to a greater risk of bleeding due to the thrombolytic effect. Endovascular therapy most often uses a set of tools to mechanically remove the embolus, with or without thrombolytic therapy.

[0007] The full spectrum of endovascular treatments includes mechanical embolectomy using a retractable structure, such as a coil-tipped retractable stent (also known as a stent retriever or ), braided wire stents, or laser-cut stents with struts that can be opened within a clot in the brain anatomy to allow the clot to engage with the stent struts, forming a channel in the embolus to restore a certain amount of blood flow, and then retrieving the retractable structure by pulling it out of the anatomy together with aspiration techniques. Other intravascular techniques for mechanically removing AIS-associated emboli include manual aspiration thrombectomy (MAT) (also known as the "ADAPT" technique). MAT is an intravascular procedure in which a large-bore catheter is inserted through the femoral artery and manipulated through complex anatomical structures to the level of the embolus, which may be located in the extracranial carotid artery, vertebral artery, or intracranial artery. Aspiration techniques can be used to remove emboli through a large-bore catheter. Another intravascular procedure is Stentriever-mediated manual aspiration thrombectomy (SMAT) (similar to the Stentriever-assisted "Solumbra" technique). Like MAT, SMAT involves entering the embolus through the femoral artery. However, after access is achieved, a retractable structure is used to pull the embolus back into the large bore catheter.

[0008] In order to enter the brain anatomical structure, a guide catheter or guide sheath is used to guide the interventional device from the arterial access site (usually the femoral artery) to the target anatomical structure. The length of the guide is determined by the distance between the access site and the desired position of the distal tip of the guide. Interventional devices such as guidewires, microcatheters, and intermediate catheters for sub-selective guidance and suction are inserted and advanced to the target site through the guide. Typically, the device is used in a coaxial manner, that is, the guidewire is inside the microcatheter and the microcatheter is inside the intermediate catheter as an assembly to advance to the target site in a step-by-step manner, wherein the most non-traumatic internal element first advances to the distal end and provides support for the advancement of the external element. The length of each element of the coaxial assembly takes into account the length of the guide, the length of the proximal connector on the catheter, and the length required to extend from the distal end.

[0009] A typical triaxial system, such as that used for aspiration or delivery of stent retrievers and other interventional devices, requires an overlapping series of catheters, each with its own rotating hemostatic valve (RHV). For example, a guidewire can be inserted through a Penumbra Velocity microcatheter having a first proximal RHV, which can be inserted through a Penumbra ACE 68 having a second proximal RHV, which can be inserted through a Penumbra NeuronMAX 088 access catheter having a third proximal RHV positioned in the high carotid artery via a femoral introducer. Maintaining a coaxial relationship between these catheters can be technically challenging. The three RHVs must be constantly adjusted with two hands or, more commonly, four hands. Further, the working area of ​​a typical triaxial system for aspiration and / or intracranial device delivery may require a 3-5 foot working area at the base of the operating table.

[0010] The time required to access the occlusion site and even partially restore flow to the vessel is critical in determining the successful outcome of such surgery. Similarly, the occurrence of distal emboli during surgery and potential negative neurological effects and surgical complications (e.g., perforation and intracerebral hemorrhage) are limitations to surgical success. A system of devices and methods is needed that allow rapid access, optimized catheter aspiration, and treatment to fully restore flow to an obstructed cerebral vessel. Summary of the invention

[0011] According to a first aspect, a rapid exchange microcatheter for accessing the intracranial neurovascular system is disclosed. The microcatheter includes a catheter body having a side wall extending between a proximal end and a distal tip, the side wall defining an inner lumen having an inner diameter sized to accommodate a payload of a brain treatment device. The microcatheter includes: a distal opening that exits the inner lumen near the distal tip; a side opening that passes through the side wall of the catheter body; and a proximal opening that is located proximal to the side opening. The side opening is located at a first distance proximal to the distal tip of the catheter body. The proximal opening is positioned a second distance from the distal tip of the catheter body. The microcatheter includes: a distal reinforced catheter portion that extends between a distal region of the catheter body to a point near the side opening; and a proximal reinforced catheter portion that extends a distance from a point near the side opening toward the proximal end of the catheter body. The side opening is positioned within a gap between the proximal end of the distal reinforced catheter section and the distal end of the proximal reinforced catheter section. The payload of the brain treatment device is housed within the lumen of the proximal end of the side opening.

[0012] The first distance can be between about 10 cm and about 20 cm. The second distance can be greater than about 20 cm. The distal opening can be located at the distal-most tip of the catheter. The side opening can be sized to allow a guidewire having an outer diameter equal to or less than about 0.018" to pass through. The proximal reinforced catheter portion can be less flexible than the distal reinforced catheter portion. The distal reinforced catheter portion can have a first reinforcement structure. The proximal reinforced catheter portion can have a second reinforcement structure. The first reinforcement structure can be coupled to the second reinforcement structure by a rigid coupler. The rigid coupler can form a reinforcement structure that is different from the first reinforcement structure or the second reinforcement structure. The first reinforcement structure and the second reinforcement structure can be structurally similar to each other or different structures. The first reinforcement structure can be less rigid than the second reinforcement structure, and the second reinforcement structure can be less rigid than the rigid coupler. The first reinforcement structure can be a coil, and the second reinforcement structure can be a coil, wherein the pitch of the coil of the first reinforcement structure is greater than the pitch of the coil of the second reinforcement structure. The first reinforcement structure can be a coil, and the second reinforcement structure can be a webbing.

[0013] The coupler may have a window aligned with the side opening. The side opening may be configured to allow the guidewire to pass into and out of the inner lumen while preventing the payload from engaging or hooking on the side opening when the payload moves through the inner lumen during deployment. The side wall of the microcatheter may also include: a lubricated tubular lining; and a reinforcement layer positioned above the tubular lining and more rigid than the tubular lining. The reinforcement layer may include a first reinforcement structure extending within the reinforcement catheter portion at the distal end. The second reinforcement structure extending within the reinforcement catheter portion at the proximal end may have a distal end, and the proximal end of the first reinforcement structure is separated from the distal end of the second reinforcement structure, thereby creating a gap. A short tubular rigid coupler may be positioned above the proximal end of the first reinforcement structure and above the distal end of the second reinforcement structure. The coupler may have an elongated window extending through the side wall of the coupler. An outer sheath may be positioned above the coupler and the reinforcement layer. The coupler can be sized to span the gap so that the elongated window of the coupler is aligned with the gap, while at least a first portion of the coupler is positioned above the proximal end of the first reinforcement structure, and at least a second portion of the coupler is positioned above the distal end of the second reinforcement structure. The tubular liner and the outer sheath can be sealed together at the elongated window to form a bi-laminated film encapsulating the side opening of the microcatheter. A slit can extend through the film to allow a guidewire to pass through the side opening.

[0014] The inner diameter of the microcatheter may be less than about 0.035" to about 0.0165". The outer diameter of the catheter body may be less than about 0.050" to about 0.023".

[0015] In a related aspect, a system is disclosed that includes a rapid exchange microcatheter and a distal access catheter having: a flexible distal lumen portion having a proximal end; a proximal region; a proximal opening; a distal end; and a lumen extending between the proximal end and the distal end. The lumen of the distal access catheter is sized to receive a catheter body of the rapid exchange microcatheter.

[0016] The distal access catheter may also include a proximal extension that is less flexible than the flexible distal lumen and is configured to control movement of the distal access catheter. The proximal extension may extend proximally from an attachment point of the flexible distal lumen adjacent to the proximal opening. The flexible distal lumen may have an outer diameter at the attachment point that is larger than the outer diameter of the proximal extension at the attachment point. The proximal extension of the distal access catheter may be solid or hollow.

[0017] The distal access catheter can be assembled with the tapered inner member to form an assembled coaxial catheter system. The tapered inner member can include a flexible elongated body having a proximal region, an outer diameter, a tapered distal tip, a distal opening, and a single lumen extending longitudinally through the flexible elongated body to the distal opening. The tapered inner member can include a proximal portion extending proximally from the proximal region to the nearest end of the tapered inner member. When assembled, the tapered inner member can extend through the lumen of the distal access catheter, and the tapered distal tip extends to the distal end of the distal end of the distal access catheter. The flexible elongated body of the tapered inner member can include a proximal opening sized to accommodate a guide wire. The proximal opening can be positioned to pass through the sidewall of the proximal region of the flexible elongated body. The proximal portion can be a hypotube with an opening that is fluidly connected to the single lumen of the flexible elongated body.

[0018] The system may also include a guide sheath having a working lumen extending between a proximal region and a distal region, the distal region of the guide sheath having at least one opening communicated with the working lumen of the guide sheath. The guide sheath may have a working length sufficient to position the distal region of the guide sheath within a portion of the carotid artery and to position the proximal region near the femoral access site. The flexible distal lumen portion of the distal access catheter may be dimensioned to coaxially extend through the working lumen of the guide sheath and pass through at least one opening of the guide sheath so that the distal end of the flexible distal lumen portion telescopically extends beyond the distal region of the guide sheath. The catheter body of the rapid exchange microcatheter may be dimensioned to coaxially extend through the lumen of the distal access catheter coaxially extending through the working lumen of the guide sheath so that the distal tip of the microcatheter passes through the opening at the distal end of the distal access catheter. The distal region of the guide sheath may also include an occlusion balloon on the outer surface, which is configured to block flow through the blood vessel when the sealing element expands. The brain treatment device may be a stent, a stent retractor, or a drain.

[0019] In a related aspect, a method of accessing an intracranial neurovasculature using a catheter system is disclosed. The method includes the following steps: positioning a guide sheath having a working lumen communicating with a port at a proximal end within a patient's blood vessel. The distal end of the guide sheath is advanced to at least the internal carotid artery. The method includes the following steps: inserting a distal access catheter through the port into the working lumen of the guide sheath, the distal access catheter having a lumen and a distal end. The method includes the following steps: positioning the distal end of the distal access catheter beyond the distal end of the guide sheath. The method includes the following steps: inserting a microcatheter loaded with a payload of a brain treatment device through the lumen of the distal access catheter. The microcatheter includes: a lumen; a distal region having a distal opening exiting from the lumen; and a side opening exiting from the lumen and positioned at a distance proximal to the distal opening. The payload is contained within the lumen proximal to the side opening when loaded. The method includes the steps of advancing a microcatheter loaded with a payload through a lumen of a distal access catheter until a distal region of the microcatheter is advanced at least to a distal end of the distal access catheter. The method includes the steps of deploying a payload of a brain treatment device within the intracranial neurovasculature.

[0020] The distal access catheter may include: a flexible distal lumen portion having a proximal end, a proximal region, a proximal opening, a lumen extending between the proximal end and the distal end; and a proximal extension extending proximally from an attachment point adjacent to the proximal opening. The proximal extension may be less flexible than the flexible distal lumen portion and configured to control movement of the distal access catheter. The flexible distal lumen portion may have an outer diameter at the attachment point that is larger than an outer diameter of the proximal extension at the attachment point.

[0021] The distal access catheter can be assembled with the tapered inner member to form an assembled coaxial catheter system. The tapered inner member may include: a flexible, elongated body having a proximal region, an outer diameter, a tapered distal tip, a distal opening, and a single lumen extending longitudinally through the flexible, elongated body to the distal opening; and a proximal portion extending proximally from the proximal region to the nearest end of the tapered inner member. When assembled, the tapered inner member extends through the lumen of the distal access catheter, and the tapered distal tip extends distally to the distal end of the distal end of the distal access catheter. The proximal portion of the tapered inner member may be a hypotube with an opening that is fluidly connected to the single lumen of the flexible, elongated body. The flexible, elongated body of the tapered inner member may include a proximal opening sized to accommodate a guidewire. The proximal opening may be positioned to pass through the sidewall of the proximal region of the flexible, elongated body.

[0022] The method may further include the step of preventing blood flow by inflating an occlusion balloon on an outer surface of the distal region of the introducer sheath.

[0023] In a related aspect, a method for accessing an intracranial neurovasculature using a catheter system is disclosed, the method comprising the following steps: loading a guidewire into a microcatheter. The microcatheter comprises: a lumen; a distal region having a distal opening that exits from the lumen; and a side opening that exits from the lumen and is positioned at a distance proximal to the distal opening. When loaded, the guidewire is positioned in the lumen of the microcatheter so that the distal end of the guidewire extends out of the distal opening and the proximal end of the guidewire exits the lumen at the side opening. The payload is contained in the lumen proximal to the side opening. The method comprises the following steps: inserting the microcatheter loaded with the guidewire and the payload into a patient's blood vessel until the distal region of the microcatheter advances into the intracranial neurovasculature.

[0024] The method may also include the following steps: positioning a guide sheath having a working lumen communicating with the port within a patient's blood vessel, the working lumen having a distal end. The method may also include the following steps: inserting a distal access catheter through the port into the working lumen of the guide sheath, the distal access catheter having a lumen and a distal end, the distal end of the distal access catheter extending beyond the distal end of the guide sheath to at least one level of the internal carotid artery. The distal access catheter may also include: a flexible distal lumen element having a proximal end, a proximal region, and a proximal opening; and a proximal extension extending proximally from an attachment point adjacent to the proximal opening. The proximal extension may be less flexible than the distal lumen element and is configured to control the movement of the distal access catheter. The proximal extension may have an outer diameter at the attachment point that is smaller than the outer diameter of the distal lumen element at the attachment point.

[0025] The method may further include the step of positioning an introducer sheath having a working lumen communicating with the port within a blood vessel of the patient. The distal region of the introducer sheath may further include an occlusion balloon on an outer surface configured to block flow through the blood vessel when the sealing element is expanded.

[0026] The distal access catheter can be assembled with the tapered inner member to form an assembled coaxial catheter system. The tapered inner member may include: a flexible, elongated body having a proximal region, an outer diameter, a tapered distal tip, a distal opening, and a single lumen extending longitudinally through the flexible, elongated body to the distal opening; and a proximal portion extending proximally from the proximal region to the nearest end of the tapered inner member. When assembled, the tapered inner member may extend through the lumen of the distal access catheter, and the tapered distal tip extends distally to the distal end of the distal end of the distal access catheter. The proximal portion of the tapered inner member may be a hypotube having an opening that is fluidly connected to the single lumen of the flexible, elongated body. The flexible, elongated body of the tapered inner member may include a proximal opening sized to accommodate a guidewire. The proximal opening may be positioned to pass through the sidewall of the proximal region of the flexible, elongated body.

[0027] In a related aspect, a method for accessing an intracranial neurovasculature using a catheter system is disclosed, the method comprising the steps of inserting a distal access catheter into a patient's blood vessel, the distal access catheter being assembled with a tapered inner member to form an assembled coaxial catheter system. The distal access catheter comprises: a flexible distal lumen element having a proximal opening into a lumen extending between a proximal end and a distal end; and a proximal extension extending proximally from an attachment point adjacent to the proximal opening. The proximal extension is less flexible than the distal lumen element and is configured to control movement of the distal access catheter. The proximal extension has an outer diameter at the attachment point that is smaller than the outer diameter of the distal lumen element at the attachment point. The conical inner member includes: a flexible, elongated body having a proximal region, an outer diameter, a conical distal tip, a distal opening, and a single lumen extending longitudinally through the flexible, elongated body to the distal opening; and a proximal portion extending proximally from the proximal region to the proximal end of the conical inner member. When assembled, the conical inner member extends through the lumen of the distal access catheter, and the conical distal tip extends distally of the distal end of the distal access catheter. The method also includes the steps of: removing the conical inner member from the lumen of the distal access catheter; inserting a microcatheter into the lumen of the flexible distal lumen element. The microcatheter includes: a lumen; a distal region having a distal opening emerging from the lumen; and a side opening emerging from the lumen and positioned a distance proximal to the distal opening. A payload is received within the lumen proximal to the side opening. The method further includes the step of advancing the microcatheter through the lumen of the distal access catheter until the distal region of the microcatheter extends to at least the distal end of the distal access catheter.

[0028] The proximal end of the tapered inner member may be a hypotube having an opening in fluid communication with a single lumen of the flexible elongated body. The method may further include the steps of inserting a second distal access catheter through the lumen of the first distal access catheter until the second distal access catheter extends toward the distal end of the first distal access catheter, wherein inserting the microcatheter into the lumen of the flexible distal lumen element further comprises inserting the microcatheter into the lumen of the second distal access catheter.

[0029] In related aspects, a rapid exchange microcatheter system for entering the intracranial neurovascular system is disclosed, the microcatheter system includes a catheter body, the catheter body having an outer diameter, an inner diameter and a distal tip, an inner lumen defined by the inner diameter. The catheter body is suitable for carrying a payload in the inner lumen, and the payload is transported from the inner lumen to a target position in the intracranial neurovascular system. The inner diameter size is set to allow a guide wire to pass through, and the outer diameter has a maximum size less than 0.048 inches. The guide wire side opening size in the inner lumen is set to allow a guide wire to pass through. The guide wire side opening is positioned at a distance of 10-20cm from the distal tip of the catheter body. The proximal opening in the inner lumen, which is different and distinguished from the guide wire side opening, is positioned at a distance greater than 20cm from the distal tip. The enhanced catheter portion at the distal end extends between the distal region of the catheter body to a point near the guide wire side opening. The enhanced catheter portion at the proximal end extends a distance from a point near the guide wire side opening toward the proximal end of the catheter body. The guidewire side opening is positioned within a gap between the proximal end of the distal reinforced catheter section and the distal end of the proximal reinforced catheter section. The system includes instructions for use that instruct a payload to be loaded into the inner lumen at a location proximal to the guidewire side opening prior to use of the catheter body.

[0030] In related aspects, a rapid exchange microcatheter system for entering the intracranial neurovascular system is disclosed, the microcatheter system includes a catheter body, the catheter body having an outer diameter, an inner diameter and a distal tip. The inner diameter defines an inner lumen. The catheter body is suitable for carrying a payload in the inner lumen, and the payload is transported from the inner lumen to a target location in the intracranial neurovascular system. The inner diameter size is set to allow a guide wire to pass through, and the outer diameter body has a maximum size less than 0.048 inches. The guide wire side opening in the inner lumen that is sized to allow a guide wire to pass through is positioned to a distance of 10-20cm from the distal tip of the catheter body. The proximal opening in the inner lumen that is different and distinguished from the guide wire side opening is positioned to a distance greater than 20cm from the distal tip. The distal enhanced catheter portion extends between the distal region of the catheter body to a point near the guide wire side opening. The proximal enhanced catheter portion extends a distance from a point near the guide wire side opening toward the proximal end of the catheter body. The guidewire side opening is positioned in a gap between the proximal end of the distal reinforced catheter section and the distal end of the proximal reinforced catheter section. The payload is loaded into the inner lumen at the location of the proximal end of the guidewire side opening, so that the payload can be carried in the inner lumen and delivered from the inner lumen to a target location in the intracranial neurovascular system.

[0031] In some variations, one or more of the following may be optionally included in the above methods, devices, apparatuses, and systems in any feasible combination. More details of the apparatuses, systems, devices, and methods are set forth in the accompanying drawings and the following description. Other features and advantages will be apparent from the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] These and other aspects will now be described in detail with reference to the following drawings. In general, the drawings are not to scale, either absolutely or comparatively, but are intended to be illustrative. Moreover, the relative placement of features and elements may be modified for purposes of illustration clarity.

[0033] Figure 1A to Figure 1B The course of the terminal internal carotid artery up to the cerebral vessels is illustrated;

[0034] Figure 2A is an exploded view of an embodiment of a single operator delivery system including a distal access system and a work device delivery system;

[0035] Figure 2B yes Figure 2A Assembly diagram of the remote entry system;

[0036] Figure 2C is extended through Figure 2A Assembly diagram of the working device conveying system of the remote entry system;

[0037] Figure 2D An embodiment of an arterial access device having a distal occlusion balloon is illustrated;

[0038] Figure 3 is a side view of an embodiment of a spined distal access catheter;

[0039] Figure 4A is a cross-sectional view of a first embodiment of a proximal control element of a distal access catheter having a ridge;

[0040] Figure 4B is a cross-sectional view of another embodiment of a proximal control element of a distal access catheter having a ridge;

[0041] Figure 4C It is in the working lumen of the access sheath. Figure 4A A cross-sectional view of a proximal control element;

[0042] Figure 4D It is in the working lumen of the access sheath. Figure 4B a cross-sectional view of a proximal control element of the catheter with the catheter advancement element extending through the access sheath;

[0043] Figure 4E It is relatively Figure 4D The working lumen of the access sheath Figure 4A The proximal control element and Figure 4B A schematic cross-sectional view of a surface area of ​​a proximal control element;

[0044] Figure 5Ais a side view of an embodiment of a distal access catheter having a ridge;

[0045] Figure 5B yes Figure 5A A top plan view of a ridged distal access catheter;

[0046] Figure 5C It is along Figure 5B A cross-sectional view of the distal access catheter with a ridge taken along line CC;

[0047] Figure 5D It is along Figure 5B A cross-sectional view of the distal access catheter with a ridge taken along line DD;

[0048] FIG. 5E to FIG. 5F yes Figure 5A A partial stereoscopic view of a distal access catheter with a ridge;

[0049] Fig. 6A is a side view of an embodiment of a distal access catheter having a ridge;

[0050] Figure 6B yes Fig. 6A A top plan view of a ridged distal access catheter;

[0051] Figure 6C It is along Figure 6B A cross-sectional view of the distal access catheter with a ridge taken along line CC;

[0052] Fig.6D It is along Figure 6B A cross-sectional view of the distal access catheter with a ridge taken along line DD;

[0053] FIG. 6E to FIG. 6F yes Fig. 6A A partial stereoscopic view of a distal access catheter with a ridge;

[0054] Fig. 7A is a side view of an embodiment of a catheter advancement element;

[0055] Figure 7B yes Fig. 7A A cross-sectional view of a catheter advancement element;

[0056] Figure 7C It is taken along circle CC Figure 7B Detailed diagram of

[0057] Fig.7D is a side view of another embodiment of a catheter advancement element;

[0058] Fig. 7E yes Fig.7D A cross-sectional view of an embodiment of a proximal portion of a catheter advancement element;

[0059] FIG. 7F to FIG. 7J is used to couple to Fig. 7E Various views of an embodiment of a proximal hub of the proximal portion are shown;

[0060] FIG. 8A to FIG. 8C Various embodiments of a single operator working device delivery system configured for delivery through a distal access system are illustrated;

[0061] FIG. 9A to FIG. 9I An embodiment of a method of delivering a stent retriever using a single operator delivery system through a distal access system is illustrated;

[0062] FIG. 10A to FIG. 10H An embodiment of a method of using a double-ended rotary hemostatic valve is illustrated;

[0063] FIG. 11A to FIG. 11B Illustrated is the flexibility of a distal access catheter that passes through the carotid artery and beyond the introducer sheath, which provides a conduit for inserting less flexible components into the cervical ICA and beyond;

[0064] FIG. 12A to FIG. 12B An embodiment of a single operator working device delivery system in a side-by-side arrangement with a surgical guidewire is illustrated;

[0065] FIG. 13A to FIG. 13B An embodiment of a single operator working device delivery system in a coaxial arrangement with a surgical guidewire is illustrated;

[0066] FIG. 14A to FIG. 14B An embodiment of a single operator working device delivery system having a microcatheter with an increase in outer diameter is illustrated;

[0067] Fig.15A Schematic diagram illustrating an embodiment of a rapid exchange microcatheter for delivering a working device to the neurovasculature for treating stroke;

[0068] Fig. 15B It is taken along line BB. Fig.15A Cross-sectional view of the microcatheter;

[0069] Fig. 15C It is taken along line CC. Fig.15A Cross-sectional view of the microcatheter;

[0070] Fig.15D It is taken along line DD. Fig.15A Cross-sectional view of the microcatheter;

[0071] Fig.15E It is intercepted at circle EE Fig.15A Detailed diagram of the microcatheter;

[0072] FIG. 16A to FIG. 16Cillustrates upper and lower partial views of an embodiment of a rapid exchange microcatheter for delivering a working device to the neurovasculature for treating stroke;

[0073] 17A to 17D Example for FIG. 16A to FIG. 16C A top view, a side view and a cross-sectional view of an embodiment of a coupler of a microcatheter;

[0074] 18A to 18C Example for FIG. 16A to FIG. 16C A top view, a side view and a cross-sectional view of an embodiment of a coupler of a microcatheter;

[0075] FIG. 19A to FIG. 19C Example for FIG. 16A to FIG. 16C A top view, a side view and a cross-sectional view of an embodiment of a coupler of a microcatheter;

[0076] Fig. 20 Example for FIG. 16A to FIG. 16C Embodiment of the coupler of the microcatheter;

[0077] Fig.21 Embodiments of a nested catheter system are illustrated.

[0078] It should be understood that the drawings are merely illustrations and are not intended to be to scale. It should be understood that the devices described herein may include features that are not necessarily depicted in each of the drawings. DETAILED DESCRIPTION

[0079] Navigating the carotid anatomy to treat various neurovascular pathologies at the cerebral artery level, such as acute ischemic stroke (AIS), requires a catheter system with excellent flexibility and deliverability. The internal carotid artery (ICA) originates from the bifurcation of the common carotid artery (CCA) at the level of the intervertebral disc between the C3 and C4 vertebrae. Figure 1AAs shown, the route of ICA is divided into four parts-cervical Cr, petrous segment Pt, cavernous Cv and brain Cb. In the anterior circulation, the consistently tortuous terminal carotid artery is locked into its position by bone elements. The cervical carotid artery Cr enters the petrous bone and is locked into a set of turns as it is wrapped in the bone. The cavernous carotid artery is an artery that passes through the venous bed (cavernous sinus), and although flexible, it is locked by another bone element when it leaves the cavernous sinus, which surrounds and is fixed to the entrance in the cranial cavity. Due to these bone fixation points, the petrous segment carotid artery Pt and its upper part are relatively consistent in their tortuosity. The carotid siphon CS is the S-shaped part of the terminal ICA. The carotid siphon CS starts at the back bend of the cavernous ICA and ends at the ICA bifurcation to the anterior cerebral artery ACA and the middle cerebral artery MCA. The ophthalmic artery originates from the brain ICA, which represents the common point where the catheter hangs up when entering the anterior circulation. These points at which the catheter hangs up can significantly increase the amount of time required to restore blood perfusion to the brain, a drawback with serious consequences in the treatment of AIS.

[0080] As age increases, large blood vessels often become larger and longer. The carotid arteries fixed at the proximal and distal ends often become tortuous. The common carotid artery CCA is relatively fixed in the chest cavity by the clavicle when it leaves the neck area. The external and internal carotid arteries ECA, ICA are not fixed relative to the common carotid artery CCA, so as the whole carotid system is extended, they form tortuosity as they age. This may make them elongate and form kinks and tortuosity, or in the worst case, form a complete ring or so-called "neck ring". If the catheter used to pass through these kinks or bending areas is too rigid or not flexible, these areas may be subjected to the straightening that may make the blood vessels entangled or cause the concentrated kinks and folding of the blood vessels. The extreme tortuosity of these types may also significantly increase the amount of time required for blood perfusion to the brain, particularly in the elderly population. In some cases, the twisting of the blood vessels on themselves or if the untwisted artery is kinked, the normal antegrade flow may be reduced to stillness, which produces ischemia. Managing dekinking or delooping of vessels such as the ICA in the neck may also increase the time it takes to perform the procedure.

[0081] A major disadvantage of current catheter systems used for stroke intervention procedures is the amount of time required to restore blood perfusion to the brain, including the time spent accessing one or more occluded sites in the cerebral arteries and the time spent completely removing the occlusion in the arteries. Because it is often the case that more than one attempt must be made to completely remove the occlusion, reducing the number of attempts and reducing the time required to exchange devices for additional attempts are important factors in minimizing the total time. In addition, each attempt is associated with potential surgical risks as the device is advanced in the fragile cerebral vasculature. Another limitation is the need for multiple operators to deliver and effectively manipulate long triaxial systems, which are typically used with traditional guide and distal access catheters.

[0082] A catheter system for treating various neurovascular pathologies, such as acute ischemic stroke (AIS), is described herein. The system described herein provides rapid and simple single operator access to distal target anatomical structures, particularly tortuous anatomical structures of cerebral vessels. The medical methods, devices, and systems described herein allow navigation of complex tortuous anatomical structures to perform rapid and safe delivery of intracranial medical devices, with or without suction for removing cerebral occlusions when treating acute ischemic stroke. The system described herein can be particularly useful for the treatment of AIS, whether the user intends to perform stent retractor delivery alone, suction alone, or a combination of suction and stent retractor delivery as a first-line treatment for AIS. Further, the extreme flexibility and deliverability of the distal access catheter system described herein allow the catheter to take the shape of a tortuous anatomical structure, rather than applying a straightening force that creates a new anatomical structure. The distal access catheter system described herein can pass through a tortuous loop while maintaining the natural curvature of the anatomical structure therein, which reduces the risk of vascular straightening. Thus, the distal access catheter systems described herein can create a secure tract through the neurovasculature that maintains the natural tortuosity of the anatomy for passage of other catheters (e.g., interventional device delivery catheters). The catheters that pass through the tract do not need to have the same degree of flexibility and deliverability such that if they were delivered directly to the same anatomical structure rather than through the tract, straightening, kinking, or folding of the anterior circulation would result.

[0083] It should be understood that, although some embodiments are described herein in particular with respect to the delivery of access to the neurovascular system anatomy or expandable brain treatment device, the systems and methods described herein should not be limited thereto and may also be applicable to other uses. For example, the catheter system described herein may be used to deliver a working device to a target vessel of a coronary artery anatomy or other vascular anatomy. It should also be understood that where the phrase "aspiration catheter" is used herein, such a catheter may also be used for other purposes in addition to aspiration or for such other purposes and aspiration, such as delivering fluid to a treatment site or as a support catheter or distal access catheter that provides a conduit for facilitating and guiding the delivery or exchange of other devices (e.g., guidewires or interventional devices, such as stent retractors). Alternatively, the access system described herein may also be used to access other parts of the body outside of a blood vessel. Similarly, where the working device is described as an expandable brain treatment device, a stent retractor, or a self-expanding stent, the delivery system described herein may be used to deliver other interventional devices.

