CN116710170A

CN116710170A - Vascular tubing to facilitate temporary direct access to a blood vessel

Info

Publication number: CN116710170A
Application number: CN202180090970.3A
Authority: CN
Inventors: S·M·久米; Z·泰格尔斯; K·利普舒尔茨; B·斯蒂尔
Original assignee: Silk Road Medical Inc
Current assignee: Silk Road Medical Inc
Priority date: 2020-12-18
Filing date: 2021-12-17
Publication date: 2023-09-05

Abstract

Methods, devices, and systems establish and facilitate arterial access for interventional procedures, such as stent implantation, angioplasty, grafting, replacement valve therapy, and atherectomy.

Description

Vascular tubing to facilitate temporary direct access to a blood vessel

Cross Reference to Related Applications

The present application claims priority from co-pending U.S. provisional application serial No. 63/127,818 filed on 12 months of 2020 and from co-pending U.S. provisional application serial No. 63/187,759 filed on 5 months of 2021. The entire contents of each application are incorporated herein by reference.

Background

Obtaining temporary access to a blood vessel such as the Common Carotid Artery (CCA) using an arterial access sheath is a key aspect of different interventional procedures, including transcervical arterial revascularization (TCAR) procedures and other procedures in which an arterial access sheath is inserted directly into the CCA. The distance between the collarbone and carotid bifurcation is preferably at least 5 cm to ensure safe insertion of the arterial sheath into the CCA. This portion of the CCA is also preferably relatively disease free. Atherosclerotic disease generally consists of a deposit of plaque P that narrows the interface between the CCA and the Internal Carotid Artery (ICA), which is the artery that provides blood flow to the brain. Insertion of an arterial sheath at this location may release embolic material if one or more system components contact plaque deposits. For example, a introducer guidewire, an arterial dilator, or an arterial sheath may all cause plaque rupture, resulting in the release of embolic particles. The embolic particles produced may enter the cerebral vasculature, leading to neurological consequences such as transient ischemic attacks TIA, ischemic strokes, or death. Furthermore, if such stenosis becomes severe, blood flow to the brain is inhibited with serious, sometimes even fatal, consequences. The shorter the CCA, the greater the risk of this complication.

Furthermore, arterial sheath insertion in CCA may result in arterial dissection, especially for patients with CCA located relatively deep below the skin surface. The insertion angle of the arterial sheath of a deep CCA patient is also generally steeper (e.g., 50-80 degrees from horizontal). The steep insertion angle of the arterial sheath and any sheath dilator used to advance the sheath through the vessel wall also increases the risk of arterial dissection and possibly perforation of the arterial back wall.

In addition, some carotid artery patients or procedures (e.g., short/deep vascular procedures, patients with disease, anatomy, patients with scar tissue, etc.) may require a larger caliber sheath or delivery system, and thus a larger access point into the carotid artery. Such patients and procedures would benefit from the use of large bore tubing (e.g., as part of a large bore delivery system). Furthermore, the tubing described herein may improve the surgical outcome and reduce patient discomfort. For example, sutures such as purse-string sutures may be used to connect the tubing to the access site during left ventricular apex access. The use of a tube (such as the tube described herein) stabilizes the access site tissue, thereby improving the surgical outcome and reducing patient discomfort.

Disclosure of Invention

Solutions to these and other problems in the art are provided herein, among others. Aspects of the present subject matter relate, inter alia, to a system for accessing an artery through a trans-carotid access. Related systems and methods are also provided.

Consistent with some aspects of the present subject matter, a system for accessing an artery through a transcervical access is disclosed. The system comprises: an arterial access device comprising a distal connector, a lumen, and a hemostatic valve spaced apart from the distal connector by the lumen; and a conduit having a lumen extending between a proximal end and a distal end and a coupler at the proximal end, the distal end of the conduit configured for operative end-to-side coupling with a blood vessel, wherein the distal connector of the arterial access device is configured for operative coupling with the coupler at the proximal end of the conduit to place the lumen of the arterial access device in fluid communication with the lumen of the conduit.

In variations, one or more of the following features may be included in any feasible combination. For example, in some embodiments, the conduit is a flexible tubular structure formed from a biological fabric. In some embodiments, the conduit is a vascular graft. In some embodiments, the vascular graft is formed from a substrate selected from the group consisting of polyethylene terephthalate, polyester, nylon, expanded polytetrafluoroethylene, heparin-bonded ePTFE, cap PTFE, ring-reinforced ePTFE, and nylon-ePTFE woven mixtures. In some embodiments, the lumen of the tube has a diameter of greater than about 2mm up to about 10 mm. In some embodiments, the lumen of the tube has a diameter of between about 6mm and about 16 mm. In some embodiments, the lumen of the tube has a diameter of between about 8mm and about 10 mm. In some embodiments, the arterial access device further comprises a distal sheath coupled to and extending distally from the distal connector, the distal sheath comprising a sheath lumen. In some embodiments, the sheath lumen has a size of 7Fr to 10Fr. In some embodiments, the sheath lumen has a size of 12Fr to 36Fr. In some embodiments, the sheath lumen has a size of 14Fr to 20Fr. In some embodiments, the length of the tubing between the proximal end and the distal end is longer than the length of the distal sheath such that the distal end of the distal sheath remains proximal of the distal end of the tubing and within the tubing lumen as the distal sheath extends through the lumen of the tubing. In some embodiments, the length of the tubing is 5cm to 30cm, and wherein the length of the distal sheath is 4cm to 29cm. In some embodiments, the blood vessel is the common carotid artery, femoral artery, radial artery, brachial artery, ulnar artery, or subclavian artery.

In some embodiments, the system further comprises a shunt fluidly connected to the arterial access device, wherein the shunt provides a path for blood to flow from the arterial access device to the return site. In some embodiments, the system further comprises a flow control assembly coupled to the shunt and adapted to regulate blood flow through the shunt. In some embodiments, the system further comprises a suction device coupled to the port on the shunt. In some embodiments, the aspiration device is a syringe or pump. In some embodiments, the system further comprises a distal adapter coupled to and extending distally from the distal sheath.

In another interrelated aspect, a system for accessing an artery through a transcervical access is provided. The system comprises: a tube having a lumen extending between a proximal end and a distal end, the distal end of the tube configured for operative end-to-side coupling with a blood vessel; a coupler located at a proximal end of the tube; and a shunt fluidly connected to the coupler such that an inner lumen of the conduit is coupled to a lumen of the shunt, the lumen of the shunt providing a path for blood from the conduit to flow through the shunt and to the return site.

In variations, one or more of the following features may be included in any feasible combination. For example, in an embodiment, the system further comprises a port in fluid communication with the shunt, wherein the port is configured to connect the aspiration device to the shunt, wherein the distal connector of the arterial access device is configured to operably couple with the coupler at the proximal end of the tube, thereby fluidly communicating the lumen of the arterial access device with the lumen of the tube. In an embodiment, the conduit is a flexible tubular structure formed from a biological fabric. In an embodiment, the conduit is a vascular graft. In embodiments, the tubing provides an access port for procedures in the innominate arterial orifice, aorta, aortic root, carotid artery, or cerebral vessel.

In another interrelated aspect, a method of treating a patient is provided. The method comprises the following steps: attaching a tube to a wall of a blood vessel, the tube having a lumen extending between a proximal end and a distal end, the distal end of the tube being attached to the wall; forming an arteriotomy in a wall of the blood vessel; inserting the device through the lumen of the tube and into the blood vessel; treatment is performed with the device.

In another interrelated aspect, a method for treating a patient having atypical anatomy is provided. The method comprises the following steps: attaching a tube to a wall of the vessel, the tube having a lumen extending between a proximal end and a distal end, the distal end of the tube being attached to the wall; forming an arteriotomy in a wall of a blood vessel; inserting the device through the lumen of the tube and into the blood vessel; treatment is performed with the device.

In variations, one or more of the following features may be included in any feasible combination. For example, in an embodiment, the proximal end of the tube includes a coupler, wherein the device is inserted into the lumen of the tube through the coupler. In an embodiment, attaching the conduit to the wall further comprises suturing the conduit to the wall with a suture. In embodiments, the method further comprises cinching the suture after the treatment is performed to perform a primary closure of the vessel. In an embodiment, the distal end of the tube comprises a mechanical element to facilitate attachment of the tube to a blood vessel. In an embodiment, the mechanical element comprises a cap, a washer, or a sewing ring. In an embodiment, forming the arteriotomy includes forming the arteriotomy through a lumen of a tube attached to a wall of the blood vessel. In embodiments, the method further comprises reversing blood flow through the blood vessel while the treatment is being performed. In embodiments, the blood vessel comprises the common carotid artery. In embodiments, the blood vessel comprises a vein, left ventricular apex, axillary artery, or aorta. In embodiments, the method further comprises advancing the device through the common carotid artery to the innominate artery, aortic arch, descending aorta, ascending aorta, aortic root, coronary artery, internal carotid artery, external carotid artery, or intracranial vessel. In embodiments, the method further comprises advancing the device through a vein, left ventricular apex, axillary artery, or aorta to a innominate artery, aortic arch, descending aorta, ascending aorta, aortic root, coronary artery, internal carotid artery, external carotid artery, or intracranial vessel. In embodiments, the device comprises a balloon catheter, a stent delivery catheter, or an aspiration catheter. In an embodiment, the device comprises a vascular ring. In embodiments, the treatment comprises one or more of stent delivery, angioplasty expansion, stent graft delivery, valve delivery, aspiration embolectomy, and combinations thereof. In embodiments, the diameter of the lumen of the conduit is between about 6mm and about 16 mm. In an embodiment, the diameter of the lumen of the tube is between about 8mm and about 10 mm. In an embodiment, the catheter further comprises a vascular ring controller located at a proximal end of the catheter opposite the blood vessel, wherein the vascular ring controller is configured to actuate one or more vascular rings.

