Sheath configured for vascular access

Abstract

Systems and methods are configured to access an artery, such as a carotid artery. The system includes a sheath stop positioned on an exterior of a distal section of an artery access sheath such that a portion of the distal section of the sheath is covered by the sheath stop and a portion of the distal section of the sheath is exposed. The sheath stopper is configured to limit insertion of the sheath into the artery to the exposed portion, wherein a length of the exposed portion is adjustable.

Description

Cross - Reference to Related Applications

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 63 / 408,549, filed on September 21, 2022, and entitled "Occlusive Sheath Configured for Percutaneous Vascular Access", the entire content of which is incorporated herein by reference. Background Art

[0002] The present invention generally relates to medical methods and devices. More particularly, the present invention relates to methods, systems, and devices for accessing and treating arterial vascular systems, such as the carotid vascular system, and optionally establishing retrograde flow during the performance of carotid stenting and other procedures.

[0003] The present invention also relates to methods and systems for accessing and treating the cerebral arterial vascular system, such as for treating stroke, intracranial atherosclerotic disease (ICAD), transient ischemic attack (TIA), acute ischemic stroke (AIS), tandem lesions, embolization of ruptured and unruptured intracranial and extracranial aneurysms, chronic occlusion, and other diseases of the vascular system. Summary of the Invention

[0004] Disclosed herein are methods, devices, and systems that can optionally establish and promote retrograde or reverse blood circulation in the carotid bifurcation region, such as to limit or prevent the release of emboli into the cerebrovascular system, particularly into the internal carotid artery. The carotid artery can be accessed from various access locations, including via the neck region (such as directly into the carotid artery) or via another region (such as in the region of the femoral artery).

[0005] In one aspect, a system for accessing an artery is disclosed, the system including a sheath stopper positioned externally on a distal segment of an arterial access sheath such that a portion of the distal segment of the sheath is covered by the sheath stopper and a portion of the distal segment of the sheath is exposed, wherein the sheath stopper is configured to limit insertion of the sheath into the artery to the exposed portion, and wherein the length of the exposed portion is adjustable.

[0006] Other aspects, features, and advantages should become apparent from the following description of various embodiments, which illustrate the principles of the invention by way of example. Brief Description of the Drawings

[0007] Figure 1A is a schematic diagram of a retrograde blood flow system, which includes a flow control component, wherein an arterial access device accesses the common carotid artery via a transcarotid approach, and a venous return device communicates with the internal jugular vein;

[0008] Figure 1BSchematic diagram of a retrograde blood flow system, where an arterial access device enters the common carotid artery via a transcarotid approach, and a venous return device is in communication with the femoral vein;

[0009] Figure 1C Schematic diagram of a retrograde blood flow system, where an arterial access device enters the common carotid artery via a transfemoral approach, and a venous return device is in communication with the femoral vein;

[0010] Figure 1D Schematic diagram of a retrograde blood flow system, where retrograde flow is collected in an external container;

[0011] Figure 2A Magnified view of the carotid artery, where the carotid artery is occluded with an occlusion element on a sheath and connected to a reverse blood flow diverter, and an intervention device, such as a stent delivery system or other working catheter, is introduced into the carotid artery via the arterial access device;

[0012] Figure 2B Alternative system, where the carotid artery is occluded with a separate external occlusion device and connected to a reverse blood flow diverter, and an intervention device, such as a stent delivery system or other working catheter, is introduced into the carotid artery via the arterial access device;

[0013] Figure 3 Alternative system, where the carotid artery is connected to a reverse flow diverter, and an intervention device, such as a stent delivery system or other working catheter, is introduced into the carotid artery via the arterial access device, and the carotid artery is occluded with a separate occlusion device;

[0014] Figure 4 Shows a normal cerebral circulation diagram including the Circle of Willis;

[0015] Figure 5 Shows the vascular system of a patient's neck, including the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA), and internal jugular vein (IJV);

[0016] Figure 6A Shows an arterial access device that can be used in the methods and systems of the present invention;

[0017] Figure 6B Shows the configuration of an additional arterial access device with a reduced-diameter distal end;

[0018] Figure 7A and Figure 7B Shows a tube that can be used with the Figure 6A sheath;

[0019] Figure 7C Shows an embodiment of a sheath stopper;

[0020] Figure 7Dshows a sheath stopper positioned on the sheath; Figure 7C of the sheath;

[0021] Figure 8A shows the configuration of an additional arterial access device having an expandable occlusion element;

[0022] Figure 8B shows the configuration of an additional arterial access device having an expandable occlusion element and a distal end with a reduced diameter;

[0023] Figure 9A and Figure 9B shows an additional embodiment of the arterial access device;

[0024] Figure 9C and Figure 9D shows an embodiment of a valve on the arterial access device;

[0025] Figures 10A to 10C and Figure 11 shows an embodiment of a venous return device for use in the methods and systems of the present invention;

[0026] Figure 12 shows the system of FIG. 1 including a flow control assembly;

[0027] Figures 13 to 14 shows an embodiment of a variable flow resistance component for use in the methods and systems of the present invention;

[0028] Figures 15 to 18 shows another embodiment of the sheath stopper;

[0029] Figure 19 and Figure 20 shows another embodiment of the sheath stopper;

[0030] Figure 21 shows another embodiment of the sheath stopper;

[0031] Figure 22 and Figure 23 shows another embodiment of the sheath stopper;

[0032] Figure 24 and Figure 25 shows another embodiment of the sheath stopper;

[0033] Figure 26 and Figure 27 shows another embodiment of the sheath stopper. DETAILED DESCRIPTION

[0034] The disclosed methods, devices, and systems can optionally establish and promote retrograde or reverse blood flow circulation in the carotid bifurcation region to limit or prevent the release of emboli into the cerebrovascular system, particularly into the internal carotid artery. In non-limiting examples, the methods can be used in interventional procedures such as stenting and angioplasty, atherectomy, which are performed using open surgical techniques or using percutaneous techniques such as the modified Seldinger technique or micro-puncture technique via a carotid approach, a femoral approach, or other approaches to an artery such as the common carotid artery.

[0035] Access to the common carotid artery (such as Figure 5 shown) is established by placing an access sheath or other tubular access cannula into the arterial lumen, which typically positions the distal end of the sheath proximal to the intersection or bifurcation B of the common carotid artery to the internal and external carotid arteries. The percutaneous version of the sheath may have an occlusion member at the distal end, for example, a compliant occlusion balloon. A catheter or wire with an occlusion member such as a balloon can be placed through the access sheath and positioned in the proximal external carotid artery ECA to inhibit the entry of emboli, but without the need to occlude the external carotid artery. A second return sheath is placed in the venous system, such as the internal jugular vein IJV or the femoral vein FV. The arterial access and the venous return sheath are connected to create an external arteriovenous shunt.

[0036] Retrograde flow is established and adjusted to meet the patient's requirements. For example, the blood flow through the common carotid artery is occluded using an external vascular loop or tape, a vascular clamp, an internal occlusion member such as a balloon, or other types of occlusion devices. When the flow through the common carotid artery is blocked, the natural pressure gradient between the internal carotid artery and the venous system causes blood to flow retrograde or in reverse from the cerebrovascular system, through the internal carotid artery and through the shunt into the venous system.

[0037] Alternatively, the venous sheath can be eliminated and the arterial sheath can be connected to an external collection reservoir or container. The reverse blood flow can be collected in this container. If needed, the collected blood flow is filtered and then returned to the patient during or at the end of the procedure. The pressure of the container can be open to atmospheric pressure, which causes a pressure gradient for the blood to flow in reverse from the cerebrovascular system to the container, or the pressure of the container can be negative.

[0038] Optionally, to achieve or enhance the reverse flow from the internal carotid artery, the flow from the external carotid artery can be blocked, which is typically done by deploying a balloon or other occlusion element in the external carotid artery just above (i.e., distal to) the bifurcation within the internal carotid artery.

[0039] Although the procedures and protocols described below are sometimes discussed in relation to carotid artery stenting, it should be understood that the methods for accessing the carotid artery described herein can also be used for angioplasty, endarterectomy, and any other interventional procedures that may be performed in the carotid artery system (or other arterial locations), such as at locations near the bifurcation between the internal carotid artery and the external carotid artery. In addition, it should be understood that some of these access, vascular closure, and embolic protection methods will be applicable to other vascular interventional procedures, such as the treatment of acute stroke.

[0040] The present invention includes a number of specific aspects for improving the performance of carotid artery access protocols. At least some of these individual aspects and improvements can be performed alone or in combination with one or more of the improvements in order to facilitate and enhance the performance of a particular intervention in the carotid artery system.

[0041] Figure 1A A first embodiment of a retrograde flow system 100 is shown that is adapted to establish and promote retrograde or reverse flow blood circulation in the carotid artery bifurcation region in order to limit or prevent the release of emboli into the cerebrovascular system, particularly into the internal carotid artery. The system 100 interacts with the carotid artery to provide retrograde flow from the carotid artery to a venous return site, such as the internal jugular vein (or to another return site, such as another large vein or an external container in an alternative embodiment). The retrograde flow system 100 includes an arterial access device 110, a venous return device 115, and a diverter 120 that provides a pathway for retrograde flow from the arterial access device 110 to the venous return device 115. A flow control assembly 125 interacts with the diverter 120. The flow control assembly 125 is adapted to regulate and / or monitor retrograde flow from the common carotid artery to the internal jugular vein, as described in more detail below. The flow control assembly 125 interacts with the flow path through the diverter 120, which can be external to the flow path, within the flow path, or both. The arterial access device 110 is at least partially inserted into the common carotid artery CCA, and the venous return device 115 is at least partially inserted into a venous return location, such as the internal jugular vein IJV, as described in more detail below. The arterial access device 110 and the venous return device 115 are coupled to the diverter 120 at connection locations 127a and 127b. When flow through the common carotid artery is obstructed, the natural pressure gradient between the internal carotid artery and the venous system causes blood to flow from the cerebrovascular system in a retrograde or reverse direction RG ( Figure 2A ) through the internal carotid artery and the diverter 120 into the venous system. The flow control assembly 125 regulates, enhances, assists, monitors, and / or otherwise modulates the retrograde blood flow.