[0084] Referring now to the accompanying drawings, FIG. 2A to FIG. 2B A system 10 is illustrated, which includes a device for accessing and removing a brain occlusion to treat acute ischemic stroke from an access site. The system 10 can be a single operator system so that the various components and systems can be transported and used together by one operator using minimal hand movement. As will be described in more detail below, all wire and catheter manipulations can occur at or near a single rotary hemostasis valve (RHV) 434 or at more than a single RHV co-located in the same device. The system 10 may include a distal access system 200 and an intracranial delivery system 700, each of which will be described in more detail below. The distal access system 100 may include a catheter 200 configured to be received by a guide sheath 400, and the catheter 200 is designed to have outstanding transportability. The catheter 200 can be a ridged distal access catheter coaxial with the lumen of the guide sheath 400, thereby providing an increase in the inner diameter (step-up) within the conduit. The catheter 200 can be delivered using a catheter advancement element 300 inserted through the lumen 223 of the catheter 200, which forms a catheter delivery system 150. The intracranial delivery system 700 may include a brain treatment device or working device 500 for treating brain occlusion. The working device 500 may have a distal expansion payload 505 and a proximal control element 510. The payload 505 is configured to be housed within an introducer sheath or microcatheter 600. The intracranial delivery system 700 may also include a surgical guidewire 805.

[0085] The distal access system 100 can produce a variable length from the entry point of a percutaneous arteriotomy (e.g., the femoral artery) to the target control point of the distal catheter. Conventional distal access systems for stroke interventions typically include a long guide sheath or guide catheter placed in the groin via a shorter "introducer" sheath (e.g., 11-30 cm in length). Long guide sheaths are typically positioned in the ICA to support neurovascular interventions including stroke thrombectomy. To increase support, these can be advanced all the way to the distal petrous segment of the bone, and rarely enter the cavernous or sellar or supraclinoid distal ICA when possible. In order to reach targets in the M1 or M2 distribution for ADAPT / MAT or Solumbra / SMAT methods, additional catheters are inserted through long guide catheters. These catheters are typically large-bore suction catheters, which can be 130 cm or longer in length. As will be described in more detail below, the distal access system 100 described herein can be shorter, for example, only 115 cm in length, which allows a shorter intracranial working device delivery system 700 to be used with the distal access system 100, which provides the advantage of being more suitable for easy use by a single operator. In addition, a single operator can use the system described herein by inserting the system described herein through a single rotary hemostasis valve (RHV) 434 on the guide sheath 400 or more than one RHV (e.g., a dual-head RHV) co-located in the same device. Thus, what was once a two-person surgery can be a one-person surgery.

[0086] Each of the various components of the various systems will now be described in greater detail.

[0087] Remote access system

[0088] Refer again FIG. 2A to FIG. 2D (as well as FIG. 8A to FIG. 8C , FIG. 9A to FIG. 9I as well as FIG. 10A to FIG. 10H ), the distal access system 100 may include an access guide sheath 400 having a body 402, and a working lumen 410 extending through the body 402 from a proximal hemostasis valve 434 coupled to a proximal region 403 of the body 402 to a distal opening 408 of the distal region. The working lumen 410 is configured to receive the support catheter 200 of the distal access system 100 therethrough, so that the distal end of the catheter 200 extends beyond the distal end of the sheath 400 through the distal opening 408. The guide sheath 400 can be used to deliver any of the catheters described herein and various working devices known in the art. For example, the working device can be configured to provide thrombosis treatment and can include a large-bore catheter, a suction thrombectomy, an advancing catheter, a wire, a balloon, a retractable structure (e.g., a coil tip retractable stent "Stentriever"). The guide sheath 400 in combination with the support catheter 200 can also be used to apply distal suction, as will be described in more detail below.

[0089] The guide sheath 400 can be any of a variety of commercially available guide sheaths. For example, the guide sheath 400 can have an inner diameter (ID) between 0.087 "-0.089", such as Cook SHUTTLE 6F (Cook Medical, Inc., Bloomington, Indiana), Terumo DESTINATION 6F (Terumo Europe NV), Cordis VISTA BRITE TIP (Cordis, Inc., Hialeah, Florida), and Penumbra NEURONMAX 088 (Penumbra, Inc., Alameda, California), or comparable commercially available guide sheaths. Typically, the French (F) scale is used here to describe sheath size. For example, where a sheath is described as 6F, it should be understood that the inner diameter of the sheath is capable of receiving a catheter having an outer diameter of 6F, which is approximately 1.98 mm or 0.078". Therefore, it should be understood that a catheter may be described herein as having a particular size of French to refer to the compatibility of its inner diameter to receive the outer diameter of another catheter. A catheter may also be described herein as having a particular size of French to refer to its outer diameter being compatible with another catheter having a particular inner diameter.

[0090] Refer again FIG. 2A to FIG. 2D , the elongated body 402 can extend from a proximal bifurcation or rotating hemostatic valve (RHV) 434 at the proximal region 403 to a tip 406 at the distal end of the body 402. The proximal RHV 434 can include one or more lumens molded into the connector body to connect to the working lumen 410 of the body 402 of the guide sheath 400. As described above, the working lumen 410 can receive any of the various working devices for delivery to the target anatomical structure of the catheter 200. The RHV 434 can be constructed of a thick wall polymer tube or a reinforced polymer tube. The RHV 434 allows the device to be introduced into the blood vessel through the guide sheath 400 while preventing or minimizing blood loss and preventing air from being introduced into the guide sheath 400. The RHV 434 can be integral with the guide sheath 400, or the guide sheath 400 can terminate on the proximal end of a female Luer adapter to which a separate hemostatic valve component, such as a passive sealing valve, a Tuohy-Borst valve, or a rotary hemostatic valve can be attached. The RHV 434 can have an adjustable opening that is open large enough to allow removal of a device with an adhered clot on the tip without causing the clot to fall off at the RHV 434 during removal. Alternatively, the RHV 434 can be removable, such as when the device is removed from the sheath 400 to prevent the clot at the RHV 434 from falling off. The RHV 434 can be a double RHV.

[0091] RHV 434 can form a Y-shaped connector on the proximal end 403 of sheath 400, so that the first port of RHV 434 can be used to insert the working catheter into the working lumen 410 of sheath 400, and the second port to arm 412 can be used for another purpose. For example, a syringe or other device can be connected to arm 412 via connector 432 to deliver forward instillation, a flushing line for contrast, or saline injection through the body 402 toward the tip 406 and into the target anatomical structure. Arm 412 can also be connected to a large-bore suction line and suction source (not shown), such as a syringe or pump, to draw suction through the working lumen 410. Arm 412 can also allow the guide sheath 400 to be flushed with saline or radiopaque contrast during surgery. The working lumen 410 can extend from the distal end to the working proximal port of the proximal region 403 of the elongated body 402.

[0092] The length of the elongated body 402 is configured to allow the distal tip 406 of the body 402 to be positioned in the internal carotid artery (ICA), for example, as far as a transfemoral approach, which has an additional length to provide adjustment when needed. In some embodiments, the length of the body 402 can be in the range of 80 to 90 cm, but it should be understood that the length of the body 402 can be longer, for example, up to about 105 cm. In an embodiment, the length of the body 402 is suitable for a transcarotid approach to the carotid bifurcation, in the range of 20-25 cm. In other embodiments, the length of the body 402 is suitable for a percutaneous transcarotid approach to the CCA or proximal ICA, and in the range of 10-15 cm. The body 402 is configured to assume and navigate the bends of the blood vessel without kinking, collapsing or causing vascular trauma, even when subjected to high suction forces, for example.

[0093] The tip 406 of the guide sheath 400 can have an outer diameter that is the same or similar to the segment of the body 402 leading to the distal end. Therefore, the tip 406 can have a distal face that is orthogonal to the longitudinal axis passing through the body 402, and the distal face can have an outer diameter that is substantially equal to the cross-sectional outer dimension of the body 402. In an embodiment, the tip 406 includes a chamfer, a rounded corner, or a taper, which makes the distal face diameter slightly smaller than the cross-sectional dimension of the body 402. In other embodiments, the tip 406 can be an elongated tubular portion that extends at the distal end of the region of the body 402 with a uniform outer diameter, so that the elongated tubular portion has a reduced diameter compared to the uniform outer diameter of the body 402. Thus, the tip 406 can be elongated or can be more bluntly shaped. Therefore, the tip 406 can be configured to smoothly track through the blood vessel and / or expand the blood vessel restriction as it tracks through the blood vessel. The working lumen 410 can have a distal end that forms a distal opening 408.

[0094] The guide sheath 400 may include a tip 406 that tapers from the section of the body 402 leading to the distal end. That is, the outer surface of the body 402 may have a diameter that decreases from a larger dimension to a smaller dimension at the distal end. For example, the tip 406 may taper from an outer diameter of approximately 0.114" to approximately 0.035". The angle of the taper of the tip 406 may vary depending on the length of the tapered tip 406. For example, in some embodiments, the tip 406 tapers from 0.110" to 0.035" over a length of approximately 50 mm.

[0095] In an embodiment, the guide sheath 400 includes one or more radiopaque markers 411. The radiopaque markers 411 can be arranged near the distal tip 406. For example, a pair of radiopaque bands can be forged, painted, embedded or otherwise arranged in or on the body 402. In some embodiments, the radiopaque markers 411 include markers of barium polymers, tungsten polymer mixtures, tungsten-filled or platinum-filled markers that maintain the flexibility of the distal end of the device and improve the transition along the length of the guide sheath 400 and its kink resistance. In some embodiments, the radiopaque markers 411 are tungsten-loaded PEBAX or polyurethane, which are heat-welded to the body 402. The markers 411 are shown in the figure as rings around the circumference of one or more regions of the body 402. However, the markers 411 can have other shapes or produce various patterns that provide the operator with orientation related to the position of the distal opening 408 within the blood vessel. Therefore, the operator can visualize the position of the distal opening 408 under fluoroscopy to confirm that the distal opening 408 points to the target anatomical structure to which the catheter 200 is to be delivered. For example, the radiopaque marker 411 allows the operator to rotate the body 402 of the guide sheath 400 at the anatomical entry point (e.g., the patient's groin) so that the distal opening provides access to the ICA by a subsequent working device (e.g., a catheter and wire advanced to the ICA). In some embodiments, the radiopaque marker 411 includes platinum, gold, tantalum, tungsten, or any other material visible under an X-ray fluoroscope. It should be understood that any of the various components of the system described herein can be incorporated into a radiopaque marker as described above.

[0096] In some embodiments, the guide sheath 400 will have similar performance characteristics to other sheaths used in carotid access and AIS surgery in terms of kink resistance, radiopacity, column strength, and flexibility. The liner can be constructed of a low-friction polymer, such as PTFE (polytetrafluoroethylene) or FEP (fluorinated ethylene propylene), to provide a smooth surface for advancing the device through the inner lumen. The outer sheath material can provide mechanical integrity for the liner, and can be constructed of materials such as PEBAX, thermoplastic polyurethane, polyethylene, nylon, etc. A third layer can be incorporated, which can provide reinforcement between the liner and the outer sheath. The reinforcement layer can prevent the inner lumen of the body 402 from flattening or kinking, to allow unimpeded device navigation and suction or reverse flow through the bends in the blood vessel. The body 402 can be enhanced circumferentially. The reinforcement layer can be made of metal (e.g., stainless steel, nitinol, nitinol webbing, spiral ribbon, spiral wire, cut stainless steel, etc.) or a rigid polymer (e.g., PEEK). The reinforcement layer can be a structure such as a coil or a webbing, or a laser cut or machine cut tube for flexibility. In another embodiment, the reinforcement layer can be a cut hypotube, such as a nitinol hypotube or a cut rigid polymer, etc. The outer sheath of the main body 402 can be formed by a material that is increasingly softer toward the distal end. For example, the proximal region of the main body 402 can be formed by a material such as nylon, and the region of the main body 402 at the distal end of the proximal region of the main body 402 can have a hardness of 72D, while the more distal region can be increasingly flexible and formed by a material with a hardness of 55D, 45D, 35D extending toward the distal tip 406, which can be formed by a material with a hardness of 35D, for example. The main body 402 may include a hydrophilic coating.

[0097] The flexibility of the body 402 can vary over its length, with increased flexibility toward the distal portion of the body 402. The variability of flexibility can be achieved in various ways. For example, the outer sheath can vary in hardness and / or material at various segments. An outer sheath material of lower hardness can be used in the distal segment of the guide sheath compared to other segments of the guide sheath. Alternatively, the wall thickness of the sheath material can be reduced, and / or the density of the reinforcement layer can be changed to improve flexibility. For example, the pitch of the coil or webbing can be stretched, or the cutting pattern in the tube can be changed to be more flexible. Alternatively, the reinforcement structure or material can vary over the length of the elongated body 402. In another embodiment, there is a transition segment between the distalmost flexible segment and the proximal segment, and one or more segments of varying flexibility are between the distalmost segment and the rest of the elongated body 402. In this embodiment, the distalmost segment is about 2 cm to about 5 cm, the transition segment is about 2 cm to about 10 cm, and the proximal segment occupies the rest of the sheath length.

[0098] The different inner diameters of the guide sheath 400 can be used to receive catheters 200 of different outer diameters. In some embodiments, the working lumen 410 of the first guide sheath 400 may have an inner diameter sized to receive a 6F catheter, and the working lumen 410 of the second guide sheath 400 may have an inner diameter sized to receive an 8F catheter. In some embodiments, the distal region of the guide sheath 400 may have an inner diameter of approximately 0.087" to 0.088". The guide sheath 400 can receive catheters having outer diameters suitable for these inner diameter sizes. It should be understood that the guide sheath 400 (and any of the various components used in combination with the sheath 400) can be an over-the-wire (OTW) or rapid exchange device, which will be described in more detail below.

[0099] In some cases, it is desirable that the sheath body 402 also be able to occlude the artery in which it is located, for example, during surgery where distal emboli may occur. Occluding the artery stops antegrade blood flow, thereby reducing the risk of distal emboli, which may cause neurological symptoms such as TIA or stroke. Figure 2D An arterial access device or sheath 400 is shown having a distal occlusion balloon 440 that, when inflated, occludes the artery at the location of the distal tip 406 of the sheath. At any point in the procedure, for example, during removal of the occlusion by suction and / or delivery of a stentriever or other interventional device, the occlusion balloon 440 can be inflated to occlude the vessel to reduce the risk of distal emboli to the cerebral vessels. The sheath 400 can include an inflation lumen in addition to the working lumen of the sheath 400, which is configured to deliver a fluid for inflating the occlusion balloon 440. The inflation lumen can fluidly connect the balloon 440 to an arm 412, such as on a proximal adapter. When vascular occlusion is desired, the arm 412 can be attached to an inflation device, such as a syringe, to inflate the balloon 440 with a fluid. The arm 412 can be connected to a passive or active suction source to further reduce the risk of distal emboli.

[0100] According to some embodiments, the length of the guide sheath 400 is long enough to enter the target anatomical structure and leave the arterial access site with the additional length outside the patient's body for adjustment. For example, the guide sheath 400 (whether or not with the distal occlusion balloon 440) can be long enough to enter the petrous ICA from the femoral artery, so that the additional length can still be used for adjustment. The guide sheath 400 can be of various sizes to accept various working devices and can adapt to the operator's preferences. For example, current MAT and SMAT techniques describe delivering an aspiration catheter with an inner diameter of 0.054"-0.072" to the embolus during AIS. Therefore, the working lumen 410 of the guide sheath 400 can be configured to receive the catheter 200 and other catheters or working devices known in the art. For example, the working lumen 410 can have an inner diameter that is sized to accommodate at least a 6 French catheter (1.98mm or 0.078" OD), or preferably at least a 6.3 French catheter (2.079mm or 0.082" OD). However, the inner diameter of the guide sheath 400 can be smaller or larger to be compatible with other catheter sizes. In some embodiments, the working lumen 410 can have an inner diameter that is sized to accommodate a 7 French (2.31 mm or 0.091" OD) catheter or an 8 French (2.64 mm or 0.104" OD) or larger catheter. In some embodiments, the working lumen 410 can have an inner diameter of at least about 0.054" up to about 0.070", 0.071", 0.074", 0.087", 0.088" or 0.100", thereby being configured to receive a catheter 200 having an outer diameter that fits snugly with these sizes. Regardless of the length and inner diameter, the guide sheath 400 resists kinking during distal advancement through a vessel.

[0101] The working lumen 410 included in the sheath 400 can be sized to receive its corresponding working device with a sliding fit. The working lumen 410 can have an inner diameter that is at least 0.001 inches larger than the outer diameter of any catheter 200 it is intended to receive, particularly when the catheter 200 is to be used for suction as will be described in more detail below. As described in more detail below, the catheter 200 can include a slit 236 in the lumen portion 222 that is configured to slightly widen and improve the seal between the catheter 200 and the guide sheath 400 when suction is applied from a suction source. The strength of the seal achieved allows a continuous suction lumen from the distal tip of the catheter 200 to the proximal end 403 of the guide sheath, where the guide sheath 400 is connected to the suction source, even in the presence of a lower suction force with minimal or no leakage. Typically, when there is sufficient overlap between the catheter 200 and the guide sheath 400, there is substantially no leakage. However, when attempting to reach distal anatomical structures, the catheter 200 may be advanced to its limit with minimal overlap between the catheter 200 and the introducer sheath 400. Thus, additional sealing may be desired to prevent leakage around the catheter 200 into the sheath 400. The seal between the catheter 200 and the introducer sheath 400 may prevent this leakage at maximum extension of the catheter 200 relative to the sheath 400.

[0102] Distal access catheter

[0103] Refer again FIG. 2A to FIG. 2C as well as Figure 3 , the distal access system 100 may include a distal access or support catheter 200 that is configured to extend through and out of the distal end of a sheath 400. Figure 3 A side view of an embodiment of a support catheter 200 is illustrated. The catheter 200 may include a relatively flexible distal lumen portion 222 coupled to a more rigid, kink-resistant proximal control element 230. The support catheter 200 provides a rapid means of simply accessing a stroke site even through the extreme tortuosity of the cerebral vasculature. The support catheters described herein have a degree of flexibility and deliverability that makes them optimally suited for advancement through the cerebral vascular anatomy without kinking or ovulation, even when navigating sharp turns. For example, the distal lumen portion 222 may perform a 180 degree turn (see FIG. 2 ). Figure 1BThe distal lumen portion 222 has a degree of flexibility that maintains the natural tortuosity of the vessel, and the distal lumen portion is advanced through the vessel without applying a straightening force so that the natural shape and curvature of the anatomical structure is maintained during use. The support catheter 200, particularly in combination with the catheter advancement element 300 described in more detail below, provides an extended conduit beyond the guide sheath 400 that has superior delivery capabilities through tortuous anatomical structures, which allows for the transfer of suction forces to the target stroke site and the delivery of stroke interventional devices, such as stent retrievers, stents, drains, or other working devices.

[0104] The inner lumen 223 extends through the lumen portion 222 between the proximal and distal ends of the lumen portion 222. The inner lumen 223 of the catheter 200 can have a first inner diameter, and the working lumen 410 of the guide sheath 400 can have a second, larger inner diameter. When the catheter 200 is inserted through the working lumen 410 of the sheath 400, the lumen 223 of the catheter 200 can be configured to be fluidly connected and continuous with the working lumen 410 of the sheath 400, so that fluid flow into and / or out of the sheath 400 is possible, for example, by applying suction from a suction source coupled to the system 100 at the proximal end. As the catheter 200 is advanced and withdrawn, the combination of the sheath 400 and the catheter 200 can be in continuous communication with the blood flow during suction at the proximal end.

[0105] The spine catheter system can produce advantages over conventional catheters, particularly in distal access, in terms of aspiration. The step change in the catheter column inner diameter produces a great advantage in the aspiration flow and force that can be generated by the spine catheter 200 in combination with a conventional guide catheter. For example, where a spine catheter 200 having a 0.070" inner diameter is paired with a standard 6F OD / 0.088" ID guide catheter (e.g., Penumbra Neuron MAX 088), an aspiration physics can be created in which the 0.088" catheter diameter will dominate and produce a 0.080 equivalent flow throughout the system.

[0106] In addition to aspiration procedures, the support catheter 200 and distal access system 100 can be used for delivery tools and interventional work devices. As will be described in more detail below, a typical stent retractor to be delivered through the support catheter 200 can have a 180cm push wire control element. The distal access system 100 with a ridged support catheter 200 allows a shorter length (e.g., 120cm-150cm) to be used to reach the distal stroke site. The total length can be as important as the diameter and radius when aspiration is performed through the catheter. The shorter length is combined with the elimination of multiple RHVs typical in a triaxial system, allowing a single operator to use.

[0107] It should be understood that where the distal access catheter is described herein as an aspiration catheter, it should not be limited to aspiration only. Similarly, where the catheter is described herein as a means of delivering a stent retriever or other working device 500, it should not be limited as such. It should also be understood that the systems described herein can be used to perform procedures that incorporate a combination of treatments. For example, the support catheter 200 can be used to deliver a stent retriever delivery system, optionally in the presence of aspiration through the support catheter 200. As another example, a user can begin performing a first interventional procedure using the system described herein, such as an aspiration thrombectomy, and switch to another interventional procedure, such as delivering a stent retriever or implant.

[0108] It should also be understood that the catheter 200 need not have a ridge or include a proximal control element 230, but can be a conventional catheter with a uniform diameter without a ridge. The terms "support catheter," "ridged catheter," "distal access catheter," and "intermediate catheter" are used interchangeably herein.

[0109] It is desirable to have a catheter 200 with as large an inner diameter as possible that can be safely navigated to the occlusion site in order to optimize suction forces and / or provide sufficient clearance for delivery of working devices in the event of suction. Depending on the patient anatomy and the clot size and composition, suitable sizes for the inner diameter of the distal lumen portion 222 can range between 0.040" and 0.100". The outer diameter of the distal lumen portion 222 can be sized to navigate into a cerebral artery, for example, at the level of the M1 segment or M2 segment of the cerebral vessel. The outer diameter (OD) should be as small as possible while still maintaining the mechanical integrity of the catheter 200. In an embodiment, the difference between the OD of the distal lumen portion 222 of the catheter 200 and the inner diameter of the working lumen 410 of the guide sheath 400 is between 0.001" and 0.002". In another embodiment, the difference is between 0.001" and 0.004".

[0110] In some embodiments, the distal lumen portion 222 of the catheter 200 has an outer diameter (OD) that is configured to fit through a 6F introducer sheath (0.071"), and the lumen 223 has an inner diameter (ID) that is sized to receive a 0.054" catheter. In some embodiments, the distal lumen portion 222 of the catheter 200 has an OD that is configured to fit through an 8F introducer sheath (0.088"), and the lumen 223 has an ID that is sized to receive a 0.070" or 0.071" catheter. In some embodiments, the OD of the distal lumen portion 222 is 2.1 mm, and the lumen 223 has an ID of 0.071". In some embodiments, the lumen 223 has an ID of 0.070" to 0.073". The outer diameter of the guide sheath 400 can be suitable for insertion into at least the carotid artery, and the working lumen 410 is suitably sized to provide a passage for the catheter 200 to treat occlusions at the distal end of the carotid artery toward the brain. In some embodiments, the ID of the working lumen 410 can be approximately 0.074", and the OD of the body of the guide sheath 400 can be approximately 0.090", corresponding to a 5 French sheath size. In some embodiments, the ID of the working lumen 410 can be approximately 0.087", and the OD of the body of the guide sheath 400 can be approximately 0.104", corresponding to a 6 French sheath size. In some embodiments, the ID of the working lumen 410 can be approximately 0.100", and the OD of the body of the guide sheath 400 can be approximately 0.117", corresponding to a 7 French sheath size. In some embodiments, the introducer sheath 400 ID is between 0.087" and 0.088", and the OD of the distal lumen 222 of the catheter 200 is approximately 0.082" and 0.086", resulting in a diameter difference of between 0.001" and 0.005".

[0111] In an embodiment, the lumen 222 of the catheter 200 has a uniform diameter from the proximal end to the distal end. In other embodiments, the lumen 222 of the catheter 200 is tapered and / or has a reduction (step-down) towards the distal end of the distal lumen 222, so that the distal end of the catheter 200 has a smaller outer diameter than the more proximal region of the catheter 200, for example, near this more proximal region, the distal lumen 222 is sealed with the guide sheath 400. In another embodiment, as will be described in more detail below, the lumen 222 of the catheter OD is increased at or near the overlapping portion to more closely match the sheath inner diameter. This embodiment is particularly useful in a system with more than one catheter suitable for use with a single entry sheath size. It should be understood that smaller or larger sheath sizes are considered here.

[0112] The length of the lumen portion 222 can be shorter than the length of the working lumen 410 of the guide sheath 400, so that when the lumen portion 222 is advanced toward the target location, a short overlap region 348 between the lumen portion 222 and the working lumen 410 still exists (see Figure 2B to Figure 2C ). Taking into account the variation of the occlusion site and the site where the distal tip 406 of the guide sheath 400 can be positioned, the length of the lumen portion 222 can range from about 10 cm to about 40 cm. In some embodiments, the distal lumen portion 222 of the catheter 200 can be between 20-40 cm, and the proximal control element 230 of the catheter 200 can be between about 90-100 cm, so that the catheter 200 can have a total working length of approximately 115 cm. The body 402 of the guide sheath 400 can be between 80-90 cm. In other embodiments, the working length of the catheter 200 between the proximal end of the catheter and the distal end of the catheter can be greater than 115 cm up to about 130 cm. In some embodiments, the catheter 200 can have a working length of 133 cm between the proximal tab 234 (or proximal hub) and the distal tip, and the distal lumen portion 222 can have an axial length of about 38.7 mm.

[0113] The length of the lumen portion 222 can be less than the length of the body 402 of the guide sheath 400, so that as the catheter 200 extends from the working lumen 410, a seal is maintained between the overlap region 348 of the catheter 200 and the inner diameter of the working lumen 410. In some embodiments, the length of the lumen portion 222 is sufficient to reach the region of the M1 segment of the middle cerebral artery (MCA) and other major vessels from the internal carotid artery region, so that the proximal region of the lumen portion 222 of the catheter 200 avoids extending within the aortic arch. This limits the number of severe abnormal bend formations (angulations) that the lumen portion 222 of the catheter 200 must navigate while still reaching the target site in the more distal brain anatomy. In embodiments where the catheter 200 reaches the ICA and the distance to the embolus can be less than 20 cm, a guide sheath 400 having a sheath body 402 and a working lumen 410 is used in combination.

[0114] The distal lumen portion 222 having a length of approximately 25 cm can allow for an overlap region 348 with the body 402, which creates a seal. As the lumen portion 222 extends into the target anatomical structure, an overlap region 348 can be maintained between the working lumen 410 of the introducer sheath 400 near the distal region of the sheath body 402 and the lumen portion 222 of the catheter 200. It should be understood that a seal against insufflated or aspirated fluids can be achieved by the overlap region 348 when the OD of the catheter 200 along at least a portion of the distal lumen portion 222 substantially matches the inner diameter of the introducer sheath 400, or the difference can be between 0.001"-0.002". The difference between the catheter OD and the inner diameter of the introducer sheath 400 can vary, for example, between one thousandth and two thousandths of an inch, or between one thousandth and four thousandths of an inch, or between one thousandth and twelve thousandths of an inch. Sealing between the catheter and sheath to insufflated or aspirated fluids may be accomplished by the overlap 348 between their substantially similar dimensions without incorporating any separate sealing structure or sealing feature.

[0115] The overlap region 348 can have a length of several centimeters and can vary depending on the distance from the embolus to the distal end of the distal lumen portion 222 (e.g., depending on how far the catheter 200 is advanced relative to the guide sheath). The overlap region 348 is sized and configured to create a seal that allows a continuous suction lumen from the distal tip region of the catheter 200 to the proximal region 403 of the guide sheath where the guide sheath 400 can be connected to a suction source. The strength of the seal achieved can be a function of the difference between the outer diameter of the catheter 200 and the inner diameter of the working lumen 410 and the length of the overlap region 348, the suction force applied, and the material of the component. For example, the seal can be improved by increasing the length of the overlap region 348. However, increasing the length of the overlap region 348 may create a greater length through which the suction is pulled through the smaller diameter lumen portion 222 rather than through the larger diameter working lumen 410. As another example, a higher suction force applied by the suction source can create a stronger seal between the lumen portion 222 and the working lumen 410 even when there is a shorter overlap region 348. Further, even if the suction force is less and the overlap region 348 is shorter, the relatively softer material forming the lumen portion and / or body 402 can still provide an adequate seal. In an embodiment, the overlap region 348 is configured to enable sealing for vacuums up to 28 inHg. In an embodiment, the overlap region 348 is configured to enable sealing for pressures up to 300 mmHg, or up to 600 mmHg, or up to 700 mmHg with minimal or no leakage.

[0116] It should be understood that the seal at the overlapping area can be due to the small difference between the inner diameter and the outer diameter and / or can be due to the other sealing elements located on the outer surface of the distal lumen or the inner surface of the sheath body. The sealing element can include an increased diameter or protruding feature in the overlapping area. The sealing element can include one or more external ridge features. When the lumen is inserted into the lumen of the sheath body, one or more ridge features can be compressible. The ridge geometry can make the sealing element appear as an O-ring, a square ring or other piston seal design. The sealing element can include one or more inclined surfaces that are biased on the inner surface of the sheath body lumen. The sealing element can include one or more expandable members that are actuated to seal. The expandable or expandable member can be a balloon or a covered webbing structure, which can expand or expand at any time (including after the catheter is positioned at the desired position) and provide a seal between the two devices. Thus, there is no need to apply a sealing force on the catheter during positioning, but to apply or actuate a sealing force to seal after the positioning catheter. The sealing element can be positioned on the outer surface of the distal lumen, for example, near the proximal region of the distal lumen, and can be located in the overlapping area. More than one sealing element may be positioned along the length of the catheter.

