Systems and methods for accessing small arteries for delivering catheters to target vessels

Abstract

The present invention describes a system and method for accessing small arteries for delivering a catheter to a target vessel, such as a cerebral vessel. In particular, the present invention describes a system that allows for direct introduction of a catheter through a vascular opening without an external sheath. The distal tip of the catheter is protected by a protective cover. Methods for introducing the catheter into the vessel and a kit are also described.

Description

[Technical Field]

[0001] Systems and methods for accessing small arteries for delivering catheters to target vessels, such as cerebral vessels, are described. In particular, the present invention describes a system that allows for direct introduction of a catheter through a vascular opening without an external sheath, with the distal tip of the catheter protected by a protective cover. Methods and kits for introducing a catheter into a vessel are also described. [Background technology]

[0002] Neuro-interventional (NI) procedures utilizing catheter systems to access cerebral arteries for the treatment of ischemic stroke vary in the technique and catheter systems utilized. Similarly, other interventional procedures to access other target vessels or other target sites via the vasculature, including the heart, utilize a variety of catheter systems.

[0003] In many cases, particularly in NI and cardiac-intervention (CI) procedures, access to the vascular system is gained via the femoral artery, primarily due to its size and proximity to the skin. While the femoral artery is a valuable access point, there are drawbacks to its use, primarily due to the recovery time associated with performing NI and CI procedures via this location. For example, procedures performed via the femoral artery typically require patients to remain in the treatment center for longer periods of time because the access wound requires more time to heal before allowing the patient to ambulate.

[0004] In contrast, performing NI or CI procedures via the radial artery allows patients to be discharged more quickly because healing of the access wound does not prevent the patient from becoming ambulatory almost immediately after surgery. Therefore, performing procedures via the brachial artery, when appropriate, is preferred to reduce hospital and other treatment costs. Summary of the Invention [Problem to be solved by the invention]

[0005] However, the smaller size of the radial brachial artery generally presents certain surgical limitations and complications. Specifically, there is an upper limit to the size of the catheter that can be introduced into the brachial artery using conventional arterial access devices. [Means for solving the problem]

[0006] In accordance with the present invention, a system for introducing a catheter into the vascular system via a vascular opening (VO) is described. The system includes a catheter having an inner diameter and an outer diameter, and an internal guide sized for telescopic movement within the catheter to support the catheter and protect its distal tip as the catheter is introduced through the VO. The internal guide has a tapered distal tip for introducing the system through the VO, and a protective cover connected to the proximally extending tapered distal tip and expandable for engagement with the distal tip of the catheter. The protective cover is movable between engaged and disengaged positions on the catheter. Selective movement of the internal guide relative to the catheter moves the protective cover from the engaged position to the disengaged position, and when the protective cover is in the disengaged position: the above Inside Department Guide (internal guide ) and the protective cover is withdrawn proximally through the catheter.

[0007] In various embodiments, The protective cover has a plurality of inwardly biased arms, and the inner guide has corresponding recesses for receiving the arms in a compressed position. The protective cover is an elastic sheath that circumferentially covers the distal tip of the catheter in the engaged position. The resilient sheath abuts the inner guide in the disengaged position. During withdrawal of the inner guide, the elastic sheath inverts to the disengaged position. The catheter has a catheter end stop and the inner guide has an inner guide end stop, and when the protective cover is in the engaged position, movement of the inner guide end stop toward the catheter end stop causes the protective cover to move to the disengaged position. The catheter is an aspiration catheter having a soft distal tip region and a length sufficient to extend from the radial artery VO to the cerebral vasculature for the treatment of ischemic stroke. The above suction catheter is 5 to 8F. The above suction catheter is 6 to 8F. The inner guide is hollow and has a through bore formed in the tapered distal tip that allows the inner guide to ride over a wire. The above system is Department Guide and an outer diameter of the catheter, and an expandable ring having a distal edge with a thickness that is disposed below the proximal edge of the elastic sheath when the elastic sheath is assembled to the catheter.