[0042] In Figure 1AIn an embodiment, the arterial access device 110 enters the common carotid artery CCA via a transcarotid approach. The transcarotid access provides a short and non-tortuous path from the vascular access point to the target treatment location, thereby reducing the time and difficulty of the procedure, e.g., as compared to a transfemoral approach. In one embodiment, the arterial distance (measured through the artery) from the arteriotomy to the target treatment location is 15 cm or less. In one embodiment, the distance is between 5 and 10 centimeters. Additionally, this access route reduces the risk of generating emboli due to navigating in diseased, angulated, or tortuous aortic arch or common carotid artery anatomies. At least a portion of the venous return device 115 is placed in the internal jugular vein IJV. In one embodiment, the transcarotid access to the common carotid artery is percutaneous via an incision or puncture in the skin, and the arterial access device 110 is inserted through the incision or puncture. If an incision is used, the length of the incision can be, e.g., approximately 0.5 cm. An occlusion element 129, such as an expandable balloon, can be used to occlude the common carotid artery CCA at a location proximal to the distal end of the arterial access device 110. The occlusion element 129 can be located on the arterial access device 110 or it can be located on a separate device. In an alternative embodiment, the arterial access device 110 enters the common carotid artery CCA via a direct surgical transcarotid approach. In the surgical approach, a tourniquet 2105 can be used to occlude the common carotid artery. The tourniquet 2105 is shown in dashed lines to indicate that it is a device for an optional surgical approach.

[0043] In another embodiment, as Figure 1B shown, the arterial access device 110 enters the common carotid artery CCA via a transcarotid approach, while the venous return device 115 enters a venous return location other than the jugular vein, such as a venous return location consisting of the femoral vein FV. The venous return device 115 can be inserted percutaneously into a central vein, such as the femoral vein FV, via a puncture in the groin.

[0044] In another embodiment, as Figure 1C shown, the arterial access device 110 enters the common carotid artery via a transfemoral approach. According to the transfemoral approach, the arterial access device 110 enters the CCA via the femoral artery FA, such as via a percutaneous puncture in the groin, and travels up along the aortic arch AA to the target common carotid artery CCA. The venous return device 115 can communicate with the jugular vein JV or the femoral vein FV.

[0045] Figure 1DAnother embodiment is shown where the system provides retrograde flow from the carotid artery to an external container 130 instead of to a venous return location. The arterial access device 110 is connected to the container 130 via a diverter 120 which communicates with a flow control assembly 125. The retrograde flow of blood is collected in the container 130. If desired, the blood can be filtered and then returned to the patient. The pressure in the container 130 can be set to zero pressure (atmospheric) or even lower, causing blood to flow from the cerebrovascular system in a reverse direction to the container 130. Optionally, to achieve or enhance the reverse flow from the internal carotid artery, the flow from the external carotid artery can be occluded, typically by deploying a balloon or other occlusive element in the external carotid artery just above the bifurcation within the internal carotid artery. Figure 1D The arterial access device 110 arranged in the carotid approach together with the CCA is shown, however it should be understood that the external container 130 can also be used with the arterial access device 110 in a femoral approach.

[0046] Reference Figure 2A In the enlarged view of the middle carotid artery, a treatment or intervention device, such as a stent delivery system 135 or other working catheter, can be introduced into the carotid artery via the arterial access device 110 or a percutaneous sheath, as described in detail below. The stent delivery system 135 can be used to treat plaque P, such as deploying a stent into the carotid artery. Figure 2A The arrow RG in shows the direction of retrograde flow. As Figure 2B shown, in an alternative embodiment, a clamp element is used to occlude the artery.

[0047] Figure 3 An alternative embodiment is shown where an occlusive element 129 can be introduced into the carotid artery on a second sheath 112 which is separated from the distal sheath 605 of the arterial access device 110. The second or "proximal" sheath 112 can be adapted to be inserted into the common carotid artery in a proximal or "downward" direction away from the cerebrovascular system. The second proximal sheath can include an inflatable balloon 129 or other occlusive element, generally as described above. The distal sheath 605 of the arterial access device 110 can then be placed in the common carotid artery distal to the second proximal sheath and is generally oriented in a distal direction towards the cerebrovascular system. By using separate occlusive and access sheaths, the size of the arteriotomy required to introduce the access sheath can be reduced. Anatomical description Collateral Cerebral Circulation

[0048] The Willis circle CW is the main arterial anastomotic trunk of the brain, where all the major arteries supplying the brain, namely the two internal carotid arteries (ICA) and the vertebrobasilar system, are connected. Blood is transported from the Willis circle to the brain by the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery. This connection between the arteries enables collateral circulation through the brain. It allows blood to flow through alternative routes, providing a safety mechanism in the event of blockage of one or more blood vessels supplying the brain. In most cases, even when an obstruction occurs somewhere in the arterial system (e.g., when the ICA is ligated, as described herein), the brain can continue to receive an adequate blood supply. Blood flowing through the Willis circle ensures adequate cerebral blood flow by redistributing blood to multiple pathways on the deprived side.

[0049] It is believed that the collateral potential of the Willis circle depends on the presence and size of its component blood vessels. It should be understood that there can be considerable anatomical differences between individuals in these blood vessels, and many of the blood vessels involved may be diseased. For example, some people are missing one of the communicating arteries. If an obstruction occurs in these people, collateral circulation will be impaired, leading to ischemic events and potential brain damage. In addition, the autoregulatory response to decreased perfusion pressure may include the dilation of collateral arteries in the Willis circle, such as the communicating arteries. This compensatory mechanism occasionally requires a regulatory time before collateral circulation can reach a level to support normal function. This autoregulatory response can occur within a space of 15 to 30 seconds and can only compensate within a certain range of pressure and flow decreases. Therefore, transient ischemic attacks may occur during the regulation period. Very high retrograde flow rates over an extended period can lead to a condition where the patient's brain does not receive adequate blood flow, resulting in patient intolerance, manifested as neurological symptoms or in some cases as transient ischemic attacks.

[0050] Figure 4 The normal cerebral circulation and formation of the Willis circle CW are depicted. The aorta AO gives rise to the brachiocephalic artery BCA, which branches into the left common carotid artery LCCA and the left subclavian artery LSCA. The aorta AO further gives rise to the right common carotid artery RCCA and the right subclavian artery RSCA. The left and right common carotid arteries CCA give rise to the internal carotid arteries ICA, which branch into the middle cerebral artery MCA, the posterior communicating artery PcoA, and the anterior cerebral artery ACA. The anterior cerebral artery ACA transports blood to some parts of the frontal lobe and striatum. The middle cerebral artery MCA is a major artery with dendritic branches that carry blood to the entire lateral view of each hemisphere of the brain. The left and right posterior cerebral arteries PCA originate from the basilar artery BA and transport blood to the posterior part of the brain (occipital lobe).

[0051] In the anterior portion, the circle of Willis is formed by the anterior cerebral artery (ACA) and the anterior communicating artery (ACoA) that connects the two ACAs. Two posterior communicating arteries (PCoA) connect the circle of Willis to the two posterior cerebral arteries (PCA), which branch from the basilar artery (BA) and complete the circle in the posterior portion.

[0052] The common carotid artery (CCA) also gives rise to the external carotid artery (ECA), which branches extensively to supply most of the structures of the head, except for the brain and orbital contents. The ECA also contributes to the supply of structures in the neck and face. Carotid Bifurcation

[0053] Figure 5 An enlarged view of the relevant vascular system in the patient's neck is shown. The common carotid artery (CCA) bifurcates at the bifurcation (B) into the internal carotid artery (ICA) and the external carotid artery (ECA). The bifurcation is approximately at the level of the fourth cervical vertebra. Figure 5 A plaque (P) formed at the bifurcation (B) is shown.

[0054] As discussed above, the arterial access device 110 can enter the common carotid artery (CCA) via a transcarotid approach. According to the transcarotid approach, the arterial access device 110 is inserted into the common carotid artery (CCA) at the arterial access location (L), which can be, for example, a surgical incision or a puncture in the wall of the common carotid artery (CCA). The distance (D) between the arterial access location (L) and the bifurcation (B) is typically about 5 to 7 cm. When the arterial access device 110 is inserted into the common carotid artery (CCA), it is not desirable to have the distal tip of the arterial access device 110 contact the bifurcation (B), as this may disrupt the plaque (P) and cause the generation of embolic particles. To minimize the likelihood of the arterial access device 110 contacting the bifurcation (B), in one embodiment, only about 2 - 4 cm of the distal region of the arterial access device is inserted into the common carotid artery (CCA) during the surgery.

[0055] Each side of the common carotid artery is wrapped in a layer of fascia called the carotid sheath. The sheath also encloses the internal jugular vein and the vagus nerve. The anterior part of the sheath is the sternocleidomastoid muscle. Transcarotid access to the common carotid artery and the internal jugular vein, whether percutaneous or surgical, can be carefully performed immediately above the clavicle, between the two heads of the sternocleidomastoid muscle, and through the carotid sheath to avoid the vagus nerve.