It is to be understood that all combinations of the foregoing concepts and additional concepts discussed in more detail below (assuming such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of the presently disclosed claimed subject matter are considered to be part of the inventive subject matter disclosed herein. It will be further understood that terms, such as those specifically used herein, that may also be present in any disclosure incorporated by reference should be given the most consistent meaning with the specific concepts disclosed herein.

Drawings

These and other aspects will now be described in detail with reference to the following drawings. In general, the figures are not drawn to absolute or relative scale, but are intended to be illustrative. Furthermore, the relative arrangement of the features and elements may be modified for clarity of illustration.

Fig. 1A is a schematic diagram of a retrograde blood flow system including a flow control assembly in which an arterial access device enters the common carotid artery via a transcervical access and a venous return device communicates with the internal jugular vein.

Fig. 1B is a schematic diagram of a retrograde blood flow system in which an arterial access device enters the common carotid artery via a transcervical arterial access and a venous return device communicates with the femoral vein.

Fig. 1C is a schematic diagram of a retrograde blood flow system in which an arterial access device enters the common carotid artery via a trans-femoral access and a venous return device communicates with the femoral vein.

FIG. 1D is a schematic diagram of a retrograde blood flow system in which retrograde blood flow is collected in an external container.

Fig. 2A is an enlarged view of a carotid artery where the carotid artery is occluded by an occlusion element on the sheath and connected to a reflux shunt, and an interventional device, such as a stent delivery system or other working catheter, is introduced into the carotid artery through an arterial access device.

Fig. 2B is an alternative system in which the carotid artery is occluded by a separate external occlusion device and connected to a reflux shunt, and an interventional device, such as a stent delivery system or other working catheter, is introduced into the carotid artery through an arterial access device.

Fig. 2C is an alternative system in which the carotid artery is connected to a retrograde shunt and an interventional device, such as a stent delivery system or other working catheter, is introduced into the carotid artery via an arterial access device and the carotid artery is occluded by a separate occlusion device.

Fig. 2D is an alternative system in which the carotid artery is occluded, the artery is connected to a retrograde shunt through an arterial access device, and an interventional device, such as a stent delivery system, is introduced into the carotid artery through a separate arterial introducer.

Fig. 2E is a system in which an arterial access device is inserted through a tube attached to the common carotid artery.

Fig. 3 illustrates a normal brain circulation diagram including a wilis ring (Circle of Willis).

Fig. 4 illustrates the vasculature of a patient's neck, including the common carotid artery CCA, internal carotid artery ICA, external carotid artery ECA, and internal jugular vein IJV.

Fig. 5A illustrates an embodiment of an arterial access device that may be used with the methods and systems of the present disclosure.

Fig. 5B illustrates an embodiment of an arterial access device configuration with a reduced diameter distal end.

Fig. 5C illustrates an embodiment of a tube for use with a retrograde blood flow system.

Figures 5D-5E illustrate an embodiment of an arterial access device for use with a catheter.

Fig. 5F illustrates an embodiment of a tube attached to an arterial access device without a sheath.

Fig. 6 illustrates an embodiment of a sheath inserted into a blood vessel.

Fig. 7 shows the sheath positioned within a deep blood vessel.

Fig. 8A shows a sheath extending through a conduit attached to a blood vessel.

Fig. 8B shows the sheath extending partially through a conduit attached to a blood vessel.

Fig. 8C shows the sheath coupled with a hemostatic valve attached to a conduit of a blood vessel.

Fig. 9A-9D illustrate an embodiment of an intravenous reflux apparatus that may be used with the methods and systems of the present disclosure.

Fig. 10A-10E illustrate a procedure for implanting a stent at a carotid bifurcation in accordance with the principles of the present disclosure.

FIG. 11 illustrates an embodiment of a heavy caliber delivery system having a heavy caliber delivery system useful in the methods and systems of the present disclosure.

Fig. 12A-12E illustrate components and parts of the system shown in fig. 11.

13A-13B illustrate interrelated embodiments of a large caliber delivery system for delivering devices useful in the methods and systems of the present disclosure.

14A-14B illustrate a conduit having a side port consistent with embodiments of the present disclosure.

15A-15B illustrate a vascular ring assembly consistent with embodiments of the present disclosure.

Fig. 16 illustrates an example of a coupler consistent with embodiments of the present disclosure.

17A-17C illustrate interrelated embodiments of tubing assemblies for transporting devices useful in the methods and systems of the present disclosure.

Detailed Description

The disclosed methods, devices, and systems establish and facilitate access to blood vessels. These methods, devices and systems may provide temporary access to blood vessels for a variety of indications, including in the case of retrograde or reverse flow blood circulation in the bifurcation area of the carotid artery, to limit or prevent embolic release to the cerebral vasculature or peripheral vasculature leading to the cerebral vasculature, such as the internal carotid artery. These methods are particularly useful for interventional procedures such as stenting, stent graft or valve delivery, angioplasty, atherectomy, etc. by accessing the common carotid artery via the carotid artery. Interventional procedures may vary, including access to and treatment of cerebral vasculature, such as treatment of stroke, intracranial atherosclerotic disease (ICAD), transient Ischemic Attacks (TIA), acute Ischemic Strokes (AIS), tandem injuries, ruptured and unbroken intracranial and extracranial aneurysm embolism, chronic occlusion, and other disease conditions of the neurovasculature. The present disclosure also relates to methods and systems for accessing and treating other vessels, particularly where the access vessel is particularly deep or has a short stroke prior to bifurcation, including treatment of innominate orifice lesions, delivery of stent grafts (TEVARs) in the aorta, delivery of valves to the aortic root (TAVR), and the like.

Access to an artery, such as the common carotid artery, may be established by catheterizing a sheath or other tubular access into the lumen of the artery. In the case of the common carotid artery, the distal end of the sheath is typically located proximal to the junction or bifurcation B from the common carotid artery to the internal and external carotid arteries. In other indications, such as for neural access, the sheath may be positioned deeper and advanced beyond bifurcation B, e.g., beyond the rock crest within the intracranial portion of the Internal Carotid Artery (ICA), e.g., into the distal rock or cavernous portion of the internal carotid artery, through the carotid siphon, into the cerebral portion of the internal carotid artery and more distal sites, such as the anterior and middle cerebral arteries.

For a reflux system, the sheath may have an occlusion member, such as a compliant occlusion balloon, at the distal end. A catheter or guidewire with an occlusion member (e.g., balloon) may be placed through the access sheath and positioned in the proximal external carotid artery ECA to inhibit embolic access, but is generally not required to occlude the external carotid artery. A second return sheath may be placed in the venous system, such as the internal jugular vein IJV or the femoral vein FV. An arterial access sheath and a venous return sheath may be connected to create an external arteriovenous shunt. Retrograde flow may be established and regulated to meet patient requirements. The flow through the common carotid artery may be occluded with an external vascular ring or tape, vascular clamps, internal occlusion members such as balloons, or other types of occlusion devices. When flow through the common carotid artery is impeded, the natural pressure gradient between the internal carotid artery and the venous system will cause retrograde or reverse flow of blood from the cerebral vasculature, through the internal carotid artery and through the shunt into the venous system. Alternatively, the venous sheath may be removed and the arterial sheath connected to an external collection reservoir or container. The counter flow may be collected in this vessel. The collected blood may be filtered if desired and then returned to the patient during or at the end of the procedure. The pressure of the container may be open to atmospheric pressure, resulting in a pressure gradient that produces blood to flow back from the cerebral vasculature to the container or the pressure of the container may be negative. Alternatively, to achieve or enhance regurgitation from the internal carotid artery, flow from the external carotid artery may be blocked, typically by deploying a balloon or other occlusion element in the external carotid artery just above (i.e., distal to) the bifurcation of the internal carotid artery.

The tubing described herein may facilitate direct, temporary access to the CCA for the sheath and interventional tool or for the interventional tool alone in the absence of a sheath. If the access site vessel is a CCA and is very short between the access site and the bifurcation, no instrument need be inserted into the vessel. Instead, the tube may be sutured to the vessel and only instruments inserted into the tube, thereby reducing the risk of cutting the vessel at the access site. The pipeline sewn on the blood vessel can also conveniently and directly enter a very deep place of the blood vessel. Deep blood vessels tend to increase the risk of dissection because the introduction device needs to undergo severe rotation in order to be inserted into the lumen of the deep blood vessel or otherwise strike the back wall. The tubing sewn to the deeply positioned vessel may reduce the risk of posterior wall dissection as the tubing allows access to the vessel without requiring the instrument to make a sharp turn.

The systems, tools, procedures, and protocols described below may be used for carotid disease treatment, such as carotid stenting, angioplasty, atherectomy, and any other interventional procedure that may be performed in the carotid system, particularly at a location near the bifurcation of the internal and external carotid arteries. In addition, the systems and methods may be used in other vascular interventional procedures, such as treating acute strokes in more distal neuroanatomy. The systems and methods described herein may provide a conduit pathway for TCAR and neurovascular procedures, such as, for example, very short or very deep CCAs. The systems and methods described herein may provide access to procedures other than TCAR or neurovascular surgery (e.g., aspiration embolization). The tubing may be attached to the CCA to facilitate delivery of devices to be directed into the proximal CCA, aorta, and other locations. The systems and methods described herein may be used to treat innominate orifice lesions, deliver stent grafts (TEVARs) in the aorta, deliver valves to the aortic root (TAVR), and other procedures. The left and right carotid arteries can be used as access points, the right CCA enters the innominate artery, and the left CCA directly feeds the aorta, including aortic arch, ascending and descending aorta, aortic root, coronary artery, internal carotid artery, external carotid artery, intracranial vessel, etc. Devices for treating innominate, aortic or aortic valve disorders tend to be very large (e.g., 20-24F or larger). Delivery of these devices through the CCA and manipulation of the devices within the CCA may result in vascular injury and bleeding inside and around the device. Delivering large caliber devices via a tube directly sutured to the CCA may provide a safer, easier way to access the proximal CCA, the innominate artery, the aorta, and other locations.