[0008] In another aspect, the present invention provides a method for preparing a sterile Department Guide The present invention describes a kit comprising an inner guide sized for telescopic movement within a catheter to support the catheter and protect its distal tip when the catheter is introduced via a VO. The internal guide has a tapered distal tip for introducing the system through the VO and an expandable protective cover connected to the proximally extending tapered distal tip and adapted to engage the distal tip of the catheter. The protective cover is movable between an engaged position and a disengaged position on the catheter. Selective movement of the internal guide relative to the catheter moves the protective cover from the engaged position to the disengaged position, and when the protective cover is in the disengaged position, the internal guide moves. Department Guide and the protective cover is withdrawn proximally through the catheter.

[0009] In various embodiments, Above Department Guide and the catheter are packaged in the same sterile package. The catheter and the internal Department Guide However, the catheter package and Department Guide The package and the separate package. Inside Department Guide The package is as above Department Guide and an outer diameter of the catheter, and an expandable ring having a distal edge with a thickness that is disposed under the proximal edge of the protective cover when the protective cover is assembled to the catheter.

[0010] Another aspect of the present invention describes a method for introducing a catheter into a blood vessel via a vascular opening (VO), comprising: The above method is a) puncturing a blood vessel with a hollow needle to form a VO; b) introducing a wire through said hollow needle; c) withdrawing the needle over the wire; d) introducing an arterial access assembly comprising an inner guide having a tapered proximal tip and a catheter carried by the inner guide and having a distal tip operably engaging a protective cover configured on the inner guide; e) advancing the assembly away from the VO; f) advancing the inner guide proximally relative to the catheter to disengage the protective cover from the distal tip of the catheter; g) withdrawing the inner guide and the protective cover through the catheter.

[0011] Various objects, features, and advantages of the present invention will become apparent from the following description of specific embodiments of the invention, as illustrated in the accompanying drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the invention. Like reference numerals refer to like elements. [Brief explanation of the drawings]

[0012] [Figure 1A] Figures 1A-1G are schematic diagrams showing a typical prior art arterial access procedure. Typical steps include needle insertion (Figure 1A), wire insertion (Figure 1B), needle removal (Figure 1C), arterial access system insertion (Figure 1D), and inner guide removal (Figure 1G). Figures 1E and 1F show the inner guide and outer sheath, respectively. [Figure 1B] FIG. 10 shows the insertion of a wire. [Figure 1C] FIG. 10 illustrates needle removal. [Figure 1D] FIG. 1 illustrates the insertion of an arterial access system. [Figure 1E] FIG. 1E shows the inner guide and outer sheath. [Figure 1F] FIG. 1F shows the inner guide and outer sheath. [Figure 1G]FIG. 10 illustrates the removal of the inner guide. [Figure 2A] 2A-2C are schematic diagrams of an arterial access assembly (AAA) and arterial access method with a distal tip protection system (DTPS) according to one embodiment of the present invention. [Figure 2B] 1 is a schematic diagram of an arterial access assembly (AAA) and arterial access method with a distal tip protection system (DTPS) according to one embodiment of the present invention. [Figure 2C] 1 is a schematic diagram of an arterial access assembly (AAA) and arterial access method with a distal tip protection system (DTPS) according to one embodiment of the present invention. [Figure 3A] 3A-3D are schematic illustrations of an arterial access assembly (AAA) and arterial access method with a distal tip protection system (DTPS) according to another embodiment of the present invention. [Figure 3B] 1 is a schematic diagram of an arterial access assembly (AAA) and arterial access method with a distal tip protection system (DTPS) according to another embodiment of the present invention. [Figure 3C] 1 is a schematic diagram of an arterial access assembly (AAA) and arterial access method with a distal tip protection system (DTPS) according to another embodiment of the present invention. [Figure 3D] 1 is a schematic diagram of an arterial access assembly (AAA) and arterial access method with a distal tip protection system (DTPS) according to another embodiment of the present invention. [Figure 4A] 4A-4F are schematic diagrams illustrating a method of assembling an arterial access assembly (AAA) with a distal tip protection system (DTPS) to an aspiration catheter according to one embodiment of the present invention. [Figure 4B] 1A-1C are schematic diagrams illustrating a method of assembling an arterial access assembly (AAA) with a distal tip protection system (DTPS) to an aspiration catheter according to one embodiment of the present invention. [Figure 4C] 1A-1C are schematic diagrams illustrating a method of assembling an arterial access assembly (AAA) with a distal tip protection system (DTPS) to an aspiration catheter according to one embodiment of the present invention. [Figure 4D] 1A-1C are schematic diagrams illustrating a method of assembling an arterial access assembly (AAA) with a distal tip protection system (DTPS) to an aspiration catheter according to one embodiment of the present invention. [Figure 4E] 1A-1C are schematic diagrams illustrating a method of assembling an arterial access assembly (AAA) with a distal tip protection system (DTPS) to an aspiration catheter according to one embodiment of the present invention. [Figure 4F] 1 shows an assembly ring according to one embodiment of the present invention. [Figure 5] 1 is a flowchart illustrating steps for assembling an AAA at a treatment center according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Detailed Description reason The present inventors, having experience treating acute ischemic stroke, recognized that problems exist when introducing large diameter aspiration catheters into small arteries, such as the radial artery, using current arterial access devices. The invention described herein describes a method for effectively introducing larger diameter catheter systems into small arteries during the arterial access phase of an endovascular / neurointerventional procedure.