[0056] At the upper end of the sheath, the common carotid artery bifurcates into the internal carotid artery and the external carotid artery. The internal carotid artery continues upward without branching until it enters the skull to supply blood to the retina and the brain. The external carotid artery branches to supply blood to the scalp, face, eyes, and other superficial structures. Several facial and cranial nerves are intertwined in front of and behind the artery. Additional neck muscles may also cover the bifurcation. During carotid endarterectomy, these nerve and muscle structures can be dissected and pushed aside to access the carotid bifurcation. In some cases, the carotid bifurcation is closer to the level of the mandible, where access is more challenging and there is less space available to separate it from the various nerves that should be preserved. In these cases, the risk of accidental nerve injury may increase, and open artery endarterectomy may not be a good option. Retrograde blood flow system

[0057] As discussed, the retrograde flow system 100 includes an arterial access device 110, a venous return device 115, and a shunt 120 that provides a pathway for retrograde flow from the arterial access device 110 to the venous return device 115. The system also includes a flow control assembly 125 that interacts with the shunt 120 to regulate and / or monitor the retrograde blood flow through the shunt 120. Exemplary embodiments of the components of the retrograde flow system 100 are now described. Artery Access Device

[0058] Figure 6A An exemplary embodiment of the arterial access device 110 is shown and includes a distal sheath 605, a proximal extension 610, a streamline 615, an adapter or Y-connector 620, and a hemostatic valve 625. The arterial access device may also include a dilator 645 with a tapered tip 650 and an introducer guidewire 611. The arterial access device is used with the dilator and the introducer guidewire to access a blood vessel. The features of the arterial access device may be optimized for transcarotid access. For example, the design of the access device components can be optimized to limit potential damage to the blood vessel due to acute angle insertion, allow non-invasive and safe sheath insertion, and limit the length of the sheath, sheath dilator, and introducer guidewire inserted into the blood vessel. The arterial access device 110 may include or incorporate any embodiment of the percutaneous sheath described herein.

[0059] The distal sheath 605 is adapted to be introduced through an incision or puncture in the wall of the common carotid artery, which can be an open surgical incision or a percutaneous puncture established, for example, using the Seldinger technique. The length of the sheath can be in the range of 5 to 15 cm, such as 10 cm to 12 cm. The inner diameter can vary and can be in the range of 7 Fr (1 Fr = 0.33 mm) to 10 Fr, for example 8 Fr. Especially when the sheath is introduced through a transcarotid approach, above the clavicle but below the carotid bifurcation, the sheath 605 can be highly flexible while maintaining hoop strength to resist kinking and buckling. Thus, the distal sheath 605 can be circumferentially reinforced, such as by a braid, coils (such as a helical band, helix), cut tubing, etc., and has a liner such that the reinforcing structure is sandwiched between an outer jacket layer and the liner. The liner can be a low-friction material, such as PTFE. The outer jacket can be one or more of a group of materials including Pebax, thermoplastic polyurethane, or nylon. In one embodiment, the reinforcing structure or material and / or the outer jacket material or thickness can vary along the length of the sheath 605 to vary the flexibility along the length. In an alternative embodiment, the distal sheath is adapted to be introduced through a percutaneous puncture into the femoral artery, such as in the groin, and up along the aortic arch AA into the target common carotid artery CCA.

[0060] The distal sheath 605 can have a stepped or other configuration having a distal region 630 with a reduced diameter, as Figure 6B shown, which shows an enlarged view of the distal region 630 of the sheath 605. The dimensions of the distal region 630 of the sheath can be sized to be inserted into the carotid artery, which typically has an inner diameter in the range of 2.16 mm (0.085 inches) to 2.92 mm (0.115 inches), where the remaining proximal region of the sheath has a larger outer diameter and lumen diameter, where the inner diameter is typically in the range of 2.794 mm (0.110 inches) to 3.43 mm (0.135 inches). The larger lumen diameter of the proximal region minimizes the overall flow resistance of the sheath. In one embodiment, the distal section 630 with the reduced diameter has a length of approximately 2 cm to 4 cm. The relatively short length of the distal section 630 with the reduced diameter allows this section to be positioned in the common carotid artery CCA via a transcarotid approach, where the risk that the distal end of the sheath 605 will contact the bifurcation B is reduced. Additionally, the section 630 with the reduced diameter also allows for a reduction in the size of the arteriotomy used to introduce the sheath 605 into the artery while having a minimal impact on the flow resistance level. Additionally, the distal section with the reduced diameter can be more flexible and thus more conformable to the lumen of the blood vessel.

[0061] Referring again to Figure 6A, the proximal extension 610 of the elongate body has a lumen that abuts the lumen of the sheath 605. The lumen can be joined by a Y-connector 620 that also joins the lumen of the flow line 615 to the sheath. In the assembled system, the flow line 615 is connected to the retrograde diverter 120 (FIG. 1) and forms its first leg. The proximal extension 610 can have a length sufficient to space the hemostatic valve 625 away from the Y-connector 620 adjacent the percutaneous or surgical insertion site. By spacing the hemostatic valve 625 away from the percutaneous insertion site, the physician can introduce a stent delivery system or other working catheter into the proximal extension 610 and sheath 605 while remaining outside the fluoroscopy field during fluoroscopy. In one embodiment, the distance from the most distal intersection of the proximal extension with the sheath 605 (such as at the hemostatic valve) to the proximal end of the proximal extension is about 16.9 cm. In one embodiment, the proximal extension has an inner diameter of 0.125 inches and an outer diameter of 0.175 inches. In one embodiment, the proximal extension has a wall thickness of 0.025 inches. The inner diameter can range, for example, from 0.60 inches to 0.150 inches, where the wall thickness is from 0.010 inches to 0.050 inches. In another embodiment, the inner diameter can range, for example, from 0.150 inches to 0.250 inches, where the wall thickness is from 0.025 inches to 0.100 inches. The dimensions of the proximal extension can vary. In one embodiment, the proximal extension has a length in the range of about 12 - 20 cm. In another embodiment, the proximal extension has a length in the range of about 20 - 30 cm.

[0062] In one embodiment, the distance along the sheath from the hemostatic valve 625 to the distal tip of the sheath 605 is in the range of about 25 to 40 cm. In one embodiment, the distance is in the range of about 30 to 35 cm. In a system configuration that allows a 2.5 cm sheath to be introduced into an artery and the arterial distance from the arteriotomy site to the target site is between 5 and 10 cm, the system provides a distance from the hemostatic valve 625 (the location of the interventional device introduced into the sheath) to the target site in the range of about 32.5 cm to 42.5 cm, between 32 and 43 cm. This distance is about one-third of the distance required by the prior art.

[0063] The flush line 635 can be connected to the side of the hemostatic valve 625 and can have a stopcock 640 at its proximal or distal end. The flush line 635 can allow the introduction of saline, contrast fluid, etc. during the procedure. The flush line 635 can also allow pressure monitoring during the procedure. A dilator 645 with a tapered distal end 650 can be provided to facilitate introduction of the distal sheath 605 into the common carotid artery. The dilator 645 can be introduced through the hemostatic valve 625 such that the tapered distal end 650 extends through the distal end of the sheath 605, as in Figure 7ABest shown in. The dilator 645 may have a central lumen to accommodate a guide wire. Typically, the guide wire is first placed in the blood vessel, and the dilator / sheath combination is advanced over the guide wire as it is introduced into the blood vessel.

[0064] A sheath stopper 705, such as in the form of a tube, may be provided that is coaxially received over the exterior of the distal sheath 605, also as Figure 7A shown in. The sheath stopper 705 is configured to act as a stop to prevent the sheath from being inserted too deeply into the blood vessel or from being inserted into the blood vessel beyond a desired depth. Additional embodiments are described below that are configured to allow a user to selectively adjust the depth of insertion of the sheath into the blood vessel using the sheath stopper. The sheath stopper 705 is sized and shaped to be positioned on the sheath body 605 such that it covers a portion of the sheath body 605 and exposes the distal portion of the sheath body 605. The sheath stopper 705 may have a distal end 715 and a flared proximal end 710 that mates with the adapter 620. Optionally, the distal end 715 may be beveled, as Figure 7B shown in. The sheath stopper 705 may be used for at least two purposes. First, the length of the sheath stopper 705 limits the introduction of the sheath 605 to the exposed distal portion of the sheath 605, as Figure 7AAs shown, the insertion length of the sheath is limited to the exposed distal portion of the sheath. In one embodiment, the sheath stopper limits the exposed distal portion to a range between 2 and 3 cm. In one embodiment, the sheath stopper limits the exposed distal portion to 2.5 cm. In other words, the sheath stopper can limit the insertion of the sheath into the artery to a range between about 2 and 3 cm or to 2.5 cm. Secondly, the sheath stopper 705 can engage a pre-deployed puncture closure device (if any) disposed in the carotid artery wall to allow the sheath 605 to be withdrawn without removing the closure device. The sheath stopper 705 can be made of a transparent material such that the sheath body can be clearly visible below the sheath stopper 705. The sheath stopper 705 can also be made of a flexible material, or the sheath stopper 705 can include a hinge section with increased flexibility such that it allows the sheath to be bent in place as needed once inserted into the artery. The sheath stopper can be plastically bendable such that it can be bent into a desired shape and maintain that shape when released by the user. The distal portion of the sheath stopper can be made of a harder material and the proximal portion can be made of a more flexible material, or vice versa. In one embodiment, the harder material has a hardness of 85A and the more flexible section has a hardness of 50A. In one embodiment, the harder distal portion is 1 to 4 cm of the sheath stopper 705. The sheath stopper 705 can be removed from the sheath such that if the user desires a greater sheath insertion length, the user can remove the sheath stopper 705, cut it shorter, and reassemble the sheath stopper 705 to the sheath such that a greater insertable sheath length extends from the sheath stopper 705.