[0117] In some embodiments, the sealing element can be a cup seal, a balloon seal or a disc seal formed by a soft polymer, which is positioned around the outside of the distal lumen near the overlap area to provide additional sealing. The sealing element can be a thin-walled tube having an outer diameter that roughly matches the inner diameter of the sheath body lumen. The tube can be sealed on one end to produce a cup seal, or sealed on both ends to form a disc or balloon seal. The balloon seal can include the trapped air that produces a collapsible space. One or more slits can be formed through the wall tube so that the balloon seal can be collapsible and more easily pass through the RHV. The balloon seal does not need to include a slit for maintaining a smaller collapsible sealing element for the trapped air. The sealing element can be adjustable to achieve sheath coordination and collapse.

[0118] Refer again Figure 3 , the proximal control element 230 is configured to move the distal lumen portion 222 in a bidirectional manner through the working lumen 410 of the guide sheath 400 so that the distal lumen portion 222 can be advanced out of the guide sheath 400 and into a target location for treatment within a target vessel. Figure 3As shown, the proximal control element 230 of the catheter 200 can have a smaller outer diameter than the outer diameter of the distal lumen portion 222, which forms a proximal spine or tether of the catheter 200. The smaller outer diameter for the proximal control element 230 than the outer diameter of the distal lumen portion 222 allows the larger diameter working lumen 410 of the sheath 400 to maintain a greater suction force than would otherwise be provided by the smaller diameter lumen portion 222 of the catheter 200, or allows a working device to be delivered through the lumen with less friction. The significantly shorter length of the lumen portion 222 results in an increase in lumen diameter between the lumen portions 222 that are continuous with the working lumen 410, which provides a significantly increased radius and lumen area for delivering a working device and / or aspirating clots, particularly compared to other systems where the aspiration lumen extends along the entire inner diameter of the aspiration catheter. More specifically, the combined volume of the lumen area of ​​the catheter 200 and the lumen area of ​​the working lumen 410 proximal to the distal lumen portion 222 is greater than the lumen area of ​​a large-bore catheter along the entire length of the system. Thus, the likelihood of removing an embolus during a single aspiration attempt can be increased. More specifically, the increased lumen diameter along the proximal control element 230 can enable greater aspiration forces, which results in improved aspiration of the embolus. Further, this configuration of the catheter 200 and the proximal control element 230 greatly accelerates the time required to retract and re-advance the catheter 200 and / or the working device 500 through the working lumen 410 to exit the distal lumen 408. The proximal control element 230 of the catheter 200 has a length and structure that extends through the working lumen 410 of the guide sheath 400 to the proximal end of the system 100, such that the proximal control element 230 can be used to advance and retract the catheter 200 through the working lumen 410. However, the proximal control element 230 of the catheter 200 occupies only a portion of the luminal space of the system 100, which results in an increased luminal area for aspiration and / or delivery of working devices. The increased luminal diameter also increases the annular area available for forward flushing of contrast agent, saline or other solutions, while devices such as microcatheters or other devices can be coaxially positioned in the luminal portion 222 and / or working lumen 410 of the catheter 200. This can improve the ease and ability to perform angiography during device navigation.

[0119] In an embodiment, the distal lumen 222 of the catheter 200 is constructed to be flexible and lubricated so as to enable safe navigation to the target location. The distal lumen 222 can be kink-resistant and anti-collapse when subjected to high suction forces so as to enable effective suction of clots. The lumen 222 can have an increased flexibility toward the distal end, with a smooth material transition along its length to prevent any kinks, abnormal bend formations or sharp bends in its structure, for example, during navigation of severe abnormal bend formations (e.g., severe abnormal bend formations with 90° or greater to 180° turns), such as at the aorta-iliac junction, the left subclavian artery lead-out point from the aorta, the lead-out point of the brachiocephalic (innominate) artery from the ascending aorta, and many other peripheral locations, just as in the carotid siphon. For example, a first portion of the distal lumen portion 222 can be formed of a material having a durometer of 72D along a first length, a second portion can be formed of a material having a durometer of 55D along a second length, a third portion can be formed of a material such as Pebax MX1205 (40D) along a third length, a fourth portion can be formed of a material having a durometer of 35D along a fourth length, a fifth portion can be formed of a material having a durometer of 25D along a fifth length, a sixth portion can be formed of a material such as Tecoflex having a durometer of 85A along a sixth length, and a final distal portion of the catheter can be formed of a material such as Tecoflex having a durometer of 80A. Thus, the distal lumen portion 222 transitions from being less flexible near its junction with the proximal control element 230 to being more flexible at the distal end, from which the distal tip of the catheter advancement element 300 can extend, for example. It should be understood that other surgical catheters described herein can have similar configurations, as will be described elsewhere herein, that provide a variable relative stiffness transitioning from the proximal end to the distal end of the catheter.

[0120] In some embodiments, the distal lumen portion 222 can transition from being less flexible near its junction with the proximal control element 230 to being more flexible at the most distal end. The change in flexibility from the proximal end to the distal end of the distal lumen portion 222 can be achieved by any of the various methods as described herein. In some embodiments, the distal lumen portion 222 has a reinforcement structure that is a nitinol band wrapped into the coil. The coil can be heat set before the coil is transferred to the catheter. The pitch of the coil can increase from the proximal end of the distal lumen portion 222 toward the distal end. For example, the band coils can have gaps between them, and the size of the gaps can increase toward the distal end of the distal lumen portion 222. For example, the size of the gaps between the band coils can be approximately 0.016" gaps near the proximal end of the distal lumen portion 222, and the size of the gaps between the band coils near the distal end can be larger, such as 0.036" gaps. This variation in pitch provides increased flexibility near the distal-most end of the distal lumen portion 222 .

[0121] In an embodiment, the distal end of the distal lumen portion 222 has a maximum force of 1500 to 3000 N-mm. 2 The flexural rigidity (E*I) within the range of 200° and the remainder of the distal lumen 222 has a higher flexural rigidity, where E is the elastic modulus and I is the area moment of inertia of the device. These units are N-mm 2 The bending stiffness range can be measured by evaluating the grams of force generated when the device is deflected a specific distance using a specific length gauge. For example, using a 3mm length dynamometer and deflecting the tip of the catheter by 2mm can generate a force of 30-60 grams, or can be between 1500-3000N-mm 2 The flexibility of the distal lumen portion 222 can be based on deflection measurements and related calculations. In comparison, the flexibility of the catheter advancement element 300 based on similar deflection measurements and calculations can be as follows. At 2 mm deflection and 3 mm dynamometer length, the catheter advancement element 300 can range between 1-5 grams of force, or can be 50-200 N-mm in bending stiffness. 2 It should be understood that other surgical catheters described herein can have a similar range of flexibility, as will be described elsewhere herein, that provides a variable relative stiffness transitioning from the proximal end to the distal end of the catheter.

[0122] In some embodiments, the distal lumen 222 includes two or more layers. In some embodiments, the distal lumen 222 includes an inner lubricating lining, a reinforcing layer, and an outer sheath layer. The outer sheath layer can be composed of discrete segments of polymers with different hardness, composition, and / or thickness to change the flexibility along the length of the distal lumen 222. In an embodiment, the lubricating lining is a PTFE liner with one or more thicknesses along a variable flexible segment. In an embodiment, the reinforcing layer is a generally tubular structure formed, for example, by a winding belt or coil or braid. The material used for the reinforcing structure can be stainless steel, such as 304 stainless steel, nitinol, cobalt-chromium alloy, or other metal alloys that provide a desired combination of strength, flexibility, and crush resistance. In an embodiment, the reinforcing structure includes a variety of materials and / or designs, again changing the flexibility along the length of the distal lumen 222. In an embodiment, the outer surface of the catheter 200 is coated with a lubricating coating, such as a hydrophilic coating. In some embodiments, the coating can be on the inner surface and / or the outer surface to reduce friction during tracking. The coating can include various materials as known in the art. The proximal control element 230 may also be coated to improve tracking through the working lumen 410. Suitable lubricating polymers are well known in the art and may include silicones and the like, hydrophilic polymers (e.g., high density polyethylene (HDPE), polytetrafluoroethylene (PTFE), polyarylene oxides, polyvinyl pyrrolidone, polyvinyl alcohol, hydroxyalkyl cellulose, alginic acid, sugars, caprolactones, and the like, and mixtures and combinations thereof. The hydrophilic polymers may be mixed with each other or with a defined amount of a water-insoluble compound (including some polymers) to produce a coating having suitable lubricity, binding, and solubility.

[0123] Refer again FIG. 2A to FIG. 2C, the distal lumen portion 222 of the catheter 200 may have a radiopaque marker 224a at the distal tip region to assist in navigation under fluoroscopy and proper positioning of the tip. In addition, the proximal region of the catheter 200 may have one or more proximal radiopaque markers 224b so that the overlap region 348 can be visualized as the relationship between the radiopaque marker 411 on the guide sheath 400 and the radiopaque marker 224b on the catheter 200. In an embodiment, the two radiopaque markers (the marker 224a at the distal tip and the more proximal marker 224b) are different to minimize confusion of the fluoroscopic image, for example, the catheter proximal marker 224b may be a single band, and the marker 411 on the guide sheath 400 may be a double band, and any marker on the working device delivered by the distal access system may have another type of band or marker. The radiopaque markers 224 of the distal lumen 222, particularly markers near the distal tip region for navigating extremely tortuous anatomies, may be relatively flexible so that they do not affect the overall flexibility of the distal lumen 222 near the distal tip region 222. The radiopaque markers 224 may be tungsten-loaded or platinum-loaded markers, which are relatively flexible compared to other types of radiopaque markers used in devices where flexibility is not of utmost importance.

[0124] As previously mentioned, the control element 230 is configured to allow the catheter 200 to be advanced distally and retracted proximally through the working lumen 410 of the guide sheath 400, including passing out of the distal lumen 408. In an embodiment, the length of the proximal control element 230 is longer than the entire length of the guide sheath 400 (from the distal tip to the proximal valve), for example, about 5 cm to 15 cm. The length of the body 402 can be in the range of 80 to 90 cm, or up to about 100 cm, or up to about 105 cm, and the length of the proximal control element 230 can be between 90 and 100 cm.

[0125] Refer again Figure 3 , the proximal control element 230 may include one or more markings 232 to indicate overlap between the distal lumen portion 222 of the catheter 200 and the sheath body 402 and overlap between the distal lumen portion 222 of the catheter 200 and other interventional devices that may extend through the distal lumen portion 222. At least a first marking 232 may be a RHV proximity marking positioned so that when the marking 232 is aligned with the sheath proximal hemostasis valve 434 during insertion of the catheter 200 through the introducer sheath 400, the catheter 200 is positioned in the most distal position with the minimum overlap length required to create a seal between the catheter 200 and the working lumen 410. At least a second marking 232 may be a fluorine protection marking that may be positioned on the proximal control element 230 and located a distance from the distal tip of the distal lumen portion 222. In some embodiments, the marking 232 may be positioned about 100 cm from the distal tip of the distal lumen portion 222.

[0126] The proximal control element 230 may include a gripping feature, such as a tab 234 on the proximal end, which makes the proximal control element 230 easy to grasp and advance or retract. As will be described in more detail below, the tab 234 can be coupled to one or more other components of the system. The proximal tab 234 can be designed to be easily identified in any other device (such as a guide wire or a retractable stent device wire) that can be inserted into the sheath proximal valve 434. A portion of the proximal control element 230 and / or the tab 234 can be colored in a bright color or marked with a bright color so that it can be easily distinguished from a guide wire, a retractable stent tether, etc. In the case of using multiple catheters 200 together in a nested manner to reach a more distal position in the brain, each proximal control element 230 and / or tab 234 can be color-coded or otherwise marked to clearly show the operator which proximal control element 230 of which catheter 200 it is coupled to.

[0127] The tab 234 may be integrated with or in addition to a proximal hub that is coupled to the proximal end of the proximal control element 230. For example, as will be described in more detail below, the proximal control element 230 may be a hypotube having a lumen. The lumen of the hypotube may be in fluid communication with the proximal hub at the proximal end of the proximal control element 230 so that suction and / or fluid may be delivered through the hypotube via the proximal hub.

[0128] The proximal control element 230 can be constructed with sufficient rigidity to allow advancement and retraction of the distal lumen portion 222 of the catheter 200, yet flexible enough to navigate through the brain anatomy as needed without kinking. The configuration of the proximal control element 230 can vary. In some embodiments, the proximal control element 230 can be a tubular element having an outer diameter that is approximately the same as the outer diameter of the distal lumen portion 222, similar to a typical catheter device. In other embodiments, the outer diameter of the proximal control element 230 is sized as described above to avoid occupying too much lumen area in the lumen 410 of the guide sheath 400.

[0129] The proximal control element 230 may be a solid wire having a circular or elliptical cross-sectional shape. Figure 4A The flattened ribbon may have a rectangular cross-sectional shape as shown. The flattened ribbon may also have a square, rectangular, or other cross-sectional shape. The ribbon may be curved into a circular, oval, C-shaped, or quarter-circular or other cross-sectional area along an arc. The proximal control element 230 may be a hollow wire having a lumen 235 extending through it, such as Figure 4BThe hypotube shown. The hypotube can have an oval or circular shape. In an embodiment, the proximal control element 230 is a stainless steel strip having dimensions of approximately 0.012"×0.020". In an embodiment, the proximal control element 230 is a round wire having dimensions from 0.014" to 0.018". In another embodiment, the proximal control element 230 is a strip having dimensions ranging from 0.010" to 0.015" thick, and 0.015" thick to 0.025" thick. In an embodiment, the proximal control element 230 is a hypotube formed from a flattened strip of rigid material that is rolled into a tubular shape to have a lumen 235. In some embodiments, the proximal control element 230 can be formed from a flattened stainless steel strip and rolled into a hypotube such that the proximal control element 230 has a wall thickness of approximately 0.007", an inner diameter of approximately 0.004", and an outer diameter of approximately 0.018" prior to modifying the hypotube into an elliptical cross-sectional shape. The ovalized hypotube can maintain an inner diameter of at least 0.001" along at least a first dimension and an outer diameter of at least 0.015" along at least a first dimension. In an embodiment, the proximal control element 230 material is a metal (e.g., stainless steel or nitinol) and a plastic (e.g., any of a variety of polymers).

[0130] In an embodiment, the proximal control element 230 is a stainless steel hypotube having an elliptical cross-sectional shape (see Figure 4B ). The oval tubular shape can increase the column strength, pushability, and kink resistance of the proximal control element 230 to improve advancement through tortuous anatomical structures. The cross-sectional area of ​​the oval hypotube minimizes the effect of the catheter 200 on the movement of other tools through the working lumen 410 of the sheath 400. Figure 4C Illustrated is a cross-sectional view of a working lumen 410 of a sheath 400 having a proximal end portion 230 extending therethrough. The proximal end portion 230 has a rectangular cross-sectional shape. Figure 4D A cross-sectional view of a working lumen 410 is illustrated having an ovalized hypotube proximal portion 230 and a catheter advancing element 300 extending therethrough. Figure 4E A comparison of surface area between a rectangular ribbon and an oval hypotube is illustrated. The oval hypotube has a smaller surface area than the rectangular ribbon, which allows for a greater flow rate through the working lumen 410, for example, during application of suction forces.

[0131] Now refer to FIG. 5A to FIG. 5F, the junction between the distal lumen portion 222 of the catheter 200 and the proximal control element 230 can be constructed to allow a smooth transition of flexibility between the two parts so as not to create kinks or weak points. The smooth transition of the junction between the distal lumen portion 222 and the proximal control element 230 also allows the device to smoothly pass through the continuous inner lumen created by the working lumen 410 of the guide sheath 400 and the lumen 223 of the lumen portion 223 of the catheter 200. In an embodiment, the distal lumen portion 222 has a transition section 226, near which the lumen portion 222 is coupled to the proximal control element 230 (see Figure 5A ). The transition section 226 may have an angled cut so that there is no abrupt step transition from the working lumen 410 of the guide sheath 400 to the inner lumen 223 of the catheter 200. The angled cut may be substantially planar. In an alternative embodiment, the angled cut is curved or stepped to provide a more gentle transition zone. It should be understood that the proximal region of the distal lumen portion 222 may be angled in an oblique manner relative to the longitudinal axis of the catheter 200 so that the proximal end and the proximal opening entering the lumen are at an angle different from 90° to the longitudinal axis of the catheter 200, for example, between approximately 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40° or 45° until less than 90°. The proximal region of the distal lumen portion 222 may also be aligned approximately vertically with the longitudinal axis of the catheter 200 so that the proximal end and the proximal opening entering the lumen are approximately 90° to the longitudinal axis of the catheter 200. Similarly, the distal region of the distal lumen portion 222 can be angled in an oblique manner relative to the longitudinal axis of the catheter 200, such that the distal end and the distal opening away from the lumen 223 are at an angle different from 90° to the longitudinal axis of the catheter 200, such as between approximately 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, or 45° up to less than 90°. The distal region of the distal lumen portion 222 can also be aligned approximately perpendicularly to the longitudinal axis of the catheter 200, such that the distal end and the distal opening into the lumen are approximately 90° to the longitudinal axis of the catheter 200.

[0132] The proximal control element 230 can be coupled to the proximal region of the catheter 200 and / or can extend along at least a portion of the distal lumen portion 222 such that the proximal control element 230 is coupled to the distal lumen portion 222 a distance away from the proximal end. The proximal control element 230 can be coupled to the distal lumen portion 222 by various mechanisms, including bonding, welding, gluing, clamping, stringing, tying or fastening one or more components that make up the proximal control element 230 and / or portion 222. The distal lumen portion 222 and the proximal control element 230 can be joined by a welded bond, a mechanical bond, an adhesive bond, or some combination thereof. In some embodiments, the proximal control element 230 and the lumen portion 222 are coupled together by sandwiching the proximal control element 230 between layers of the distal lumen portion 222. For example, the proximal control element 230 can be a hypotube or a rod having a distal end that is thinned, ground, or cut so that the distal end can be laminated or otherwise attached to a layer of the catheter portion 222 near the proximal region. The area of ​​overlap between the distal end of the proximal control element 230 and the lumen portion 222 can be at least about 1 cm. This type of coupling allows for a smooth and uniform transition from the proximal control element 230 to the lumen portion 222.

[0133] Still refer to FIG. 5A to FIG. 5F , the transition section 226 of the distal lumen 222 can open upward into a slot 238 that extends a length proximal to the transition section 226. In some embodiments, the slot 238 has a generally curved cross-sectional geometry. For example, the slot 238 can extend about 20 to about 90 degrees along the arc of the longitudinal axis of the catheter 200. In other embodiments, the edges of the slot 238 are curved so that the slot 238 is generally uneven. In other embodiments, the slot 238 is generally flat. When the device is forced to bend, the slot 238 can provide a smooth transition between the distal lumen 222 and the proximal control element 230. This can reduce the possibility of kinking and promote push resistance.

[0134] The distal end of the proximal control element 230 and / or the distal lumen portion 222 may have features that facilitate mechanical engagement during welding, such as a textured surface, protruding features, or cut-off features. During the thermal welding process, the features will facilitate mechanical bonding between the polymer distal lumen portion 222 and the proximal control element 230. For example, 6A to 6FAs shown, the proximal end of the distal lumen portion 222 may include a short mating sleeve 240 that is coupled to the proximal edge 221 of the distal lumen portion 222. The sleeve 240 may include an inner lumen extending between the proximal opening 242 and the distal opening 241. The distal end of the proximal control element 230 may be inserted through the proximal opening 242 and the inner lumen of the sleeve 240 to couple the proximal control element 230 to the distal lumen portion 222. In some embodiments, the proximal control element 230 may be coupled to the distal lumen portion 222 such that the distal opening 231 of the hypotube forming the proximal control element 230 may communicate with the lumen 223 of the distal lumen portion 222, for example, through the distal opening 241 of the sleeve 240. The sleeve 240 may also provide a transition between the distal lumen portion 222 and the proximal control element 230 similar to the slot 238. The distal lumen portion 222 need not include a mating sleeve 240 to couple with the proximal control element 230. For example, the distal end of the proximal control element 230 can be inserted through the wall of the slot 238 at the proximal end of the distal lumen portion 222 (see Figure 5A , FIG. 5E to FIG. 5F ). The distal end of the proximal control element 230 can extend along the length of the slot 238 and along at least a length of the wall of the distal lumen portion 222.

[0135] As mentioned above, the lumen 222 of the catheter 200 can have a uniform diameter from the proximal end to the distal end, or the lumen 222 can have different outer diameters along its length. For example, the distal end of the distal lumen 222 can have a smaller outer diameter than the more proximal region of the distal lumen 222. FIG. 5A to FIG. 5B , FIG. 5E to FIG. 5F as well as Figures 6A to 6B , FIG. 6E to FIG. 6F The distal lumen portion 222 is shown having a distal tubular region or distal tube 245 having a smaller outer diameter, and a proximal tubular region or proximal tube 246 having a larger outer diameter. The distal tube 245 transitions to the proximal tube 246 via an increase 247. Figure 5A and Fig. 6A As best shown, the inner diameters of the distal tube 245 and the proximal tube 246 are approximately the same, which provides a smooth inner wall surface for the lumen 223. The outer diameter of the distal tube 245 is less than the outer diameter of the proximal tube 246. The increase 247 is formed by the transition of the wall thickness between the distal tube 246 and the proximal tube 247. In some embodiments, the outer diameter of the distal tube 246 can be about 0.080" to about 0.084", and the outer diameter of the proximal tube 247 can be about 0.087" to about 0.088".

[0136] At least a portion of the wall of the larger outer diameter proximal tube 246 may be discontinuous such that it includes the slit 236 (see FIG. 5A to FIG. 5C , FIG. 5E to FIG. 5F , FIG. 6A to FIG. 6C as well as FIG. 6E to FIG. 6F ). The slit 236 can extend a distance along the length of the proximal tube 246. The slit 236 can extend from the edge 221 of the proximal tube 246 for at least about 2 cm of the length of the proximal tube 247. The slit 236 can, but need not, extend along the entire length of the proximal tube 247 to the location of the increased portion 247. In addition, the proximal tube 247 can include more than one slit 236. The slit 236 can be positioned in the larger diameter proximal tube 246 at a location opposite to where the distal end of the proximal control element 230 couples with the wall of the distal tube cavity portion 222. It can be seen that the distal end of the proximal control element 230 embedded in the wall of the proximal tube 246 is located opposite the slit 236 (see Figure 5C and Figure 6C ). It should be appreciated that the slit 236 may be positioned around the proximal tube 246 at another location.

[0137] The slit 236 can allow the proximal tube 246 to expand slightly so that the ends of the wall forming the slit 236 separate, which forms a gap therebetween. For example, when the catheter 200 is inserted through the working lumen 410 of the sheath 400, the outer diameter can be received in a sliding fit so that at least the overlap area 348 is retained. When a suction force is applied through the working lumen 410, for example by applying suction from a suction source coupled to the proximal end 403 of the guide sheath 400, the seal provided at the overlap area 348 can be enhanced by slightly widening the gap formed by the slit 236. This slight expansion provides a better seal between the outer diameter of the proximal tube 246 and the inner diameter of the working lumen 410 of the sheath 400 because the outer surface of the wall of the catheter 200 can be pressed against the inner surface of the working lumen 410, which creates a tight fit between the catheter 200 and the sheath 400. This improved seal between the outer surface of the catheter 200 and the inner surface of the working lumen 410 minimizes leakage of blood directly from the blood vessel into the working lumen 410 through the distal opening 408. Thus, the larger outer diameter of the proximal tube 246 combined with the slit 236 can enhance the seal between the catheter 200 and the sheath 400 by accommodating changes in the inner diameter of the sheath. The slit 236 can effectively increase the outer diameter of the proximal tube 246 depending on whether the walls forming the slit 236 are separated by a distance. The walls forming the slit 236 can separate from each other and increase the width of the slit. The outer diameter of the proximal tube 246, including the increased width when the walls forming the slit 236 are separated, can be the same as or larger than the inner diameter of the sheath through which the proximal tube 246 is inserted. This allows a single catheter to be compatible with a wider range of inner diameters. In some embodiments, the outer diameter of the proximal tube 246 can be 0.081" when the walls forming the slit 236 are close together and no gap exists. When the walls forming the slit 236 are separated from each other by a maximum distance, the outer diameter of the proximal tube 246 can increase to about 0.087". In addition, the increased wall thickness of the proximal tube 246 allows for a more robust joint between the distal lumen 222 and the proximal control element 230 of the catheter.

[0138] Catheter Advancement Element

[0139] As mentioned above, the distal access system 100 may, but need not, include a catheter advancement element 300 for delivering the catheter 200 to the distal anatomical structure. It should be understood that in the case where the catheter 200 is described herein as being used with or advanced with the catheter advancement element 300, the catheter advancement element 200 need not be used to deliver the catheter 200 to the target location. For example, other advancement tools, such as microcatheters and / or guidewires known in the art, are contemplated herein. Similarly, the catheter advancement element 300 can be used together to advance other catheters other than the catheter 200 described herein. For example, the catheter advancement element 300 can be used to deliver a 5MAX reperfusion catheter (Reperfusion Catheter) (Alameda, California, Pinumblr, Inc.) or other reperfusion catheters known in the art for clot removal in patients with acute ischemic stroke. Although the catheter advancement element 300 is described herein with reference to the catheter 200, it should be understood that the catheter advancement element can be used to advance other catheters and is not intended to limit its use.

[0140] As described above, the distal access system 100 can provide fast and simple access to distal target anatomical structures, particularly tortuous anatomical structures of cerebral vessels. The flexibility and deliverability of the distal access catheter 200 allow the catheter 200 to take the shape of tortuous anatomical structures and avoid applying straightening forces that create new anatomical structures. The distal access catheter 200 can achieve this even in the presence of a catheter advancement element 300 extending through the lumen of the distal access catheter 200. Thus, the flexibility and deliverability of the catheter advancement element 300 are equal to or better than the flexibility and deliverability of the distal lumen portion 222 of the distal access catheter 200, because both are constructed to reach the middle cerebral artery (MCA) circulation without clearing the curves of anatomical structures along the way.

[0141] The catheter advancement element 300 may include a non-expandable flexible elongated body 360 coupled to a proximal portion 366. The elongated body 360 may be received within and extend through the inner lumen 223 of the distal lumen portion 222 of the catheter 200 (see Figure 2B ). The distal tip 346 of the catheter advancement element 300 may be as Figure 2B360 and the catheter system 100 as a whole. The elongated body 360 is shown extending beyond the distal end of the catheter 200. The proximal portion 366 of the catheter advancement element 300 is coupled to the proximal region of the elongated body 360 and extends proximally therefrom. The proximal portion 366 can be less flexible than the elongated body 360 and is configured to enable bidirectional movement of the elongated body 360 of the catheter advancement element 300 within the lumen portion 222 of the catheter 200 and movement of the catheter system 100 as a whole. The elongated body 360 can be inserted through the inner lumen 223 of the lumen portion 222 in a coaxial manner. The outer diameter of at least one region of the elongated body 360 can be sized to substantially fill the inner lumen 223 of the lumen portion 222.

[0142] The overall length of the catheter advancement element 300 (e.g., between the proximal end and the distal-most tip) can vary, but is generally long enough to extend through the support catheter 200 plus at least a distance beyond the distal end of the support catheter 200, while at least a length of the proximal portion 366 remains outside the proximal end of the guide sheath 400. In some embodiments, the overall length of the catheter advancement element 300 is about 149 cm, and the working length is 143 cm from the proximal tab or hub to the distal-most tip. The elongated body 360 can have a length at least as long as the lumen portion 222 of the catheter 200, but it should be understood that the elongated body 360 can be shorter than the lumen portion 222, as long as at least a length remains within the lumen portion 222 when the distal portion of the elongated body 360 extends at the distal end of the lumen portion 222. In some embodiments, the axial length of the distal lumen 222 may be about 39 cm, and the insertion length of the elongated body 360 may be at least about 48.5 cm, 49 cm, or about 49.5 cm. The proximal portion 366 may also have a varying length. In some embodiments, the proximal portion 366 is about 94 cm. The distal portion extending distally of the distal end of the lumen 222 may include a distal tip 346 that protrudes beyond a length of the distal end of the lumen 222 during use of the catheter advancement element 300. As will be described in more detail below, the distal tip 346 of the elongated body 360 that is configured to protrude distally from the distal end of the lumen 222 assists in the navigation of the catheter system through the tortuous anatomical structure of the cerebral blood vessels. The proximal portion 366 coupled to the elongated body 360 and extending proximally from the elongated body 360 can be aligned generally side by side with the proximal control element 230 of the catheter 200. As will be described in more detail below, the structure between the elongated body 360 and the lumen portion 222 can be maintained during advancement of the catheter through tortuous anatomical structures to reach a target location for treatment in a distal vessel and assist in preventing the distal end of the catheter 200 from becoming stuck on a tortuous branch vessel.