[0014] Scope of the term It should be noted that the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the terms "comprises" and / or "comprising," when used herein, are intended to specify the presence of stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, and / or components. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0015] Spatially relative terms such as "distal," "proximal," "anterior," "posterior," "below," "lower," "lower side," "upper," and the like may be used herein to facilitate describing the relationship of one element or feature to another, as shown in the figures. It will be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a feature in the figures is inverted, another element or feature described as being "below" or "below" the element or feature would instead be in the "above" orientation of the element or feature. Thus, the exemplary term "below" can encompass both an orientation of "up" and "below." Features may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be interpreted accordingly. Similarly, terms such as "upward," "downward," "vertical," "horizontal," and the like are intended to be used herein for descriptive purposes only, unless otherwise specified.

[0016] It will be understood that when an element is referred to as being "on" another element, "attached," "connected," "coupled," or "in contact" with another element, it may also be referred to as being "directly on" the other element and directly "attached," "connected," "coupled," or "in contact" with the other element. In contrast, for example, when an element is referred to as being "directly on" another element and "directly attached," "directly connected," "directly coupled," or "directly in contact" with the other element, there are no intervening elements present.

[0017] In this specification, terms such as "first," "second," etc. may be used to describe various elements, components, etc., but it will be understood that these elements, components, etc. are not limited by these terms. These terms are used only to distinguish one element, component, etc. from another element, component, etc. Thus, a "first" element or component discussed in this specification could also be referred to as a "second" element or component without departing from the teachings of the present invention. Furthermore, the order of operations (or steps) is not limited to the order described in the claims or drawings unless otherwise specified.

[0018] Additionally, except as otherwise described herein or expressly indicated, any numerical ranges, amounts, values, or percentages in the following specification and the appended claims, such as amounts of materials, element contents, times, temperatures, and ratios of quantities, can be read as if preceded by the word "about," even if the word "about" is not explicitly stated in connection with the value, amount, or range. Accordingly, the numerical parameters set forth in the following specification and the appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention, unless expressly indicated otherwise. At the very least, and without intending to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of at least the number of reported significant digits and by applying ordinary rounding techniques.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0020] Various aspects of the present invention will be described with reference to the drawings. Note that, for ease of explanation, the components illustrated in the drawings are not necessarily drawn to scale. In particular, the width and length directions may be distorted relative to one another in that width generally reflects the internal diameter of an artery (typically on the mm scale) and length generally reflects the length of the artery (typically on the cm+ scale). Thus, for clarity, the "length" scale is typically (but not necessarily) compressed relative to the width scale and / or indicates breaks in the length of the components. As such, emphasis is placed on highlighting the various contributions of the components to the function of various aspects of the present invention. In the course of this description, as many alternative features as possible will be introduced. It should be understood that, according to the knowledge and judgment of those skilled in the art, such alternative features may be substituted in various combinations to arrive at different embodiments of the present invention.

[0021] Systems and methods for introducing a catheter into a small artery are described with reference to the drawings, in which Figures 1A-1G illustrate known steps for accessing an artery and are provided for background purposes.

[0022] As shown in Figure 1A, in the first step, the artery is punctured using a hollow bore needle N. The needle has a typical outer diameter of approximately 1 mm and an inner diameter of approximately 0.5 mm.