[0065] Figure 7C Another embodiment of the sheath stopper 705 is shown, which is positioned adjacent to the sheath 605 that has a dilator 645 positioned therein. Figure 7C The sheath stopper 705 can be deformed from a first shape, such as a straight shape, into a second shape different from the first shape, where the sheath stopper maintains the second shape until sufficient external force is applied to the sheath stopper to change its shape. For example, the second shape can be non-straight, curved, or other contoured or irregular shapes. For example, Figure 7C A sheath stopper 705 having multiple bends and straight sections is shown. Figure 7C Only one example is shown, but it should be understood that the shape of the sheath stopper 705 can be configured to have any number of bends along its longitudinal axis. Figure 7DShows a sheath stopper 705 positioned on a sheath 605. The sheath stopper 705 has a greater stiffness than the sheath 605, such that the sheath 605 assumes a shape or profile that conforms to the profile shape of the sheath stopper 705.

[0066] The sheath stopper 705 can be shaped according to the angle of insertion of the sheath into the artery and the depth of the artery or the body size of the patient. This feature reduces the force of the sheath tip in the vessel wall, particularly in cases where the sheath is inserted into the vessel at a steep angle. The sheath stopper can be bent or otherwise deformed into a shape that helps to coaxially orient the sheath with the artery to be entered, even in cases where the angle of entry into the arterial incision is relatively steep. The sheath stopper can be shaped by the operator prior to inserting the sheath into the patient. Alternatively, the sheath stopper can be shaped and / or reshaped after the sheath has been inserted into the artery.

[0067] In another embodiment, as Figure 9A shown, the sheath stopper 705 includes a distal base, leg or flange 710 sized and shaped to distribute the force of the sheath stopper over a larger area of the vessel wall and thereby reduce the risk of vessel injury or accidental insertion of the sheath stopper through the arteriotomy and into the vessel. The flange 710 can have a circular or other non-invasive shape that is large enough to distribute the force of the sheath stopper over a large area of the vessel wall. In one embodiment, the flange is inflatable or mechanically expandable. For example, the arterial sheath and sheath stopper can be inserted through a small puncture in the skin into the surgical area and then expanded prior to inserting the sheath into the artery.

[0068] The sheath stopper can include one or more incisions or indentations 720 along the length of the sheath stopper, patterned in a staggered configuration such that the indentations increase the bendability of the sheath stopper while maintaining axial strength to allow forward force of the sheath stopper against the arterial wall. The indentations can also be used to facilitate securing the sheath to the patient via sutures to impede removal of the sheath. The sheath stopper can also include a connector element 730 on the proximal end that corresponds to a feature on the arterial sheath such that the sheath stopper can be locked or unlocked from the arterial sheath. For example, the connector element is a hub with a slot 740 that is generally L-shaped and corresponds to a pin 750 on the hub to create a bayonet mount connection. In this way, the sheath stopper can be securely attached to the hub to reduce the likelihood of the sheath stopper being inadvertently removed from the hub unless it is unlocked from the hub.

[0069] The distal sheath 605 can be configured to establish a curved transition from a generally anteroposterior access on the common carotid artery to an axially oriented lumen direction within the common carotid artery. Arterial access through the common carotid artery wall, whether by direct surgical resection or percutaneous access, may require an entry angle that is generally larger than that of other arterial access locations. This is because the common carotid artery insertion location is closer to the treatment location (i.e., the carotid bifurcation) than other access points. A larger entry angle is needed to increase the distance from the insertion location to the treatment location to allow the sheath to be inserted at a sufficient distance without the distal tip of the sheath reaching the carotid bifurcation. For example, the sheath insertion angle via carotid artery access is typically 30 - 45 degrees or even greater, while the sheath insertion angle for accessing the femoral artery may be 15 - 20 degrees. Thus, the sheath must incorporate a greater bend than is typically employed for introducer sheaths so as not to kink or exert excessive force on the opposing arterial wall. Additionally, it is desirable that the sheath tip not abut or contact the arterial wall in a manner that restricts flow into the sheath. The sheath insertion angle is defined as the angle between the lumen axis of the artery and the longitudinal axis of the sheath.

[0070] Another sheath configuration includes a curved dilator inserted into a straight but flexible sheath such that the dilator and sheath bend during insertion. The sheath is flexible enough to conform to the anatomy after the dilator is removed.

[0071] In one embodiment, the sheath has an in - built puncturing ability and a non - invasive tip similar to that of a guide wire tip. This eliminates the current need for needle and wire exchanges for arterial access according to micro - puncture techniques and thus can save time, reduce blood loss, and require less surgical skill.

[0072] Figure 8A Another embodiment of the arterial access device 110 is shown. This embodiment is the same as Figure 6AThe embodiments shown are substantially the same. If the occlusion element 129 is an inflatable structure, such as a balloon, etc., the sheath 605 may include an inflation lumen in communication with the occlusion element 129. The occlusion element 129 may be an inflatable balloon, but it may also be an inflatable cuff, a conical or other circumferential element that flares outward to engage the inner wall of the common carotid artery to block the flow therethrough, a covered fabric, a slotted tube that expands radially when axially compressed, or a similar structure deployable mechanically, etc. In the case of balloon occlusion, the balloon may be compliant, non-compliant, elastomeric, reinforced, or have various other characteristics. In one embodiment, the balloon is an elastomeric balloon that is tightly received on the outside of the distal end of the sheath before inflation. When inflated, the elastomeric balloon may expand and conform to the inner wall of the common carotid artery. In one embodiment, the elastomeric balloon is capable of expanding to at least twice the diameter of its undeployed configuration, often capable of being deployed to at least three times the diameter of its undeployed configuration, more preferably at least four times the diameter of its undeployed configuration, or a larger diameter.

[0073] As Figure 8B shown, the distal sheath 605 with the occlusion element 129 may have a stepped or other configuration that has a distal region 630 with a reduced diameter. The dimensions of the distal region 630 may be set to insert into the carotid artery, where the remaining proximal region of the sheath 605 has a larger outer diameter and lumen diameter, and the inner diameter is typically in the range of 2.794 mm (0.110 inches) to 3.43 mm (0.135 inches). The larger lumen diameter of the proximal region minimizes the overall flow resistance of the sheath. In one embodiment, the distal section 630 with the reduced diameter has a length of about 2 cm to 4 cm. The relatively short length of the distal section 630 with the reduced diameter allows this section to be positioned in the common carotid artery CCA via a transcarotid approach, where the risk that the distal end of the sheath 605 will contact the bifurcation B is reduced.

[0074] In cases where the sheath inserted into the artery has a sharp sheath insertion angle and / or a short length, such as may be seen in a transcarotid access procedure, the distal end of the sheath is more likely to be positioned partially or fully against the vessel wall, thereby restricting flow into the sheath. In one embodiment, the sheath is configured to lift the tip off the vessel wall (or optimally center the tip in the lumen of the vessel). One such embodiment includes a balloon, such as the occlusion element 129 described above. In another embodiment, the balloon may not occlude blood flow, but still lift the tip off the vessel wall or center the tip of the sheath away from the vessel wall, like an inflatable buffer. In another embodiment, an expandable feature is located at the tip of the sheath and will mechanically expand once the sheath is in place. Examples of mechanically expandable features include a braided structure or a helical structure or longitudinal struts that expand radially when shortened.

[0075] In one embodiment, occlusion of the blood vessel proximal to the distal tip of the sheath can be performed from the outside of the blood vessel, such as with a Rumel tourniquet or vascular loop proximal to the sheath insertion site. In an alternative embodiment, the occlusion device can be assembled around the sheath tip outside the blood vessel, for example, an elastic ring, an inflatable cuff, or a mechanical clamp that can be tightened around the blood vessel and the distal sheath tip. In a flow reversal system, this method of blood vessel occlusion minimizes the area of static blood flow, thereby reducing the risk of thrombus formation and also ensuring that the sheath tip is axially aligned with the blood vessel and is not partially or completely blocked by the blood vessel wall.

[0076] In Figures 9A to 9D is shown another arterial access device. This configuration has a different connection to the blood flow diverter than the previous version. Figure 9A Shown are the components of the arterial access device 110, including an arterial access sheath 605, a sheath dilator 645, a sheath stopper 705, and a sheath guidewire 611. Figure 9B Shown is the arterial access device 110 assembled for insertion into the carotid artery over the sheath guidewire 611. After the sheath is inserted into the artery and during the procedure, the sheath guidewire 611 and the sheath dilator 705 are removed. In this configuration, the sheath has a sheath body 605, a proximal extension 610, and a proximal hemostatic valve 625, which has a flush line 635 and a stopcock 640. The proximal extension 610 extends from a Y-adapter 660 to the hemostatic valve 625, and the flush line 635 is connected at the hemostatic valve 625. The sheath body 605 is the portion sized to be inserted into the carotid artery and actually inserted into the artery during use.

[0077] Instead of a Y-connector with a streamline connection terminating in a valve, the sheath has a Y-adapter 660 that connects the distal portion of the sheath to the proximal extension 610. The Y-adapter can also include a valve 670 that can be operated to open and close the fluid connection to a connector or hub 680 that can be removably connected to a streamline, such as a diverter. The valve 670 is positioned adjacent to the lumen of the adapter 660, which communicates with the lumen of the sheath body 605. Figure 9C and Figure 9D Details of the Y-adapter 660 with the valve 670 and the hub 680 are shown in cross-section. Figure 9C Shown is the valve closed to the connector. This is the position the valve will be in during the preparation of the arterial sheath. The valve is configured such that there can be no trapped air during the preparation of the sheath. Figure 9DShows a valve opened to the connector. Once the flow diverter 120 is connected to the hub 680, this position will be used and blood flow from the arterial sheath to the diverter will be allowed. This configuration eliminates the need to prepare flush lines and flow lines, instead allowing preparation from a single flush line 635 and stopcock 640. This single-point preparation is the same as that for a conventional introducer sheath, which does not have a connection to a diversion line and is thus more familiar and convenient for the user. Additionally, the absence of flow lines on the sheath makes it easier to handle the arterial sheath during preparation and insertion of the artery.