[0143] In some embodiments, the elongated body 360 can have a region of relatively uniform outer diameter extending along at least a portion of its length, and the distal tip 346 tapers downward from the uniform outer diameter. When the catheter advancement element 300 is inserted through the catheter 200, the tapered distal tip 346 is configured to extend beyond and protrude through the distal end of the lumen 222, while the more proximal region of the body 360 with uniform diameter remains within the lumen 222. As mentioned, the distal end of the lumen 222 can be blunt and have no variation in the size of the outer diameter, while the distal tip 346 can be tapered, which provides an overall elongated tapered geometry of the catheter system. The outer diameter of the elongated body 360 is also close to the inner diameter of the lumen 222, minimizing the increase in the outer diameter from the elongated body 360 to the lumen 222. Minimizing this increase prevents problems with the lip formed by the distal end of the lumen portion 222 getting caught on tortuous neurovasculature (e.g., around the carotid siphon near the ophthalmic artery bifurcation) as the distal tip 346 bends and curves along within the vascular anatomy. In some embodiments, the inner diameter of the lumen portion 222 can be 0.072" and the outer diameter of the elongated body 360 is 0.070", so that the difference between them is only two thousandths of an inch. In other embodiments, the outer diameter of the elongated body is 0.062". Despite this, the lumen portion 222 and the elongated body 360 extending coaxially therethrough are flexible enough to navigate the tortuous anatomy that leads to the level of the M1 or M2 artery without kinking and without damaging the vessel.

[0144] The length of the distal tip 346 can vary. In some embodiments, the length of the distal tip 346 can be in the range of about 0.50 cm to about 3.0 cm from the most distal end of the slender body 360. In other embodiments, the length of the distal tip 346 is between 2.0 cm and about 2.5 cm. In some embodiments, the length of the distal tip 236 varies depending on the inner diameter of the slender body 360. For example, the length of the distal tip 236 can be as short as 0.5 cm, and the inner diameter can be 0.054". The distal tip 346 can be a constant taper from the outer diameter of the slender body 360 downward to a second smaller outer diameter at the most distal tip. The constant taper of the distal tip 346 can be from a 0.062" outer diameter to about a 0.031" outer diameter. The length of the constant taper of the distal tip 346 can vary, for example, between 1 cm and 3 cm or between 2.0 cm and 2.5 cm.

[0145] It should be understood that the distal tip 346 does not need to taper, and its soft, atraumatic and flexible properties can be achieved due to material properties rather than changes in outer dimensions to facilitate intravascular navigation of emboli in tortuous anatomical structures. In addition or alternatively, the distal tip 346 of the elongated body 360 can have a flexible transition along its length. The most flexible area of ​​the distal tip 346 can be its distal terminus. Moving along the length of the distal tip 346 from the distal terminus toward the area proximal to the distal terminus, the flexibility can gradually approach the flexibility of the distal end of the lumen portion 222. For example, the distal tip 346 can be formed of a material with a hardness of 35D, and transition to a harder and harder material of 55D and 72D toward the proximal end until the proximal end 366, which can be a stainless steel hypotube, or a combination of material properties and a tapered shape. The material used to form the region of the elongated body 360 can include Pebax (e.g., Pebax 25D, 35D, 55D, 72D) with a lubricating additive compound. Incorporating lubricating additives directly into the polymer elongated body means that incorporating a separate lubricating lining (e.g., Teflon lining) is unnecessary. This allows for a more flexible element that can navigate distal brain anatomy and is less likely to kink. Similar materials can be used to form the distal lumen portion 222 of the catheter 200, which provides similar advantages. It should also be understood that the flexibility of the distal tip 346 can be achieved by a combination of flexible lubricating materials and a tapered shape. For example, the length of the tip 346 can be kept shorter than 2cm-3cm, but the best delivery capacity is maintained due to the change of the flexible material from the distal tip toward the more proximal region at a distance from the distal tip. In an embodiment, the elongated body 360 is formed by a silicone embedded with PEBAX (polyether block amide), which is designed to maintain the highest degree of flexibility. It should be understood that the wall thickness of the distal end of the lumen portion 222 can also be made thin enough so that the lip formed by the distal end of the lumen portion 222 relative to the elongated body 360 is minimized.

[0146] As mentioned above, the elongated body 360 can be configured to have variable stiffness between the distal and proximal ends of the elongated body 360. The flexibility of the elongated body 360 is highest at the most distal terminus of the distal tip 346, and can gradually transition in flexibility to the flexibility of the distal end near the lumen portion 222, which is generally not as flexible as the most distal terminus of the distal tip 346. When the catheter advancement element 300 is inserted through the catheter 200, the region of the elongated body 360 extending beyond the distal end of the lumen portion 222 can be the most flexible, and the region of the elongated body 360 that is configured to align with the distal end of the lumen portion 222 during advancement in the blood vessel can have approximately the same flexibility as the distal end of the lumen portion 222 itself. It can be seen that the flexibility of the distal end of the lumen portion 222 and the flexibility of the body 360 just proximal to the extension (whether tapered or not tapered) can be approximately the same. This provides a smooth transition in material properties to improve tracking of the catheter system through tortuous anatomical structures. Further, the more proximal segments of the elongated body 360 can be less flexible and increasingly rigid. It should be understood that the change in flexibility of the elongated body 360 can be a function of material differences, size changes (e.g., by tapering), or a combination of both. The benefit of the elongated body 360 over a microcatheter is that it can have a larger outer diameter that is only 0.003"-0.010" smaller than the inner diameter of the catheter 200 and still maintain a high degree of flexibility for navigating tortuous anatomical structures.

[0147] The elongated body 360 can be formed of various materials that provide suitable flexibility and lubricity. Example materials include high density polyethylene, 72D PEBAX, 90D PEBAX, or equivalent stiffness and lubricity materials. The flexibility of the elongated body 360 can increase toward the distal tip, making the distal region of the elongated body 360 softer, more flexible, and easier to articulate and bend than the more proximal region. For example, the more proximal region of the elongated body can have a bending stiffness that is flexible enough to navigate tortuous anatomical structures, such as the carotid siphon, without kinking.

[0148] In some embodiments, the elongated body 360 can be generally tubular along at least a portion of its length such that it has a lumen 368 that extends parallel to the longitudinal axis of the catheter advancement element 300 (see FIG. 7A to FIG. 7C). In an embodiment, the lumen 368 of the elongated body 360 is sized to accommodate a guidewire, however it should be understood that the use of the catheter advancement element 300 generally eliminates the need for a guidewire lead. The guidewire can extend through the lumen 368 from the proximal opening to the distal opening through which the guidewire can extend. In some embodiments, the proximal opening is at the proximal end of the catheter advancement element 300, such that the catheter advancement element 300 is configured for an over-the-wire (OTW) approach. In other embodiments, the proximal opening has a rapid exchange opening 362, such that the catheter advancement element 300 is configured for rapid exchange rather than for OTW or in addition to OTW. In this embodiment, the proximal opening 362 is positioned a distance away from the proximal tab 364 and at the distal end of the proximal portion 366 (see FIG. 7A to FIG. 7B and Fig.7D ). The lumen 368 of the elongated body 360 can be configured to receive a guidewire having a diameter in the range of 0.014" and 0.018", or in the range of 0.014" and 0.022". In this embodiment, the inner lumen diameter of the elongated body 360 can be between 0.020" and 0.024". The guidewire, catheter advancement element 300, and catheter 200 can all be coaxially assembled for insertion through the working lumen 410 of the guide sheath 400. The inner diameter of the lumen 368 of the elongated body 360 can be 0.019" to about 0.021".

[0149] Fig.7D Another embodiment of a catheter advancement element 300 configured for rapid exchange is shown. The rapid exchange configuration can significantly shorten the device length, reduce staffing requirements, and reduce fluoroscopy. Similar to the other embodiments described herein, the catheter advancement element 300 can include a non-expandable flexible elongated body 360 coupled to a proximal portion 366, which is coupled to a proximal tab 364 or a hub 375. As described elsewhere herein, the area near the distal tip 346 can be tapered so that the outer diameter tapers over a length of about 1 cm to about 3 cm. In some embodiments, the distal taper length is 2.5 cm. In some embodiments, the distal tip 346 tapers from about 0.080" to about 0.031". Also as described elsewhere herein, the distal tip 346 can be formed of a material having a hardness of 35D and transitions proximally toward increasingly harder materials having hardnesses of 55D and 72D until the proximal portion 366. For example, Fig.7DIt is illustrated that the segment 371 of the elongated body 360 including the distal tip 346 can have a hardness of 35D and a length of about 10 cm. The segment 372 of the elongated body 360 can have a hardness of 55D and have a length of about 8 cm. The segment 373 of the elongated body 360 can have a hardness of 72D and can be about 31 cm in length. The three segments 371, 372, 373 combined can form an insertion length of the elongated body 360, and the proximal portion 366 is coupled to the elongated body 360 from the insertion length to the end of the distal tip 346, which can be about 49 cm in length.

[0150] Still refer to Fig.7D , the entry port 362 for the surgical guide wire 805 can be positioned a distance from the distal end of the elongated body 360. In some embodiments, the entry / exit port 362 can be about 18 cm from the distal end, which creates a rapid exchange wire entry / exit segment 370. The outer diameter of the elongated body 360 within the segments 370 (segments 371 and 372) can be about 0.080"-0.082", while the segment 373 at the proximal end of the rapid exchange wire entry / exit segment 370 can have a reduction in outer diameter, for example, about 0.062"-0.064".

[0151] In other embodiments, the entire catheter advancement element 300 can be a tubular element that is configured to receive a guidewire through the proximal portion 366 and the elongated body 360. For example, the proximal portion 366 can be a hypotube or a tubular element having a lumen that communicates with a lumen 368 extending through the elongated body 360 ( Figure 3 366). In some embodiments, the proximal portion 366 can be a skived hypotube of stainless steel coated with PTFE having an outer diameter of 0.026". In other embodiments, the outer diameter can be between 0.024" and 0.030". In some embodiments, such as an over-the-wire version, the proximal portion 366 can be a skived hypotube coupled to a proximal hub 375. The proximal portion 366 can extend eccentrically or concentrically with the distal lumen portion 222. As shown in FIG. Fig. 7E As best shown in , the proximal portion 366 can be a stainless steel hypotube as described elsewhere herein. The hypotube can have a lubricating coating, such as PTFE. The hypotube can have an inner diameter of about 0.021", an outer diameter of about 0.0275", and a total length of about 94 cm, which provides the catheter advancement element 300 with a working length of about 143 cm. Including the proximal hub 375, the catheter advancement element 300 can have a total length of about 149 cm. In some embodiments, the hypotube can be a tapered portion having a length of about 100 mm, which begins at the proximal end with a thickness of 0.3 mm and ends with a thickness of 0.10 mm to 0.15 mm. In yet other embodiments, the elongated body 360 can be a solid element coupled to the proximal portion 366, which has no guidewire lumen.

[0152] like FIG. 7F to FIG. 7J , the proximal end of the hypotube can be coupled to a proximal hub 375. The proximal hub 375 can be an overmolded component with Luer threads 377 and a Luer taper 378 formed on the interior of the proximal hub 375. The proximal hub 375 can incorporate tabs 364 that provide a user with an easier grip. The proximal hub 375 prevents the catheter advancement element 300 and catheter 200 from advancing beyond the distal tip of the base sheath 400 or guide catheter by limiting insertion into the proximal RHV 434, which provides a critical functional and safety feature for proper operation of the system 10.

[0153] At least a portion of the solid elongated body 360, such as the elongated distal tip 346, can be formed of a forgeable material or embedded with or attached to the material, which is thinned down to a smaller size at the distal end. The distal tip 346 can be formed into a desired angle or shape similar to the way a guide wire can be used. The forgeable length of the elongated body 360 can be at least about 1 cm, 3 cm, 5 cm and up to about 10 cm, 15 cm or longer. In some embodiments, the forgeable length can be about 1%, 2%, 5%, 10%, 20%, 25%, 50% or more of the total length of the elongated body 360. In some embodiments, the catheter advancement element 300 can have a working length of about 140 cm to about 143 cm, and the elongated body 360 can have an insertion length of about 49 cm. The insertion length can be the PEBAX portion of the elongated body 360 of about 49.5 cm. It can be seen from this that the forgeable length of the elongated body 360 can be between about 0.5 cm and about 25 cm or more. The shape change may be a function of the user manually shaping the malleable length prior to insertion. Alternatively, the shape change may be a reversible and actuatable shape change such that the tip forms a shape upon user actuation such that the tip may be used in a straight format until the user desires a shape change.

[0154] It should be understood that, as described above, the elongated body 360 can extend along the entire length of the catheter 200, including the distal lumen portion 222 and the proximal control element 230, or the elongated body 360 can incorporate a proximal portion 366 that is generally aligned side by side with the proximal control element 230 of the catheter 200. The proximal portion 366 of the elongated body 360 can be coaxially or eccentrically positioned with the elongated body 360. The proximal portion 366 of the elongated body 360 can have a lumen extending therethrough. Alternatively, the portion 366 can be a solid rod or ribbon without a lumen.

[0155] Refer again FIG. 7A to FIG. 7DAs with the distal lumen portion 222 of the catheter 200, the elongated body 360 can have one or more radiopaque markers 344 along its length. The size, shape, and location of the one or more markers 344 can vary. The one or more markers 344 can be incorporated along one or more portions of the catheter advancement element 300, such as a tip-to-tip marker, a tip-to-cone marker, an RHV approach marker, a fluorine protection marker, or other markers that provide various information about the relative position of the catheter advancement element 300 and its components. In some embodiments and as Figure 7C As best shown in FIG. 1 , the distal region can have a first radiopaque marker 344a, and a second radiopaque marker 344b can be positioned to indicate the boundary between the tapering of the distal tip 346 and the more proximal region of the elongated body 360 having a uniform or maximum outer diameter. This provides the user with information about the optimal extension of the distal tip 346 relative to the distal end of the lumen portion 222, which minimizes the lip at the distal end of the lumen portion 222 for advancement through tortuous anatomical structures. In other embodiments, such as where the distal tip 346 is not necessarily tapered but has a change in overall flexibility along its length, the second radiopaque marker 344b can be positioned to indicate an area where the relative flexibility of the elongated body 360 (or the distal tip 346 of the elongated body 360) and the distal end of the lumen portion 222 is approximately the same. The marker material can be a platinum / iridium ribbon, tungsten, a platinum or tantalum impregnated polymer, or other radiopaque markers that do not affect the flexibility of the distal tip 346 and the elongated body 360. In some embodiments, the radiopaque marker is an extruded Pebax loaded with tungsten for radiopacity. In some embodiments, the proximal marker band can be about 2.0 mm wide and the distal marker band can be about 2.5 mm wide to provide discernible information about the distal tip 346.

[0156] As mentioned above, the proximal control element 230 of the catheter 200 may include a proximal tab 234 on the proximal end of the proximal control element 230. Similarly, the proximal end 366 coupled to the elongated body 360 may include a tab 364. Tabs 234, 364 can be configured to be removably and adjustably connected to each other and / or to their corresponding proximal ends. The coupling allows the catheter advancement element 300 to be reversibly connected to the catheter 200 to lock (and unlock) the relative extension of the distal lumen 222 and the elongated body 360. This allows the catheter 200 and the catheter advancement element 300 to advance as a single unit. In the locked configuration, the tab 364 or the proximal end 366 can engage with the catheter tab 234. In the unlocked configuration, the tab 364 can be disengaged from the catheter tab 234. The tab 364 or proximal end 366 can be attached to the catheter tab 234 in a manner with respect to the relationship of the elongated body 360 and the corresponding section of the catheter 200 that maintains a locked configuration, for example, clicked or locked into the catheter tab 234. It should be understood that the tab 364 can be a proximal hub 375 (e.g., FIG. 7F to FIG. 7J Features on the hub 375) shown.

[0157] This locking can be achieved by, for example, using a detent on the tab 364 that snaps into place in a recess formed in the catheter tab 234, or vice versa. For example, the tab 234 of the catheter 200 can form a ring having a central opening extending through it. The tab 364 of the body 360 can have an annular detent having a central column that is sized to be inserted through the central opening of the tab 234 so that the ring of the tab 234 is received in the annular detent of the tab 364, which forms a single grasping element for the user to advance and / or withdraw the catheter system through the entry sheath. Tabs 234, 364 can be fixed or can be slidable to accommodate different relative positions between the elongated body 360 and the lumen 222 of the catheter 200. In some embodiments, the proximal end of the proximal control element 230 of the catheter 200 may include a coupling feature 334 configured to receive the proximal end 366 of the catheter advancement element 300, such as a clip, clamp, c-shaped element, or other connector (see Figure 2A). The coupling feature 334 can be configured to snap together with the proximal portion 366 via an interference fit, such that a first level of force is required to insert the proximal portion 366 into the clip of the tab 234, and a second, greater level of force is required to remove the proximal portion 366 from the clip of the tab 234. However, when the proximal portion 366 is inserted into the coupling feature 334, the catheter advancement element 300 and the catheter 200 can still be slidably adjusted relative to each other along the longitudinal axis of the system. The amount of force required to slidably adjust the relative position of the two components can be such that unintentional adjustment is avoided, and the relative position can be maintained during use, but the position can be adjusted upon conscious modification. It should be understood that the configuration of the coupling between the proximal portion 366 of the catheter advancement element 300 and the proximal extension 360 of the catheter 200 can vary. However, in general, the coupling is configured to be reversible and adjustable while still providing adequate retention between the two elements in a manner that is relatively user-friendly (e.g., allowing one-handed use) and organizes the proximal ends of the components (e.g., preventing the proximal extension 360 and the proximal end portion 366 from becoming twisted and tangled with each other). It should also be understood that the coupling features 334 configured to prevent tangling and assist in the organization of the proximal end portion can be integrated with the tabs, or can be separate features located along their proximal region.

[0158] The catheter advancement element 300 can be placed in a locking configuration, wherein the catheter 200 is configured to improve tracking through the tortuous and often diseased blood vessels in acute ischemic stroke. Other configurations are contemplated herein. For example, the elongated body 360 can include one or more ratchets on the outer surface. The ratchets can be located near the proximal region and / or distal region of the elongated body 360. The ratchets are configured to lock together with correspondingly shaped surface features on the inner surface of the lumen portion 222, through which the elongated body 360 extends. The catheter advancement element 300 and the catheter 200 can incorporate more than a single locking connection point between them. For example, as described elsewhere herein, a coupling feature 334, such as a clip, a clamp, a c-shaped element or other connector, is configured to hold the proximal control element 230 or tab 234 of the catheter advancement element 300 and the catheter 200 together.

[0159] In some embodiments, the proximal control element 230 of the catheter 200 can extend beside or within a dedicated channel of the proximal portion 366. The channel can be located along the length of the proximal portion 366 and have a cross-sectional shape that matches the cross-sectional shape of the catheter proximal control element 230, so that the proximal control element 230 of the catheter 200 can be received in the channel and smoothly slide along the channel in both directions. Once the catheter 200 and the elongated body 360 are secured, the combined system (i.e., the catheter 200-catheter advancement element 300) can be delivered to the target site, for example, through the working lumen 410 of the introducer sheath 400 described elsewhere herein.

[0160] Intracranial delivery system

[0161] Described herein are intracranial delivery systems that allow for delivery of stent retractors, intracranial stents, drains, or other microcatheter delivery devices through a conduit produced by a support catheter 200 extending distally from a guide sheath 400. In some embodiments, an intracranial delivery system (IDS) is a rapid exchange system that allows a single operator to perform all steps in distal entry and device delivery. As will be described in more detail below, an intracranial delivery system allows for only a short length (e.g., 10-20 cm) of an interventional device to be "pushed" through a microcatheter lumen, as opposed to always passing through the entire microcatheter lumen.

[0162] FIG. 8A to FIG. 8C Various systems 10 including a single operator intracranial working device delivery system 700 are illustrated, which is configured to be delivered through a support catheter 200 of a distal access system 100, which is used to access and remove brain occlusions to treat acute ischemic stroke. The intracranial delivery system 700 may include a working device 500, which is used to treat brain occlusions and is configured to be accommodated in a microcatheter 600. The intracranial delivery system 700 may optionally include a surgical guide wire 805, which is used to deliver the support catheter 200 extending through the guide sheath 400 of the distal access system 100, and is used to deliver the microcatheter 600 preloaded with the working device 500.

[0163] The working device 500 can be a stent retriever (e.g., Medtronic's Solitaire or Stryker's Trevo), a stent (e.g., self-expanding or balloon-expandable), a drain, and other devices known in the art. The working device 500 can include: a distal expandable payload 505 that is coupled to a proximal control element 510; or a push wire that is coupled to the proximal end of the expandable payload 505. As will be described in more detail below, the payload 505 can be collapsed and contained within a portion of the microcatheter 600. The proximal control element 230 of the catheter 200 and the proximal control element 510 of the working device 500 can extend outside the proximal end of the guide sheath 400 so that they can be used to control the relationship between the microcatheter 600 and the catheter 200 that contain the working device 500. In some embodiments, the proximal control element 510 of the working device 500 can be removable, for example, when the working device 500 is a stent or other type of interventional device intended to remain in place within a blood vessel. The proximal control element 510 can be a ridge, a push wire, a push tube, or other elements having any of a variety of structures that allow the control element 510 to be used for bidirectional movement of the working device 500 relative to the IDS 700 and / or other components of the distal access system 100, for example, to advance and position the expandable payload 505 relative to the lumen 605 of the microcatheter 600. The proximal control element 510 can be a hollow tubular element or can be a solid wire, rod, band, or other type of structure. The working device 500 can include one or more markers 545 along its length. In some embodiments, the working device 500 includes one or more radiopaque markers 545 that are positioned near the payload 505, for example, at the distal tip, middle region, and / or just proximal end of the expandable payload 505. The working device 500 may also include one or more markings 545 on the area of ​​the proximal control element 510 that are easily visible to an operator outside the RHV 434 and illustrate the position of the payload 505 relative to the microcatheter 600, guidewire 805 and / or support catheter 200 without the need for fluoroscopy.

[0164] Refer again FIG. 8A to FIG. 8C , the intracranial delivery system 700 also includes a microcatheter 600. The microcatheter 600 is designed so that at least a portion of its length (i.e., the portion extending beyond the distal catheter 200) can be independently navigated through the neurovasculature (e.g., the bony petrous portion of the carotid artery and the carotid siphon) into the anterior circulation of the cerebrovascular anatomy. For example, by incorporating sufficient structural reinforcement during delivery without kinking or collapse. The microcatheter 600 can have a single lumen configured for rapid exchange delivery.

[0165] In some embodiments, the microcatheter 600 can have a distal microcatheter portion 615, a payload portion 620 located proximal to the distal portion 615, and a proximal control element 625. As will be described in more detail below, each of these portions of the microcatheter 600 can be designed to have different flexibilities depending on whether the portion will extend outside of the distal access system (e.g., the distal portion 615) or remain inside a conduit provided by the distal access system (e.g., the proximal control element 625).

[0166] The distal microcatheter portion 615 is designed to be very flexible and deliverable so that it can extend beyond the distal end of the support catheter 200 and be used to independently navigate the distal tortuosity. For example, the distal portion 615 can be used to navigate the neck loop, such as from the petrous carotid artery to the Willis circle, with minimal straightening force. The distal portion 615 is designed to be the only portion of the microcatheter 600 that leaves the distal access catheter 200 and interacts directly with the cerebrovascular anatomy, while more rigid portions such as the proximal control element 625 of the microcatheter 600 remain within the distal access catheter.

[0167] The length of distal portion 615 can vary, but is usually between 10cm-20cm long. In some embodiments, distal portion 615 is between 12cm and about 15cm. In some embodiments, distal portion 615 is between 15cm-18cm long. In other embodiments, distal portion 615 is at least 18cm long. This length allows the distal portion 615, which is the most flexible region of microcatheter 600, to reach the M2 level when, for example, support catheter 200 only advances to the level of the petrous carotid artery, and the remainder of microcatheter 600, including a more rigid middle portion extending between 15cm-30cm at the proximal end of distal portion 615, is shielded by the pipeline (for example, in the carotid artery) provided by the distal access system 100. Thus, as described elsewhere herein, the less transportable portion of microcatheter 600 remains coated and is prevented from causing a straightening force to a tortuous anatomical structure.

[0168] The more flexible region at the distal end may be about 18 cm in length, while the more rigid portion may be between 15-30 cm in length. The proximal control element 625 may be longer, for example between 90 cm and 115 cm in length. Typically, the microcatheter 600 and the working device 500 are shorter in length than conventional stent retractor systems. The length of the proximal control element 625 may be maintained such that the proximal control element 625 and the intermediate rigidity portion of the microcatheter 600 combined are no longer than the total length of the ridged distal catheter 200. This relative length ensures that the only portion of the microcatheter 600 that can extend at the distal end of the distal access system to interact with the artery is the distal-most flexible portion 615. In some embodiments, the total length of the delivery system 700 may be between 120 cm and 150 cm.

[0169] The collapsed payload 505 of the working device 500 can be housed within the payload portion 620 of the microcatheter 600. The payload portion 620 can be much shorter than the length provided above. In some embodiments, the payload portion 620 can be between 4cm-8cm in length. The collapsed working device 500 can be advanced to the target location as a unit within the payload portion 620 of the microcatheter 600. This prevents the need to advance the "naked" payload 505 through the entire length of the microcatheter 600, and eliminates the friction and push-pull trouble of pushing the working device 500 alone for such a long distance. In some embodiments, the payload portion 620 may have an outer diameter that is larger than or similar in size to the diameter of a conventional microcatheter, which is typically 3F. Typically, the outer diameter of the payload portion 620 is sized to be received within the inner diameter of the support catheter 200, which can be 0.054", 0.070" or 0.088". The distal portion 615 can have a reduced outer diameter compared to the payload portion 620 (see Figure 8B ), or may have an outer diameter similar to that of the payload portion 620 (see Fig. 8A and Figure 8C ). Further, the distal portion 615 can have an inner diameter between 0.017" and 0.027". The inner diameter of the distal portion 615 can allow the surgical guidewire 805 to move freely within the distal portion and the working device 500 when deployed from the payload portion 620 of the microcatheter 600. Typically, the outer diameter 600 of the microcatheter has a maximum dimension of less than 0.048 inches, and the inner diameter is sized to allow the guidewire 805 to pass through it.

[0170] Where the distal end 615 is the most flexible portion of the microcatheter 600, the proximal control element 625 of the microcatheter 600 is typically the most rigid component of the entire system 700. The proximal control element 625 can be used as a single element for controlling bidirectional movement of the microcatheter 600 relative to the surgical guidewire 805 and the control element 510. The proximal control element 625 of the microcatheter 600 can provide support for pushing the distal end 615 across tortuous anatomy (e.g., terminal ICA) from the less tortuous anatomy of the entry puncture site (e.g., common femoral artery) to the proximal common carotid artery or aorta exit point.

[0171] like FIG. 8B to FIG. 8CAs shown, the proximal control element 625 can have a reduced outer diameter compared to one or both of the payload portion 620 and the distal portion 615. For example, the proximal control element 625 can be a ridge or hypotube or other rigid component similar to the components described above with respect to the proximal control element supporting the catheter 200 and the catheter advancement element 300. As will be described in more detail below, as a hypotube, the proximal control element 625 allows the guidewire 805 or the control element 510 of the working device 500 to pass through it in an OTW manner so that they extend through a single RHV 434 of the guide sheath 400 of the distal access system 100. However, it should be understood that a single track format with two exit ports for the microcatheter is also contemplated herein and will be described in more detail below.

[0172] It should be understood that the microcatheter 600 of the delivery system 700 need not have ridges or include a hypotube, but instead may be Fig. 8A When a complete microcatheter 600 is used, the control element 510 for the working device 500 can be longer than the distal access system 100. It should be similarly understood that the catheter 200 of the distal access system 100 does not need to have a ridge, but can be a complete catheter with a uniform inner diameter from the proximal end to the distal end. FIG. 8A to FIG. 8C 600 and having a proximal control element 230. The microcatheter 600 housing the working device 500 can also be advanced through a conventional catheter extending from the guide sheath 400 without a spine.

[0173] The delivery system 700 may also be advanced through a series of nested support catheters 200 that provide sequential extensions of length for the delivery system 700 to pass through. Fig.21In the illustrated embodiment, the guide sheath 400 can be deployed as described elsewhere herein so that the distal end of the sheath 400 is advanced to a position in, for example, the internal carotid artery (ICA). The first catheter 200a can be advanced through the working lumen of the guide sheath 400 and leave the distal end. As described elsewhere herein, the first catheter 200a can have a distal lumen portion 222a coupled to a proximal control element 230a. The proximal control element 230a can have a smaller outer diameter than the outer diameter of the distal lumen portion 222a, and can be coupled near the proximal opening coming out of the lumen of the distal lumen portion 222a. The first catheter 200a can be advanced using a catheter advancement element as described elsewhere herein. The catheter advancement element can assist the first catheter 200a in advancing through the blood vessel without hanging on severe abnormal bend formation and / or branch vessels. The first catheter 200a can be advanced through the working lumen of the guide sheath 400, and then through the blood vessel to reach the first target position. The catheter advancement element 300 can be removed from the lumen of the first catheter 200a. The second catheter 200b having the second catheter advancement element 300 can be advanced through the lumen of the first catheter 200a. The second catheter 200b can also include a distal lumen portion 222b, which is coupled to a proximal control element 230b near the proximal opening coming out of the lumen of the distal lumen portion 222b. Similar to the first catheter 200a, the proximal control element 230b of the second catheter 200b can have a smaller outer diameter than the outer diameter of the distal lumen portion 222b. The distal end of the second catheter 200b can be extended using its proximal control element 230b to extend through the distal end of the first catheter 200a, so that the second catheter 200b of smaller diameter can reach a target site that is positioned to a distal blood vessel with a narrower size than the position of the first catheter 200a. In this embodiment, the first spine catheter 200a can serve as a support catheter for the second spine catheter 200b. The inner lumen of the second spine catheter 200b can be in fluid communication with the inner lumen of the first spine catheter 200a, which is in fluid communication with the working lumen of the guide sheath 400, forming a continuous lumen formed by three segments having increasingly larger sizes toward the proximal end of the catheter system. For example, as described elsewhere herein, the first catheter 200a can have a distal lumen portion 222a having an inner diameter of approximately 0.088", and the second catheter 200b can have a distal lumen portion 222b having an inner diameter of approximately 0.070". It should be understood that more than two nested spine catheters are contemplated, and their respective inner and outer diameter dimensions are configured to receive each other for use together. The corresponding IDs and ODs of the catheters can be sized so that they slide relative to each other, but still provide an adequate seal. For example, adjacent lumens created by the nested structure can be sealed to each other so that suction can be induced through them, and appropriate pressure can be applied through the nested catheters to achieve a suction force sufficient for, for example, aspiration thrombectomy of a distal clot.As described elsewhere herein, the adjacent lumens formed by the nested catheters can be used to advance a working device 500 housed within a microcatheter 600 .