[0023] 1B, a wire W is introduced into the needle so that it passes through the needle and exits the distal tip N1 of the needle. The wire has a diameter that allows it to pass through the needle.

[0024] The needle is then withdrawn over the wire, leaving the wire in place within the vessel and protruding through the vessel opening VO, as shown in FIG. 1C.

[0025] As shown in Figures 1D, 1E, and 1F, an arterial access system (AAS) is guided through the VO into a blood vessel via a wire. According to the prior art, an AAS typically includes an inner guide / introducer 20 having a sharp distal tip 22 and an outer sheath 30. Both the inner guide and outer sheath have known extracorporeal connectors 24, 32 that are connected at a junction 25 that allows the assembled AAS to be inserted together during insertion into the BV (blood vessel). The overall length of the inner guide 20 is typically in the range of 15 cm, and the overall length of the outer sheath 30 is typically about 12 cm.

[0026] After the AAS has been introduced as shown in FIG. 1D, the inner guide 20 and wire W are removed (FIG. 1G), thereby providing a conduit into the blood vessel via the outer sheath 30 that allows fluids and / or instruments to be introduced into the blood vessel via the AAS.

[0027] In accordance with the present invention, the inventors have recognized that larger diameter catheters, such as aspiration catheters (ACs) suitable for aspirating thrombi (blood clots) from cerebral arteries, are too large to be introduced into smaller blood vessels (radial or brachial arteries) through an outer sheath 30. That is, the outer sheath of a radial artery AAS has a substantial maximum inner diameter of about 6F (outer diameter (OD) of about 7.2F) to allow a 6F AC to pass through the outer sheath, but it is desirable to introduce an AC into cerebral blood vessels with an outer diameter larger than 6F (e.g., about 6-8F).

[0028] Therefore, there is a need for an arterial access assembly (AAA) that allows for the introduction of larger catheters, such as aspiration catheters (AC), into the radial artery. Although AAAs are described herein with reference to AC and cerebral access procedures, it is understood that different types of catheters for different procedures are contemplated.

[0029] As described in Applicant's co-pending applications, U.S. Provisional Application No. 62 / 878,652, filed July 25, 2019, U.S. Provisional Application No. 63 / 029,401, filed May 23, 2020, and International Patent Application No. PCT / CA2020 / 051026, filed July 24, 2020, are all incorporated herein by reference. The aspiration catheter design, operable from an arterial access point (e.g., the groin or radial artery), is characterized by a soft distal tip that is sufficiently flexible to remain atraumatic when navigating through cerebral arteries, flexible enough to negotiate tight curves, and capable of effectively aspirating thrombus. The tip is also radiopaque to allow visualization during navigation through cervical and intracranial vessels.

[0030] Importantly, to ensure that an AC is suitable for aspiration, it generally cannot have a tapered distal tip (i.e., a narrow wall thickness at the distal tip that tapers to a wider wall thickness proximally) because it requires some radial stiffness to prevent the distal tip from collapsing when the AC is aspirating the thrombus.

[0031] When an AAS is deployed through a VO, minimizing the risk of vessel wall damage is also important. For this reason, AAS are typically designed with an internal taper that allows for a smooth transition between the inner guide and outer sheath without significant edges at point 27, ensuring the device engages the vessel as it is pushed through the vessel (see Figure 1D). The lack of significant edges at the interface between the inner guide and outer sheath allows the outer sheath to be pushed through the VO while engaging the vessel wall without damaging it.

[0032] The inventors also recognized that it would be desirable to introduce an AC into the radial artery while it was supported internally by the inner guide 20, with the tapered tip 22 of the inner guide protruding from the end of the AC. However, the inventors recognized that the beveled shape of the AC's distal tip, the softness and flexibility of the AC's distal tip, the presence of radiopaque markers, and the lack of a distal taper make the transition between the inner guide 20 and the AC problematic. In other words, without the same stiffness as a comparable outer sheath (shown in FIG. 1F), the distal tip of an AC supported solely by the inner guide would tend to wrinkle or buckle against the inner guide when both were combined as an inner guide and an AC. This problem arises particularly when such an assembly is pushed only a few centimeters upstream through the vascular opening VO.