[0078] Referring again to Figure 9A , the sheath may also include a second more distal connector 690, which is separated from the Y-adapter 660 by a section of tubing 665. The purpose of this second connector and tubing 665 is to allow the valve 670 to be positioned in a more proximal location at the distal tip of the sheath, while still limiting the length of the insertable portion of the sheath 605 and thus allowing a reduced level of exposure of the user to the radiation source when the flow diverter is connected to the arterial sheath during the procedure. In one embodiment, the distal connector 690 includes suture eyelets to assist in securing the sheath to the patient once positioned.

[0079] During a carotid artery revascularization procedure, the arterial sheath 605 may be inserted into the common carotid artery (CCA) of a patient. As described elsewhere herein, in order to achieve reverse blood flow, the CCA may be occluded to prevent antegrade blood flow through the CCA from the aorta. The flow through the CCA may be occluded with an external vascular loop or tape, a vascular clamp, an internal occlusion member such as a balloon, or other types of closure devices. When the flow through the CCA is blocked, the natural pressure gradient between the internal carotid artery (ICA) and the venous system will cause blood to flow from the cerebrovascular system in a retrograde or reverse direction. Blood from the ICA and the external carotid artery (ECA) flows in the retrograde direction, and the system described herein allows the retrograde blood to flow into the sheath 605, through the flow controller 1130, the venous sheath 910, and then back to the patient's femoral vein, as described elsewhere herein. Loose embolic material may be carried into the arterial sheath 605 with the retrograde blood flow. Venous Return Device

[0080] Now referring to Figure 10A and Figure 10B , the venous return device 115 may include a distal sheath 910 and a flow line 915, which is connected to the diverter 120 and forms its leg when the system is in use. The distal sheath 910 is adapted to be introduced into a venous return location, such as the jugular vein or femoral vein, through an incision or puncture. The distal sheath 910 and the flow line 915 may be permanently attached or attached using a conventional Luer fitting, as Figure 10A shown. Optionally, as Figure 10BAs shown, the sheath 910 can be coupled to the flow line 915 by a Y-connector 1005. The Y-connector 1005 can include a hemostatic valve 1010. The venous return device also includes a venous sheath dilator 1015 and an introducer guide wire 611 to facilitate introduction of the venous return device into the internal jugular vein or other veins. Similar to the arterial access dilator 645, the venous dilator 1015 includes a central guide wire lumen so that the combination of the venous sheath and dilator can be placed over the guide wire 611. Optionally, the venous sheath 910 can include a flush line 1020 with a stopcock 1025 at its proximal or distal end.

[0081] An alternative configuration is shown in FIGS. 10 and Figure 11 illustrated. Figure 10C Components of the venous return device 115 are shown, including the venous return sheath 910, the sheath dilator 1015, and the sheath guide wire 611. Figure 11 The venous return device 115 is shown assembled for insertion into a central vein over the sheath guide wire 611. Once the sheath is inserted into the vein, the dilator and guide wire are removed. The venous sheath can include a hemostatic valve 1010 and a flow line 915. The stopcock 1025 at the end of the flow line allows the venous sheath to be flushed via the flow line prior to use. This configuration allows the sheath to be prepared from a single point, similar to a conventional introducer sheath. The connection to the blood flow diverter 120 is made with a connector 1030 on the stopcock 1025.

[0082] To reduce the overall system flow resistance, the arterial access flow line 615 ( Figure 6A ), and the venous return flow line 915, as well as the Y-connectors 620 ( Figure 6A ) and 1005, can each have a relatively large flow lumen inner diameter, typically in the range of 2.54 mm (0.100 inches) to 5.08 mm (0.200 inches), and a relatively short length, typically in the range of 10 cm to 20 cm. Lower system flow resistance is desirable because it allows for maximizing flow during the surgical portion where the embolus risk is greatest. Lower system flow resistance also allows for using variable flow resistance to control the flow in the system, as described in more detail below. The venous return sheath 910 can generally be the same size as the arterial access sheath 605 described above. In the venous return sheath, no extension for the hemostatic valve 1010 is required. Retrograde Shunt

[0083] The diverter 120 can be formed from a single tube or multiple connected tubes that provide fluid communication between the arterial access catheter 110 and the venous return catheter 115 to provide a path for retrograde blood flow between them. As Figure 1AAs shown, the shunt 120 is connected at one end (via connector 127a) to the streamline 615 of the arterial access device 110 and at the opposite end (via connector 127b) to the streamline 915 of the venous return catheter 115.

[0084] In one embodiment, the shunt 120 can be formed of at least one tube in communication with the flow control assembly 125. The shunt 120 can be any structure that provides a fluid path for blood flow. The shunt 120 can have a single lumen or it can have multiple lumens. The shunt 120 can be removably attached to the flow control assembly 125, the arterial access device 110, and / or the venous return device 115. Prior to use, the user can select a shunt 120 whose length is most suitable for use with the arterial access location and the venous return location. In one embodiment, the shunt 120 can include one or more extension tubes that can be used to vary the length of the shunt 120. The extension tubes can be modularly attached to the shunt 120 to achieve the desired length. The modular aspect of the shunt 120 allows the user to extend the shunt 120 as needed, depending on the location of the venous return. For example, in some patients, the internal jugular vein (IJV) is small and / or tortuous. Due to proximity to other anatomical structures, the risk of complications at this location may be higher than at some other locations. Additionally, a neck hematoma can cause airway obstruction and / or cerebrovascular complications. Thus, for such patients, it may be necessary to locate the venous return at a location other than the internal jugular vein (IJV), such as the femoral vein. The femoral vein return can be achieved percutaneously with a lower risk of serious complications and also provides an alternative venous access to the central vein if the internal jugular vein (IJV) is not available. Additionally, femoral vein return changes the layout of the reverse flow shunt such that the shunt controls can be located closer to the introduction device and the "working area" of the intervention where the contrast injection port is located.

[0085] In one embodiment, the shunt 120 has an inner diameter of 4.76 mm (3 / 16 inch) and has a length of 40 - 70 cm. As mentioned, the length of the shunt can be adjusted. In one embodiment, the connectors between the shunt and the arterial and / or venous access devices are configured to minimize flow resistance. In one embodiment, the arterial access sheath 110, the retrograde shunt 120, and the venous return sheath 115 are combined to create a low flow resistance arteriovenous (AV) shunt, as Figures 1A to 1D shown. As described above, the connections and streamlines of all these devices are optimized to minimize or reduce flow resistance. In one embodiment, the AV shunt has a flow resistance that enables a flow of up to 300 mL / minute when there is no device in the arterial sheath 110 and when the AV shunt is connected to a fluid source having a blood viscosity and a static head of 60 mmHg. The actual shunt resistance may depend on the presence of a check valve 1115 or a filter 1145 (asFigure 12 vary with the length of the shunt shown or the length of the flow divider and may be capable of achieving flows between 150 and 300 mL / minute.

[0086] When there is a device in the arterial sheath, such as a stent delivery catheter, the flow resistance of a section of the arterial sheath increases, which in turn increases the flow resistance of the entire AV shunt. This increase in flow resistance will correspondingly reduce the flow. In one embodiment, as Figure 6A the Y-shaped arm 620 shown connects the arterial sheath body 605 to the streamline 615 at a distance from the hemostatic valve 625 where the catheter is introduced into the sheath. This distance is set by the length of the proximal extension 610. Thus, the section of the arterial sheath restricted by the catheter is limited to the length of the sheath body 605.

[0087] The actual flow through the AV shunt during use will further depend on the patient's cerebral blood pressure and flow resistance. Flow Control Component - Regulation and Monitoring of Retrograde Flow

[0088] The flow control assembly 125 interacts with the retrograde shunt 120 to regulate and / or monitor the retrograde flow rate from the common carotid artery to a venous return location, such as the femoral vein, internal jugular vein, or to an external container 130. In this regard, the flow control assembly 125 enables the user to achieve a higher maximum flow rate than existing systems and also selectively adjust, set, or otherwise regulate the retrograde flow rate. Various mechanisms can be used to regulate the retrograde flow rate. The flow control assembly 125 enables the user to configure the retrograde blood flow in a manner suitable for various treatment regimens, as described below.

[0089] Figure 12 An example of a system 100 with a schematic diagram of the flow control assembly 125 is shown. The flow control assembly 125 is positioned along the shunt 120 such that the retrograde flow passes through at least a portion of the flow control assembly 125 or otherwise communicates therewith. The flow control assembly 125 may include various controllable mechanisms for regulating and / or monitoring the retrograde flow. The mechanisms may include various devices for controlling the retrograde flow, including one or more pumps 1110, valves 1115, syringes 1120, and / or variable resistance components 1125. The flow control assembly 125 may be manually controlled by the user and / or automatically controlled via a controller 1130 to change the flow through the shunt 120. For example, by changing the flow resistance, the rate of retrograde blood flow through the shunt 120 can be controlled. The controller 1130, which will be described in more detail below, may be integrated into the flow control assembly 125 or it may be a separate component in communication with the components of the flow control assembly 125.

[0090] In addition, the flow control assembly 125 may include one or more flow sensors 1135 and / or anatomical data sensors 1140 (described in detail below) for sensing one or more aspects of retrograde flow. A filter 1145 may be positioned along the shunt 120 for removing emboli before the blood returns to the venous return location. When the filter 1145 is positioned upstream of the controller 1130, the filter 1145 may prevent emboli from entering the controller 1145 and potentially clogging the variable flow resistance component 1125. It should be understood that the various components of the flow control assembly 125 (including the pump 1110, valve 1115, syringe 1120, variable resistance component 1125, sensors 1135 / 1140, and filter 1145) may be positioned at various locations along the shunt 120 and at various upstream or downstream positions relative to each other. The components of the flow control assembly 125 are not limited to Figure 12 the positions shown in. In addition, the flow control assembly 125 does not necessarily include all components, but may include various sub-combinations of components. For example, a syringe may optionally be within the flow control assembly 125 for regulating flow, or it may be external to the assembly for purposes other than flow regulation, such as to introduce a fluid, such as a radiopaque contrast agent, into the artery in the antegrade direction via the shunt 120.