[0174] The proximal end of the nested catheter system can incorporate various gripping, tissue, and attachment features as described elsewhere herein. For example, the guide sheath 400 can include a proximal end coupled to a rotary hemostatic valve 434 that provides access to a working lumen through which a catheter can be inserted. Various components of the catheter system can extend proximally out of the valve 434. For example, the proximal control elements 230a, 230b of the catheters 200a, 200b and the proximal end of the microcatheter 600 can extend through the valve 434. The catheter advancement element ( Fig.21 The proximal extension of the proximal end of the catheter 430a, 230b (not shown) can also extend proximally through the valve 434. Each of these components in the nested or telescoping catheter set can incorporate identification features at their proximal regions that distinguish them from each other. For example, each proximal control element 230a, 230b can include a tab 234a, 234b having a distinctive shape, color, or other visual characteristics specific to that particular catheter. Each proximal control element 230a, 230b can include a coupling feature, such as a clip or other connector, that organizes the various control elements and prevents entanglement. The nested catheters and their corresponding catheter advancement elements can be incorporated into a kit.

[0175] The term "control element" as used herein may refer to a proximal region that is configured to cause a push movement in the distal direction and a pull movement in the proximal direction for a user. The control elements described herein may include a spine, a push wire, a push tube, or other elements having any of a variety of configurations. The proximal control element may be a push tube because it is hollow or tubular. The proximal control element may also be solid and have no inner lumen, such as a solid rod, a band, or other solid wire-type element. Typically, the proximal control element described herein is configured to enable its corresponding component (to which the proximal control element may be attached or integral therewith) to move through the lumen in a bidirectional manner.

[0176] As mentioned, the microcatheter 600 can be configured as an over-the-wire (OTW) device or a rapid exchange device. Fig. 8A) can allow the guidewire 805 and / or the control element 510 of the working device 500 (e.g., a stent retractor) to enter / exit the lumen 605 of the microcatheter 600 at the proximal Luer interface 634 coupled to the proximal end of the control element 625. In the rapid exchange device, the side opening or distal wire port 604 for the guidewire 805 can be positioned at a distance from both the distal and proximal ends of the device 600. The distal wire port 604 can be 5-30 cm from the distal tip of the microcatheter 600. In some embodiments, the distal wire port 604 is positioned 30-38 mm from the distal end of the microcatheter 600. In some embodiments, the distal wire port 604 can be positioned at a distance between 10 cm and 20 cm from the most distal tip of the catheter 600.

[0177] FIG. 12A to FIG. 12B , FIG. 13A to FIG. 13B as well as Fig.14A An example of a rapid exchange version of the microcatheter 600 is illustrated. As described above, the microcatheter 600 may include: a payload portion 620 configured to accommodate the working device 500; and a proximal control element 625 configured to manipulate the microcatheter 600 in a bidirectional sliding manner relative to the support catheter 200. The distal wire port 604 for the guidewire 805 (or the side opening 606 for the working device control element 510 to exit the lumen 605) may be located in a portion of the microcatheter 600 near which the working device 500 is housed within the payload portion 620 or may be located more proximally, such as within a hypotube proximal control element 625. This is in contrast to the OTW version where the guidewire 805 and / or the control element 510 exit the proximal Luer interface 634 of the hypotube 625.

[0178] In some embodiments, the proximal control element 625 is a hypotube coupled to a proximal luer 634. The lumen of the hypotube and the microcatheter portion can be in fluid communication with the luer 634 so that distal angiographic contrast injection can be performed through the luer 634 exiting the end of the microcatheter 600. The contrast agent can flow through the working device 500 housed in the payload portion 620 (through one or more ports 604, 606 in the case of a rapid exchange device) and primarily into the distal end 615 of the microcatheter 600.

[0179] The microcatheter 600 can transition in rigidity along its length, which is similar to the content described above about the support catheter 200 and the catheter advancement element 300. The distal microcatheter portion 615 (i.e., the portion intended to extend beyond the support catheter 200) is the most flexible, and the proximal control element 625 is the most rigid portion of the microcatheter 600. The proximal control element 625 of the microcatheter 600 can be more rigid than the rigidity of the distal end 615 and the payload portion 620 alone. The guidewire 805 and the control element 510 can extend "side by side" in the proximal control element 625 of the microcatheter 600, and the three components together can even be more rigid than the surgical guidewire 805 and the working device control element 510 extending through these catheter portions therein. The more rigid proximal control element 625 can keep the pipeline formed by the lumen of the support catheter 200 and the guide sheath 400 closed so that it does not directly contact the anatomical structure.

[0180] Because the proximal control element 625 of microcatheter 600 has the maximum degree of rigidity, this part of the device can withstand the impact of greater thrust, for example, so that it is transported across the expected tortuosity as it approaches the terminal carotid artery. This may potentially place it at the highest kink risk in the system 700. Microcatheter 600 (and other catheters with rapid exchange ports mentioned above) can be designed to avoid kinking and articulation near the distal wire port 604, which may produce the advancement problem of microcatheter 600. The risk of kinking and bending, particularly at the weak point of the distal wire port 604, can also be minimized by making the flexibility in the microcatheter 600 at the distal wire port 604 or just at its distal end transition. The flexibility of microcatheter 600 transitions from the distal end 615 towards the "middle" catheter portion that is less flexible, and the intermediate catheter portion can include a payload portion 620 and a distal wire port 604. Or the intermediate catheter portion can transition to the proximal control element 625 before producing the distal wire port 604. The intermediate flexible portion of the microcatheter 600 can resist kinking of the distal wire port 604 of the surgical guide wire 805 and the proximal port 606 of the control element 510 for the working device 500, as will be described below with reference to FIGS. 15 to 16. Fig. 20 Described in more detail. The distal wire port 604 can be positioned within the stiffened mid-section between the distal end 615 and the proximal control element 625. The variable stiffness of the microcatheter 600 can be achieved in a variety of ways.

[0181] The more rigid middle and proximal portions of the microcatheter 600 will tend to straighten the cervical ICA loop and various anatomical structures that may be encountered when directly applied. Thus, the more rigid portion of the microcatheter 600 is designed to remain in the pipeline formed by the distal end lumen 222 of the distal access catheter 200 during use. As discussed above, only the distal end 615 is intended to extend at the distal end of the distal access catheter 200. The total length of the microcatheter 600 and the length of the ridged catheter 200 relative to a single RHV 434 can be designed to prevent any other part of the microcatheter 600 except the flexible distal end 615 from leaving the catheter 200 to prevent the straightening force from being imposed on the anatomical structure. The ridged catheter 200 can be long enough so that it extends across the entire length of the cervical ICA and the terminal ICA, so as to reach the target of the ACA and M2 segments as far as the middle cerebral artery. The distal end lumen 222 is flexible along this entire distance. The total length of the microcatheter 600 can also be controlled to ensure that the distal wire port 604 and the proximal wire port 606 on either end of the intermediate catheter portion remain within the distal lumen portion 222 of the catheter 200 when the intended movement will occur. For example, when the microcatheter 600 is extended to the distal end and the microcatheter 600 passes through the terminal carotid artery (with or without the distal access catheter 200) to the level of the ACA, M1 or M2 branch of the MCA. Thus, the distal wire port 604 can remain "cannulated" during movement, thereby minimizing the risk of kinking or folding of the surgical guidewire 805 and / or the control element 510 of the working device 500.

[0182] FIG. 11A to FIG. 11B The ridged distal access catheter 200 is shown to have great flexibility to pass through the carotid artery in the neck extending beyond the introducer sheath 400 and provide a conduit for inserting the less flexible components of the working device delivery system 700. Sometimes, the tortuosity of the ICA in the neck and the carotid artery distal to the carotid terminus can result in distal access only reaching the petrous carotid artery (see Fig. 11B ). The spinal catheter 200 can be delivered via an introducer sheath 400 (see Fig. 11B), the guide sheath is usually more rigid and supported to prevent the catheter system from kinking from the entry point (e.g., the common femoral artery) as the lead-out point of the great vessels is approached and enters the carotid anatomy. Rigid guide sheath 400 can be placed as high as possible in the ICA. However, when the tortuosity of the cervical ICA exists (which may be common in the elderly), the guide sheath 400 is usually positioned below the area of ​​severe kinking or looping, to avoid straightening the section. In this embodiment, the length of the extremely flexible catheter portion 222 of the ridged distal entry catheter 200 can be at least 30cm, and can be 38cm-40cm in length, to provide enough overlap with the guide sheath 400 when the catheter 200 is just positioned at the proximal end of the cervical ICA of severe kinking or looping. The length of the entire ridged catheter 200 can make the distal lumen portion 222 the only part of the device leaving the guide sheath 400, which can be between 80cm-90cm long, and this still maintains a certain length of overlap, so as to seal. The microcatheter 600 can extend 3-5 cm beyond the distal end of the spine catheter 200. If the distal access obtained by the spine catheter 200 is to the proximal carotid artery, then delivering the working device 500 to the M2 branch can involve a microcatheter length extending beyond the support catheter 200, which is approximately 12 cm to 15 cm. Thus, the distal portion 615 of the microcatheter 600 can be approximately 18 cm to ensure sufficient length to enter these sites, even if the distal access obtained by the spine catheter 200 is limited. The flexibility of the distal portion 615 combined with the kink resistance of the more rigid proximal portion of the microcatheter 600 allows it to independently navigate through the bony petrous portion of the carotid artery and the carotid siphon and reach the anterior circulation of the cerebrovascular anatomy. However, typically, the microcatheter 600 only needs to navigate through the conduit provided by the access catheter lumen.

[0183] Components of the distal access system 100 and the working device delivery system 700 may include one or more markings that provide information about their positions relative to each other and relative to the vascular anatomy. Figure 2AAs shown, one or more radiopaque markers 411 may be disposed near the distal tip 406 of the guide sheath 400. One or more radiopaque markers 224 may also be positioned near the distal tip of the distal access catheter 200, and one or more radiopaque markers 344 may be positioned near the distal tip of the catheter advancement element 300. The proximal control element 230 of the distal access catheter 200 may include one or more markers 232, and the proximal control element 366 of the catheter advancement element 300 may also include one or more markers 232. The proximal control element 625 of the microcatheter 600, the proximal control element 510 of the working device 500, and the guidewire 805 may each include one or more markers along their lengths to provide information about their relative positions to each other and to the RHV 434 of the guide sheath 400. Specific markers may minimize fluoroscopic use and accidental advancement of one of the components beyond a desired point (e.g., the microcatheter 600 beyond the distal tip of the catheter 200). The markings may vary in size, shape, and position, and may be different from one another, to provide quick and simple information about the component on which it is positioned and its overlap with one or more of the other components.

[0184] The distal access system 100 and the delivery system 700 can have a working device 500 that is preloaded and received within the lumen of the microcatheter 600 adjacent to the side opening (e.g., on the proximal side of the side opening) and advanced over a surgical guidewire 805. The working device 500 can be preloaded by pulling the working device 500 into the distal opening at the distal tip of the microcatheter 600 and directing the working device control element 510 away from the proximal port 606 in the microcatheter 600. The proximal port 606 can be positioned a distance proximal to the location where the working device 500 is received in the payload portion 620. The expandable payload 505 can be positioned outside the distal opening outside the lumen 605 of the microcatheter 600, and the proximal control element 510 can be positioned to extend through the lumen 605 and exit through the proximal opening 606. The expandable payload 505 of the working device 500 can be withdrawn or pulled into the payload portion 620 of the microcatheter 600 until the expandable payload of the working device 500 enters the lumen 605 through the distal opening and slides proximally through the side opening of the guide wire 805 (i.e., the distal wire port 604) until the expandable payload 505 is received in the lumen 605 adjacent to the distal wire port 604 on the proximal side of the port. The surgical guide wire 805 can also be post-loaded into the distal tip of the microcatheter 600 and guided out of the distal wire port 604 of the microcatheter 600. The distal wire port 604 through which the surgical guide wire 805 extends can be located at the distal end of the payload portion 620 that receives the working device 500, so that the surgical guide wire 805 does not extend through the payload portion 620 and the payload of the working device 500. The surgical guide wire 805 can be loaded within the lumen 605 of the microcatheter 600 after the expandable payload 505 is positioned on the proximal side of the side opening 604 , such that the push wire 510 and the surgical guide wire 805 do not extend side by side within the lumen 605 .

[0185] The proximal end of the working device control element 510 may have a wire introducer or torquer 544 applied thereto. Similarly, the proximal end of the guidewire 805 may have a wire introducer or torquer 844 applied thereto. The torquer 844 for the guidewire 805 may be distinguished, for example, by color, shape or other identifiers from the torquer 544 on the control element 510 of the working device 500 to allow for easy identification. The surgical guidewire 805 may be pulled into a tip-to-tip position with the distal tip of the microcatheter 600 to facilitate passage into the support catheter 200. The microcatheter 600, the guidewire 805, and the working device 500 may be prepared in advance and preloaded and set aside until needed during surgery (e.g., during a CT scan (e.g., after identifying the diameter and length of the working device 500 or during patient delivery)) or when obtaining femoral access. The microcatheter 600, the guidewire 805, and the working device 500 may also be prepared simultaneously with obtaining distal access and obtaining a basic catheter position in the internal carotid artery.

[0186] The microcatheter 600 preloaded with the working device 500 and the surgical guide wire 805 can be advanced until the microcatheter 600 extends across the target located within the intracranial neurovascular system. A preassembled stent retractor system for neurovascular use in stroke treatment has never been possible because preloading the stent retractor into the microcatheter sacrifices the system's ability to deliver at the level required to treat the stroke. However, the support catheter 200 of the present system is specifically constructed to manually navigate the tortuous neuroanatomy, which extends the length of the guide sheath 400 and provides a complete and smooth conduit until the target anatomical structure, so as to facilitate the advancement of the preloaded delivery system 700, which does not apply a straightening force and maintains the natural curvature of the anatomical structure. The smooth conduit provided by the support catheter 200 and the guide sheath 400 means that the delivery system 700 can be preloaded with the working device 500.

[0187] In use and as FIG. 9A to FIG. 9I As best shown, the support catheter 200 can be inserted through a single RHV 434 coupled to the proximal end of the guide sheath 400, such that the distal lumen portion 222 extends the length of the catheter tubing just enough to allow access from the entry site entry point (e.g., the common femoral artery) to just the proximal end of the target for implant delivery. Due to the telescoping of the catheter 200 relative to the guide sheath 400, the use of a ridged support catheter 200 can allow for a minimum distance to the target. The RHV 434 can be as Fig. 9A As shown with a single head or as FIG. 10A to FIG. 10H The illustrated may include a double ended RHV.After securing distal entry, the operator may secure the distal entry point in place with a pinch P, which creates a control point that secures the catheter 200 to provide support for smaller catheters and wires that may pass through it. Fig. 9BA microcatheter 600 is shown which inserts a preassembled, unexpanded payload 505 of a working device 500 contained therein, along with a surgical guidewire 805, through the single RHV 434 of the distal access system 100. The three components advance in unison through the RHV 434 to advance the distal end of the microcatheter 600 to be very close to the target. If a double-headed RHV is used, the microcatheter 600 and guidewire 805 can be inserted through a single head of a single RHV 434 of a guide sheath 400 or through its own dedicated head. The double-headed RHV allows the support catheter 200 to be inserted through its own dedicated port to eliminate the need to manage catheter positioning when working with a dedicated working channel for the IDS 700. Regardless of whether the single RHV is single-headed or double-headed, the system provides greater ease of use compared to a typical three-axis system, in which each of the microcatheter, distal access catheter, and guide sheath will be coupled to their respective RHVs, which results in a significantly longer system requiring multiple operator's hands to manage multiple interactive sites. This can be particularly troublesome when two-handed manipulation is required at one of the RHVs (e.g., advancing a microcatheter, advancing a guidewire, etc. at the RHV). As mentioned above, the torquer 844 can be attached near the proximal end of both the guidewire 805 and the control element 510 of the working device 500. In a conventional triaxial system, the torquer must be removed and replaced to provide a grip to the working device control element 510 because emboli are typically very adherent and often require a firm pull to move. It should be understood that although the system is described here as being capable of delivery through a single RHV 434, in a more typical triaxial system, more than a single RHV may also be used.

[0188] Refer again Fig. 9B , advancing the loaded IDS 700 into the RHV 434 can include a first hand holding the RHV 434 and a second hand grasping the microcatheter 600, the guidewire 805, and the proximal region of the working device 500 together in a single pinch point P. The configuration of these three components can be pre-set as described elsewhere herein, and their juxtaposition maintained with each throw of advancement through the system. Once the tip of the IDS 700 reaches the distal lumen portion 222 of the spinal catheter 200, the guidewire 805 can be isolated from the other components (e.g., the control element 510 of the working device 500, the proximal control element 625 of the microcatheter, and the proximal control element 230 of the support catheter 200), which can be gathered into a single pinch point P and held together in a stationary position while the guidewire 805 is independently advanced (see Fig. 9C). The guidewire 805 can be advanced across the embolus to allow placement of the microcatheter 600. Once the guidewire 805 is positioned across the target, it can be held in place by adding the proximal region of the guidewire 805 to the pinch point P that holds the support catheter 200 while adjusting the microcatheter 600, which houses the working device 500, to advance it over the guidewire (see Fig.9D ). The system allows the guidewire 805 to remain stationary while the microcatheter 600 is advanced (rather than a back and forth piston movement as can occur in conventional systems).

[0189] The microcatheter 600 can cross the embolus to reach the target with minimal to no movement of the distal tip of the guidewire 805 . Fig.9E The microcatheter 600 is shown after the guidewire 805 is removed. When the guidewire 805 is removed, the proximal control element 230 of the support catheter 200 and the microcatheter 600 can be gathered in a single clamp point P, and the control element 510 of the working device 500 can be advanced to fix the position of the microcatheter 600 and advance the working device 500 into a suitable position to deploy the expandable payload 505 from the lumen 605 of the microcatheter 600 through the distal opening to treat the target. Thus, the working device 500 can be advanced distally through the lumen 605 to the distal region of the microcatheter 600 while the microcatheter 600 and the support catheter 200 are clamped together and fixed in the static position P. Once the expandable payload 505 of the working device 500 is in place, the control element 510 of the working device 500 and the proximal control element 230 of the support catheter 200 can be clamped together P and remain generally fixed in a static position as the microcatheter 600 is withdrawn proximally by pulling its control element at the RHV 434 (see Fig.9F ). The expandable payload 505 of the working device 500 is pulled out, which allows the payload 505 to be deployed or expanded at the target (see FIG. 9F to FIG. 9G). Once the working device 500 is pulled out, the single RHV 434 can be tightened. The single RHV 434 is tightened only once during the procedure in preparation for starting suction to create a sealing system. It should also be noted that the torquer 544 on the control element 510 of the working device 500 does not need to be removed or adjusted. After the delivery microcatheter 600 and the guidewire 805 are withdrawn, suction can be turned on at the single RHV 434, for example, in an AIS embolectomy procedure. Suction can be performed before the working device 500 is withdrawn into the supporting catheter 200 and removed, and the removal is then performed via the "SMAT" of suction via the catheter 200 to remove embolic fragments with suction alone or with suction while withdrawing the catheter 200 by pulling the proximal control element 230. In the "Solumbra" method, the working device 500 and the distal access segment 200 can be withdrawn as a unit by clamping both P control elements 510, 230 and pulling them out of the RHV 434 as a unit. The single RHV suction port 412 facilitates this by virtue of continuous suction at a single point ( FIG. 9H to FIG. 9I ).

[0190] The delivery system described herein allows a three-axis system of catheters to be advanced and positioned through a single RHV to deliver a working device while avoiding the requirement to "push" the device payload 505 the entire length of the catheter delivery system 700 as is typically done in conventional stent retractor systems and methods. The working device payload 505 of the delivery system 700 described herein can be preloaded within the microcatheter 600 so that they can be advanced to the target in unison and avoid the need to advance the payload "naked" throughout the length of the microcatheter. Further, the microcatheter 600 of the delivery system 700 described herein can be shorter than conventional stent retractor microcatheters, which are typically about 145 cm or longer and are configured to accept a stent retractor with a push wire of 180 cm in length. For example, compared to conventional stent retractor systems, the microcatheter 600 of the delivery system 700 described herein can be about 130 cm in working length, and in some cases 30-50 cm shorter than conventional systems. This shortened length allows the operator to work with a working device 500 having a proximal control element 510 that is significantly shorter than a typical stent retractor pushwire and is used with a shorter distal access system 100. For example, the distal lumen portion 222 of the support catheter 200 can be 20-40 cm long, and the proximal control element 230 can be 90-100 cm long. The guide sheath 400 through which the support catheter extends can be 80-90 cm long. When the support catheter 200 extends beyond the distal end of the guide sheath 400 while maintaining the overlap 348, a passageway approximately 115 cm long for device delivery can be created.

[0191] A single operator can use the system described herein by inserting the delivery system 700 through the support catheter 200 that extends the length of the artificial guide sheath 400 because, rather than the delivery system 700 and the support catheter 200 each having their own RHV in addition to the RHV of the guide sheath, they are both inserted through a single RHV 434 on the guide sheath 400. It should be understood that the catheter 200 and the microcatheter 600 housing the working device payload 505 can be advanced through the same port of the single RHV 434, or can be advanced through separate ports of the single RHV 434, for example, where the RHV 434 is such as FIG. 10A to FIG. 10H When a dual-ended RHV is shown. In either scenario, whether a single channel RHV or a dual-ended RHV is used, an additional RHV is eliminated, and the additional length and additional hand movements required to deliver the interventional device are eliminated. The shorter length of the systems described here combined with their insertion through a single RHV on an introducer sheath provides the advantage of ease of use to any operator or team of operators, and can change the procedure from a two-person procedure to a one-person, single-operator procedure. In the traditional long stent retriever and microcatheter setting, the distance the stent retriever microcatheter extends off-stage and the distance the RHV of the microcatheter extends away from the first operator requires a second operator to manage the position of the microcatheter to maintain hemostasis and manage any manipulation at the microcatheter RHV. Traditional tri-axial or quad-axial or penta-axial systems used in stroke interventions require at least two operators.

[0192] FIG. 10A to FIG. 10H An embodiment of a method using a double-ended RHV is illustrated. The RHV 434 allows the introduction of a device through the sheath 400 while preventing or minimizing blood loss and preventing the introduction of air into the sheath 400. The double-ended RHV 434 may include two working ports 435, 436 configured to receive one or more components of the system 10. The double-ended RHV 434 may include an arm 412 that may be used as a suction point or a line for flushing the sheath 400 with saline or radiopaque contrast agent during a portion of the operation. In an embodiment, the first port 435 is dedicated to receiving the control element 230 of the catheter 200 and locking it in place, and the second port 436 is dedicated to receiving components of the delivery system 700 including the surgical guide wire 805. This avoids the need to manually perform this by a pinch point during the remainder of the surgical steps as described above. This configuration provides better organization and handling of the components in the system 10 while still maintaining them well within the reach of a single operator. The RHV 434 may be integral with the sheath 400, or the sheath 400 may terminate on the proximal end of a female Luer adapter to which a separate hemostatic valve component, such as a passive sealing valve, a Tuohy-Borst valve, or a RHV may be attached. It should be understood that the structure of the RHV may vary. As described elsewhere herein, FIG. 10A to FIG. 10HThe upper head is shown as the "working" head, and the second head is dedicated to securing the distal entry ridged catheter 200. This allows the operator to secure the distal entry point in place with a "clamp" from the locked RHV 434. As previously described, this becomes the "control point" that the secured catheter 200 provides support for smaller catheters and wires passing through it.

[0193] The support catheter 200 can be inserted through the port of a single RHV 434 coupled to the proximal end of the guide sheath 400, such that the distal lumen 222 extends the length of the catheter tubing just enough to allow just enough access from the entry site entry point (e.g., the common femoral artery) to the target proximal end for implant delivery. The proximal control element 230 of the spinal catheter 200 can be locked in place by a dedicated RHV 434 (see Fig. 10A ). The guidewire 805, working device 500, and microcatheter 600 can be advanced as a unit to a separate port of the RHV 434 ("working RHV") and to the tip of the distal access catheter 200 (see Fig. 10B Once positioned at the distal tip of the catheter 200, the guidewire 805 can be independently advanced by adjusting the clamp to capture both the working device 500 and the microcatheter 600 as the guidewire 805 is advanced across the target (see Fig. 10C ).

[0194] In some embodiments, a wire introducer or torquer can be placed that allows the RHV port 436 for the working device delivery system 700 to lock down, which secures the microcatheter 600, working device 500, and wire introducer 644 in place. Fig. 10D Shown is how a wire introducer 644 may be placed which allows the microcatheter 600 and working device 500 to be locked down, which secures them in place. The wire introducer 644 may free the guidewire 805 from being secured by the RHV 434 and allow conventional torque / guidewire advancement to be used with free delivery of torque to the tip of the guidewire 805 (which may be a preformed tip) to manipulate the guidewire 805. The wire introducer 644 may also allow advancement and withdrawal of the guidewire 805 while the RHV 434 secures the microcatheter 600 and working device 500. Once the guidewire 805 is positioned across the target, it may be held in place by adjusting and clamping the proximal guidewire 805 and loosening the working RHV 434 to allow the control element 625 of the microcatheter 600 and the control element 510 of the working device 500 to advance together as a unit (see Fig.10E). The clamping action can secure the guidewire 805 and allow the microcatheter control element 625 and the working device control element 510 to be advanced over the guidewire 805. Again, any fore-aft piston movement of the guidewire 805 during advancement of the delivery system 700 is prevented. The microcatheter 600 can be safely advanced without concern for distal guidewire trauma. Once the working device 500 is in position, the guidewire 805 can be removed. The position of the working device 500 is secured by clamping the control element 510 together with the proximal element 230 supporting the catheter 200 (see Fig.10F ) and removed by pulling the microcatheter 600 (see Figure 10G ). The microcatheter 600 can be removed while holding the working device 500 in place with clamping followed by a short exchange. When the microcatheter 600 is completely removed, the RHV 434 can be tightened at both heads 436 and suction initiated through the arm 412 ( Fig. 10H ).

[0195] Standard stent retriever techniques require that the stent segment be fully released, which allows the struts to become one with the embolus for several minutes. The operator may then choose to perform either a "Solumbra" or "SMAT" procedure. For example, the stent retriever may be withdrawn into the distal access catheter 200 and removed, followed by "SMAT" via aspiration of the distal catheter 200 to remove the embolus with aspiration alone or while withdrawing the distal access segment by pulling on the spine catheter 200. FIG. 10A to FIG. 10H The dual-ended RHV configuration shown is particularly useful. With the "Solumbra" approach, the stent retriever and distal access segment are withdrawn simultaneously by clamping two pull wires. The two pull wires can be approximated and pulled as a unit from their closed RHV. FIG. 9A to FIG. 9I The single head RHV configuration shown is particularly useful.

[0196] It should be understood that there is no need to remove or adjust the torquer 544 on the working device 500. Instead, if the pulling of the working device 500 requires additional gripping of the control element 510 when engaging the plug, the torquer 544 can be positioned to be tightened.

[0197] Fig. 12A , Fig.13A as well as Fig.14A The complete catheter delivery system 700 is illustrated in relation to a stent retractor as a self-expanding payload 505 . Fig. 12B , Fig. 13B as well as Fig. 14B5 illustrates a spine delivery system 700 relative to a stent retriever as a self-expanding payload 505. Although the working device 500 is illustrated as a stent retriever, it should be understood that any of a number of working devices are contemplated herein (eg, drains, intracranial stents, etc.).

[0198] FIG. 12A to FIG. 12B An embodiment of a single operator delivery system 700 is illustrated having an integral microcatheter 600 ( Fig. 12A ) or ridged microcatheter 600 ( Fig. 12B ). A surgical guide wire 805 can run alongside the catheter delivery system 700 and enter the lumen 605 of the microcatheter 600 at a thinning or entry port 604 that is just distal to the point at which the payload 505 rests within the payload portion 620. The guide wire 805 can extend through the microcatheter 600 near the distal region 615 and exit the distal opening 610 of the microcatheter 600. The unexpanded payload 505 itself can be controlled in its position within the microcatheter 600 by the control element 510. The control element 510 can run through the lumen 605 of the proximal length of the microcatheter 600 and as Fig. 12A The proximal Luer connector 634 of the complete microcatheter 600 is shown as leaving the proximal Luer connector 634 of the complete microcatheter 600, or as shown in FIG. Fig. 12B The microcatheter lumen 605 is shown exiting the proximal opening 611 of the spine microcatheter 6000. A guidewire 805 can enter the microcatheter 600 through a port 604 located just distal to the payload portion 620 housing the payload 505. The guidewire 805 can be used to navigate distally across the distal opening exiting the lumen 223 of the catheter 200 entering the system 100 and remain in place as the microcatheter 600 housing the payload 505 is advanced to the target. Fig. 12B In the case of the spinal microcatheter 600 shown, the control element 510 of the working device 500 and the control element 625 of the microcatheter 600 can be advanced together. The microcatheter 600 of the delivery system 700 can be advanced across the target as is typical for an intracranial working device 500 for placement of, for example, a stent retriever. The delivery system 700 can remain in place while the guidewire 805 is withdrawn. After the guidewire 805 is removed, the lumen 605 of the microcatheter 600 is free to advance the payload 505 into position across the target site. The payload 505 can be advanced by its control element 510 while maintaining the microcatheter 600 secured across the brain target from the payload portion 620 toward the distal opening 610 through the lumen 605 of the microcatheter 600. Once the payload 505 is visualized as being in the proper position, the microcatheter 600 can be removed. The payload 505 can be advanced within the microcatheter 600 as Fig. 12AAs shown, the RHV 634 is retracted and withdrawn while the microcatheter 600 is retracted. Fig. 12B As shown with ridges at the control element 625, the control element 510 is used to hold it in place. The payload 505 is then pulled out as the microcatheter 600 is removed from the system and allowed to self-expand. The above sequence of delivery and deployment can avoid the need to push the payload 505 through the entire length of the microcatheter, which runs the entire length of the distal access system 100, and the support catheter 200 of the distal access system extends through the guide sheath 400. Instead, the payload 505 only passes through the distal end 615 of the microcatheter 600 before withdrawing the microcatheter 600.