The system and method may be part of a retrograde shunt loop. The reverse flow system can be attached directly to the tubing, thus excluding the larger arterial sheath from the system. The elimination of arterial sheaths can significantly reduce the overall flow resistance of the system, thereby providing increased reflux and improved embolic protection.

The present application relates to U.S. patent No.8,157,760 entitled "method and System for retrograde carotid blood flow (Methods and Systems for Establishing Retrograde Carotid Arterial Flow)" and U.S. patent publication No.2014/0296769 entitled "method and System for retrograde carotid blood flow (Methods and Systems For Establishing Retrograde Carotid Arterial Blood Flow)", both of which are incorporated herein by reference.

Fig. 1A shows a first embodiment of a retrograde flow system 100 adapted to establish and promote retrograde or retrograde blood circulation in the carotid bifurcation area to limit or prevent the release of emboli into the cerebral vasculature, in particular 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 external container in alternative embodiments). Retrograde flow system 100 includes tubing 105, arterial access device 110, venous return device 115, and shunt 120, shunt 120 providing a channel for retrograde flow from arterial access device 110 to venous return device 115. The arterial access device 110 may be inserted into the arterial lumen directly or through a tube 105 attached to the arterial wall. The flow control assembly 125 interacts with the flow splitter 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 flow divider 120 either external to the flow path, internal to the flow path, or both. Arterial access device 110 is at least partially inserted into the common carotid artery CCA and venous return device 115 is at least partially inserted into a venous return site, such as the internal jugular vein IJV, as described in more detail below. In one embodiment, the arterial access device 110 may be inserted through the tubing 105 attached to the common carotid artery such that the distal tip of the arterial access device 110 enters the vessel lumen, or the arterial access device 110 may be only partially inserted through the tubing 105 such that the distal tip of the arterial access device 110 does not directly enter the vessel lumen. In some embodiments, arterial access device 110 and tubing 105 are coupled together such that both are in fluid communication, but a portion of arterial access device 110 is not substantially inserted into the lumen of tubing 105. In still further embodiments, the system need not incorporate an arterial access device 110. The tubing 105 attached directly to the access site vessel may form part of a retrograde shunt loop. The flow dynamics of the retrograde shunt loop are improved for improved embolic protection by attaching the retrograde shunt loop directly to the tubing 105 without the need for a smaller diameter arterial access device 110. Where the system is described as having an arterial access device 110 and a tubing 105 interfacing with the device 110, the system may also be used without the device 110, but instead rely on the tubing 105, as will be described in more detail below.

Arterial access device 110 and venous return device 115 are coupled to shunt 120 at connection locations 127a and 127 b. When flow through the common carotid artery is impeded, the natural pressure gradient between the internal carotid artery and the venous system causes blood to pass from the cerebral vasculature through the internal carotid artery and through the shunt 120 into the venous system in a retrograde or reverse direction RG (fig. 2A). The flow control assembly 125 regulates, enhances, assists, monitors and/or otherwise regulates retrograde blood flow.

In the embodiment of fig. 1A, the arterial access device 110 enters the common carotid artery CCA via a transcervical access. The transcatheter arterial access provides a short length and non-tortuous path from the vascular access point to the target treatment site, as compared to, for example, a transfemoral access, thereby reducing the time and difficulty of the procedure. The arterial distance from the arteriotomy to the target treatment site (measured along the artery) is typically 15cm or less, but can be as short as 5cm to 10cm. Furthermore, this access path reduces the risk of embolic generation compared to navigating diseased, angled or distorted aortic arch or common carotid anatomy from the approach of the transfemoral site. At least a portion of the venous return device 115 is placed in the internal jugular vein IJV. In one embodiment, access to the common carotid artery via the carotid artery is achieved percutaneously by an incision or puncture in the skin through which the arterial access device 110 is inserted. If used, the incision may be about 0.5cm in length. An occlusion element 129, such as an inflatable balloon, may 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 may be located on the arterial access device 110 or it may be located on a separate device. In an alternative embodiment, the arterial access device 110 enters the common carotid CCA via a direct surgical trans-carotid approach. In a surgical approach, the common carotid artery may be occluded using tourniquet 2105. Tourniquet 2105 is shown in phantom to indicate that it is a device for an alternative surgical procedure. The tourniquet 2105 may be a Rummel device or an arterial loop or other hemostatic technique or tool.

In another embodiment, as shown in fig. 1B, arterial access device 110 enters the common carotid artery CCA by transcervical access, and venous return device 115 enters a venous return site other than the jugular vein, such as a venous return site including femoral vein FV. The venous return device 115 may be inserted into a central vein, such as the femoral vein FV, by percutaneous penetration in the groin.

In another embodiment, as shown in fig. 1C, the arterial access device 110 is passed through a femoral approach into the common carotid artery. Depending on the femoral approach, the arterial access device 110 accesses the CCA by percutaneous penetration into the femoral artery FA, for example in the groin, and up into the aortic arch AA into the target common carotid artery CCA. The venous return device 115 may be in communication with the jugular vein JV or the femoral vein FV.

Fig. 1D shows yet another embodiment in which the system provides retrograde flow from the carotid artery to the external vessel 130 rather than to the venous return site. Arterial access device 110 is connected to a reservoir 130 via a shunt 120, the shunt 120 being in communication with a flow control assembly 125. The retrograde flow of blood is collected in the container 130. If desired, the blood may be filtered and then returned to the patient. The pressure of the container 130 may be set to zero pressure (atmospheric pressure) or even lower, resulting in a reverse flow of blood from the cerebral vasculature to the container 130. Alternatively, to achieve or enhance reverse flow from the internal carotid artery, flow from the external carotid artery may typically be blocked by deploying a balloon or other occlusion element in the external carotid artery just above the internal carotid bifurcation. Fig. 1D shows the arterial access device 110 arranged with a CCA trans-carotid approach, but it should be understood that the use of the outer vessel 130 may also be used with the arterial access device 110 with a femoral approach.

Referring to the enlarged view of the carotid artery in fig. 2A, an interventional device (e.g., stent delivery system 135 or other working catheter) may be introduced into the carotid artery via arterial access device 110, as described in detail below. The stent delivery system 135 may be used to treat plaque P, such as deploying a stent into the carotid artery. Arrow RG in the table of fig. 2A indicates the direction of retrograde flow. Alternatively, the tubing 105 may be directly attached to the CCA and the stent delivery system 135 inserted directly through the tubing 105 without intervention of the arterial access device 110. The tubing 105 may be part of a retrograde shunt loop providing improved embolic protection due to the larger inner diameter. The conduit 105 may be sized to receive 4F to 6F, 10F to 15F, 20F-24F or more up to about 28F and any location therebetween. Devices used in transcervical arterial revascularization can be delivered through tubing 105 (e.g., stent delivery systems, balloons) and are often in the 4F to 6F size range. The conduit 105 may also allow devices in the range of 10F to 15F to pass through while still maintaining retrograde flow. In some embodiments where the device is introduced in a retrograde direction (e.g., toward the innominate artery or aorta), the device introduced through the conduit 105 may be in the size range of 24F to 36F.

Fig. 2B shows another embodiment in which an arterial access device 110 is used for the purpose of creating an arterial-venous shunt and introducing at least one interventional device into the carotid artery. A separate arterial occlusion device 112 with an occlusion element 129 may be used to occlude the common carotid artery CCA (see fig. 2C) at a location near the distal end of the arterial access device 110.

Fig. 2D shows yet another embodiment in which the arterial access device 110 is used for the purpose of creating an arterial-venous shunt and arterial occlusion using an occlusion element 129. A separate arterial introducer device may be used to introduce at least one interventional device into the carotid artery at a location distal to the arterial access device 110.