[0033] The inventors have recognized that in order for the soft distal tip of the AC to pass through the VO, the operator must push the AC upstream, e.g., toward the aortic arch, to protect a portion of the distal tip of the AC from passing through the first 0-15+ cm (approximately) of the vessel. Generally, internal support in the form of an introducer is not necessary after the first approximately 15 cm, as the artery becomes large enough that the AC tip is not rigidly engaged against the VW and can be pushed forward without internal support and without collapsing.

[0034] Therefore, in a first embodiment of the present invention, a system (referred to herein as an arterial access assembly (AAA)) is described that allows an AC to enter such a small artery via a VO, as shown in Figures 2A to 2C.

[0035] FIG. 2A shows the assembled AC and inner guide 40 (AAA) with the AC distal tip protection system (DTPS). The inner guide 40 is similar in design to the prior art inner guide 20 in that it has a tapered distal tip 40a and an inner bore through which a wire can pass. In contrast to conventional inner guides, the length of the inner guide 40 extends the entire length of the AC (or equals it), sufficient to protrude beyond the proximal end of the AC. FIGS. 2A-2C show the assembled AC / inner guide assembly (AAA) pushed a short distance through the VO into the internal zone (IC) of the vessel, as well as the extracorporeal zone (EC) where it can be manipulated.

[0036] More specifically, the inner guide 40 has a length sufficient to extend beyond and be operable from the proximal end of the AC, and the inner guide 40 includes a DTPS formed as part of the inner guide to protect the AC tip and prevent buckling when inserted into the artery via the VO.

[0037] 2A and 3A, in various embodiments, the DTPS includes biased or resilient multiple arms (FIG. 2A) or sheath (FIG. 3A) 42 configured adjacent to and / or forming part of the tapered surface 40a of the inner guide 40 to act as a protective sheath for the distal tip AC1 of the AC during the critical steps of pushing the distal tip AC1 of the AC through the skin (i.e., VO) and forward through the narrowest part of the blood vessel. The resilient arms / sheath 42, whether single arm or multiple arms, provides partial or full circumferential coverage for the distal tip AC1 of the AC.

[0038] The DTPS has a distal end 42a that is fixed to the inner guide 40 and a proximal end 42b that covers the distal tip AC1 of the AC. The DTPS extends proximally a sufficient distance to frictionally engage a sufficient length of the AC to prevent AC1 from separating or buckling relative to the inner guide 40.

[0039] As shown, the proximal end of the AC includes a stop AC3 that defines the proximal end of the AC. Similarly, inner guide 40 includes a proximal end stop 40b. End stop 40b and AC2 are separated by a small distance, indicated by "a" in FIGS. 2A and 3A. As can be seen, by manipulating both end stop 40b and AC2 relative to one another, the AC and inner guide 40 can be telescopically moved relative to one another.

[0040] As shown in FIG. 2B, end stop 40b and AC2 are moved toward one another a distance "b." As can be seen, this moves inner guide 40 distal to AC so that proximal edge 42b of resilient arm 42 is distal to AC. Distance b may be zero when end stop 40b and AC2 abut one another.

[0041] The inner guide 40 may include one or more recesses 42d in the inner guide 40 so that as the resilient arm ends 42b of the DTPS move beyond AC1, they are drawn into the recesses 42d (dotted lines) and become flush against the outer surface of the inner guide 40.

[0042] Thereafter, by moving the end stop 40b proximally by a length (indicated by c) longer than a relative to AC2, the inner guide 40 can be withdrawn from the AC, and the DTPS can enter the AC via AC1 (FIG. 2C).

[0043] The inner guide 40 can then be completely removed from the AC, allowing the AC to be introduced into the vessel to complete further steps of the procedure.

[0044] Typically, the AC / inner guide assembly (AAA) will be pushed forward a maximum distance of approximately 15 cm from the VO before performing the steps described above.

[0045] 3A-3D show another embodiment of the DTPS. In this embodiment, the DTPS is a resiliently flexible "umbrella" 42 attached at point 44 to the tapered surface 40a of the inner guide 40. Initially, at the start of surgery, the umbrella 42 extends above AC1 a distance X sufficient to frictionally hold the umbrella 30 on AC1. The umbrella may be made of a resilient material.