[0199] FIG. 13A to FIG. 13B An embodiment of a single operator delivery system 700 is illustrated having an integral microcatheter 600 ( Fig.13A ) or ridged microcatheter 600 ( Fig. 13B ). The surgical guide wire 805 can run the entire length of the delivery system 700. Fig.13A In the embodiment of the present invention, the guide wire 805 can enter the lumen 605 of the microcatheter 600 at the proximal Luer interface 634. Fig. 13B In an embodiment of the present invention, the guide wire 805 can enter the lumen 605 of the microcatheter 600 at the proximal opening 611 in the payload portion 620 of the microcatheter 600, which contains the expandable payload 505 in a collapsed configuration. The guide wire 805 can extend through the self-expanding payload 505 contained within the payload portion 620 and exit the distal opening 610 of the microcatheter. This can allow the guide wire 805 to move coaxially through the microcatheter 600, rather than FIG. 12A to FIG. 12B , which provides better wire torque and responsiveness. The unexpanded payload 505 can be positioned within the microcatheter 600 by control element 510. Control element 510 can exit payload portion 620 at port 604 just proximal to the location of the expanded payload 505. Guidewire 805 can be used to navigate distally across the distal opening exiting the lumen 223 of catheter 200 entering system 100 and remain in place as the microcatheter 600 housing the payload 505 is advanced to the target. Fig. 13BIn the case of the spine microcatheter 600 shown, the control element 510 of the working device 500 and the control element 625 of the microcatheter 600 can be advanced together. The microcatheter 600 of the delivery system 700 can be advanced across the target as is typical for an intracranial working device 500 for placement of, for example, a stent retriever. The guidewire 805 can then be removed or the payload 505 can be advanced over the guidewire 805. The payload 505 can be advanced through the lumen 605 of the microcatheter 600 from the payload portion 620 toward the distal opening 610 after the distal microcatheter 600 is delivered across the target. The payload 505 can be advanced by keeping the microcatheter 600 fixed and advancing the payload 505 by the proximal control element 510 under fluoroscopic guidance to the target. Once the payload 505 is visualized as being in the proper position, the microcatheter 600 can be withdrawn. The expanded payload 505 can be kept fixed via the control element 510, and a single track exchange is performed as the control element 510 leaves the RHV 634.

[0200] FIG. 14A to FIG. 14B An embodiment of a single operator delivery system 700 is illustrated having an integral microcatheter 600 ( Fig.14A ) or ridged microcatheter 600 ( Fig. 14B ). The microcatheter 600 in each of these embodiments has an outer diameter that increases from the distal end 615 to the payload portion 620. As with the previous embodiments, the surgical guidewire 805 can run the entire length of the delivery system 700 and Fig.14A In the case of a proximal Luer interface 634, the lumen 605 of the microcatheter 600 may be entered, or Fig. 14B In the case of a catheter 600, the lumen 605 of the microcatheter 600 can be entered at the proximal opening 611 in the payload portion 620 of the microcatheter 600, which contains the expandable payload 505 in the collapsed configuration. The guidewire 805 can extend through the self-expanding payload 505 contained within the payload portion 620 and exit the distal opening 610 of the microcatheter. This can allow the guidewire 805 to move coaxially through the microcatheter 600, rather than FIG. 12A to FIG. 12B The distal end 615 of the microcatheter can have a smaller outer diameter, resulting in an increase in the payload portion 620. The increase in the payload portion 620 can allow the control element 510 to extend at least a portion of the entire length of the payload portion 620 inside the lumen 605 of the microcatheter 600 along the edge of the surgical guide wire 805, and the control element controls the positioning of the unexpanded payload 505 within the microcatheter 600. Fig.14A In an embodiment of the present invention, the control element 510 can exit the payload portion 620 at the port 604 just proximal to the location of the expanded payload 505. Fig. 14B In an embodiment of the present invention, the control element 510 can be separated from the payload portion 620 at the proximal opening 611. When a working device such as a stent retriever is released into the embolus, the expanded payload 505 is embedded in the embolus and in turn fixed in place. The microcatheter 600 and guidewire 805 can be withdrawn on the control element 510 in sequence or as a unit with a quick pull with minimal risk of pulling the expanded payload 505 out of the embolus.

[0201] As mentioned above, the guidewire 805 can be run through the self-expanding payload 505 within the microcatheter 600 (see, e.g., FIG. 13A to FIG. 13B as well as FIG. 14A to FIG. 14B ), which provides the operator with a sense of coaxial relationship and provides better wire torque and responsiveness. The coaxial relationship can include a tool or consideration of the characteristics of the payload 505, which will avoid catching or capturing the guidewire 805 tip as the system 700 is "loaded" with the guidewire 805. The tool can be a simple tubule sized to be embedded in the microcatheter 600 interior and docked in the payload 505, once the guidewire 805 in the confirmation system passes, the payload can be removed. The increase in catheter diameter can allow easier loading and can improve guidewire interaction.

[0202] Fig. 12B , Fig. 13B as well as Fig. 14B The control elements 510 for the working device 500 are each illustrated as having a proximal wire introducer, torquer, or other gripping feature 544 that allows the proximal control element 510 to be easily grasped, advanced, and / or retracted. The gripping feature 544 can be easily identifiable or distinguishable from other components of the delivery system 700 and / or distal access system 100 by color and / or shape or other identifiers or characteristics. After the working device 500 is deployed, the gripping feature 544 of the control element 510 can be removed before the delivery system 700 is withdrawn onto the control element 510. Alternatively, the control element 510 for the working device 500 need not include a proximal wire introducer, torquer, or other gripping feature 544 that allows the proximal control element 510 to be easily grasped, advanced, and / or retracted. Fig. 12A , Fig.13A as well as Fig.14AAny proximal gripping features shown allow for more rapid deployment and removal. Thus, after placing the distal access system 100 including the guide sheath 400 and the catheter 200 extending through the guide sheath 400 and securing the distal access, the operator can use a single hand to secure the distal access point in place with a clamp point, which forms a control point that secures the catheter 200 to provide support for smaller catheters and wires passing through it. Keeping the distal catheter 200 secured with the clamp point, the guidewire 805 can be advanced through the single operator delivery system 700 with the working device 500, which can be accommodated and loaded within the microcatheter 600. The guidewire 805 extending through the delivery system 700 can be loaded as a unit into the RHV 434 of the guide sheath 400 and advanced toward the end of the distal tip of the catheter 200, the position of which is held fixed by the clamp point. Once positioned at the distal tip of the catheter 200, the guidewire 805 can be independently advanced by adjusting the "pinch point" to capture the proximal control element 230 of the catheter 200, the proximal control element 510 of the working device 500, and the proximal control element 625 of the microcatheter 600. The system can be fixed with a single hand by clamping their respective proximal control elements gathered together near the proximal end. The guidewire 805 can be advanced across the target while all control elements remain fixed. The guidewire can then be kept fixed in the following manner: the proximal guidewire 805 is added to the pinch point, and the control element 625 and the control element 510 are adjusted to advance on the guidewire 805. This fixation prevents the unintentional movement of the guidewire tip as the system 700 advances to the target, especially the forward and backward piston movement, which avoids trauma and extravascular bleeding. Each single operator system can be used while applying distal suction by supporting the catheter 200 and the guide sheath 400, for example, as the withdrawal of the clot material occurs next. In an acute ischemic stroke embolectomy procedure, after delivery of the system 700 and withdrawal of the guidewire 805, suction is applied at the RHV 434. Fixing the working device 500 in place allows the payload 505 to be pulled out by clamping the control element 510 and pulling the microcatheter control element 625. Suction can be initiated, and the operator can then choose to perform a "Solumbra" or "SMAT" procedure. For example, under continuous suction, the operator can start withdrawing the working device 500 by pulling the control element 510 while holding the catheter 200 in a fixed position inside, which causes the payload 505 to be re-wrapped into the lumen of the catheter 200. The working device 500 can then be removed under continuous suction with the catheter 200 held in place, or the working device 500 and the catheter 200 can be removed together as a unit. They can be withdrawn as a unit by clamping the proximal control elements 510 and 230. A single RHV 434 facilitates this by providing continuous suction at a single point.

[0203] It should be understood that the method described herein can be performed using a "wire first" approach, in which, once distal access is obtained, a guidewire is initially placed across the target, similar to how the surgery can be performed under guidewire guidance and retained during coronary surgery. Once the guidewire is placed across the target, a delivery system 700 with a working device 500 in the proximal portion of the catheter 200 with a payload 505 can be prepared, and a guidewire 805 preloaded onto the distal tip of the microcatheter 600 leaves a port near the distal tip. The guidewire 805 can also, for example, pass through an internal channel designed to receive the guidewire 805 to pass through the payload 505.

[0204] FIG. 15A to FIG. 15E Various views of an embodiment of a rapid exchange microcatheter for delivering a working device to the neurovascular system for treating a stroke are illustrated. A single inner lumen 605 extends from the distal opening 610 of the microcatheter 600 through the distal region of the microcatheter 600 to the distal guidewire port 604 and further to the proximal port 606. It can be seen that the surgical guidewire 805 and the working device 500 utilize the same inner lumen 605 of the microcatheter 600. The guidewire port 604 can be a side opening coming out of the lumen 605, which is positioned at a distance proximal to the distal opening 610. The distal guidewire port 604 can be 5-30cm from the distal tip of the microcatheter 600. In some embodiments, the distal guidewire port 604 is positioned about 18cm from the distal tip of the microcatheter 600. The proximal port 606 can be positioned at the proximal end of the distal guidewire port 604, such as, for example, about 30cm to about 45cm from the distal tip. The distal guidewire port 604 is designed to receive a surgical guidewire 805 therethrough, while the proximal port 606 is designed to receive the proximal control element 510 of the working device 500. As can be seen, both the guidewire 805 and the working device 500 extend through the same inner lumen 605 of the microcatheter 600, but exit the lumen 605 using their own ports, which are located in a structure that prevents the guidewire 805 and the payload 505 of the working device 500 from interfering with each other.

[0205] The guidewire 805 may extend from the distal opening 610 through the lumen 605 of the microcatheter 600 to the distal guidewire port 604. A working device 500 (e.g., a brain treatment device such as a stent retriever) may be loaded within the lumen 605 of the catheter 605 and withdrawn, for example, by pulling the payload proximally through the distal opening 610 into the lumen 605 so that the payload 505 rests at a location just proximal to the side opening or distal guidewire port 604. The expandable payload 505, when loaded in the microcatheter 600, may be received within the lumen 605 adjacent to the distal guidewire port 604 on the proximal side of the port 604. The surgical guidewire 805 can extend through the same lumen 605 of the microcatheter 600, such that the distal end of the surgical guidewire 805 extends out of the distal opening 610, and the proximal end of the surgical guidewire 805 exits the lumen 605 through the distal guidewire port 604 in the wall of the microcatheter 600. The proximal control element 510 of the working device 500 can extend proximally from the payload 505 through the lumen 605 and exit from the proximal port 606. This prevents the proximal control element 510 of the working device 500 and the guidewire 805 from running adjacent to each other within a single lumen 605 or needing to pass through the same access port (which is incompatible with the rapid exchange system).

[0206] Reference again FIG. 15A to FIG. 15E , the proximal port 606 can be located near the location where the proximal control element 625 is coupled to the middle portion of the microcatheter 600. In some embodiments, the proximal control element 625 can be a hypotube having a lumen. However, the hypotube lumen is truncated to a single lumen 605 at a location near the proximal port 606. As will be described in more detail below, an outer shaft tube 670 can connect the proximal control element 625 and the reinforcement 652 of the microcatheter. The tapered mandrel extension 675 can bridge and support the outer shaft tube 670, which connects the proximal control element 625 and the reinforcement 652 of the microcatheter.

[0207] FIG. 16A to FIG. 16CDetailed view of the distal wire port 604 of different embodiments of a rapid exchange microcatheter for delivering a working device to the neurovascular system for the treatment of stroke. The microcatheter 600 includes an enhancement that allows the microcatheter 600 to advance independently through the neurovascular system to reach the target treatment position. Without this enhancement, the microcatheter 600 tube will not be able to navigate through this tortuous anatomical structure. However, the enhancement required for the microcatheter 600 to navigate the tortuous neuroanatomical structure presents a challenge to rapid exchange delivery, in which, as discussed above, the guide wire 805 and the control element 510 need to pass through the port of the wall of the microcatheter 600 to leave the lumen 605. In order to solve this problem, the microcatheter 600 can have an enhancement layer, which is formed by two independent enhancement structures 650, 652 spaced apart from each other along the length of the microcatheter 600. A gap G is formed between the enhancement structures 650, 652 near the location of the distal guide wire port 604. Thus, the microcatheter 600 includes: a distal enhanced catheter portion extending between the distal region of the catheter body to a point near the side opening 604; and a proximal enhanced catheter portion extending a distance from a point near the side opening 604 toward the proximal end of the catheter body. The catheter body has: a distal opening that comes out of the inner lumen near the distal tip; and a side opening 604 that passes through the side wall of the catheter body and is positioned a distance proximal to the distal tip of the catheter body. The side opening 604 is positioned in a gap G between the proximal end of the distal enhanced catheter portion and the distal end of the proximal enhanced catheter portion. The payload of the device housed in the lumen can be positioned at the proximal end of the side opening. The proximal enhanced catheter portion may be less flexible than the distal enhanced catheter portion. The distal enhanced catheter portion may have a first enhanced structure, and the proximal enhanced catheter portion may have a second enhanced structure. The coupler 660 may form another enhanced structure. The first reinforcement structure and the second reinforcement structure may be structurally similar or different from each other and from coupler 660. The first reinforcement structure may be less rigid than the second reinforcement structure, and the second reinforcement structure may be less rigid than coupler 660.

[0208] The size of the gap between the reinforcing structures 650, 652 can vary, but is generally 3mm-4mm wide. The reinforcing structures 650, 652 can be coupled together by a short, more rigid coupler 660. The coupler 660 can be sized to span the gap G so that the elongated window of the coupler is aligned with the gap G, while at least the first portion of the coupler 660 is positioned above the proximal end of the first reinforcing structure, and at least the second portion of the coupler 660 is positioned above the distal end of the second reinforcing structure. The coupler 660 can include a side opening (e.g., an elongated window 654) extending through its side wall, a slit 655 extending along the length of the coupler 660, or other discontinuities in its side wall that are configured to align with the gap between the reinforcing structures 650, 652. The window 654 in the coupler 660 forms a distal wire port 604 in the gap G between the adjacent reinforcing structures 650, 652 of the microcatheter 600.

[0209] Typically, the microcatheter 600 may have an inner liner 656 formed of a flexible material typical of catheters, such as PTFE. The inner liner 656 may be covered by reinforcing structures 650, 652, and the reinforcing structures 650, 652 may in turn be at least partially encased by an outer sheath 658 formed of PEBAX or other suitable material (see Fig.17D ). The inner liner 656 and the outer sheath 658 form a bi-laminate film that encases the coupler 660 and thereby the window 654. The distal wire port 604 is created by forming a slit 662 through the bi-laminate film that encases the coupler 660 at the location of the window 654, which will be described in more detail below.

[0210] Refer again FIG. 16A to FIG. 16C , the reinforcement structures 650, 652 can be braided reinforcements, coiled reinforcements, or other reinforcement structures. As described elsewhere herein, the structures 650, 652 can be formed from wires having a specific diameter and formed to a specific pitch or PPI. In some embodiments, both reinforcement structures 650, 652 are braids having diameters / PPIs that may be the same or different. For example, the distal reinforcement structure 650 may be a braid having a 70PPI, and the proximal reinforcement structure 652 may be a braid having a 40PPI. In other embodiments, both reinforcement structures 650, 652 are coils having diameters / pitch that may be the same or different. In yet other embodiments, the first of the reinforcement structures 650, 652 is a coil, and the second of the reinforcement structures 650, 652 is a braid (see Fig. 16B). For example, the distal reinforcement structure 650 can be a coil with a wire diameter of 0.001" and a pitch of 0.010", and the proximal reinforcement structure 652 can be a webbing with a braided wire size of 0.0005"x0.0025" and a PPI of 75. In some embodiments, at least the first of the reinforcement structures 650, 652 has a wire size of 0.0005"x0.0015" at a PPI of 150 along the entire length of the reinforcement. The wire size, pitch, and PPI considered here for the braided or coiled reinforcement structure can vary, but are generally suitable for transmitting sufficient torque typical of a nerve access microcatheter. The reinforcement structures 650, 652 of the microcatheter 600 can provide a customized amount of flexibility and torsionalness to achieve a balance of delivery capability and accessibility. As will be described in more detail below, the side opening aligned with the gap G between the proximal and distal reinforcement structures 650, 652 allows the microcatheter 600 to be delivered in a rapid exchange manner.

[0211] As mentioned, the reinforcement structures 650, 652 are coupled together by a relatively rigid coupler 660 having side openings or discontinuities extending through its sidewalls, such as elongated windows 654 or slits 655 extending along the length of the coupler, which are aligned with the gap G between the reinforcement structures 650, 652. The coupler 660 provides a local rigid portion that allows torque forces to be transferred from the proximal reinforcement end of the microcatheter 600 to the distal reinforcement end of the microcatheter 600 while alleviating kinking in this area. The coupler 660 provides stiffness, but does not provide too much stiffness that would also cause kinking during navigation of these tortuous regions of the neurovascular system.

[0212] The configuration of coupler 660 can vary. In some embodiments, coupler 660 is a short tubular structure of a relatively rigid material, which includes polymers such as polyimide or PET and metal materials such as stainless steel. The length of coupler 660 can vary, but is generally between about 3mm and about 15mm, preferably between 8mm and 12mm. In some embodiments, coupler 660 is 7mm long. The length of coupler 660 is enough to cover at least one end of each reinforcement structure 650, 652, while leaving enough length to produce a distal wire port 604 via a window 654 or slit 655 aligned with the gap G. Thus, coupler 660 can cover at least about 1-2mm of each reinforcement structure 650, 652 on either end of coupler 660, and has an area of ​​about 3-4mm, and a window 654 or slit 655 aligned with the gap between reinforcement structures 650, 652 (which forms a distal wire port 604) can be located in this area. Window 654 can have varying shapes and sizes. In some embodiments, window 654 is about 0.015" wide and oval in shape. In other embodiments, coupler 660 is a discontinuous tube and has a slit 655 extending along its length from a first end to a second end, which forms a c-shaped cross-section. Coupler 660 can have only window 654 (see 17A to 17D ), having only slit 655 (see 18A to 18C ), or having both a window 654 and a slit 655 (see FIG. 19A to FIG. 19C ). The coupler 660 may further include one or more openings 657 (eg, radially) to provide additional flexibility to the region between the reinforcement structures 650, 652 (see Fig. 20 ). Depending on whether the coupler 660 has a window 654, a slit 655, an opening 657, or a combination of these features, the size of the material can vary. For example, in some embodiments, the coupler 660 is formed from a 7 mm long polyimide tube with a single slit 655 extending along one side, an inner diameter of about 0.023", and a wall thickness of about 0.001". In another embodiment, the coupler 660 is formed from a 7 mm long polyimide tube with a 3 mm window 654, a slit 655 extending along the back side, an inner diameter of about 0.027", and a wall thickness of about 0.001". The wall thickness of coupler 660 can be between about 0.005" and about 0.002", preferably about 0.001". The length and wall thickness of coupler 660 are selected to ensure that coupler 660 is thick enough to transmit torque from proximal reinforcement structure 652 to distal reinforcement structure 650 while reducing kink-prone areas along the length of microcatheter 600.

[0213] As mentioned above, coupler 660 may include a slit 655 extending along its length, which creates a c-shaped cross-section (see Fig.18C and Fig.19C ). The c-shaped cross-section of the coupler 660 can provide an additional coupling effect in that it snaps down onto the ends of the respective reinforcing structures 650, 652, which provides additional radial compression or squeezing forces downward onto the components of the microcatheter 600. The reinforcing structures 650, 652, particularly where they are formed from webbing, can additionally be sealed with a polymer during manufacture, which prevents the ends from unraveling (see Fig. 16C ). The polymer auxiliary components lightly applied to their ends fuse together, which, combined with the radial compression provided by the c-shaped coupler 660, provides a better seal with the outer sheath 658.

[0214] The outer sheath 658 can be formed of a material as is known in the art, such as PEBAX having a Shore hardness in the range of 25D, 35D, 45D, 55D, 72D, depending on which portion of the length of the microcatheter 600 the sheath 658 covers. For example, a section of the outer sheath 658 located proximal to the coupler 660 can be formed of PEBAX having a hardness of about 72D, which transitions distally to a section of the outer sheath 658 formed of PEBAX having a hardness of about 25D. In some embodiments, the region of the microcatheter 600 distal to the coupler 660 has an outer sheath 658 formed of PEBAX having a hardness in the range from approximately 25D to 45D, the region of the microcatheter 600 proximal to the coupler 660 has an outer sheath 658 formed of PEBAX having a hardness of about 72D, and the region of the outer sheath 658 covering the coupler 660 (and thereby covering the window 654) is formed of PEBAX having a hardness of about 55D. In some embodiments, the farthest region of the outer sheath 658 is formed by a PEBAX of about 25D of hardness, and can be about 5cm in length. The farthest region can be transitioned to the second region of the outer sheath 658 formed by the PEBAX of about 35D of hardness toward the proximal end, and the second region can be about 6cm in length. The second region can be transitioned to the third region of the outer sheath 658 formed by the PEBAX of about 45D of hardness toward the proximal end, and the third region can be about 5cm in length. The third region can be transitioned to the first region of the outer sheath 658 formed by the PEBAX of about 55D of hardness, covering the coupler 660 and the window 654 toward the proximal end, and the first region is about 6cm in length. The fourth region can be transitioned to the other regions of the outer sheath 658 at the proximal end of the coupler 660, which are formed by the PEBAX of about 72D of hardness toward the proximal end.

[0215] As mentioned above, the microcatheter 600 can have an inner liner 656 formed of a flexible material covered by a reinforcement layer that is cut into a distal reinforcement structure 650 and a proximal reinforcement structure 652 that is separated from the distal reinforcement structure 650 by a distance that forms a gap G. The reinforcement structures 650, 652 are in turn at least partially encased by an outer sheath 658. The reinforcement structures 650, 652 are coupled together by a coupler 660 that has side openings or discontinuities extending through its sidewalls, such as windows 654 or slits 655, that are aligned with the gap G between the reinforcement structures 650, 652. The inner liner 656 and the outer sheath 658 encase the coupler 660 and the side openings (e.g., windows 654 and / or slits 655). Thus, at least at the gap G between the discontinuous position and the reinforcing structure 650,652 in the coupler 660, the liner 656 and the outer sheath 658 contact each other. When the liner 656 and the outer sheath 658 meet, they fuse together, which forms a double laminated film at the discontinuous position. The distal guide wire port 604 is produced by forming a slit 662 that passes through the double laminated film that envelops the discontinuous (for example, along the window 654 or slit 655 on the rear side of the coupler 660). The slit 662 in the double laminated film can extend along at least one discontinuous length. The distal guide wire port 604 is not just the hole that the device enters and leaves the lumen 605 through. On the contrary, the distal guide wire port 604 is produced by the slit 662 in the double laminated film at the position of the window 654 (or other discontinuous like slit 655) of the coupler 660. The distal guidewire port 604 forms a flap valve that can remain closed when not in use and allows the guidewire 805 to be pushed through. The presence of the bi-laminate film at the distal guidewire port 604 mitigates fluid loss from the lumen 605, for example, during injection and / or aspiration through the lumen of the catheter 600.

[0216] The flap valve-like structure of the distal guidewire port 604 and the coupling 660 combination also alleviate the problem that the working device 500 (e.g., stent retractor) deployed from the microcatheter lumen 605 is caught, hooked or partially leaves the lumen 605 at this position. Some working devices 500 (e.g., stent retractors with open elements at their distal regions) may hook certain features of the microcatheter that convey the working device when being pushed through the lumen 605 of the microcatheter 600, such as these openings. The distal guidewire port 604 is selective for the guidewire 805 to leave the lumen 605, and makes it less likely that these open elements of the working device 500 conveyed by the microcatheter 600 are captured during deployment (e.g., to the level of the ICA to the M3 anatomical structure). The rigidity of the coupling 660 prevents the microcatheter 600 from bending near the position of the side opening 604, which makes it less likely that the working device 500 conveyed through the lumen of the microcatheter 600 is pushed toward the side opening 604. The rigidity of the coupler 660 aided by the dual laminate film encapsulating the coupler 660 mitigates the risk of an open device snagging or being pushed through the guidewire port 604 during distal advancement.

[0217] The microcatheter 600 can be packaged with the working device 500 at least partially inserted into the lumen 605. For example, the proximal control element 510 of the working device 500 can extend through the lumen 605 and exit from the proximal port 606, while the payload 505 of the working device 500 can remain outside the distal opening 610 of the microcatheter 600. Thus, the payload 505 of the working device 500 can remain extended out of the distal end of the microcatheter 600 until the user is ready to "dock" the payload 505 in the lumen 605 of the microcatheter 600 at a position proximal to the distal wire port 604. Once "docked", the surgical guide wire 805 can freely extend through the lumen 605 and exit the distal guide wire port 604 at the distal end of the docked payload 505. It should be understood that the working device 500 does not need to be pre-inserted in this way. In addition, the working device 500 can be post-installed to the appropriate position before use. The surgical guide wire 805 can also be pre-installed or post-installed before use.

[0218] The lumen 605 of the microcatheter 600 may include additional features to improve the possibility that only the guidewire 805 leaves the distal wire port 604 and the working device 500 docked in the lumen 605 does not leave. The effective load 505 of the working device 500 can be an expandable element, which is configured to change the shape from a compressed structure to an expanded structure after being deployed from the lumen 605. A deflector or local thickening can be formed on the inner surface of the lumen 605 just at the proximal end of the distal guidewire port 604, so that the working device 500 deployed from the lumen 605 (for example, by advancing through the lumen 605 in the distal direction) can be pushed to another compressed structure as it is pushed through the thickening. This reduces the risk that the open component on the distal end of the working device 500 will hook or leave through the distal guidewire port 604. Another way to prevent the open stent-like working device from hooking or escaping through the window 654 is to reduce the width of the window 654 or discontinuity in the coupler 660 to make the flap on either side of the discontinuity more rigid. Visibility in and around the distal guidewire port 604 allows the user to easily confirm the position of the payload 505 of the working device 500 relative to the port 604. For example, the working device 500 can be docked in the microcatheter lumen 605 at a position just at the proximal end of the distal wire port 604. The payload 505 can be withdrawn using the proximal control element 510, thereby pulling the payload 505 into the distal opening 610 of the microcatheter 600. The payload 505 can be further withdrawn through the lumen 605 of the microcatheter 600 until the user visually confirms that the payload 505 has been retracted at the proximal end of the distal guidewire port 604. This ensures that the payload 505 is free of the distal guidewire port 604, so that the guidewire 805 can leave / enter the port 604 without interfering with the working device 500. In some embodiments, the materials in and around the distal guidewire port 604, such as the coupler 660 and the double laminate film with a slit, can generally be translucent so that a visible area is formed. In other embodiments, the color of coupler 660 can be selected to provide a high contrast between coupler 660 and its discontinuity. In some embodiments, coupler 660 is black or yellow in color.

[0219] In some embodiments, the microcatheter 600 may have a semi-transparent area near the gap G. Fig.15EAs best shown, coupler 660 can be coupled to only one of the reinforcement structures (in this case, distal reinforcement structure 650) and coupled to the second reinforcement structure through translucent coupler layer 661. Translucent coupler layer 661 can be formed by two layers of PEBAX. Layer 661 combined with coupler 660 can compensate for the gap in the reinforcement between reinforcement structures 650, 652 and prevent kinking near distal wire port 604. At the same time, coupler layer 661 can provide visualization for the working device, which is loaded in the area of ​​the microcatheter cavity just at the proximal end of the distal wire opening 604. It should be understood that in the case where microcatheter 600 is described as having a coupler that spans the gap G between reinforcement structures 650, 652, this can include an embodiment in which the gap G is spanned by the coupler 660 combined with the translucent coupler layer 661.