Fig. 2E shows an embodiment of the system wherein an arterial access device 110 is inserted through tubing 105, the tubing 105 being attached to the common carotid artery and having a coupler 107, such as a female luer fitting, a single-head, double-head or multi-head Rotary Hemostasis Valve (RHV), or other adapter or coupler. The coupler 107 may be any of a variety of adapters for vascular grafts that allow sealing and access to the lumen of the tube 105. Additional embodiments of the coupler 107 and conduit 105 are shown in fig. 11-17C. The distal end of the tube 105 may be temporarily attached to the vessel wall and the proximal end of the tube 105 may extend outside the body so that a user may access the lumen of the tube 105 through the coupler 107 to insert an interventional device (e.g., a catheter such as a balloon catheter, a large-bore aspiration catheter, a stent delivery catheter, etc.). The arterial access device 110 may extend completely through the tubing 105 such that the distal end of the device 110 is inserted into an artery (see also fig. 5E and 8A). The arterial access device 110 may extend partially through the tubing 105 such that the distal end of the arterial access device 110 does not directly enter the artery (see also fig. 8B). And further embodiments are contemplated in which the arterial access device 110 is not inserted into the tube 105 at all, but is coupled only at the coupler 107 to place the tube 105 and the arterial access device 110 in fluid communication with each other (see fig. 5F). Although fig. 2E shows the tube 105 attached to the common carotid artery, the tube 105 may also be attached to another access site, including a radius, ulna, subclavian, humeral, or femoral access site. The tubing 105 may be used in conjunction with a counter flow system such that a larger ID of the tubing 105 may provide advantages from a hydrodynamic standpoint to improve suction and/or counter flow. As described above, the tubing 105 may be directly attached to the CCA and form part of a retrograde shunt loop without any arterial access device 110. The interventional device may be inserted into a blood vessel through the tubing 105 without passing through a smaller diameter access sheath. The interventional device may have a size significantly smaller than the tubing 105 such that retrograde flow through the circuit is improved compared to the case where the interventional device is inserted through an 8F arterial sheath. The large bore tubing 105 may also allow for insertion of larger devices that would otherwise be difficult to advance through conventional sheath systems. Because the neuroprotective system can be directly attached to the tubing 105 without any arterial sheath, the overall flow resistance of the system can be significantly reduced and improved by embolic protection against reflux. This is a significant advantage during balloon or stent system delivery, when positioned within an arterial sheath, can occlude a substantial portion of the sheath cross-sectional area. The risk of emboli generated during part of the procedure, such as TCAR procedures, increases when catheters and instruments are delivered to the vasculature. Increasing retrograde flow rates during these "high risk" phases of the procedure may improve overall procedure results. Reducing the flow resistance may also reduce or eliminate the need to increase the patient's systemic blood pressure during TCAR procedures. In general, TCAR procedures may involve raising the patient's blood pressure to a hypertensive state (e.g., 140-160 mmHg) during the high risk phase of the procedure. Elevated blood pressure increases the arterial-venous pressure difference, thereby increasing reflux through the system, thereby theoretically improving embolic protection. The low resistance in the large bore tubing 105 may achieve good embolic protection without the need to raise the patient's blood pressure from the inside, thereby simplifying the procedure and benefiting the patient.

Each of the embodiments mentioned above and other embodiments will be discussed in more detail below.

Anatomical description

Lateral cerebral circulation

The wilis's ring is the main arterial anastomosis trunk of the brain where all main arteries supplying the brain, i.e. the two Internal Carotid Arteries (ICA) and the vertebral basilar arterial system are connected. Blood is delivered from the wilis's ring to the brain by the anterior, middle and posterior cerebral arteries. This communication between the arteries makes possible a collateral circulation through the brain. It is possible to flow blood through alternative routes, providing a safety mechanism in the event of one or more angiogenic obstructions supplying blood to the brain. In most cases, the brain can continue to receive an adequate blood supply even when an occlusion occurs somewhere in the arterial system (e.g., when an ICA is linked as described herein). Adequate cerebral blood flow is ensured by the flow of the Willis loop through a number of pathways that redistribute the blood to the deprived side.

The attendant potential of the wilis ring is believed to depend on the presence and size of its constituent vessels. It should be appreciated that there may be considerable anatomical differences among individuals in these blood vessels, and that many affected blood vessels may be diseased. For example, some people lack one of the traffic arteries. If an obstruction develops in these individuals, the collateral circulation is compromised, resulting in ischemic events and potential brain damage. Furthermore, the autoregulation response to decreasing perfusion pressure may include enlarging a side branch artery in the wilis's loop, such as a traffic artery. This compensation mechanism sometimes requires adjustment time before the side branch cycle can reach a level that supports normal function. This self-regulating reaction can take place in 15 to 30 seconds and can only compensate within a certain pressure and flow drop. Thus, transient ischemic attacks may occur during the adjustment. Very high retrograde flow rates over time can lead to conditions where the patient's brain is unable to obtain adequate blood flow, resulting in intolerance to the patient, manifested as neurological symptoms or in some cases, transient ischemic attacks.

Fig. 3 depicts normal brain circulation and formation of wilis's loop. The aorta AO produces the brachiocephalic artery BCA, which branches into the left common carotid artery LCCA and the left subclavian artery LSCA. The aorta AO further produces the right common carotid artery RCCA and the right subclavian artery RSCA. The vertebral artery VA branches off from LSCA and RSCA. The left and right common carotid arteries CCA produce the internal carotid artery ICA, which branches into middle cerebral artery MCA, posterior transport artery PcoA, and anterior cerebral artery ACA. The anterior cerebral artery ACA delivers blood to certain parts of the frontal lobe and striatum. Middle cerebral artery MCA is a large artery with tree branches that can deliver blood to the entire side of each hemisphere of the brain. The left and right posterior cerebral arteries PCA originate in the basilar artery BA and deliver blood to the posterior brain (occipital lobe).

In the front, the wilis' loop is formed by the anterior cerebral artery ACA and the anterior traffic artery ACoA connecting the two ACAs. Two posterior communicating arteries PCoA connect the wilis loop to two posterior cerebral arteries PCA, which branch from the basilar artery BA and complete the loop posteriorly.

The common carotid CCA also produces an external carotid artery ECA that branches widely to supply most of the structure of the head, except for the brain and orbital contents. ECA also helps to supply the neck and face structures.

Carotid bifurcation

Fig. 4 shows an enlarged view of the patient's neck-related vasculature. The common carotid artery CCA branches into an internal carotid artery ICA and an external carotid artery ECA at bifurcation B. The bifurcation is approximately at the level of the fourth cervical vertebra. Fig. 4 shows plaque P formed at bifurcation B.

As described above, the common carotid CCA may be accessed via a trans-carotid approach. The common carotid CCA may be accessed at an arterial access location L, which may be, for example, a surgical incision or puncture in the common carotid CCA wall, depending on the transcervical access. There is typically a distance D of about 5 to 7cm between the arterial access site L and the bifurcation B. When the arterial access device 110 is inserted into the common carotid CCA, it is undesirable for the distal tip of the arterial access device 110 to contact the bifurcation B, as this may destroy the plaque P and result in the generation of embolic particles. This is particularly dangerous for shorter CCAs. To minimize the likelihood that the arterial access device 110 will contact the bifurcation B, in one embodiment, only about 2-4cm of the distal region of the arterial access device may be inserted into the common carotid artery CCA during the procedure.

In other embodiments, the arterial access device 110 is placed in fluid communication with the common carotid artery via a conduit 105 attached to a vessel wall, such as the anterior vessel wall (see fig. 2E and fig. 8A-8C). The distal tip of arterial access device 110 may be inserted through the lumen of tubing 105 and into the lumen of the blood vessel a short distance (fig. 8A), or not enter the lumen of the blood vessel at all and remain within the lumen of tubing 105 (fig. 8B). The tubing 105 may provide for safer insertion of the arterial access device 110 and reduce the risk of plaque rupture. The tubing 105 may also reduce the risk of damage to the artery due to, for example, dissection or perforation of the blood vessel.

In still further embodiments, the tubing 105 is directly attached to the CCA and the system entirely excludes the arterial access device 110. The interventional tool is inserted directly through the tubing 105, the tubing 105 forming part of a retrograde shunt loop. Where the arterial access device 110 is described as being inserted through the tubing 105, it should be understood that the interventional device or tool may be inserted through the tubing without the need to incorporate any arterial access device 110 into the system.

Each side of the common carotid artery is enclosed in a layer of fascia called the carotid sheath. The sheath also encloses the internal jugular vein and the vagus nerve. In front of the sheath is the sternocleidomastoid muscle. Access to the common carotid artery and internal jugular vein, whether percutaneous or surgical, can be made directly over the collarbone, between the two heads of the sternocleidomastoid muscle and through the carotid sheath, taking care of avoiding the vagus nerve. One complication during insertion of the arterial access device 110 is the dissection of the CCA, particularly for anatomical structures in which the CCA is located relatively deep below the surface of the skin S. When the CCA is deep under the skin and sternocleidomastoid muscle, the insertion angle may be greater than 50 degrees, for example up to about 80 degrees. It is this angle that may lead to dissection of the vessel wall and even perforation of the arterial wall during insertion.

The tubing 105 may facilitate safe insertion of a catheter (e.g., interventional tool, arterial access device 110, etc.) into the CCA, even in these challenging anatomical structures that result in steep access angles. The tube 105 may be a temporary vascular tube attached to the anterior wall of the CCA via suturing using standard surgical techniques. As used herein, "temporary" refers to a period of time sufficient to perform an interventional procedure. The tubing 105, which is secured to the blood vessel and provides temporary access for the procedure, is temporary in that after the procedure, flow from the blood vessel through the tubing 105 is occluded, because the tubing 105 is removed from the blood vessel and the opening in the blood vessel is closed or because the lumen of the tubing 105 is occluded or sealed, such that flow through the tubing 105 is prevented after the procedure. Instead of being inserted directly through the vessel wall, the arterial access device 110 may be inserted through a conduit lumen and need not be advanced into the vessel lumen to be in fluid communication with the vessel lumen. The tubing 105 mitigates the risk of inadvertent release of CCA dissection or embolic material from plaque at the carotid bifurcation.

The device inserted through the conduit 105 may be advanced proximally from the common carotid artery, for example, into the innominate artery, a portion of the aorta (including the aortic arch, descending or ascending aorta, aortic root), or into the coronary artery. The tubing 105 may also provide access to devices intended to be inserted into the internal carotid artery, external carotid artery, or intracranial vessel for the purpose of performing a neurovascular procedure.