[0091] Both the variable resistance component 1125 and the pump 1110 may be coupled to the shunt 120 to control the retrograde flow rate. The variable resistance component 1125 controls the flow resistance, while the pump 1110 provides positive displacement of the blood through the shunt 120. Thus, the pump may be activated to drive retrograde flow rather than relying on the perfusion stump pressures of the ECA and ICA and the venous backpressure to drive retrograde flow. The pump 1110 may be a peristaltic tube pump or any type of pump, including a positive displacement pump. The pump 1110 may be activated and deactivated (manually or automatically via the controller 1130) to selectively effect blood displacement through the shunt 120 and control the flow rate through the shunt 120. Blood displacement through the shunt 120 may also be effected in other ways, including using a suction syringe 1120, or a suction source, such as a vacuum blood collection tube, a vacuum lock syringe, or wall suction. The pump 1110 may be in communication with the controller 1130.

[0092] One or more flow control valves 1115 may be positioned along the path of the shunt. The valves may be actuated manually or automatically (via the controller 1130). The flow control valve 1115 may be, for example, a one-way valve, a check valve, or a high-pressure valve that prevents flow in the antegrade direction in the shunt 120, which will close the shunt 120, for example, during a high-pressure contrast agent injection (which is intended to enter the arterial vascular system in the antegrade direction). In one embodiment, the one-way valve is a low-flow resistance valve, such as the low-flow resistance valve described in U.S. Patent 5,727,594 or other low-resistance valves.

[0093] In one embodiment of the diverter having a filter 1145 and a one-way check valve 1115, the check valve is located downstream of the filter. In this way, if there is debris traveling in the diverter, it will be trapped in the filter before reaching the check valve. Many check valve configurations include a sealing member that seals against a housing containing a flow chamber. Debris may become trapped between the sealing member and the housing, thus affecting the valve's ability to seal against reverse pressure.

[0094] The controller 1130 is in communication with the components of the system 100, including the flow control assembly 125, to effect manual and / or automatic regulation and / or monitoring of retrograde flow through the components of the system 100, including, for example, the diverter 120, the arterial access device 110, the venous return device 115, and the flow control assembly 125. For example, a user may actuate one or more actuators on the controller 1130 to manually control the components of the flow control assembly 125. The manual controls may include switches or dials or similar components located directly on the controller 1130, or components located remotely from the controller 1130, such as foot pedals or similar devices. The controller 1130 may also automatically control the components of the system 100 without input from the user. In one embodiment, the user may program the software in the controller 1130 to effect such automatic control. The controller 1130 may control the actuation of the mechanical portions of the flow control assembly 125. The controller 1130 may include circuitry or programming that interprets signals generated by the sensors 1135 / 1140 such that the controller 1130 can control the actuation of the flow control assembly 125 in response to such signals generated by the sensors.

[0095] Figure 12 The representation of the controller 1130 in is merely exemplary. It should be understood that the appearance and structure of the controller 1130 may vary. The controller 1130 is shown in Figure 12 as integrated into a single housing. This allows the user to control the flow control assembly 125 from a single location. It should be understood that any of the components of the controller 1130 may be separated into individual housings. Additionally, Figure 12 the controller 1130 and the flow control assembly 125 are shown as separate housings. It should be understood that the controller 1130 and the flow control regulator 125 may be integrated into a single housing or may be divided into multiple housings or components. Flow State Indicator

[0096] The controller 1130 may include one or more indicators that provide visual and / or audio signals to the user regarding the retrograde flow status. The audio indication advantageously alerts the user of the flow status without the user having to visually inspect the flow controller 1130. The indicator may include a speaker 1150 and / or a light 1155 or any other device for communicating the retrograde flow status to the user. The controller 1130 may communicate with one or more sensors of the system to control the activation of the indicator. Alternatively, the activation of the indicator may be directly tied to the user actuating one of the flow control actuators 1165. The indicator need not be a speaker or a light. The indicator may simply be a button or a switch that visually indicates the status of the retrograde flow. For example, the button being in a certain state (such as, pressed or down state) may be a visual indication that the retrograde flow is in a high state. Or, a switch or a dial pointing to a particular marked flow status may be a visual indication that the retrograde flow is in the marked state. Flow Rate Actuator

[0097] The controller 1130 may include one or more actuators that the user can press, turn, manipulate, or otherwise actuate or adjust the retrograde flow rate and / or monitor the flow rate. For example, the controller 1130 may include flow control actuators 1165 (such as, one or more buttons, knobs, dials, switches, etc.) that the user can actuate to cause the controller to selectively change an aspect of the reverse flow. For example, in the illustrated embodiment, the flow control actuator 1165 is a knob that can be turned to various discrete positions, each of which corresponds to the controller 1130 causing the system 100 to achieve a particular retrograde flow status. The statuses include, for example, (a) off; (b) low flow; (c) high flow; and (d) suction. It should be understood that the above statuses are merely exemplary and different statuses or combinations of statuses may be used. The controller 1130 achieves the various retrograde flow statuses through interaction with one or more components of the system, including sensors, valves, variable resistance components, and / or pumps. It should be understood that the controller 1130 may also include circuitry and software for regulating the retrograde flow rate and / or monitoring the flow rate such that the user does not need to actively actuate the controller 1130.

[0098] The closed state corresponds to a state where there is no retrograde blood flow through the shunt 120. When the user sets the flow control actuator 1165 to closed, the controller 1130 causes the retrograde flow to stop, such as by closing a valve or a stopcock in the shunt 120. The low flow and high flow states correspond to low and high retrograde flow rates, respectively. When the user sets the flow control actuator 1165 to low flow or high flow, the controller 1130 interacts with components of the flow control regulator 125, including the pump 1110, the valve 1115, and / or the variable resistance component 1125, to increase or decrease the flow rate accordingly. Finally, the aspiration state corresponds to opening the circuit to an aspiration source, e.g., a vacuum blood collection tube or an aspiration unit (if active retrograde flow is desired).

[0099] The system can be used to vary blood flow between various states, including an active state, a passive state, an aspiration state, and a closed state. The active state corresponds to the system using a device that actively drives retrograde blood flow. Such an active device can include, for example, a pump, a syringe, a vacuum source, etc. The passive state corresponds to when retrograde blood flow is driven by the perfusion stump pressures of the ECA and ICA and possibly by venous pressure. The aspiration state corresponds to the system using an aspiration source, e.g., a vacuum blood collection tube or an aspiration unit, to drive retrograde blood flow. The closed state corresponds to the system having zero retrograde blood flow, such as as a result of closing a stopcock or a valve. The low and high flow rates can be passive or active flow states. In one embodiment, specific values for the low and / or high flow rates (e.g., in ml / minute) can be pre-determined and / or pre-programmed into the controller such that the user does not actually set or input the value. Instead, the user simply selects "high flow" and / or "low flow" (such as by pressing an actuator, such as a button on the controller 1130), and the controller 1130 interacts with one or more components of the flow control assembly 125 to cause the flow rate to achieve the pre-determined high or low flow rate value. In another embodiment, the user sets or inputs the value of the low and / or high flow rate, such as setting or inputting it into the controller. In another embodiment, the low and / or high flow rate is not actually set. Instead, external data (such as data from the anatomical data sensor 1140) is used as a basis for influencing the flow rate.

[0100] The controller 1130 or various components of the controller 1130 can be located at various positions relative to the patient and / or relative to other components of the system 100. In one embodiment, the controller 1130 can be positioned at a sufficient distance from the system 100 to allow the controller 1130 to be positioned outside the radiation field when using fluoroscopy.

[0101] Any one of the controller 1130 and its components can interact with other components of the system (such as pumps, sensors, diverters, etc.) in various ways. For example, any one of various mechanical connections can be used to achieve communication between the controller 1130 and the system components. Alternatively, the controller 1130 can communicate electronically or magnetically with the system components. Electromechanical connections can also be used. The controller 1130 can be equipped with control software that enables the controller to implement control functions with the system components. The controller itself can be a mechanical, electrical, or electromechanical device. The controller can be mechanically, pneumatically, or hydraulically actuated or electromechanically actuated (for example, in the case of solenoid actuation in a flow control state). The controller 1130 can include a computer, a computer processor, and a memory, as well as data storage capabilities.

[0102] Figure 13 An exemplary embodiment of the variable flow control element 1125 is shown. In this embodiment, the flow resistance through the diverter 120 can be changed by providing two or more alternative flow paths to create low-resistance and high-resistance flow paths. As Figure 13 shown, the flow through the diverter 120 passes through the main chamber 1700 and the secondary chamber 1705. The secondary chamber 1705 is longer and / or has a smaller diameter than the main chamber 1700. Therefore, the secondary chamber 1705 has a higher flow resistance than the main chamber 1700. By passing blood through these two chambers, the flow resistance will be at a minimum. Due to the pressure drop created across the inlet and outlet of the secondary chamber 1705 in the main chamber 1700, blood can flow through the two chambers 1700 and 1705. This has the benefit of preventing stasis. As Figure 14 shown, by blocking the flow through the main chamber 1700 of the diverter 120, the flow is completely diverted to the secondary chamber 1705, thereby increasing the flow resistance and reducing the blood flow rate. It should be understood that additional flow chambers can also be provided in parallel to allow for three, four, or more discrete flow resistances. The diverter 120 can be equipped with a valve 1710 that controls the flow to the main chamber 1700 and the secondary chamber 1705. The position of the valve can be controlled by an actuator, such as a button or switch on the housing of the flow controller 125. Figure 13 and Figure 14 The embodiments of have the advantage that even at the lowest flow rate settings, they maintain precise flow chamber sizes. The size of the secondary flow chamber can be configured to prevent thrombus formation even at the lowest flow rates or during long-term blood flow conditions. In one embodiment, the inner diameter of the chamber of the secondary chamber 1705 is 0.063 inches or greater.