[0046] In this embodiment, after the AC / inner guide assembly is inserted into the blood vessel, the inner guide 40 is removed using steps similar to those described above. That is, the inner guide is first pushed distally to push the umbrella past AC1 so that AC1 is uncovered (FIG. 3B). Depending on the umbrella design, the umbrella can resiliently contract (as indicated by the facing arrows in FIG. 3B) over the inner guide to lie flush with the inner guide 40 within an appropriate recess 40e on the inner guide 40, as shown in FIG. 3B.

[0047] In other embodiments, the umbrella 30 can be "flipped" relative to the inner guide 40 as it is subsequently pulled out, as shown in Figures 3C and 3D. Figure 3C shows the umbrella beginning to be inverted, and Figure 3D shows the umbrella being inverted and being pulled out AC. The umbrella inversion occurs when the inner guide 40 is Department Guide This may be done by pushing the forward to disengage the umbrella from the AC, or by simply pulling back on the AC.

[0048] This allows the inner guide to then be fully withdrawn, as described above.

[0049] assembly The arterial access assemblies described above may be assembled at a factory or may be assembled at a treatment center immediately prior to use.

[0050] When assembled at a factory, the inner guide may be packaged together with a kit containing various catheters. Typically, the inner guide and catheter with the DTPS are manufactured with appropriate inner and outer diameters to engage with each other, and then the two components are assembled so that the DTPS properly engages the distal end of the catheter. After assembly and sterilization, the AAA is packaged in a single package for delivery and subsequent use at the treatment facility.

[0051] As will be appreciated by those skilled in the art, various catheter and inner guide combinations can be assembled based on the characteristics of the particular catheter and its diameter.

[0052] For example, a factory assembled kit may include any of the 6-8F ACs with specific functional characteristics for endovascular neurosurgery configured into an appropriately sized internal guide.

[0053] In practice, it may not be commercially feasible for an internal guide manufacturer to assemble an internal guide with a wider range of catheters, as a physician may prefer to use a particular brand of catheter. As a result, it is desirable to assemble the internal guide with the physician-selected catheter at the treatment center.

[0054] As shown in Figures 4A-4F and 5, a system and method for assembling an inner guide 40 with an AC is described.

[0055] According to one embodiment, the contents are manufactured and packaged in a sterile package through the following steps: Department Guide 40 (referred to as package A) can be assembled with a catheter (AC) from another manufacturer (referred to as package B) that has been packaged and sterilized in a separate package.

[0056] From one supplier / manufacturer, Department Guide Package A containing 40 and ring 50 is selected. Department GuideThe ring 40 has the indicated outer diameter (OD) and length. Department Guide an inside diameter (ID) substantially corresponding to the OD of the Department Guide You can slide on it.

[0057] Package B is selected, which contains catheters of known OD, ID and length. The catheters may be from other suppliers / manufacturers.

[0058] Package A Department Guide 40 has a length greater than the length of the catheter in package B. Package A may further include a wire.

[0059] Open the two packages and Department Guide The distal end of 40 is inserted into the proximal end of the catheter through the proximal end of the catheter until it extends from the distal end of the catheter. Inside Department Guide The DTPS 42 of 40 is pushed past the distal end of the catheter AC1 a sufficient distance to allow the ring to be positioned over and proximal to the DTPS.

[0060] As shown in FIG. 4A, the ring 50 has an inner Department Guide After the distal tip of 40 is slid and positioned proximally of the DTPS, it is moved distally so that the distal edge 50a acts under the proximal edge 42b of the DTPS. Another edge lifting device (e.g., a non-traumatic spatula, not shown) is utilized to lift the inner ring so that the proximal edge 42b completely surrounds the distal edge 50a of the ring, as shown in FIG. 4B. Department Guide May assist with lifting DTPS from 40.

[0061] As shown in Figures 4C, 4D and 4F, the ring 50 is resiliently expandable or openable, with at least a portion having a flexible or openable joint 50b that allows for expansion or opening of the OD of the ring. Preferably, the ring 50 is provided with a flange 50c that allows a user to grip and / or apply pressure to the link.

[0062] As shown in Figure 4C, the DTPS is expanded onto the AC by pushing the catheter AC forward, manipulating flange 50c to open ring 50, and inserting the AC into ring 50. The AC is pushed forward far enough so that the DTPS overlaps the AC and frictionally engages the distal tip of the DTPS. Next, as shown in Figure 4D, the ring is pulled back from the DTPS, engaging the DTPS onto the AC and disengaging it from the DTPS.