Detailed description of retrograde blood flow System with additional tubing

As discussed, embodiments of the retrograde flow system 100 include an arterial access device 110, a venous return device 115, a shunt 120 providing a channel for retrograde flow from the arterial access device 110 to the venous return device 115, and a conduit 105 configured to attach to an arterial wall and place the arterial access device 110 in fluid communication with an arterial lumen (see fig. 5D). The system also includes a flow control assembly 125, the flow control assembly 125 interacting with the shunt 120 to regulate and/or monitor retrograde blood flow through the shunt 120. The arterial access device 110 may be accessed into the blood vessel directly or through a separate tube 105. In an embodiment, the retrograde flow system 100 may incorporate a tubing 105, the tubing 105 having a distal end configured to be directly attached to a vessel wall and having a proximal end configured to be coupled to the shunt 120, for example, via a connector 107. In this embodiment, the arterial access device 110 is not included. An exemplary embodiment of the components of the retrograde flow system 100 will now be described.

Pipeline

Fig. 5C illustrates an embodiment of the conduit 105. Conduit 105 may be designed for use in a retrograde flow system 100. The tubing 105 may be a flexible tubular structure that is attachable to a vessel wall. The tubing material may be compliant and allowed to radially expand. This allows a larger device to be delivered through the tube 105 while minimizing the size of the arteriotomy/anastomosis. The inner and/or outer surfaces of the tubing may be coated with an antithrombotic material (e.g., heparin) and/or a hydrophilic material to facilitate delivery of the instruments and devices through the lumen of the tubing 105. The tubing 105 may be configured to accommodate patient anatomy and/or medical conditions that are detrimental to large caliber access, such as short/deep vessel procedures, diseased patients, anatomical, scar tissue patients, etc., and may reduce the difficulty or risk involved with such procedures or patients. Fig. 11-17C illustrate other interrelated embodiments of the conduits, which will be described in more detail below.

The conduit body may be a knitted or woven fabric that may provide flexibility and may be coated with a polymer to prevent blood leakage through the fabric. For example, the knitted or woven fabric may be PET and the coating may be polyurethane or a similar polymer. The leakage-preventing coating may be concentrated at the location where the suture is to be pulled through. The coating may also reduce wear of the fabric at the distal and/or proximal ends. The fabric may be a polyester polyethylene terephthalate fabric impregnated with collagen to create a leak-free tubing (e.g., maquet, getingab, hemashield Gold grafts).

The tubing 105 may be a synthetic arterial prosthesis or a molded biological fabric. The tubing 105 may be an arterial vascular graft made from a base material and extruded into a tube shape. The substrate may be a synthetic polymeric material such as polyethylene terephthalate (Dacron), polyester, nylon, expanded polytetrafluoroethylene (ePTFE), heparin bonded ePTFE, covered PTFE, annular reinforced ePTFE, nylon-ePTFE mixed braids, or other suitable materials. Tubing 105 may be formed from commercially available vascular grafts such as CARBOFLOW (Bard), FLIXENE PTFE (Atrilum Medical), PROPATEN (Gore), heparin vascular grafts of double layer structure of ePTFE and PET layers (FUSION BIOLINE, getinge AB), HERO hemodialysis access grafts (Merit Medical) or ACUSEAL (Gore). The tubing 105 may be formed of a bioabsorbable material such as Polyglycolide (PGA), polyglycolide-polylactic acid (PGA-PLA), poly (lactic-co-glycolic acid) (PGLA), polycaprolactone (PCL), and the like.

The distal end of the tube 105 may be attached to the vessel wall according to techniques known in the art. In some embodiments, the tubing 105 is sutured to the vessel wall such that the lumen of the tubing 105 is placed in fluid communication with the vessel lumen. The tube 105 may be sutured to the vessel wall using standard surgical techniques to form an end-to-side anastomosis (see Criado "iliac canal for intravascular access: technical considerations (Iliac arterial conduits for endovascular access: technical considerations)" J.Endovasc. Ther.2007 14 (3): 347-351). The tube 105 may also be attached using a seamless technique to create an end-to-side anastomosis. The conduit 105 may be implanted into an artery such that it is positioned at an angle relative to the longitudinal axis of the lumen of the blood vessel. The angle between the longitudinal axes of the conduit 105 and the vessel lumen may vary between 0 and 90 degrees, preferably between 20-45 degrees. The flexibility of the tubing 105 in combination with the flexibility of the blood vessel allows for a relatively tight angle of attachment compared to conventional access sheaths, while still allowing the device to safely pass through the tubing 105 into the blood vessel.

The tube 105 may be directly sutured to the vessel prior to the anastomotic arteriotomy being formed. After anastomosis is completed, an arteriotomy can be performed from inside the tube. This approach does not require distal or proximal declarations prior to anastomosis. Sutures used to suture the tube 105 to the vessel to form an anastomosis may also be used to initially close an arteriotomy in the vessel at the end of the procedure after the tube 105 is removed from its attachment.

The distal region of the tube 105 may include mechanical features configured to promote faster anastomosis and reduce bleeding. This feature may include a cap, a grommet, a sewing ring, or similar feature located in the distal region of the tube 105. The distal region of the tube 105 may include a pre-placed or pre-stitched closure suture positioned such that at the end of a procedure performed through the tube 105, similar to the "over-the-tube-sew" technique, the pre-placed suture may be tightened to rapidly close the tube 105 and vessel. Pre-placement of overseam sutures in the distal region of the tube 105 may help ensure more accurate placement of closure sutures to more completely and effectively close the tube 105. In the over-seaming technique, although there is no blood flow through the residue, a small residue of tubing material may remain after closure.

The tube 105 may incorporate stiffening features on the proximal region. The stiffening features on the tube may include one or more coils, braids, loops, or combinations thereof configured to mitigate kinking or collapse when the tube 105 is bent. The stiffening features may extend from the proximal region, terminating 1-2cm proximal to the distal-most end of the tube 105. Thus, the distal 1-2cm of the tubing 105 may be unreinforced to maintain the flexibility and pliability of the tubing material. This unreinforced region may be sewn to the vessel.

The tubing 105 may have an inner diameter sufficient to accommodate the outer diameter of an arterial access device or an outer diameter sufficient to accommodate any of a variety of interventional devices and tools for procedures such as transcervical revascularization (TCAR), treatment of unknown orifice lesions, delivery of aortic stent grafts (TEVAR), delivery of valves to the aortic root (TAVR), neurovascular procedures, and the like. In some embodiments, the tube 105 may have an inner diameter of between about 6mm and about 16 mm. In some embodiments, the tube 105 may have an inner diameter of between about 6mm and about 15 mm. In some embodiments, the tube 105 may have an inner diameter of between about 7mm and about 12 mm. In some embodiments, the tube 105 may have an inner diameter of between about 8mm and about 10 mm. In some embodiments, the arterial access device 110 is in the range of 7Fr to 10Fr sheaths. In this case, the inner diameter of the tube 105 is sized to receive a sheath of this size. Typically, the outer diameter of an 8Fr sheath is about 10.5F (1fr=0.33 mm). A sheath of this size can be inserted through the wall of an artery into the lumen of a blood vessel without causing unnecessary damage to the artery and yet be large enough to allow strong retrograde flow to protect the embolism. The tubing 105 may be significantly larger than this size because the tubing 105 is attached to the vessel wall rather than being inserted through the vessel wall and into the vessel lumen, typically having an inner diameter of about 6 mm. Where the outer diameter of the sheath into the vessel is limited by the inner diameter of the vessel lumen, the outer diameter of the tubing 105 is not limited. The outer diameter of the tube 105 may be about 16Fr to about 20Fr and may have an inner diameter in the range of 15Fr to 18Fr (5-6 mm). The means for treating the innominate, aortic or aortic valve disorders may be in the range of 20Fr to 24Fr or greater. The conduit 105 may be sized to accommodate up to 24Fr or larger sizes for these procedures. In some embodiments, the arterial access device 110 is in the range of a 12Fr to 36Fr sheath. In some embodiments, the arterial access device 110 is in the range of a 14Fr to 20Fr sheath.

The tubing 105 may be of any reasonable inner diameter that allows implantation to the vessel wall and allows a suitable fluid to flow through the tubing 105 for embolic protection during the procedure. In some embodiments, the inner diameter of the conduit is between about 2mm to about 10mm, or between about 4mm to about 8mm. The holes in the artery may likewise be about 6-8mm, depending on the size of the conduit. In some embodiments, the inner diameter of the tubing approximates the inner diameter of the vessel to which it is to be attached. It should be appreciated that the arterial access device 110 need not be inserted into the lumen of the tube 105 to be placed in fluid communication with a blood vessel. For example, the arterial access device 110 has no distal sheath such that when the arterial access device is coupled to the coupler 107, blood flows directly from the CCA into the inner diameter of the tube 105 such that the system is virtually devoid of arterial sheath. This reduces resistance to fluid flow if blood flows into a smaller arterial sheath (e.g., 2.7mm ID), which would otherwise occur. Decreasing the resistance to fluid flow increases retrograde flow through the system. The internal dimensions of other components in the system may also be increased to further reduce the flow resistance of the blood from the point where the proximal end enters the conduit.

The length of the tube 105 between the proximal and distal openings of the tube 105 may be about 1cm to 15cm, preferably about 5cm to about 10cm, and in some applications up to about 20cm to about 30cm, when in use. For example, consider a longer length greater than 20cm to directly couple to a blood vessel while also keeping the user away from the X-ray beam during fluoroscopy. The length of the tube 105 is sufficient to attach to the anterior wall of the CCA, even in the deeper anatomy of the CCA, and to extend a length beyond the neck incision to couple with the arterial access device 110 without causing external tension on the system. The length of the tubing 105 may be customized at the time of use. Thus, the length of the tubing 105 may be made longer than might be used in the procedure, e.g., at least about 30cm or between about 20cm and about 50cm, and sized when in use, e.g., between about 5cm and about 30cm. In still other embodiments, the conduit 105 may be provided in lengths ranging from about 5cm to about 30cm in various predetermined dimensions. The length of the tubing 105 between the proximal and distal ends may be longer than the length of the distal sheath such that the distal end of the distal sheath remains within the distal proximal of the tubing and the lumen of the tubing as the distal sheath extends through the lumen of the tubing 105. For example, the tubing may have an insertable length of between about 5cm and about 30cm, and the insertable length of the distal sheath may be shorter than this, for example between about 4cm and about 29 cm.