[0220] As described herein, microcatheter 600 can be a rapid exchange microcatheter, which is a part of a system configured to enter the intracranial neurovascular system. Microcatheter 600 can include a catheter body with an outer diameter, an inner diameter and a distal tip. The catheter body can include an inner lumen 605 defined by an inner diameter, and can be adapted to carry a payload 505 in the inner lumen 605. Payload 505 can be delivered to a target location in the intracranial neurovascular system from the inner lumen 605. The inner diameter of the inner lumen 605 can be set to a size to allow a guide wire 805 to pass through, and the outer diameter can have a maximum size less than 0.048 inches. The guide wire side opening 604 size to the inner lumen 605 is set to allow a guide wire 805 to pass through, and can be positioned to a distance of 10cm to 20cm from the distal tip of catheter 600. The proximal opening 606 to the inner lumen 605, which is different and distinct from the guide wire side opening 604, can be positioned to a distance greater than 20cm from the distal tip. The microcatheter 600 may include: a distal enhanced catheter portion, which extends between the distal region of the catheter body to a point near the guidewire side opening 604; and a proximal enhanced catheter portion, which extends a distance from a point near the guidewire side opening 604 toward the proximal end of the catheter body. The guidewire side opening 604 is positioned in a gap between the proximal end of the distal enhanced catheter portion and the distal end of the proximal enhanced catheter portion. The system may additionally include instructions for use, which indicate to the user that the payload 505 is loaded in the inner lumen 605 at the position of the proximal end of the guidewire side opening 604 before using the catheter body. The payload 505 loaded in the inner lumen 605 can be at a position near the guidewire side opening 604, so that the payload 505 can be carried in the inner lumen 605 and delivered to a target position in the intracranial neurovascular system from the inner lumen.

[0221] Material

[0222] One or more components of the catheters and delivery systems described herein can be made of metals, metal alloys, polymers, metal-polymer composites, ceramics, combinations thereof, or other suitable materials. Some examples of suitable metals and metal alloys include: stainless steel, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloys, such as linear elastic and / or superelastic nickel-titanium alloys; other nickel alloys, such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, e.g., UNS: N06022, as UNS: N10276, as other alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, e.g. etc.), nickel-molybdenum alloys (e.g. UNS: N10665, e.g. ), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten alloys or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (for example, UNS: R30003 (for example etc.); platinum-rich stainless steel; titanium; combinations thereof; etc.; or any other suitable material as described elsewhere herein.

[0223] Embodiments describe catheters and delivery systems and methods for delivering catheters to target anatomical structures. However, although some embodiments are described particularly with respect to delivering catheters to target vessels (e.g., cerebral vessels) of neurovascular anatomical structures, the embodiments are not so limited, and specific embodiments may also be applicable to other purposes. For example, the catheter may be suitable for delivery to different neuroanatomical structures, such as subclavian arteries, vertebrae, carotid vessels, and coronary anatomical structures or peripheral vascular anatomical structures, to name a few possible applications. It should also be understood that although the system described herein is described as being used to treat a specific condition or pathology, the condition or pathology treated may vary and is not limited. The use of the terms "embolus," "embolus," "embolic," "thrombus," "occlusion," etc., related to the use of the device treatment targets described herein, is not intended to be limited. The terms may be used interchangeably, and may include, but are not limited to, blood clots, bubbles, small fat deposits, or other objects carried to a distant location or formed in a certain position in a blood vessel in the blood flow. The terms may be used interchangeably here to refer to the contents of partial or complete occlusion of blood flow that may cause blood flow through a blood vessel or within a blood vessel.

[0224] This application also discloses the following items (embodiments):

[0225] 1. A rapid exchange microcatheter for accessing an intracranial neurovascular system, the microcatheter comprising:

[0226] a catheter body having a sidewall extending between a proximal end to a distal-most tip, the sidewall defining an inner lumen having an inner diameter sized to accommodate a payload of a brain treatment device;

[0227] a distal opening that exits the inner lumen near the distal-most tip;

[0228] a side opening extending through the side wall of the catheter body, the side opening being located a first distance proximal to the distal-most tip of the catheter body;

[0229] a proximal opening located proximal to the side opening and a second distance from the distal-most tip of the catheter body;

[0230] a distal reinforced catheter portion extending between a distal region of the catheter body to a point proximate the side opening; and

[0231] a proximal reinforced catheter portion extending a distance from a point proximal to the side opening toward the proximal end of the catheter body,

[0232] wherein the side opening is positioned in a gap between a proximal end of the distal reinforcement catheter portion and a distal end of the proximal reinforcement catheter portion, and

[0233] Wherein, the effective load of the brain treatment device is accommodated in the lumen at the proximal end of the side opening.

[0234] 2. The rapid exchange microcatheter of item 1, wherein the first distance is between about 10 cm and about 20 cm.

[0235] 3. The rapid exchange microcatheter of item 2, wherein the second distance is greater than about 20 cm.

[0236] 4. The rapid exchange microcatheter of item 1, wherein the distal opening is located at the distal-most tip of the catheter.

[0237] 5. The rapid exchange microcatheter of item 1, wherein the side opening is sized to allow passage of a guidewire having an outer diameter equal to or less than about 0.018".

[0238] 6. The rapid exchange microcatheter of item 1, wherein the reinforced catheter portion at the proximal end is less flexible than the reinforced catheter portion at the distal end.

[0239] 7. The rapid exchange microcatheter according to item 1, wherein the reinforced catheter portion at the distal end has a first reinforcement structure.

[0240] 8. The rapid exchange microcatheter according to item 7, wherein the proximal reinforced catheter portion has a second reinforcement structure.

[0241] 9. The rapid exchange microcatheter of item 8, wherein the first reinforcement structure is coupled to the second reinforcement structure by a rigid coupler.

[0242] 10. The rapid exchange microcatheter of item 9, wherein the rigid coupler forms a reinforcement structure different from the first reinforcement structure or the second reinforcement structure.

[0243] 11. The rapid exchange microcatheter of item 10, wherein the first reinforcement structure and the second reinforcement structure are structurally similar to each other.

[0244] 12. The rapid exchange microcatheter of item 10, wherein the first reinforcement structure and the second reinforcement structure are structurally different from each other.

[0245] 13. The rapid exchange microcatheter of item 10, wherein the first reinforcement structure is less rigid than the second reinforcement structure, and the second reinforcement structure is less rigid than the rigid coupler.

[0246] 14. The rapid exchange microcatheter of item 10, wherein the first reinforcement structure is a coil and the second reinforcement structure is a coil, wherein a pitch of the coil of the first reinforcement structure is greater than a pitch of the coil of the second reinforcement structure.

[0247] 15. The rapid exchange microcatheter of item 10, wherein the first reinforcement structure is a coil and the second reinforcement structure is a webbing.

[0248] 16. The rapid exchange microcatheter of item 9, wherein the coupler has a window aligned with the side opening.

[0249] 17. The rapid exchange microcatheter of item 1, wherein the side opening is constructed to allow a guidewire to pass into and out of the inner lumen while preventing the payload from engaging or hooking on the side opening as the payload moves through the inner lumen during deployment.

[0250] 18. The rapid exchange microcatheter according to item 17, wherein the side wall of the microcatheter further comprises:

[0251] Lubricated tubular lining;

[0252] a reinforcing layer, the reinforcing layer being positioned above the tubular liner and being more rigid than the tubular liner, the reinforcing layer comprising:

[0253] a first reinforcement structure extending within the distal reinforced catheter portion, the first reinforcement structure having a proximal end; and

[0254] a second reinforcement structure extending within the proximal reinforcement conduit portion, the second reinforcement structure having a distal end,

[0255] wherein the proximal end of the first reinforcement structure is separated from the distal end of the second reinforcement structure, thereby generating the gap;

[0256] a short tubular rigid coupler positioned over the proximal end of the first reinforcement structure and over the distal end of the second reinforcement structure, the coupler having an elongated window extending through a side wall of the coupler; and

[0257] An outer jacket is positioned over the coupler and the reinforcement layer.

[0258] 19. A rapid exchange microcatheter according to item 18, wherein the coupler is sized to span the gap so that the elongated window of the coupler is aligned with the gap, and at least a first portion of the coupler is positioned above the proximal end of the first reinforcement structure, and at least a second portion of the coupler is positioned above the distal end of the second reinforcement structure.

[0259] 20. A rapid exchange microcatheter according to item 18, wherein the tubular lining and the outer sheath are sealed together at the slender window to form a double-laminated film encapsulating the side opening of the microcatheter, and wherein a slit extends through the film to allow the guide wire to pass through the side opening.

[0260] 21. The rapid exchange microcatheter of item 1, wherein the inner diameter is less than about 0.035" to about 0.0165".

[0261] 22. The rapid exchange microcatheter of item 1, wherein the outer diameter of the catheter body is less than about 0.050" to about 0.023".

[0262] 23. A system comprising a rapid exchange microcatheter according to item 1, further comprising a distal access catheter having: a flexible distal lumen portion having a proximal end; a proximal region; a proximal opening; a distal end; and a lumen extending between the proximal end and the distal end, wherein the lumen of the distal access catheter is sized to receive the catheter body of the rapid exchange microcatheter.

[0263] 24. The system of claim 23, wherein the distal access catheter further comprises a proximal extension that is less flexible than the flexible distal lumen portion and is configured to control movement of the distal access catheter.

[0264] 25. A system according to item 24, wherein the proximal extension extends proximally from an attachment point of the flexible distal lumen portion adjacent to the proximal opening, wherein the flexible distal lumen portion has an outer diameter at the attachment point that is larger than an outer diameter of the proximal extension at the attachment point.

[0265] 26. A system according to item 25, wherein the proximal extension of the distal access catheter is solid or hollow.

[0266] 27. The system of item 23, wherein the distal access catheter is configured to be assembled with a tapered inner member to form an assembled coaxial catheter system, the tapered inner member comprising:

[0267] a flexible, elongated body having a proximal region, an outer diameter, a tapered distal tip, a distal opening, and a single lumen extending longitudinally through the flexible, elongated body to the distal opening; and

[0268] a proximal portion extending proximally from the proximal region to a proximal end of the tapered inner member,

[0269] Wherein, when assembled, the tapered inner member extends through the lumen of the distal access catheter and the tapered distal tip extends distally to the distal end of the distal access catheter.

[0270] 28. A system according to item 27, wherein the flexible, slender body of the tapered inner member includes a proximal opening sized to accommodate a guide wire, and wherein the proximal opening is positioned through a side wall of the proximal region of the flexible, slender body.

[0271] 29. A system according to item 27, wherein the proximal portion is a sea wave tube having an opening that is fluidically connected to the single lumen of the flexible, slender body.

[0272] 30. The system according to item 23 further includes a guide sheath, which includes a working lumen extending between a proximal region and a distal region, and the distal region of the guide sheath has at least one opening connected to the working lumen of the guide sheath.

[0273] 31. A system according to item 30, wherein the guide sheath has a working length sufficient to position the distal region of the guide sheath within a portion of the carotid artery and to position the proximal region near a femoral access site.

[0274] 32. A system according to item 30, wherein the flexible distal lumen portion of the distal access catheter is sized to extend coaxially through the working lumen of the guide sheath and through at least one opening of the guide sheath so that the distal end of the flexible distal lumen portion telescopically extends beyond the distal region of the guide sheath.

[0275] 33. A system according to item 30, wherein the catheter body of the rapid exchange microcatheter is sized to coaxially extend through the lumen of the distal entry catheter that coaxially extends through the working lumen of the guide sheath, so that the distal-most tip of the microcatheter passes through the opening at the distal end of the distal entry catheter.

[0276] 34. A system according to item 30, wherein the distal region of the guide sheath also includes an occlusion balloon on the outer surface, the occlusion balloon being configured to prevent flow through the blood vessel when the sealing element is expanded.

[0277] 35. The system of claim 23, wherein the brain treatment device is a stent, a stent retriever, or a drain.

[0278] 36. A method of accessing the intracranial neurovasculature using a catheter system, the method comprising the steps of:

[0279] positioning an introducer sheath having a working lumen in communication with a port at a proximal end within a blood vessel of a patient, wherein a distal end of the introducer sheath is advanced to at least the internal carotid artery;

[0280] inserting a distal access catheter through the port into the working lumen of the introducer sheath, the distal access catheter having a lumen and a distal end;

[0281] positioning the distal end of the distal access catheter beyond the distal end of the introducer sheath;

[0282] Inserting a microcatheter loaded with a payload of a brain treatment device through the lumen of the distal access catheter, the microcatheter comprising:

[0283] Lumen;

[0284] a distal region having a distal opening from the lumen; and

[0285] a side opening that exits from the lumen and is positioned a distance proximal to the distal opening,

[0286] wherein the payload is contained within the lumen at the proximal end of the side opening when loaded;

[0287] advancing the microcatheter loaded with the payload through the lumen of the distal access catheter until the distal region of the microcatheter is advanced to at least the distal end of the distal access catheter; and

[0288] The payload of the brain treatment device is deployed within the intracranial neurovasculature.

[0289] 37. The method according to item 36 further comprises the following steps:

[0290] loading a guidewire within the microcatheter, wherein the guidewire, when loaded, is positioned within the lumen of the microcatheter such that a distal end of the guidewire extends out of the distal opening and a proximal end of the guidewire exits the lumen at the side opening; and

[0291] The microcatheter loaded with the guidewire and the payload is inserted through the lumen of the distal access catheter until the distal region of the microcatheter is advanced into the intracranial neurovasculature.

[0292] 38. A method according to item 37, wherein the payload of the brain treatment device within the microcatheter is loaded from the proximal region of the microcatheter toward the distal region of the microcatheter until the payload is positioned within the lumen proximal to the side opening.

[0293] 39. A method according to item 37, wherein the payload of the brain treatment device within the microcatheter is loaded by withdrawing the payload into the lumen through the distal opening and sliding the payload proximally through the side opening.

[0294] 40. The method of item 37, wherein loading the guidewire within the lumen of the microcatheter comprises loading the distal end of the guidewire into the lumen through the side opening and out of the distal opening.

[0295] 41. A method according to item 37, wherein loading the guidewire into the lumen of the microcatheter includes loading the proximal end of the guidewire into the lumen through the distal opening of the microcatheter until the proximal end of the guidewire exits the lumen through the side opening.

[0296] 42. The method of item 37, wherein the microcatheter further comprises a proximal opening emerging from the lumen, the proximal opening being positioned at a distance proximal to the side opening.

[0297] 43. The method of claim 42, wherein the brain treatment device further comprises a push wire coupled to a proximal end of the payload, the push wire being configured to advance and position the payload relative to the microcatheter lumen.

[0298] 44. A method according to item 43, wherein the push wire extends proximally from the payload through the lumen of the microcatheter and exits the lumen at the proximal opening.

[0299] 45. A method according to item 44, wherein the payload extends outside the distal opening outside the lumen of the microcatheter, and the push wire extends through the lumen and exits through the proximal opening before loading the payload into the microcatheter.

[0300] 46. ​​A method according to item 45, wherein the payload is loaded into the microcatheter by withdrawing the brain treatment device relative to the microcatheter in a proximal direction until the payload enters the lumen through the distal opening and slides proximally through the side opening until the payload is received in the lumen proximal to the side opening.

[0301] 47. A method according to item 46, wherein the guide wire is loaded into the lumen of the microcatheter after the payload is positioned proximal to the side opening so that the push wire and the guide wire do not extend side by side within the lumen.

[0302] 48. The method according to item 37 also includes the following steps: advancing the microcatheter loaded with the brain treatment device through the guide wire until the microcatheter extends across the target located within the intracranial neurovascular system.

[0303] 49. The method according to item 48 also includes the following steps: removing the guidewire from the lumen of the microcatheter and deploying the payload from the lumen of the microcatheter through the distal opening to treat the target.

[0304] 50. The method of claim 49, wherein deploying the payload from the lumen comprises advancing the payload distally through the lumen to the distal region of the microcatheter.

[0305] 51. A method according to item 50, wherein deploying the payload further includes withdrawing the microcatheter proximally while the payload remains in a substantially fixed position relative to the target, such that the payload expands into the target as it exits the lumen through the distal opening of the microcatheter lumen.

[0306] 52. A method according to item 50, wherein the side opening is constructed to allow a guide wire to pass into and out of the inner lumen while preventing the payload from engaging or hooking on the side opening as the payload moves through the inner lumen during deployment.

[0307] 53. The method according to item 52, wherein the microcatheter further comprises:

[0308] a lubricated tubular liner forming the lumen;

[0309] a reinforcement layer positioned over the tubular liner and being more rigid than the tubular liner, the reinforcement layer comprising a first reinforcement structure having a proximal end separated from a distal end of the second reinforcement structure to create a gap in the reinforcement layer;

[0310] a short, lubricated rigid coupler positioned over at least a portion of the reinforcement layer and having an elongated window extending through a side wall of the coupler; and

[0311] An outer jacket is positioned over the coupler and the reinforcement layer.

[0312] 54. A method according to item 53, wherein the coupler is sized to span the gap in the reinforcement layer so that the elongated window of the coupler is aligned with the gap, and at least a first portion of the coupler is positioned above the proximal end of the first reinforcement structure, and at least a second portion of the coupler is positioned above the distal end of the second reinforcement structure.

[0313] 55. A method according to item 54, wherein the tubular lining and the outer sheath are sealed together at the slender window to form a double-laminated film encapsulating the side opening of the microcatheter, and wherein a slit extends through the film to allow the guide wire to pass through the side opening.

[0314] 56. The method of clause 53, wherein the rigid coupler forms a reinforcement structure that is different from the first reinforcement structure or the second reinforcement structure.

[0315] 57. The method of item 56, wherein the first reinforcement structure and the second reinforcement structure are structurally similar to each other.

[0316] 58. The method according to item 56, wherein the first reinforcement structure and the second reinforcement structure are structurally different from each other.

[0317] 59. The method of item 56, wherein the first reinforcement structure is less rigid than the second reinforcement structure, and the second reinforcement structure is less rigid than the rigid coupler.

[0318] 60. The method of item 56, wherein the first reinforcement structure is a coil and the second reinforcement structure is a coil, wherein a pitch of the coil of the first reinforcement structure is greater than a pitch of the coil of the second reinforcement structure.

[0319] 61. The method of item 56, wherein the first reinforcement structure is a coil and the second reinforcement structure is a webbing.

[0320] 62. A method according to item 36, wherein the distal access catheter and the guide sheath are slidably nested relative to each other, so that the lumen of the distal access catheter and the working lumen of the guide sheath create an extended conduit that is longer than the length of either lumen alone.

[0321] 63. The method according to item 36, wherein the distal access catheter further comprises:

[0322] a flexible distal lumen portion having a proximal end, a proximal region, a proximal opening, the lumen extending between the proximal end and the distal end; and

[0323] a proximal extension extending proximally from an attachment point adjacent the proximal opening,

[0324] wherein the proximal extension is less flexible than the flexible distal lumen and is configured to control movement of the distal access catheter, and

[0325] Wherein, the flexible distal lumen portion has an outer diameter at the attachment point that is larger than an outer diameter of the proximal extension portion at the attachment point.

[0326] 64. A method according to item 63, wherein the proximal extension of the distal access catheter is solid or hollow.

[0327] 65. A method according to item 63, wherein the proximal extension of the distal access catheter is fixed in place at the level of the port, thereby fixing the distal access catheter relative to the distal end of the introducer sheath.

[0328] 66. The method of item 65, wherein the port is a single-head RHV port.

[0329] 67. The method of item 65, wherein the port is a dual-headed RHV port.

[0330] 68. The method of item 36, wherein the side opening is 10 cm to 20 cm away from the distal-most tip of the microcatheter.

[0331] 69. The method of item 68, wherein the microcatheter further comprises a proximal opening into the lumen that is different and distinct from the side opening.

[0332] 70. A method according to item 69, wherein the proximal opening is located at a distance greater than 20 cm from the distal-most tip.

[0333] 71. The method of claim 67, wherein each head of the dual-ended RHV port is constructed to be independently tightened downwardly onto a device extending therethrough.

[0334] 72. A method according to item 65, wherein the port is a double-headed RHV port, which includes two heads connected to the working lumen of the guide sheath, the microcatheter is inserted through the first head of the double-headed RHV port, and the distal entry catheter is inserted through the second head of the double-headed RHV port.

[0335] 73. The method according to item 72 also includes the following steps: while advancing the microcatheter through the first head of the dual-ended RHV port, using the second head of the dual-ended RHV port to maintain the proximal extension of the distal access catheter in a fixed position.

[0336] 74. A method according to item 63, wherein inserting the microcatheter includes advancing the microcatheter loaded with the brain treatment device and the guidewire through the port of the guide sheath while maintaining the proximal extension of the distal access catheter fixed in place.

[0337] 75. The method according to item 36, wherein the microcatheter does not apply a straightening force to the extension tube.

[0338] 76. A method according to item 75, wherein the microcatheter further comprises a proximal region proximal to the side opening, the proximal region being less flexible than the distal region of the microcatheter.

[0339] 77. The method according to item 76 also includes the following steps: advancing the microcatheter so that at least a portion of the distal region extends a distance beyond the distal end of the distal entry catheter, while the proximal region of the microcatheter remains within one or both of the guide sheath lumen and the distal entry catheter lumen.

[0340] 78. The method according to item 75 also includes the following step: advancing a guide wire through the microcatheter lumen while the microcatheter and the brain treatment device remain stationary.

[0341] 79. The method of claim 78, wherein advancing the guidewire comprises advancing the guidewire across a target located within the intracranial neurovasculature.

[0342] 80. The method according to item 79 also includes the following steps: fixing the guidewire and the distal access catheter in a fixed position, and advancing the microcatheter loaded with the brain treatment device through the guidewire until the microcatheter extends across the target.

[0343] 81. The method according to item 80 also includes the following steps: minimizing the front-to-back piston movement of the guidewire while advancing the microcatheter.

[0344] 82. The method according to item 81 also includes the following steps: removing the guidewire from the lumen of the microcatheter and deploying the payload to exit the distal opening of the microcatheter to treat the target.

[0345] 83. A method according to item 82, wherein deploying the payload from the lumen of the microcatheter includes: advancing the payload distally through the lumen of the microcatheter by pushing the push wire of the brain treatment device, while isolating the distal entry catheter and the microcatheter and fixing them in place until the payload moves through the side opening to the distal opening.

[0346] 84. A method according to item 83, wherein deploying the payload further includes withdrawing the microcatheter proximally while the payload remains in a substantially fixed position relative to the target, such that the payload expands into the target as it exits the lumen through the distal opening of the microcatheter.

[0347] 85. The method of item 83, further comprising the step of preventing the payload from engaging the side opening as the payload is pushed through the lumen.

[0348] 86. A method according to item 85, wherein the payload is open.

[0349] 87. The method according to claim 36, wherein the method is used to treat acute ischemic stroke.

[0350] 88. The method according to item 36 also includes the following step: blocking blood flow by inflating an occlusion balloon on the outer surface of the distal region of the guide sheath.

[0351] 89. A method according to item 88, wherein the distal region of the guide sheath is positioned within the distal cervical ICA or CCA.

[0352] 90. The method of clause 36, wherein the distal access catheter is assembled with a tapered inner member to form an assembled coaxial catheter system, the tapered inner member comprising:

[0353] a flexible, elongated body having a proximal region, an outer diameter, a tapered distal tip, a distal opening, and a single lumen extending longitudinally through the flexible, elongated body to the distal opening; and

[0354] a proximal portion extending proximally from the proximal region to a proximal end of the tapered inner member,

[0355] Wherein, when assembled, the tapered inner member extends through the lumen of the distal access catheter and the tapered distal tip extends distally to the distal end of the distal access catheter.

[0356] 91. A method according to item 90, wherein the proximal end of the tapered inner member is a sea wave tube having an opening that is fluidically connected to the single lumen of the flexible, elongated body.

[0357] 92. A method according to item 90, wherein the flexible, slender body of the tapered inner member includes a proximal opening sized to accommodate a guide wire, and wherein the proximal opening is positioned to pass through a side wall of the proximal region of the flexible, slender body.

[0358] 93. The method according to item 92, wherein the distal access catheter further comprises:

[0359] a flexible distal lumen portion having a proximal end, a proximal region, and a proximal opening, wherein the lumen extends between the proximal end and the distal end; and

[0360] A proximal extension extends proximally from an attachment point adjacent the proximal opening of the flexible distal lumen, wherein the proximal extension is less flexible than the flexible distal lumen and has an outer diameter at the attachment point that is smaller than an outer diameter of the distal lumen at the attachment point.

[0361] 94. The method of claim 36, wherein the brain treatment device is a stent, a stent retriever, or a drain, and wherein the payload is expandable.

[0362] 95. A method of accessing the intracranial neurovasculature using a catheter system, the method comprising the steps of:

[0363] The guide wire is loaded into a microcatheter comprising:

[0364] Lumen;

[0365] a distal region having a distal opening from the lumen; and

[0366] a side opening that exits from the lumen and is positioned a distance proximal to the distal opening,

[0367] wherein the guidewire is positioned within the lumen of the microcatheter when loaded so that the distal end of the guidewire extends out of the distal opening and the proximal end of the guidewire exits the lumen at the side opening, and

[0368] wherein a payload is received within the lumen at the proximal end of the side opening; and

[0369] The microcatheter loaded with the guidewire and the payload is inserted into a blood vessel of a patient until the distal region of the microcatheter is advanced into the intracranial neurovasculature.

[0370] 96. A method according to item 95, wherein the payload of the brain treatment device within the microcatheter is loaded from the proximal region of the microcatheter toward the distal region of the microcatheter until the payload is positioned within the lumen proximal to the side opening.

[0371] 97. A method according to item 95, wherein the payload of the brain treatment device within the microcatheter is loaded by withdrawing the payload into the lumen through the distal opening and sliding the payload proximally through the side opening.

[0372] 98. A method according to item 95, wherein loading the guidewire within the lumen of the microcatheter includes loading the distal end of the guidewire into the lumen through the side opening and out of the distal opening.

[0373] 99. A method according to item 95, wherein loading the guidewire into the lumen of the microcatheter includes loading the proximal end of the guidewire into the lumen through the distal opening of the microcatheter until the proximal end of the guidewire exits the lumen through the side opening.

[0374] 100. The method of item 95, wherein the microcatheter further comprises a proximal opening emerging from the lumen, the proximal opening being positioned at a distance proximal to the side opening.

[0375] 101. The method of item 100, wherein the brain treatment device further comprises a push wire coupled to a proximal end of the payload, the push wire being configured to advance and position the payload relative to the microcatheter lumen.

[0376] 102. A method according to item 101, wherein the push wire extends proximally from the payload through the lumen of the microcatheter and exits the lumen at the proximal opening.

[0377] 103. The method according to item 102, further comprising the following steps: loading the payload into the microcatheter, wherein, before loading the payload, the payload extends outside the distal opening outside the lumen of the microcatheter, and the push wire extends through the lumen and exits through the proximal opening.

[0378] 104. A method according to item 103, wherein loading the payload within the microcatheter includes: withdrawing the brain treatment device relative to the microcatheter in a proximal direction until the payload passes through the distal opening into the lumen and slides proximally through the side opening until the payload is received within the lumen proximal to the side opening.

[0379] 105. A method according to item 104, wherein the guide wire is loaded into the lumen of the microcatheter after the payload is positioned proximal to the side opening so that the push wire and the guide wire do not extend side by side within the lumen.

[0380] 106. The method according to item 95 also includes the following steps: advancing the microcatheter loaded with the brain treatment device through the guide wire until the microcatheter extends across the target located within the intracranial neurovascular system.

[0381] 107. The method according to item 106 also includes the following steps: removing the guidewire from the lumen of the microcatheter and deploying the payload from the lumen of the microcatheter through the distal opening to treat the target.

[0382] 108. The method of item 107, wherein deploying the payload from the lumen comprises advancing the payload distally through the lumen to the distal region of the microcatheter.

[0383] 109. A method according to item 108, wherein deploying the payload further includes withdrawing the microcatheter proximally while the payload remains in a substantially fixed position relative to the target, such that the payload expands into the target as it exits the lumen through the distal opening of the microcatheter lumen.

[0384] 110. A method according to item 108, wherein the side opening is constructed to allow a guide wire to pass into and out of the lumen through the side opening while preventing the payload from engaging or hooking on the side opening as the payload moves through the lumen during deployment.

[0385] 111. The method according to item 110, wherein the microcatheter further comprises:

[0386] a lubricated tubular liner forming the lumen;

[0387] a reinforcement layer positioned over the tubular liner and being more rigid than the tubular liner, the reinforcement layer comprising a first reinforcement structure having a proximal end separated from a distal end of the second reinforcement structure to create a gap in the reinforcement layer;

[0388] a short, lubricated rigid coupler positioned over at least a portion of the reinforcement layer and having an elongated window extending through a side wall of the coupler; and

[0389] An outer jacket is positioned over the coupler and the reinforcement layer.

[0390] 112. A method according to item 111, wherein the coupler is sized to span the gap in the reinforcement layer so that the elongated window of the coupler is aligned with the gap, and at least a first portion of the coupler is positioned above the proximal end of the first reinforcement structure, and at least a second portion of the coupler is positioned above the distal end of the second reinforcement structure.

[0391] 113. A method according to item 112, wherein the tubular lining and the outer sheath are sealed together at the elongated window to form a double-laminated membrane encapsulating the side opening of the microcatheter, and wherein a slit extends through the membrane to allow the guide wire to pass through the side opening.

[0392] 114. The method of item 111, wherein the rigid coupler forms a reinforcement structure that is different from the first reinforcement structure or the second reinforcement structure.

[0393] 115. The method of item 114, wherein the first reinforcement structure and the second reinforcement structure are structurally similar to each other.

[0394] 116. A method according to item 114, wherein the first reinforcement structure and the second reinforcement structure are structurally different from each other.

[0395] 117. A method according to item 114, wherein the first reinforcement structure is less rigid than the second reinforcement structure, and the second reinforcement structure is less rigid than the rigid coupler.

[0396] 118. A method according to item 114, wherein the first reinforcement structure is a coil and the second reinforcement structure is a coil, wherein a pitch of the coil of the first reinforcement structure is greater than a pitch of the coil of the second reinforcement structure.

[0397] 119. The method of item 114, wherein the first reinforcement structure is a coil and the second reinforcement structure is a webbing.