[0063] The ring is then removed from the assembly by opening it and pushing it forward onto the AC and DTPS, as shown in Figure 4F. The ring can also be opened at one or more joints 50b to allow removal.

[0064] After the above surgery, the AC and internal Department Guide can be introduced into the artery. Inside Department Guide Sterilization of DTPS is an important consideration. Therefore, it is desirable to manufacture DTPS from a material that can be adequately sterilized prior to packaging. Expanded polytetrafluoroethylene (EPTFE) can have sufficient porosity to allow sterilizing gases, such as ethylene oxide, to fully and adequately penetrate the structure for sterilization.

[0065] While the present invention has been described and illustrated with reference to preferred embodiments thereof and preferred examples of its use, it is not limited thereto, and modifications and variations can be made herein within the full and intended scope of the invention, as will be understood by those skilled in the art.

Claims

1. 1. A system for introducing a catheter into the vascular system via a vascular opening (VO), comprising: a catheter having an inner lumen diameter; an inner guide sized for telescopic movement within the lumen of the catheter; the inner guide having a tapered distal tip; a protective cover coupled to the tapered distal tip and expandable to engage the distal tip of the catheter; the protective cover is movable between an engaged position and a disengaged position on the catheter; The system wherein the internal guide is selectively moved relative to the catheter to move the protective cover from the engaged position to the disengaged position, wherein in the disengaged position the internal guide and the protective cover are within the lumen of the catheter.

2. The protective cover is a plurality of inwardly biased arms, The system of claim 1 , wherein the inner guide has a corresponding recess for receiving the arm in a compressed position.

3. The system of claim 1 , wherein the protective covering is an elastic sheath that circumferentially covers the distal tip of the catheter in the engaged position.

4. The system of claim 3 , wherein the elastic sheath abuts the inner guide in the disengaged position.

5. The system of claim 3 , wherein the elastic sheath flips to the disengaged position during withdrawal of the inner guide.

6. the catheter having a catheter end stop; the inner guide has an inner guide end stop; A system according to any one of claims 1 to 5, wherein when the protective cover is in the engaged position, movement of the inner guide end stop towards the catheter end stop moves the protective cover to the disengaged position.

7. 7. The system of claim 1, wherein the catheter is an aspiration catheter having a soft distal tip region and a length sufficient to extend from the radial artery VO to a cerebral vessel for the treatment of ischemic stroke.

8. The system of claim 7, wherein the suction catheter is 5-8F.

9. The system of claim 7, wherein the suction catheter is 6-8F.

10. The system of any one of claims 1 to 9, wherein the inner guide is hollow and the tapered distal tip includes a through bore that allows the inner guide to pass over a wire.

11. The system of any one of claims 3 to 5, further comprising an expandable ring having an inner diameter expandable between the outer diameter of the inner guide and the outer diameter of the catheter, and having a distal edge with a thickness that is positioned below the proximal edge of the elastic sheath when the elastic sheath is assembled to the catheter.

12. The system of claim 11 , wherein the expandable ring is openable and closable.

13. an inner guide in a sterile package, the inner guide being sized for telescopic movement within the lumen of the catheter; the inner guide having a tapered distal tip; a protective cover coupled to the tapered distal tip and expandable to engage the distal tip of the catheter, the protective cover being movable between an engaged position and a disengaged position on the catheter; The kit wherein the internal guide is selectively movable relative to the catheter to move the protective cover from the engaged position to the disengaged position, wherein in the disengaged position the internal guide and the protective cover are within the lumen of the catheter.

14. 14. The kit of claim 13, further comprising the catheter, wherein the inner guide and catheter are packaged in the same sterile package.

15. 14. The kit of claim 13, further comprising the catheter, wherein the catheter and the inner guide are in separate packages comprising a catheter package and an inner guide package.

16. 16. The kit of claim 15, further comprising an expandable ring within the inner guide package having an inner diameter expandable between an outer diameter of the inner guide and an outer diameter of the catheter, and having a distal edge with a thickness that is positioned under a proximal edge of the protective cover when the protective cover is assembled to the catheter.

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