Devices such as arterial sheath 110 or other devices may be inserted through the proximal opening of tubing 105 or through the side wall of tubing 105. An arterial sheath 110 or other device may be secured within the tube 105 using a Rummel tourniquet, vascular ring, or similar device. Regardless of how the arterial sheath 110 (or the retrograde shunt if no sheath 110 is incorporated) is placed in fluid communication with the tubing 105, leakage of blood around the sheath and unintended movement of the sheath relative to the tubing will be controlled.

In one embodiment, the tube 105 may have a coupler 107 positioned within a proximal opening of the tube 105. The coupler 107 may be a luer fitting, a Hemostatic Valve Adapter (HVA) or a Rotary Hemostatic Valve (RHV), or other type of fitting. The coupler 107 may be configured for attachment to a standard connector (e.g., a syringe, stopcock, hemostasis valve, Y-connector, or other type of connector). The coupler 107 may provide securement of a sheath, such as an arterial access device 110 or shunt, that provides proximal attachment to the tubing 105 and hemostasis that prevents blood leakage during use. Additional, interrelated embodiments of the coupler 107 are described elsewhere herein, including fig. 11, 12A, 12E-14A, and 16. The coupler 107 may be an integrated non-standard connector that limits its compatibility to a particular mating component. The coupler 107 may be a multi-port adapter, each port having a rotary hemostatic valve. The multiport adapter allows additional devices to be introduced into the tubing 105 (and optionally into the CCA). For example, one or more ports may be used to deliver a "partner" wire or support catheter to facilitate delivery of the interventional device to a target site (e.g., a 0.014 "guidewire, balloon catheter, stent delivery system). One or more of the ports may be used to attach a supplemental extra-corporeal shunt line to increase retrograde flow through the system 100. One or more of the ports may be used to deliver aspiration catheters into the blood vessel, for example to the CCA or further into the ICA to provide supplemental embolic protection during the procedure, or aspiration to remove clots/thrombi in the case of an acute ischemic stroke. The tubing 105 may be incorporated into a retrograde flow system that may be used with any of a variety of tools and for any of a variety of procedures in the neurovasculature, coronary arteries, and peripheral vessels. The internal dimensions of the tubing 105 and the stable coupling between the tubing 105 and the access site vessel provide additional flexibility for the procedure to be performed while still providing adequate embolic protection. The blood flow through the aspiration catheter may be passive or the blood flow may be supplemented by an external vacuum pump.

A distal portion of the arterial access device 110 (e.g., distal sheath 605 shown in fig. 5A) may, but need not, be inserted through the tube 105. In some embodiments, the distal sheath 605 is inserted at least partially through the coupler 107 and into the lumen of the tube 105 (see fig. 5E and 8A-8B). The distal sheath 605 inserted into the lumen of the tubing 105 may be inserted far enough so that a coupler on the arterial access device 110 (e.g., distal coupler 690 shown in fig. 5D) near the distal sheath 605 may engage and attach to the coupler 107 of the tubing 105. The distal sheath 605 also includes a sheath lumen, and the sheath lumen diameter may be sized between about 12Fr to about 36 Fr. In some embodiments, the sheath lumen diameter may be between about 14Fr to about 20Fr in size. In other embodiments, the coupler 107 of the tubing 105 may be directly attached to the coupler of the arterial access device 110 without any sheath 605 inserted through the lumen of the tubing 105 (see fig. 5F). The tubing 105 attached to the arterial wall may replace any arterial sheath that is typically inserted into the lumen of a blood vessel. As discussed elsewhere herein, eliminating the presence of a sheath body in the flow circuit can greatly reduce the flow resistance, thereby providing increased retrograde flow rates and improved embolic protection. The tubing 105 is temporary and is removed after use, for example by removing sutures and closing holes in the vessel.

Arterial access device

Fig. 5A shows an exemplary embodiment of an arterial access device 110 that may include a distal sheath 605, a proximal extension 610, a flow line 615, an adapter or Y-connector 620, and a hemostatic valve 625. The arterial access device may also include a dilator 645 having a tapered tip 650 and an introducer guidewire 611. Arterial access devices may be used in conjunction with dilators and introducer wires to access a blood vessel. The characteristics of the arterial access device may be optimized for transcervical access. For example, the design of the access device components may be optimized to limit potential damage to the vessel due to acute angle insertion, allow atraumatic and safe sheath insertion, and limit the length of the sheath, sheath dilator, and introducer guidewire inserted into the vessel.

In some embodiments, distal sheath 605 includes an occlusion element 129 for occluding flow through a blood vessel, such as the common carotid artery. If the occlusion element 129 is an inflatable structure, such as a balloon or the like, 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 may also be an inflatable cuff, a conical or other circumferential element that flares outward to engage the internal wall of the common carotid artery to prevent antegrade blood flow through the occlusion element 129, a braid covering the membrane, a slotted tube that expands radially when compressed axially, or similar structures that can be expanded by mechanical means, or the like. In the case of balloon occlusion, the balloon may be compliant, non-compliant, elastic, reinforced, or have a variety of other characteristics. In one embodiment, the balloon is an elastomeric balloon that is tightly received on the exterior of the distal end of the sheath prior to inflation. When inflated, the elastomeric balloon can expand and conform to the inner wall of the vessel. In one embodiment, the elastomeric balloon is capable of expanding to at least twice the diameter of the undeployed configuration, often to at least three times the diameter of the undeployed configuration, more preferably at least four times the diameter of the undeployed configuration, or more.

Fig. 2B shows an alternative embodiment in which the occlusion element 129 may be introduced into the blood vessel on a second sheath 112 separate from the distal sheath 605 of the arterial access device 110. The second or "proximal" sheath 112 may be adapted for insertion into a blood vessel in a proximal or "down" direction away from the brain vasculature. The second proximal sheath may include an inflatable balloon 129 or other occlusion element, substantially as described above. The distal sheath 605 of the arterial access device 110 may then be placed into the blood vessel distal to the second proximal sheath and oriented generally in a distal direction toward the cerebral vasculature. By using separate occlusion and access sheath, the size of the arteriotomy required for introducing the access sheath can be reduced.

Fig. 2C shows yet another embodiment of a double-pulse sheath system, wherein the interventional device is introduced via an introducer sheath 114 separate from the distal sheath 605 of the arterial device 110. The second or "distal" sheath 114 may be adapted for insertion into a blood vessel distal to the arterial access device 110. As with the previous embodiments, the use of two separate access sheaths allows for a reduction in the size of each arteriotomy.

In the case of a sharp sheath insertion angle and/or a short sheath length inserted into the artery, as may be seen, for example, in a transcervical access procedure into the common carotid artery, the distal tip of the sheath has a high likelihood of being positioned partially or fully against the vessel wall, thereby restricting the flow into the sheath. In one embodiment, the sheath is configured to 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 block flow, but still center the tip of the sheath away from the vessel wall, just like an inflatable bumper. In another embodiment, the expandable feature is located at the tip of the sheath and mechanically expands once the sheath is in place. Examples of mechanically expandable features include braided structures or helical structures or longitudinal struts that radially expand upon shortening.

The distal sheath 605 is adapted for introduction through an incision, arteriotomy, or puncture in the vessel wall, such as an open surgical incision or percutaneous puncture established using the Seldinger technique. The sheath 605 may have a length in the range of 5cm to 15cm, typically 10cm to 12cm. Sheath 605 may also be placed in fluid communication with a blood vessel through tubing 105, as discussed elsewhere herein. In still further embodiments, the arterial access device 110 does not have a distal sheath 605, as will be described in more detail below.

The inner diameter of the distal sheath 605 may range from 7Fr (1fr=0.33 mm) to 10Fr, typically 8Fr. When inserting the distal sheath 605 through an arteriotomy, it is preferred that the OD be in the range of about not greater than about 10 Fr. As will be discussed in more detail below, the distal sheath 605 may be larger, such as between 15Fr and about 18Fr, when used with the tube 105.

Desirably, the sheath 605 is highly flexible while maintaining hoop strength to resist kinking and buckling, particularly when the sheath is introduced into the common carotid artery through a transcervical access, above the collarbone, but below the carotid bifurcation. Thus, the distal sheath 605 may be circumferentially reinforced, e.g., by a braid, helical ribbon, spiral, cut tube, etc., and lined such that the reinforcing structure is sandwiched between the outer sheath layer and the liner. The liner may be a low friction material such as PTFE. The outer sheath may 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 sheath material or thickness may be varied over the length of the sheath 605 to vary flexibility along the length.