[0398] 120. The method according to item 95 also includes the following steps: positioning a guide sheath having a working lumen connected to a port within a blood vessel of the patient, the working lumen having a distal end.

[0399] 121. The method according to item 120 also includes the following steps: inserting a distal access catheter through the port into the working lumen of the guide sheath, the distal access catheter having a lumen and a distal end, the distal end of the distal access catheter extending beyond the distal end of the guide sheath to at least one level of the internal carotid artery.

[0400] 122. A method according to item 121, wherein the distal access catheter and the guide sheath are slidably nested relative to each other, so that the lumen of the distal access catheter and the working lumen of the guide sheath produce an extended conduit that is longer than the length of either lumen alone.

[0401] 123. The method of item 122, wherein the distal access catheter further comprises:

[0402] a flexible distal lumen member having a proximal end, a proximal region, and a proximal opening; and

[0403] A proximal extension extends proximally from an attachment point adjacent the proximal opening, wherein the proximal extension is less flexible than the distal lumen element and is configured to control movement of the distal access catheter, and wherein the proximal extension has an outer diameter at the attachment point that is smaller than an outer diameter of the distal lumen element at the attachment point.

[0404] 124. A method according to item 123, wherein the proximal extension of the distal access catheter is fixed in place at the level of the port, thereby fixing the distal access catheter relative to the distal end of the guide sheath.

[0405] 125. A method according to item 124, wherein the port is a single-head RHV port.

[0406] 126. A method according to item 124, wherein the port is a dual-headed RHV port.

[0407] 127. A method according to item 126, wherein each head of the dual-ended port is constructed to be tightened downwardly independently onto a device extending therethrough.

[0408] 128. A method according to item 124, wherein the port is a double-headed RHV port, which includes two heads connected to the working lumen of the guide sheath, the microcatheter is inserted through the first head of the double-headed RHV port, and the distal entry catheter is inserted through the second head of the double-headed RHV port.

[0409] 129. The method according to item 128 also includes the following steps: while advancing the microcatheter through the first head of the dual-ended RHV port, using the second head of the dual-ended RHV port to maintain the proximal extension of the distal access catheter in a fixed position.

[0410] 130. A method according to item 124, wherein inserting the microcatheter into the blood vessel includes advancing the microcatheter loaded with the brain treatment device and the guidewire through the port of the guide sheath while maintaining the proximal extension of the distal access catheter fixed in place.

[0411] 131. The method according to item 130 also includes the following steps: advancing the microcatheter through the lumen of the distal access catheter until the distal region of the microcatheter extends at least to the distal end of the distal access catheter.

[0412] 132. The method of claim 123, wherein the microcatheter does not apply a straightening force to the extension tube.

[0413] 133. A method according to item 132, wherein the microcatheter further includes a proximal region proximal to the side opening, which is less flexible than the distal region of the microcatheter.

[0414] 134. The method according to item 133 also includes the following steps: advancing the microcatheter so that at least a portion of the distal region extends a distance beyond the distal end of the distal entry catheter, while the proximal region of the microcatheter remains within one or both of the guide sheath lumen and the distal entry catheter lumen.

[0415] 135. The method according to item 132 also includes the following step: advancing the guide wire through the microcatheter lumen while the microcatheter and the brain treatment device remain stationary.

[0416] 136. A method according to item 135, wherein advancing the guidewire includes advancing the guidewire across a target located within the intracranial neurovasculature.

[0417] 137. The method according to item 136 also includes the following steps: fixing the guidewire and the distal access catheter in a fixed position, and advancing the microcatheter loaded with the brain treatment device through the guidewire until the microcatheter extends across the target.

[0418] 138. The method according to item 137 also includes the following steps: minimizing the forward and backward piston movement of the guide wire while advancing the microcatheter.

[0419] 139. The method according to item 138 also includes the following steps: removing the guidewire from the lumen of the microcatheter and deploying the payload to exit the distal opening of the microcatheter to treat the target.

[0420] 140. A method according to item 139, wherein deploying the payload from the lumen of the microcatheter includes: advancing the payload distally through the lumen of the microcatheter by pushing the push wire of the brain treatment device, while isolating the distal entry catheter and the microcatheter and fixing them in place until the payload moves through the side opening to the distal opening.

[0421] 141. A method according to item 140, wherein deploying the payload further includes withdrawing the microcatheter proximally while the payload remains in a substantially fixed position relative to the target, such that the payload expands into the target as it exits the lumen through the distal opening of the microcatheter.

[0422] 142. The method of item 140, further comprising the step of preventing the payload from engaging the side opening as the payload is pushed through the lumen.

[0423] 143. A method according to item 142, wherein the payload is open.

[0424] 144. The method according to item 95, wherein the method is used to treat acute ischemic stroke.

[0425] 145. The method according to item 95 further includes the following steps: positioning a guide sheath having a working lumen connected to a port within a blood vessel of the patient, wherein a distal region of the guide sheath further includes an occlusion balloon on an outer surface, the occlusion balloon being constructed to prevent flow through the blood vessel when the sealing element is expanded.

[0426] 146. The method according to item 95 also includes the following steps: inserting a distal access catheter into a target location, the distal access catheter having: a flexible distal lumen portion having a proximal end; a proximal region; a proximal opening; a distal end; and a lumen extending between the proximal end and the distal end, wherein the lumen of the distal access catheter is sized to receive the catheter body of the rapid exchange microcatheter.

[0427] 147. A method according to item 146, wherein the distal access catheter further comprises a proximal extension portion that is less flexible than the flexible distal lumen portion and is constructed to control movement of the distal access catheter.

[0428] 148. A method according to item 147, wherein the proximal extension extends proximally from an attachment point of the flexible distal lumen portion adjacent to the proximal opening, wherein the flexible distal lumen portion has an outer diameter at the attachment point that is larger than an outer diameter of the proximal extension at the attachment point.

[0429] 149. A method according to item 148, wherein the proximal extension of the distal access catheter is solid or hollow.

[0430] 150. The method of clause 146, wherein the distal access catheter is assembled with a tapered inner member to form an assembled coaxial catheter system, the tapered inner member comprising:

[0431] a flexible, elongated body having a proximal region, an outer diameter, a tapered distal tip, a distal opening, and a single lumen extending longitudinally through the flexible, elongated body to the distal opening; and

[0432] a proximal portion extending proximally from the proximal region to a proximal end of the tapered inner member,

[0433] Wherein, when assembled, the tapered inner member extends through the lumen of the distal access catheter and the tapered distal tip extends distally to the distal end of the distal access catheter.

[0434] 151. A method according to item 150, wherein the proximal end of the tapered inner member is a sea wave tube having an opening that is fluidically connected to the single lumen of the flexible, elongated body.

[0435] 152. A method according to item 150, wherein the flexible, slender body of the tapered inner member includes a proximal opening sized to accommodate a guide wire, and wherein the proximal opening is positioned to pass through a side wall of the proximal region of the flexible, slender body.

[0436] 153. A method according to item 152, wherein the distal access catheter further comprises a proximal extension extending proximally from an attachment point of the flexible distal lumen portion adjacent to the proximal opening, wherein the proximal extension is less flexible than the flexible distal lumen portion and has an outer diameter at the attachment point that is smaller than an outer diameter of the distal lumen portion at the attachment point.

[0437] 154. The method according to item 146 also includes the following steps: positioning a guide sheath within the blood vessel of the patient, the guide sheath including a working lumen extending between a proximal region and a distal region, the distal region of the guide sheath having at least one opening connected to the working lumen of the guide sheath, wherein inserting the distal access catheter into the target position includes inserting the distal access catheter through the working lumen of the guide sheath and leaving the at least one opening.

[0438] 155. A method according to item 154, wherein the distal region of the guide sheath is positioned within a portion of the carotid artery and the proximal region is positioned near a femoral access site.

[0439] 156. The method according to item 155 also includes the following steps: extending the microcatheter coaxially through the lumen of the distal entry catheter coaxially extending through the working lumen of the guide sheath, so that the distal region of the microcatheter passes through the opening at the distal end of the distal entry catheter.

[0440] 157. The method according to item 155 also includes the following steps: blocking flow through the carotid artery by expanding an occlusion balloon on the outer surface of the distal region of the introducer sheath.

[0441] 158. The method of claim 95, wherein the brain treatment device is a stent, a stent retriever, or a drain, and wherein the payload is expandable.

[0442] 159. A method of accessing the intracranial neurovasculature using a catheter system, the method comprising the steps of:

[0443] inserting the distal access catheter assembled with the tapered inner member to form an assembled coaxial catheter system into a blood vessel of a patient,

[0444] Wherein, the distal access catheter comprises:

[0445] a flexible distal lumen member having a proximal opening into a lumen extending between a proximal end and a distal end; and

[0446] a proximal extension extending proximally from an attachment point adjacent the proximal opening, wherein the proximal extension is less flexible than the distal lumen element and is configured to control movement of the distal access catheter, and wherein the proximal extension has an outer diameter at the attachment point that is smaller than an outer diameter of the distal lumen element at the attachment point, and

[0447] Wherein, the conical inner component comprises:

[0448] a flexible, elongated body having a proximal region, an outer diameter, a tapered distal tip, a distal opening, and a single lumen extending longitudinally through the flexible, elongated body to the distal opening; and

[0449] a proximal portion extending proximally from the proximal region to a proximal end of the tapered inner member,

[0450] wherein, when assembled, the tapered inner member extends through the lumen of the distal access catheter and the tapered distal tip portion extends distally to the distal end of the distal access catheter;

[0451] removing the tapered inner member from the lumen of the distal access catheter;

[0452] Inserting a microcatheter into the lumen of the flexible distal lumen element, the microcatheter comprising:

[0453] Lumen;

[0454] a distal region having a distal opening from the lumen; and

[0455] a side opening emerging from the lumen and positioned a distance proximal to the distal opening, wherein a payload is received within the lumen proximal to the side opening; and

[0456] The microcatheter is advanced through the lumen of the distal access catheter until the distal region of the microcatheter extends to at least the distal end of the distal access catheter.

[0457] 160. A method according to item 159, wherein the proximal end of the tapered inner member is a sea wave tube having an opening that is fluidically connected to the single lumen of the flexible, elongated body.

[0458] 161. The method according to item 159, further comprising the steps of: inserting a second distal access catheter through the lumen of the first distal access catheter until the second distal access catheter extends toward the distal end of the first distal access catheter,

[0459] Wherein, the second distal access catheter comprises:

[0460] a second flexible distal lumen member having a proximal opening into a lumen extending between the proximal and distal ends; and

[0461] a second proximal extension extending proximally from an attachment point adjacent the proximal opening, wherein the second proximal extension is less flexible than the second distal lumen element and is configured to control movement of the second distal access catheter, and wherein the second proximal extension has an outer diameter at the attachment point that is smaller than an outer diameter of the second distal lumen element at the attachment point, and

[0462] Wherein, inserting the microcatheter into the lumen of the flexible distal lumen element further comprises inserting the microcatheter into the lumen of the second distal access catheter.

[0463] 162. A rapid exchange microcatheter system for accessing the intracranial neurovasculature, the microcatheter system comprising:

[0464] (i) a catheter body, the catheter body comprising:

[0465] (a) Outer diameter, inner diameter and distal tip;

[0466] (b) an inner lumen defined by the inner diameter, the catheter body being adapted to carry a payload within the inner lumen and to deliver the payload from the inner lumen to a target location in the intracranial neurovasculature, wherein (i) the inner diameter is sized to allow passage of a guidewire, and (ii) the outer diameter has a maximum diameter of less than 0.048 inches.

[0467] size;

[0468] (c) a guidewire side opening into the inner lumen, the guidewire side opening being sized to allow passage of a guidewire, the guidewire side opening being positioned away from the catheter body.

[0469] The distance of the most distal tip is 10-20 cm;

[0470] (d) a proximal opening into the inner lumen, the proximal opening being different and distinct from the guidewire-side opening, the proximal opening being positioned at a distance greater than 20 cm from the distal-most tip;

[0471] (e) a distal reinforced catheter portion extending between a distal region of the catheter body to a point proximate the guidewire-side opening; and

[0472] (f) a proximal reinforced catheter portion extending a distance from a point near the guidewire-side opening toward the proximal end of the catheter body;

[0473] Wherein, the guide wire side opening is positioned between the proximal end of the distal enhanced catheter portion and

[0474] within a gap between the proximal and distal ends of the reinforced catheter portion; and

[0475] (ii) instructions for use, which instruct loading the payload into the inner lumen at a location proximal to the guidewire-side opening prior to use of the catheter body.

[0476] 163. A rapid exchange microcatheter according to item 162, wherein the reinforced catheter portion at the proximal end is less flexible than the reinforced catheter portion at the distal end.

[0477] 164. The rapid exchange microcatheter of item 162, wherein the distal reinforced catheter portion has a first reinforcement structure.

[0478] 165. The rapid exchange microcatheter of item 164, wherein the proximal reinforced catheter portion has a second reinforcement structure.

[0479] 166. The rapid exchange microcatheter of item 165, wherein the first reinforcement structure is coupled to the second reinforcement structure by a rigid coupler.

[0480] 167. The rapid exchange microcatheter of item 165, wherein the first reinforcement structure and the second reinforcement structure are structurally different from each other.

[0481] 168. The rapid exchange microcatheter of item 165, wherein the first reinforcement structure is a coil and the second reinforcement structure is a coil, wherein a pitch of the coil of the first reinforcement structure is greater than a pitch of the coil of the second reinforcement structure.

[0482] 169. The rapid exchange microcatheter of item 166, wherein the coupler has a window aligned with the side opening.

[0483] 170. The rapid exchange microcatheter of item 162, wherein the side wall of the catheter body comprises:

[0484] Lubricated tubular lining;

[0485] a reinforcing layer, the reinforcing layer being positioned above the tubular liner and being more rigid than the tubular liner, the reinforcing layer comprising:

[0486] a first reinforcement structure extending within the distal reinforced catheter portion, the first reinforcement structure having a proximal end; and

[0487] a second reinforcement structure extending within the proximal reinforcement conduit portion, the second reinforcement structure having a distal end,

[0488] wherein the proximal end of the first reinforcement structure is separated from the distal end of the second reinforcement structure, thereby generating the gap;

[0489] a short tubular rigid coupler positioned over the proximal end of the first reinforcement structure and over the distal end of the second reinforcement structure, the coupler having an elongated window extending through a side wall of the coupler; and

[0490] An outer jacket is positioned over the coupler and the reinforcement layer.

[0491] 171. A rapid exchange microcatheter system for accessing the intracranial neurovasculature, the microcatheter system comprising:

[0492] (i) a catheter body, the catheter body comprising:

[0493] (a) Outer diameter, inner diameter and distal tip;

[0494] (b) an inner lumen defined by the inner diameter, the catheter body being adapted to carry a payload within the inner lumen and to deliver the payload from the inner lumen to a target location in the intracranial neurovasculature, wherein (i) the inner diameter is sized to allow passage of a guidewire, and (ii) the outer diameter of the body has an outer diameter of less than 0.048 inches.

[0495] Maximum size;

[0496] (c) a guidewire side opening into the inner lumen, the guidewire side opening being sized to allow passage of a guidewire, the guidewire side opening being positioned away from the catheter body.

[0497] The distance of the most distal tip is 10-20 cm;

[0498] (d) a proximal opening into the inner lumen, the proximal opening being different and distinct from the guidewire-side opening, the proximal opening being positioned at a distance greater than 20 cm from the distal-most tip;

[0499] (e) a distal reinforced catheter portion extending between a distal region of the catheter body to a point proximate the guidewire-side opening; and

[0500] (f) a proximal reinforced catheter portion extending a distance from a point near the guidewire-side opening toward the proximal end of the catheter body;

[0501] Wherein, the guide wire side opening is positioned between the proximal end of the distal enhanced catheter portion and

[0502] within a gap between the proximal and distal ends of the reinforced catheter portion; and

[0503] (ii) a payload loaded into the inner lumen at a position proximal to the guidewire side opening, such that the payload can be carried in the inner lumen and delivered from the inner lumen to a target location in the intracranial neurovascular system.

[0504] 172. The rapid exchange microcatheter of item 171, wherein the reinforced catheter portion at the proximal end is less flexible than the reinforced catheter portion at the distal end.

[0505] 173. The rapid exchange microcatheter of item 171, wherein the distal reinforced catheter portion has a first reinforcement structure.

[0506] 174. The rapid exchange microcatheter of item 173, wherein the proximal reinforced catheter portion has a second reinforcement structure.

[0507] 175. The rapid exchange microcatheter of item 174, wherein the first reinforcement structure is coupled to the second reinforcement structure by a rigid coupler.

[0508] 176. The rapid exchange microcatheter of item 174, wherein the first reinforcement structure and the second reinforcement structure are structurally different from each other.

[0509] 177. A rapid exchange microcatheter according to item 174, wherein the first reinforcement structure is a coil and the second reinforcement structure is a coil, wherein a pitch of the coil of the first reinforcement structure is greater than a pitch of the coil of the second reinforcement structure.

[0510] 178. The rapid exchange microcatheter of item 175, wherein the coupler has a window aligned with the side opening.

[0511] 179. The rapid exchange microcatheter of item 171, wherein the side wall of the catheter body comprises:

[0512] Lubricated tubular lining;

[0513] a reinforcing layer, the reinforcing layer being positioned above the tubular liner and being more rigid than the tubular liner, the reinforcing layer comprising:

[0514] a first reinforcement structure extending within the distal reinforced catheter portion, the first reinforcement structure having a proximal end; and

[0515] a second reinforcement structure extending within the proximal reinforcement conduit portion, the second reinforcement structure having a distal end,

[0516] wherein the proximal end of the first reinforcement structure is separated from the distal end of the second reinforcement structure, thereby generating the gap;

[0517] a short tubular rigid coupler positioned over the proximal end of the first reinforcement structure and over the distal end of the second reinforcement structure, the coupler having an elongated window extending through a side wall of the coupler; and

[0518] An outer jacket is positioned over the coupler and the reinforcement layer.

[0519] In various embodiments, description is made with reference to the accompanying drawings. However, a particular embodiment may be practiced without one or more of these specific details or in combination with other known methods and configurations. In the description, a large number of specific details, such as specific configurations, sizes, and processes are described in order to provide a thorough understanding of the embodiments. In other cases, in order not to make the description unnecessarily vague, known processes and manufacturing techniques are not particularly described in detail. References throughout this specification to "one embodiment", "an embodiment", "an embodiment", "an embodiment", etc. mean that the specific features, structures, configurations, or characteristics described are included in at least one embodiment or embodiment. Thus, the appearance of phrases "one embodiment", "an embodiment", "an embodiment", "an embodiment", etc. in various places throughout this specification does not necessarily refer to the same embodiment or embodiment. In addition, specific features, structures, configurations, or characteristics may be combined in one or more embodiments in any suitable manner.

[0520] The use of relative terms throughout the description may indicate a relative position or direction. For example, "distal end" may indicate a first direction away from a reference point. Similarly, "proximal end" may indicate a position in a second direction opposite to the first direction. However, such terms are provided to create a relative frame of reference and are not intended to limit the use and orientation of the catheter and / or delivery system to the specific configurations described in the various embodiments.

[0521] Although the specification includes many details, these details should not be interpreted as limitations on the scope of claiming or claiming, but should be interpreted as descriptions of features specific to a particular embodiment. The specific features described in the specification under the background of a separate embodiment can also be implemented in combination in a single embodiment. On the contrary, the various features described under the background of a single embodiment can also be implemented individually in multiple embodiments or in any suitable sub-combination. Moreover, although the features can be described above as working in a specific combination and even initially claiming protection as such, one or more features from the claimed combination can be cut out from the combination in some cases, and the claimed combination can be dedicated to a variant of a sub-combination or a sub-combination. Similarly, although operations are depicted in the drawings in a particular order, this should not be understood as requiring such operations to be performed or all illustrated operations in the particular order shown or in a sequential order in order to achieve the desired result. Only some examples and embodiments are disclosed. Changes, modifications and enhancements of the examples and embodiments and other embodiments can be performed based on the disclosed content.

[0522] In the above description and claims, phrases such as "at least one of ..." or "one or more of ..." may appear, followed by a connected list of elements or features. The term "and / or" may also appear in a list of two or more elements or features. Unless otherwise implicitly or explicitly negated by the context in which the phrase is used, such phrases are intended to mean any one of the listed elements or features, either independently or in combination with any one of the other listed elements or features. For example, the phrases "at least one of A and B", "one or more of A and B", and "A and / or B" are each intended to mean "A alone, B alone, or A and B together". Similar explanations are also intended to be used for lists including three or more items. For example, the phrases "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, and / or C" are each intended to mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together".

[0523] Use of the term "based on" above and in the claims is intended to mean "based, at least in part, on" such that unrecited features or elements are also permissible.

Claims

1. A rapid exchange microcatheter for accessing an intracranial neurovascular system, the microcatheter comprising: a catheter body having a sidewall extending between a proximal end to a distal-most tip, the sidewall defining an inner lumen having an inner diameter sized to accommodate a payload of a brain treatment device; a distal opening that exits the inner lumen near the distal-most tip; a side opening extending through the side wall of the catheter body, the side opening being located a first distance proximal to the distal-most tip of the catheter body; a proximal opening located proximal to the side opening and a second distance from the distal-most tip of the catheter body; a distal reinforced catheter portion extending between a distal region of the catheter body to a point proximate the side opening; as well as a proximal reinforced catheter portion extending a distance from a point proximal to the side opening toward the proximal end of the catheter body, wherein the side opening is positioned in a gap between a proximal end of the distal reinforcement catheter portion and a distal end of the proximal reinforcement catheter portion, and Wherein, the effective load of the brain treatment device is accommodated in the lumen at the proximal end of the side opening.

2. The rapid exchange microcatheter according to claim 1, wherein: The first distance is between about 10 cm and about 20 cm.

3. The rapid exchange microcatheter according to claim 2, wherein: The second distance is greater than about 20 cm.

4. The rapid exchange microcatheter according to claim 1, wherein: The distal opening is located at the distal-most tip of the catheter.

5. The rapid exchange microcatheter according to claim 1, wherein: The side opening is sized to allow passage of a guidewire having an outer diameter equal to or less than about 0.018".

6. The rapid exchange microcatheter of claim 1, wherein: The proximal reinforced catheter portion is less flexible than the distal reinforced catheter portion.

7. The rapid exchange microcatheter of claim 1, wherein: The distal reinforced catheter portion has a first reinforcement structure.

8. The rapid exchange microcatheter of claim 7, wherein: The proximal reinforced catheter portion has a second reinforcement structure.

9. The rapid exchange microcatheter of claim 8, wherein: The first reinforcement structure is coupled to the second reinforcement structure by a rigid coupler.

10. The rapid exchange microcatheter of claim 9, wherein: The rigid coupler forms a reinforcement structure that is different from the first reinforcement structure or the second reinforcement structure.

11. The rapid exchange microcatheter of claim 10, wherein: The first reinforcement structure and the second reinforcement structure are similar in structure to each other.

12. The rapid exchange microcatheter of claim 10, wherein: The first reinforcement structure and the second reinforcement structure are structurally different from each other.

13. The rapid exchange microcatheter of claim 10, wherein: The first reinforcement structure is less rigid than the second reinforcement structure, and the second reinforcement structure is less rigid than the rigid coupler.

14. The rapid exchange microcatheter of claim 10, wherein: The first reinforcement structure is a coil and the second reinforcement structure is a coil, wherein a pitch of the coil of the first reinforcement structure is greater than a pitch of the coil of the second reinforcement structure.

15. A system comprising the rapid exchange microcatheter of claim 1, further comprising a distal access catheter having: a flexible distal lumen portion having a proximal end; a proximal region; a proximal opening; a distal end; and a lumen extending between the proximal end and the distal end, wherein The lumen of the distal access catheter is sized to receive the catheter body of the rapid exchange microcatheter.

16. A method of accessing the intracranial neurovasculature using a catheter system, the method comprising the steps of: positioning an introducer sheath having a working lumen in communication with a port at a proximal end within a blood vessel of a patient, wherein a distal end of the introducer sheath is advanced to at least the internal carotid artery; inserting a distal access catheter through the port into the working lumen of the introducer sheath, the distal access catheter having a lumen and a distal end; positioning the distal end of the distal access catheter beyond the distal end of the introducer sheath; Inserting a microcatheter loaded with a payload of a brain treatment device through the lumen of the distal access catheter, the microcatheter comprising: Lumen; a distal region having a distal opening from the lumen; and a side opening that exits from the lumen and is positioned a distance proximal to the distal opening, wherein the payload is contained within the lumen at the proximal end of the side opening when loaded; advancing the microcatheter loaded with the payload through the lumen of the distal access catheter until the distal region of the microcatheter is advanced to at least the distal end of the distal access catheter; and The payload of the brain treatment device is deployed within the intracranial neurovasculature.

17. A method of accessing the intracranial neurovasculature using a catheter system, the method comprising the steps of: The guide wire is loaded into a microcatheter comprising: Lumen; a distal region having a distal opening from the lumen; and a side opening that exits from the lumen and is positioned a distance proximal to the distal opening, wherein the guidewire is positioned within the lumen of the microcatheter when loaded so that the distal end of the guidewire extends out of the distal opening and the proximal end of the guidewire exits the lumen at the side opening, and wherein a payload is received within the lumen at the proximal end of the side opening; and The microcatheter loaded with the guidewire and the payload is inserted into a blood vessel of a patient until the distal region of the microcatheter is advanced into the intracranial neurovasculature.

18. A method of accessing the intracranial neurovasculature using a catheter system, the method comprising the steps of: inserting the distal access catheter assembled with the tapered inner member to form an assembled coaxial catheter system into a blood vessel of a patient, Wherein, the distal access catheter comprises: a flexible distal lumen member having a proximal opening into a lumen extending between a proximal end and a distal end; and a proximal extension extending proximally from an attachment point adjacent the proximal opening, wherein the proximal extension is less flexible than the distal lumen element and is configured to control movement of the distal access catheter, and wherein the proximal extension has an outer diameter at the attachment point that is smaller than an outer diameter of the distal lumen element at the attachment point, and Wherein, the conical inner component comprises: a flexible, elongated body having a proximal region, an outer diameter, a tapered distal tip, a distal opening, and a single lumen extending longitudinally through the flexible, elongated body to the distal opening; and a proximal portion extending proximally from the proximal region to a proximal end of the tapered inner member, wherein, when assembled, the tapered inner member extends through the lumen of the distal access catheter and the tapered distal tip portion extends distally to the distal end of the distal access catheter; removing the tapered inner member from the lumen of the distal access catheter; Inserting a microcatheter into the lumen of the flexible distal lumen element, the microcatheter comprising: Lumen; a distal region having a distal opening from the lumen; and a side opening emerging from the lumen and positioned a distance proximal to the distal opening, wherein a payload is received within the lumen proximal to the side opening; and The microcatheter is advanced through the lumen of the distal access catheter until the distal region of the microcatheter extends to at least the distal end of the distal access catheter.

19. A rapid exchange microcatheter system for accessing the intracranial neurovasculature, the microcatheter system comprising: (i) a catheter body, the catheter body comprising: (a) Outer diameter, inner diameter and distal tip; (b) an inner lumen defined by the inner diameter, the catheter body being adapted to carry a payload within the inner lumen and to deliver the payload from the inner lumen to a target location in the intracranial neurovasculature, wherein (i) the inner diameter is sized to allow passage of a guidewire, and (ii) the outer diameter has a maximum dimension of less than 0.048 inches; (c) a guidewire side opening into the inner lumen, the guidewire side opening being sized to allow passage of a guidewire, the guidewire side opening being positioned at a distance of 10-20 cm from the distal-most tip of the catheter body; (d) a proximal opening into the inner lumen, the proximal opening being different and distinct from the guidewire-side opening, the proximal opening being positioned at a distance greater than 20 cm from the distal-most tip; (e) a distal reinforced catheter portion extending between a distal region of the catheter body to a point proximate the guidewire-side opening; and (f) a proximal reinforced catheter portion extending a distance from a point near the guidewire-side opening toward the proximal end of the catheter body; wherein the guidewire side opening is positioned in a gap between a proximal end of the distal reinforced catheter portion and a distal end of the proximal reinforced catheter portion; and (ii) instructions for use, which instruct loading the payload into the inner lumen at a location proximal to the guidewire-side opening prior to use of the catheter body.

20. A rapid exchange microcatheter system for accessing the intracranial neurovasculature, the microcatheter system comprising: (i) a catheter body, the catheter body comprising: (a) Outer diameter, inner diameter and distal tip; (b) an inner lumen defined by the inner diameter, the catheter body being adapted to carry a payload within the inner lumen and to deliver the payload from the inner lumen to a target location in the intracranial neurovasculature, wherein (i) the inner diameter is sized to allow passage of a guidewire, and (ii) the outer diameter body has a maximum dimension of less than 0.048 inches; (c) a guidewire side opening into the inner lumen, the guidewire side opening being sized to allow passage of a guidewire, the guidewire side opening being positioned at a distance of 10-20 cm from the distal-most tip of the catheter body; (d) a proximal opening into the inner lumen, the proximal opening being different and distinct from the guidewire-side opening, the proximal opening being positioned at a distance greater than 20 cm from the distal-most tip; (e) a distal reinforced catheter portion extending between a distal region of the catheter body to a point proximate the guidewire-side opening; and (f) a proximal reinforced catheter portion extending a distance from a point near the guidewire-side opening toward the proximal end of the catheter body; wherein the guidewire side opening is positioned in a gap between a proximal end of the distal reinforced catheter portion and a distal end of the proximal reinforced catheter portion; and (ii) a payload loaded into the inner lumen at a position proximal to the guidewire side opening, such that the payload can be carried in the inner lumen and delivered from the inner lumen to a target location in the intracranial neurovascular system.

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