[0103] In one embodiment, the connector that connects the components of the reverse flow system is a large-bore, quick-connect connector. For example, as Figure 9BAs shown, the male large-bore hub 680 on the Y-adapter 660 of the arterial sheath 110 is connected to the female counterpart 1320 on the arterial side of the flow diverter 120. Similarly, the male large-bore connector 1310 on the venous side of the flow diverter 120 is connected to the female counterpart connector 1310 on the streamline of the venous sheath 115, as Figure 10C shown. The connection can be a standard male and female Luer connector or other styles of tubing connectors. Sensor

[0104] As mentioned, the flow control assembly 125 can include or interact with one or more sensors that communicate with the system 100 and / or with the patient's anatomy. Each of the sensors can be adapted to respond to physical stimuli (including, for example, heat, light, sound, pressure, magnetism, motion, etc.) and transmit the resulting signal for measurement or display or to operate the controller 1130. In one embodiment, the flow sensor 1135 interacts with the diverter 120 to sense an aspect of the flow through the diverter 120, such as the velocity or volumetric rate of blood flow. The flow sensor 1135 can be directly coupled to a display that directly shows the value of the volumetric flow rate or flow velocity. Alternatively, the flow sensor 1135 can deliver data to the controller 1130 for display of the volumetric flow or flow velocity.

[0105] The type of the flow sensor 1135 can vary. The flow sensor 1135 can be a mechanical device, such as a paddle wheel, a flapper valve, a rolling ball, or any mechanical component that responds to the flow through the diverter 120. The mechanical device's response to the movement of the flow through the diverter 120 can be used as a visual indication of fluid flow and can also be calibrated to a scale as a visual indication of fluid flow velocity. The mechanical device can be coupled to an electrical component. For example, the paddle wheel can be positioned in the diverter 120 such that fluid flow causes the paddle wheel to rotate, where a greater fluid flow rate causes a greater rotational speed of the paddle wheel. The paddle wheel can be magnetically coupled to a Hall effect sensor to detect the rotational speed, which indicates the fluid flow rate through the diverter 120.

[0106] In another safety mechanism, the controller 1130 includes a timer 1170 ( Figure 12 ) for recording the time at a high flow rate. The controller 1130 can be programmed to automatically return the system 100 to a low flow rate after a predetermined high flow rate period, for example, after 15, 30, or 60 seconds or more of high flow rate. After the controller returns to the low flow rate, the user can initiate another predetermined high flow rate period as needed. Additionally, the user can override the controller 1130 to move the system 100 to a low flow rate (or high flow rate) as needed. Example Embodiment of a Sheath Depth Regulator

[0107] As described above, the system can include a sheath stopper that is coupled to the sheath to limit the insertion length of the sheath into the artery to prevent rupture of plaque located in the artery. In a percutaneous procedure in which access to the blood vessel is gained through a small puncture in the skin, the depth from the skin surface to the carotid target location (or other location) can vary from patient to patient. Thus, it is beneficial for the sheath stopper to allow the user to control or otherwise adjust the depth level of the sheath stopper. The present invention discloses various embodiments of a sheath stopper that allows a user to selectively adjust the depth of insertion of the sheath into the blood vessel using the sheath stopper. The sheath stopper can be used with a sheath configured to be percutaneously positioned into an artery. The morphology of the sheath can vary and can be, for example, the arterial access device 110 described herein.

[0108] Figure 15 A perspective view of one embodiment of the sheath stopper 1505 is shown. Figure 16 The sheath stopper 1505 positioned on a sheath 1605 is shown, the sheath 1605 having an adapter, a Y-connector, or a proximal hemostatic valve 1610. The sheath 1605 has a distal region that projects distally from the distal end of the sheath stopper 1505 and a proximal region that projects proximally from the proximal end of the sheath stopper 1505. As discussed above with reference to other embodiments, the sheath stopper 1505 can be an elongate tube or tubular member having a lumen sized to fixedly or removably receive at least a portion of the sheath 1605. The size of the sheath 1605 can vary and can be, in a non-limiting example, any sheath having a size ranging from 4 to 18 French and a length of 6 to 30 cm.

[0109] The sheath stopper 1505 includes a leg or flange 1510 positioned at the distal end of the sheath stopper 1505. The size and shape of the flange 1510 are configured to abut against a portion of the anatomy, such as the skin at the percutaneous access location. The flange 1510 abuts against the anatomy and thereby prevents the sheath stopper from further passage beyond the abutted anatomy to thereby limit the insertion depth of the sheath 1605 into the blood vessel. The flange 1510 can extend along a plane that is not perpendicular to the long axis of the sheath stopper 1505 such that the flange is relative to as Figure 15 and Figure 16The long axis shown is angled. Alternatively, the flange may extend along a plane perpendicular to the long axis of the sheath stopper 1505. At least a portion (such as the distal edge) of the flange 1510 may have an adhesive configured to adhere to the patient's skin. Additionally, an aperture 1512 may be located on the sheath stopper 1505, such as on the flange 1510, for securing the sheath stopper 1505 to the patient's skin. The sheath stopper 1505 may also include a locking mechanism to prevent the sheath from withdrawing from the sheath stopper 1505. The locking mechanism may vary and may be, for example, a set screw, a clamp, a hook, a Tuohy Borst membrane, a crimp, a tie, complementary mechanical geometries, or other locking mechanisms.

[0110] Still referring Figure 15 and Figure 16 , the sheath stopper 1505 includes a series of segments 1515 along its length, where the segments 1515 are separated by boundaries (such as grooves 1520) or any other features configured to be manipulated by a user to separate the segments 1515, such as by cutting, tearing, breaking, peeling, etc. In one embodiment, at least one of the grooves 1520 extends around the entire circumference or a majority of the circumference of the sheath stopper 1505 to facilitate cutting, tearing, breaking, peeling, etc. The grooves 1520 may vary and may be, for example, perforations, ridges, etc. The length of each segment may vary (along the long axis of the sheath stopper 1505). In one non-limiting example, the length of each segment is about 5 mm, although the length may also vary. Additionally, the segments 1515 may all have equal lengths, or the lengths of the segments 1515 may vary along the sheath stopper 1505.

[0111] The user may adjust the overall length of the sheath stopper 1505 by removing one or more of the segments 1505, such as by cutting, tearing, breaking, peeling, etc. along one or more of the grooves 1520. The final length of the sheath stopper 1505 may be such that the proximal end of the sheath stopper 1505 does not overpass or otherwise cover the adapter / Y-connector / hemostatic valve 1610. Additionally, the shape of the proximal edge of each segment 1515 may be configured to fit snugly or flush against the distal region of the hemostatic valve.

[0112] Figure 15 and Figure 16 A sheath stopper 1505 is shown having five segments 1515 such that the sheath stopper 1505 has a first length including all five segments. Figure 17 and Figure 18Illustrated is the sheath stopper 1505 after several segments 1515 have been removed from the sheath stopper, leaving only two segments 1515 of the sheath stopper 1505. Thus, the sheath stopper 1505 has a shorter length. When the most proximal segment 1515 abuts the hemostatic valve 1610, the length of the distal region of the sheath that is exposed distal to the distal end of the sheath stopper 1505 is longer relative to when the sheath stopper 1505 has additional segments as shown in Figure 15 and Figure 16 . As a result, since the longer distal portion of the sheath 1605 extends beyond the distal end of the sheath stopper 1505, the sheath stopper can be sized to allow for a greater insertion depth of the sheath 1605.

[0113] Figure 19 Illustrated is an embodiment of a sheath stopper formed by an adapter element 1905, which is formed by a sleeve (such as a tubular sleeve) that fits over the sheath 1605 to expose the distal portion of the sheath 1605. The sleeve 1905 has one or more structures, such as internal ridges 1910, that mate with corresponding structures on the sheath 1605, such as external grooves 1920. The internal ridges are located on the inner surface of the lumen of the sheath stopper, while the grooves are located on the outer surface of the sheath 1605. The adapter ridges 1910 are sized and shaped to interlock with the grooves 1920 on the sheath 1605 having complementary shapes. The ridges 1910 and grooves 1920 can be spaced apart at a predetermined interval, such as a consistent interval, along the lengths of the sheath stopper and the sheath. The adapter element 1905 can be moved or positioned along the length of the sheath 1605 to selectively expose a desired length of the distal portion of the sheath beyond the distal edge of the adapter element 1905. Figure 20 Illustrated is the adapter element 1905 moved proximally along the length of the sheath 1605 as shown in Figure 19 .

[0114] When the adapter element 1905 engages the sheath 1605, the adapter element 1905 holds the sheath 1605 in place to prevent translational movement of the sheath 1605 into or out of the patient along the length of the sheath. The adapter element 1905 includes a locking or stopping mechanism that prevents the adapter element from crushing the sheath 1605 when engaged to the sheath 1605. The adapter element 1905 includes feet 1510 at its distal end to stabilize the adapter element 1905 on the skin surface. As discussed above, the adapter element 1905 can also include eyelets 1512.