The conduits described herein may be attached to any of a variety of access points, including the carotid, femoral, radial, brachial, ulnar, or subclavian arteries. Certain vascular structures (e.g., veins, left ventricular apex, axillary arteries, and aorta) may be used in place of the large caliber access, such as the access using the large caliber delivery system 1100 as described in further detail elsewhere herein. These structures are not as strong as the carotid artery, and procedures on these structures may benefit from the attachment of the tubing 105, which tubing 105 may be made of inorganic or graft materials, such as the tubing 105 of the large bore delivery system described herein (see fig. 11-17C). The tubing may be attached to the walls of these access vessels and another access device (e.g., sheath 605) advanced therethrough. Preferably, the conduit provides access without any other access device or sheath being inserted therethrough, so that the interventional device can be inserted directly through the conduit and toward the target anatomy for treatment. The interventional device may include a balloon catheter, a stent delivery catheter, an aspiration catheter, and the like. The interventional device may be inserted in a counter-current flow using a counter-current system of couplings attached directly to the tubing 105. The target vessel may also vary, including extracranial or intracranial vessels. The target vessel may include the common carotid artery CCA, external carotid artery ECA, internal carotid artery ICA, cerebral artery (middle cerebral artery M1 or M2 segments), vertebral artery, subclavian artery, brachiocephalic artery, innominate artery, ascending aorta, aortic arch, descending aorta, or aortic root. Other target vessels include vessels of the coronary anatomy, peripheral anatomy, or other vasculature. Coronary arteries include left and right coronary arteries, posterior descending branches, right peripheral arteries, left anterior descending branches, left circumflex branches, left peripheral arteries for M1 and M2, and diagonal branches for D1 and D2. Any of a variety of peripheral blood vessels are considered herein to be target blood vessels, including the popliteal artery, the anterior tibial artery, the dorsum tibial artery, the posterior tibial artery, and the fibular artery. Where specific anatomical structures are mentioned in the context of the devices described herein, other anatomical structures are considered, but may not be specified in each instance.

In some embodiments, the distal sheath 605 may have a stepped or other configuration with a distal region 630 of reduced outer diameter compared to a more proximal region, as shown in fig. 5B, which shows an enlarged view of the distal region 630 of the sheath 605. The distal region 630 of the sheath may be sized for insertion into the carotid artery, typically having an inner diameter ranging from 2.16mm (0.085 inch) to 2.92mm (0.115 inch), with the remaining proximal region of the sheath having a larger outer diameter and lumen diameter, the inner diameter generally ranging from 2.794mm (0.110 inch) to 3.43mm (0.135 inch). The larger lumen diameter of the proximal region minimizes the overall flow resistance of the sheath. In one embodiment, the reduced diameter distal portion 630 has a length of about 2cm to 4 cm. The relatively short length of the reduced diameter distal portion 630 allows the portion to be positioned in the common carotid CCA via a transcervical access while reducing the risk of the distal end of the sheath 605 contacting the bifurcation B. In addition, the reduced diameter portion 630 also allows for a reduction in the size of the arteriotomy for introducing the sheath 605 into the artery while having minimal impact on the flow resistance level. Further, the reduced distal diameter portion may be more flexible and thus more conformable to the lumen of a blood vessel.

Referring again to fig. 5A, proximal extension 610, which is an elongate body, has a lumen that abuts the lumen of sheath 605. The lumens may be joined by a Y-connector 620, the Y-connector 620 also connecting the lumen of the flow line 615 to the sheath. The flow line connection may terminate at a valve and the sheath may include a Y-adapter connecting the distal portion of the sheath to the proximal extension 610. The Y-adapter may also include a valve that may be operated to open and close a fluid connection with a connector or hub that may be removably connected to a flow line such as a diverter or the like. The valve may be positioned immediately adjacent to the lumen of the adapter that communicates with the lumen of the sheath body 605.

In the assembled system, flow line 615 connects and forms a first leg of retrograde flow splitter 120 (see fig. 1A). The proximal extension 610 may have a length sufficient to space the hemostatic valve 625 from the Y-connector 620, with the Y-connector 620 adjacent to the percutaneous or surgical insertion site. By spacing the hemostasis valve 625 from the percutaneous insertion site, the physician can introduce tools such as stent delivery systems or other working catheters into the proximal extension 610 and sheath 605 while being away from the fluoroscopic field of view when performing a fluoroscopic examination. In one embodiment, proximal extension 610 is about 16.9cm from the interface with the distal-most end of sheath 605 (e.g., at hemostasis valve 625) to the proximal end of proximal extension 610. 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 may range, for example, from 0.60 inch to 0.150 inch with a wall thickness of 0.010 inch to 0.050 inch. In another embodiment, the inner diameter may range, for example, from 0.150 inch to 0.250 inch with a wall thickness of 0.025 inch to 0.100 inch. The size of the proximal extension may vary. In one embodiment, the length of the proximal extension is 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.

In one embodiment, the distance along the sheath from the hemostasis 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 30cm to 35 cm. The system configuration allows for the introduction of a 2.5cm sheath into the artery with an arterial distance of 5cm to 10cm from the arterial incision site to the target site, and can achieve a distance ranging from the hemostasis valve 625 (the location where the interventional device is introduced into the access sheath) to about 32.5cm to 42.5cm from the target site between 32cm and 43 cm. This distance is about one third of the distance required in the prior art.

For a system configuration in which the sheath is not introduced into the artery and the tubing 105 is attached to the artery wall, the sheath dimensions may be the same or different than those described above. Likewise, sheath size may be optimized to optimize size for the access site to be used (e.g., femur, radius, humerus, ulna, subclavian bone, carotid artery, etc.) and according to the indication (e.g., carotid stenting in reverse). In some embodiments, the length of the tube 105 from the proximal opening to the distal opening may be about 5cm up to about 30cm. The coupler 107 may add additional length resulting in a total length of about 6cm to about 31cm. The distal sheath 605 may be shorter than the length, for example, between about 5cm to about 30cm, such that the distal tip of the distal sheath 605 remains within the tube 105 during use. In other embodiments, the distal sheath 605 is longer than the length such that at least a portion of the distal sheath 605 extends within the arterial lumen. The length of the distal sheath 605 extending within the arterial lumen may be between about 1cm and about 5 cm. This may depend on the anatomy of the patient and the length of the tube 105. In general, inserting arterial sheaths directly into a blood vessel presents greater difficulties and challenges when the vessel is about 4-5cm deep or deeper. Factors such as the length of the vessel, whether there is disease in the vessel near the desired insertion point, consistency of the vessel wall, operator skill, and whether there is disease distal to the insertion point all have a direct impact on sheath insertion into the vessel. The conduit 105 may be used to mitigate challenges due to any of these factors. In some embodiments, the distal sheath 605 may be inserted about 2.5cm into the blood vessel to ensure adequate stability. During insertion of the distal sheath 605, the tip of the dilator may extend beyond the tip of the distal sheath 605 (e.g., about 1.5 cm). To provide adequate support for the distal sheath 605 and dilator during insertion, a guidewire (e.g., a 0.035 "guidewire) is also inserted into the vessel beyond the minimum distance of the arteriotomy. The distance may be about 5cm and is preferably further than this. The system containing the tubing 105 can enter the blood vessel and establish a reflux in the patient without positioning any instrument distal to the arteriotomy, including a distal sheath, dilator, or guidewire.

The tubing 105 may be a pre-cut tubing. The pre-cut tubing provides an optimal access angle for the large bore device and eliminates the need for the physician to modify the tubing 105 during the surgical procedure. The tube 105 may be precut to a desired length, such as a length of about 5cm to about 30cm as described above. The improved attachment of the tubing 105 to the patient's blood vessel provides improved sealing of the tubing 105 to the access site and may allow the tubing 105 to be used in other medical professions that are not familiar with tubing attachment. In some embodiments, the tubing 105 may be formed of a bioabsorbable material that facilitates re-entry by leaving no material at the access site and a radiopaque marker that allows visualization of the previous access site. In some embodiments, the conduit 105 may be directly attached to the artery or vascular structure by suturing or other suitable attachment methods (e.g., clips, staples, etc.). In some embodiments, the tube 105 may have an angle of 15 ° -25 ° at the distal end 1125 of the tube 105, which may aid in the attachment and guiding of the tube 105 into an entry angle into an auxiliary device comprising a sheath and delivery system. In some embodiments, the tubing 105 may have pre-attached absorbent material (which is configured, for example, as gauze or suture sheath for attachment to an artery), bioabsorbable material (e.g., PGA-PLA, etc.). In some embodiments, the outer body of the tube 105 may be configured to be straight, corrugated, or have an outer ring for kink resistance. In some embodiments, the conduit 105 may have embedded radiopaque markers to aid in visualization for revisitation. The radiopaque markers may include any substance capable of absorbing X-rays, such as barium and iodine. The radiopaque markers may be embedded in the material of the tube 105, embossed onto the surface of the tube 105, adhered to the surface of the tube, or otherwise positioned on or within the tube 105, for example to facilitate visualization of the access site for possible re-entry.

Referring again to fig. 5A-5B, flush line 635 may be connected to one side of hemostasis valve 625 and may have a stopcock 640 at its proximal or distal end. The flush line 635 allows for the introduction of saline, contrast fluid, etc. during the procedure. The flush line 635 may also allow pressure monitoring during the procedure. A dilator 645 having a tapered distal end 650 may be provided to facilitate introduction of the distal sheath 605 into the common carotid artery. Dilator 645 may be introduced through hemostatic valve 625 such that tapered distal end 650 extends through the distal end of sheath 605. The dilator 645 may have a central lumen to accommodate the guidewire 611. Typically, the guidewire 611 is first placed into the vessel and the dilator/sheath combination is advanced over the guidewire 611 as it is introduced into the vessel. When used with tubing 105, the guidewire 611 is not required. Instead, the sheath 605 with the dilator 645 may be inserted through the coupler 107 of the tube 105 attached to the blood vessel.