[0115] Figure 21Another embodiment of the sheath stopper 2105 is shown, which is directly integrated on the sheath 1605 such that the sheath 1605 and the sheath stopper 2105 are an integral or integrated structure. The sheath 1605 includes a series of circumferential grooves 2110, which are located on the outer surface, such as on the distal region of the sheath 1605. The sheath 1605 may have a fixed length. The grooves 2110 may be located at fixed intervals (such as an interval of 5 mm) or at intermittent intervals along the length of the distal region of the sheath 1605.

[0116] The grooves 2110 may be made of a material different from the rest of the sheath 1605 or at least partially made thereof. The grooves 2110 may also have a different hardness from the rest of the sheath 1605. The size and shape of the grooves 2110 are set such that a suture can be wound around the groove 1610 or otherwise fixed thereto without crushing the sheath 1605 or otherwise deforming it. The suture can be fixed to the patient's skin to prevent the sheath from moving relative to the skin.

[0117] Figure 22 and Figure 23 Another embodiment of the sheath stopper 2205 positioned on the sheath 1605 is shown. The sheath stopper 2205 may be part of the sheath itself, or it may be a separate component removably positioned on the sheath. The sheath stopper 2105 is formed by an accordion-like structure 2210, such as a plurality of pleated or corrugated surfaces extending along the length of the sheath 1605. The accordion structure can be converted between a retracted state of shorter length (where the corrugations are compressed along the length of the sheath) and an expanded state of increased length (where the corrugations are stretched or flattened along the length of the sheath). When shortened, the corrugations come together to provide an increased diameter or lateral dimension to the sheath 1606 such that the increased dimension provides a stopper against the skin surface to prevent further advancement of the sheath into the patient's body. As in any embodiment, the sheath may include one or more eyelets for using sutures to fix the sheath to the patient's skin.

[0118] Figure 24 and Figure 25 Another embodiment of the sheath stopper integrated on the sheath 1605 is shown. At least one leg 2405 formed by an elongate and protrudable structure, such as a fork, is positioned along the outer surface of the sheath 1605. The leg 2405 can be converted between a constrained state ( Figure 24 ) and a protruding state ( Figure 25 ). In the constrained state, the leg 2405 is flush or substantially flush against the outer surface of the sheath 1605. In the protruding state, the leg 2405 moves to a position where the leg 2405 is suspended away from the sheath, as Figure 25As shown, when in the protruding state, the foot 2405 acts as a mechanical stopper against the patient's body (such as against the skin or the blood vessel wall) to prevent the sheath from moving into or out of the patient's body. The foot 2405 can protrude outward and stop at various angles relative to the long axis of the sheath 1605. For example, the foot 2405 can stop at an angle of 90 degrees as shown or at any other angle. The foot 2405 can be located at a predetermined distance (such as 5 cm) from the distal tip of the sheath 1605. The foot 2405 can be radiopaque and can be located on the surface of the target blood vessel for observation under fluoroscopy. The foot can be moved to a constrained state for removal from the body.

[0119] Figure 26 and Figure 27 Another embodiment of a sheath stopper 2605 formed by a cannula is shown, which can be positioned on a length of the sheath 1605. The cannula can be moved along the length of the sheath 1605 to a desired position and locked in place at the desired position. The cannula can include one or more eyelets for attachment to a suture. Exemplary Method of Use

[0120] The flow through the carotid bifurcation at different stages of the method of the present invention will be described. Initially, the distal sheath 605 of the arterial access device 110 (or any embodiment of the sheath described herein) is introduced into the common carotid artery CCA. As mentioned, access to the common carotid artery CCA can be via a carotid or femoral approach and can be by direct surgical incision or percutaneous access. After the sheath 605 of the arterial access device 110 is introduced into the common carotid artery CCA, blood flow will continue in the antegrade direction AG, where the flow from the common carotid artery enters the internal carotid artery ICA and the external carotid artery ECA.

[0121] Then the venous return device 115 is inserted into a venous return location, such as the internal jugular vein IJV or the femoral vein. The shunt 120 is used to connect the flow lines 615 and 915 of the arterial access device 110 and the venous return device 115 respectively (as Figure 1A shown). In this way, the shunt 120 provides a pathway for retrograde flow from the arterial access device 110 to the venous return device 115. In another embodiment, the shunt 120 is connected to an external container 130 instead of the venous return device 115, as Figure 1C shown.

[0122] Once all the components of the system are in place and connected, the flow through the common carotid artery CCA is stopped, such as by using an expandable occlusion element of a percutaneous sheath in the common carotid artery CCA. Alternatively, the occlusion element 129 is introduced on a second occlusion device 112 separate from the distal sheath 605 of the arterial access device 110, asFigure 2B As shown. The ECA can also be occluded with a separate occlusion element, which can be on the same device 110 or on a separate occlusion device.

[0123] At that time, retrograde flow RG from the external carotid artery (ECA) and the internal carotid artery (ICA) will begin and will flow through the sheath 605, the flow line 615, the shunt 120, and into the venous return device 115 via the flow line 915. As described above, the flow control assembly 125 regulates the retrograde flow. While maintaining the retrograde flow, a stent delivery catheter 2110 (or other intervention device) is introduced into the sheath 605. The stent delivery catheter 2110 is introduced into the sheath 605 through the hemostatic valve 615 and the proximal extension 610. The stent delivery catheter 2110 is advanced into the internal carotid artery (ICA), and the stent 2115 is deployed at the bifurcation B.

[0124] Optionally, when the flow from the common carotid artery continues and the internal carotid artery remains occluded, measures can be taken to further loosen the emboli from the treatment area. For example, mechanical elements can be used to clean or remove loose or loosely attached plaque or other potential embolization debris within the stent, thrombolytic or other fluid delivery catheters can be used to clean the area, or other procedures can be performed. For example, under retrograde flow, a balloon, atherectomy, or additional stents can be used to treat in-stent stenosis. In another example, an occlusion balloon catheter can include a flow lumen or a suction lumen or channel that opens proximal to the balloon. Saline, thrombolytic agents, or other fluids can be injected and / or blood and debris can be aspirated into or out of the treatment area without additional devices. Although the emboli released in this way will flow into the external carotid artery, the external carotid artery is generally less sensitive to emboli release than the internal carotid artery. By prophylactically removing the potential emboli left behind, the risk of emboli release is even further reduced when blood flow to the internal carotid artery is re-established. The emboli can also be released under retrograde flow such that the emboli flow through the shunt 120 to the venous system, the filter in the shunt 120, or the container 130.

[0125] After clearing the emboli at the bifurcation, the occlusion element 129 can be released or alternatively the tourniquet 2105 can be released to re-establish antegrade flow, as Figure 14 shown in E. Then, the sheath 605 can be removed.

[0126] Before withdrawing the sheath 605 at the end of the operation, a self-closing element can be deployed around the perforation in the common carotid artery wall. Generally, the self-closing element will be deployed at the beginning or near the beginning of the operation. Optionally, however, the self-closing element can be deployed when the sheath is withdrawn, typically when released from the distal end of the sheath onto the wall of the common carotid artery. The use of the self-closing element is advantageous because it significantly affects the rapid closure of the perforation in the common carotid artery when the sheath is withdrawn. This rapid closure can reduce or eliminate accidental blood loss that occurs at the end of the operation or during accidental removal of the sheath. In addition, such a self-closing element can reduce the risk of arterial wall dissection during entry. Furthermore, the self-closing element can be configured to apply frictional or other holding forces on the sheath during the operation. Such holding forces are advantageous and can reduce the chance of accidental removal of the sheath during the operation. The self-closing element eliminates the need for vascular surgical closure of the artery with sutures after the sheath is removed, thereby reducing the need for a large surgical field and significantly reducing the surgical skills required for the operation.

[0127] Although embodiments of various methods and devices are described in detail herein with reference to certain versions, it should be understood that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

Claims

1. A system for accessing an artery, the system comprising: A sheath stopper positioned externally on a distal section of an arterial access sheath such that a portion of the distal section of the sheath is covered by the sheath stopper and a portion of the distal section of the sheath is exposed, wherein the sheath stopper is configured to limit insertion of the sheath into the artery to the exposed portion; wherein the length of the exposed portion is adjustable.

2. The system according to claim 1, wherein The sheath stopper includes a flange at the distal end of the sheath stopper, the flange being configured to abut the skin in a percutaneous access position.

3. The system according to claim 1, further comprising suture eyelets on the sheath stopper.

4. The system according to claim 1, wherein The sheath stopper includes a tubular body having a series of segments, each segment separated from another by a boundary, and wherein each boundary is configured to allow a user to disassemble a segment from the tubular body to reduce the length of the tubular body.

5. The system according to claim 1, wherein, The sheath stopper includes a sleeve fitted over the sheath.

6. The system according to claim 5, wherein, The sleeve includes at least one adapter ridge sized and shaped to interlock with a complementary-shaped groove on an outer surface of the sheath.

7. The system according to claim 1, wherein The sheath stopper includes a series of corrugations positioned along the length of the sheath, wherein the corrugations are capable of expanding and contracting to adjust the length of the sheath stopper.

8. The system according to claim 7, wherein, The diameter of the sheath stopper increases as the corrugations contract.

9. The system according to claim 8, wherein, The diameter of the sheath stopper decreases as the corrugations expand.

10. The system according to claim 1, wherein The sheath stopper includes at least one prong, wherein the at least one prong transitions between a suspended state relative to the sheath and a flush state relative to the sheath.

11. The system according to claim 1, further comprising the sheath.

12. The system according to claim 1, wherein The sheath stopper is removable from the sheath.

13. The system according to claim 1, wherein, The artery is the carotid artery.

14. The system according to claim 1, wherein The sheath stopper is configured to lock in place at a desired depth on the sheath.

15. The system according to claim 11, wherein, The sheath is configured to be delivered to the carotid artery via an access position in the patient's neck.

16. The system according to claim 11, wherein, The sheath is configured to be delivered to the carotid artery via a transfemoral access position.

Images