The distal sheath 605 may be configured to establish a curved transition from a generally anterior-posterior approach on a blood vessel (e.g., common carotid artery) to a generally axial luminal direction within the blood vessel. Arterial access through the vessel wall by direct surgical incision or percutaneous access may involve different access angles that are larger than other arterial access sites, particularly where the insertion site is closer to the treatment site than other access points (i.e., carotid bifurcation). For example, arterial access through the CCA wall may require a greater access angle than access through the inguinal femoral vessel wall. In the case of CCA access and carotid artery treatment sites, a greater access angle is required to increase the distance from the insertion site to the treatment site to allow the sheath to be inserted a sufficient distance without the sheath distal tip reaching the carotid bifurcation. For example, the sheath insertion angle is typically 30-45 degrees or even greater via a transcervical passageway, while the sheath insertion angle may be 15-20 degrees to access the femoral artery. The sheath can be designed to bend more than typical introducer sheaths without kinking or undue forces on the opposing arterial wall. In addition, the sheath tip preferably does not abut or contact the arterial wall after insertion in a manner that would limit inflow into the sheath. The sheath insertion angle is defined as the angle between the arterial lumen axis and the longitudinal axis of the sheath.

The sheath body 605 may be formed in a variety of ways to allow for such greater bending as required for the angle of entry. For example, the sheath and/or dilator may have a combined flexural bending stiffness that is less than typical introducer sheaths. In one embodiment, the sheath/dilator combination (i.e., the sheath and the dilator positioned within the sheath) has a diameter of between about 80 and 100N-m ² x 10 ^-6 Combined flexural stiffness (E x I) over a range, where E is the elastic modulus and I is the area inertia of the deviceMoment. The individual sheaths may have a thickness of about 30 to 40N-m ² x 10 ^-6 Flexural rigidity in the range and with individual dilators having about 40 to 60N-m ² x 10 ^-6 Flexural rigidity in the range. Typical sheath/dilator bending stiffness is 150 to 250N-m ² x 10 ^-6 Within a range of (2). Greater flexibility may be achieved by choice of materials or by the design of the stiffener. For example, the sheath may have a stainless steel strip coil reinforcement sized from 0.002 inch to 0.003 inch thick and from 0.005 inch to 0.015 inch wide with an outer sheath hardness of between 40 and 55D. In one embodiment, the coil strap is 0.003 inch by 0.010 inch and the outer sheath hardness is 45D. In one embodiment, the sheath 605 may be preformed to have a curve or angle at a set distance from the tip, typically 0.5cm to 1cm. The preformed curve or angle may generally provide a turn in the range from 5 ° to 90 °, preferably from 10 ° to 30 °. For initial introduction, the sheath 605 may be straightened with an obturator or other straight or shaped instrument placed in its lumen, such as a dilator 645. After the sheath 605 has been introduced at least partially through a percutaneous or other arterial wall perforation, the obturator may be withdrawn to allow the sheath 605 to re-assume its preformed configuration into the arterial lumen. In order to maintain the curved or angled shape of the sheath body after straightening during insertion, the sheath may be heat set into the angled or curved shape during manufacture. Alternatively, the reinforcing structure may be composed of nitinol and thermoformed into a curved or angled shape during manufacture. Alternatively, additional spring elements may be added to the sheath body, such as spring steel or nickel titanium alloy strips, which have the correct shape to be added to the reinforcement layer of the sheath.

Other sheath configurations include having a deflection mechanism so that the sheath can be placed and the catheter can be deflected in situ to a desired deployment angle. In other configurations, the catheter has a non-rigid configuration when placed into the lumen of the common carotid artery. Once in place, a pull wire or other reinforcement mechanism may be deployed to shape and reinforce the sheath into its desired configuration. One particular example of such a mechanism is commonly referred to as a "form-locking" mechanism, also described in the medical and patent literature.

Another sheath configuration includes a curved dilator inserted into a straight, flexible sheath such that the dilator and sheath bend during insertion. The sheath is flexible enough to conform to the anatomy of the dilator after removal.

Another sheath embodiment is a sheath that includes one or more flexible distal sections such that once inserted and in an angled configuration, the sheath can bend at a large angle without kinking and without undue forces on the opposing arterial wall. In one embodiment, the distal-most portion of the sheath body 605 is more flexible than the rest of the sheath body. For example, the bending stiffness of the distal-most portion is one half to one tenth of the bending stiffness of the rest of the sheath body 605. In one embodiment, the bending stiffness of the distal-most portion is between 30 and 300N-mm ² Within a range of 500 to 1500N-mm and the remainder of the sheath body 605 ² Bending stiffness in the range. For a sheath configured for a CCA access site, the flexible distal-most portion includes a significant portion of the sheath body 605, which may be expressed as a ratio. In one embodiment, the ratio of the length of the flexible distal-most portion to the total length of the sheath body 605 is at least one tenth and at most one half of the entire sheath body 605 length. This change in flexibility may be achieved by various methods. For example, the hardness and/or material of the outer sheath may vary from part to part. Alternatively, the reinforcing structure or material may vary over the length of the sheath body. In one embodiment, the distal-most flexible portion ranges from 1cm to 3cm. In embodiments having more than one flexible portion, the less flexible portion (relative to the distal-most portion) may be 1cm to 2cm from the proximal-most portion. In one embodiment, the distal flexible portion has a thickness of about 30 to 50N-m ² x 10 ^-6 Flexural rigidity in the range of about 50 to 100N-m with the lower flex portion ² x 10 ^-6 Flexural rigidity in the range. In another embodiment, the more flexible portion is located between 0.5cm and 1.5cm and between 1cm and 2cm in length to create an articulating portion that allows the distal portion of the sheath to be more easily aligned with the vessel axis despite the angle of the sheath entering the artery. These have a variable The configuration of the flexible portion may be manufactured in a variety of ways. For example, the reinforced, less flexible portion may vary such that there is a stiffer reinforcement in the proximal portion and a more flexible reinforcement in the distal or articulating portion. In one embodiment, the outermost sheath material of the sheath has a hardness of 45D to 70D at the proximal portion and 80A to 25D at the distal-most portion. In one embodiment, the flexibility of the sheath varies continuously along the length of the sheath body. The flexible distal portion of the sheath body 605 allows the sheath to flex and the distal tip to be generally aligned with the lumen of the vessel. In one embodiment, the distal portion is made of a more flexible reinforcing structure by varying the spacing of the coils or braids or by incorporating a cutting hypotube with different cutting patterns. Alternatively, the distal portion has a different stiffening structure than the proximal portion.

In one embodiment, the distal sheath tapered tip is fabricated from a harder material than the distal sheath body. The purpose of this is to facilitate ease of sheath insertion by allowing a very smooth taper on the sheath and to reduce variations in sheath tip deformation or ovalization during and after sheath insertion into the vessel. In one example, the distal tapered tip material is made of a higher durometer material, such as a 60-72D Shore material. In another example, the distal tip is made of a separate material, such as HDPE, stainless steel, or other suitable polymer or metal. In further embodiments, the distal tip is made of a radiopaque material, either as an additive to the polymeric material (e.g., tungsten or barium sulfate) or as an inherent property of the material (as is the case with most metallic materials).

When used with the tube 105, the sheath need not be able to have such an angle, as the sheath may remain within the lumen of the tube rather than passing distally of the arteriotomy and directly into the vessel lumen.

In another embodiment, the introducer guidewire 611 is optimally configured for transcervical access. Typically, when inserting an introducer sheath into a blood vessel, an introducer guidewire is first inserted into the blood vessel. This may be accomplished by micro-piercing techniques or modified Seldinger techniques. Typically there is a long length of blood vessel in the direction in which the sheath is to be inserted, into which length the introducer wire can be inserted, for example into the femoral artery. In this case, the user may introduce a guidewire of between 10cm and 15cm or more into the vessel prior to inserting the sheath. The guidewire is designed with a flexible distal portion so as not to damage the blood vessel when introduced into the artery. The flexible portion of the introducer sheath guidewire 611 is typically 5cm to 6cm long, gradually transitioning to a stiffer portion. Insertion of the guidewire 10cm to 15cm means that the stiffer portion of the guidewire is located in the puncture area and provides stable support for subsequent insertion of the sheath and dilator into the vessel. However, in the case of insertion into the common carotid artery via the carotid sheath, there is a limit to how many guidewires can be inserted into the carotid artery. In the case of carotid bifurcation or internal carotid artery disease, it is preferable to minimize the risk of embolism by inserting a guidewire into the External Carotid Artery (ECA), which means that only about 5cm to 7cm of guidewire is inserted, or it is stopped before it reaches the bifurcation, which will only insert 3cm to 5cm of guidewire. Thus, a transcervical guidewire may have a distal flexible portion of between 3cm and 4cm, and/or a shorter transition to a stiffer portion. Alternatively, transcervical guidewires have atraumatic tip portions, but have very far and short transitions to stiffer portions. For example, the soft tip portion is 1.5cm to 2.5cm, followed by a transition portion of 3cm to 5cm in length, followed by a stiffer proximal portion that includes the remainder of the guidewire.

To use this sheath system embodiment, a micro-puncture kit may be used to initially access a blood vessel. A 0.018 inch guidewire is first inserted into a vessel through a 22Ga needle. A coaxially assembled sheath system was inserted over the 0.018 inch guidewire. The inner tube was first advanced over a 0.018 inch guidewire, which essentially translates it into an outer diameter and mechanical support equivalent to a 0.035 inch or 0.038 inch guidewire. It was locked at the proximal end to a 0.018 inch guidewire. The sheath and dilator were then advanced into the vessel through the 0.018 inch guidewire and inner tube. This configuration eliminates the guidewire replacement step, eliminates the need for longer dilator tapers as is currently required with a radial sheath, and has the same guidewire support as a standard introducer sheath. As described above, such a configuration of the sheath system may include a stop feature that prevents inadvertent advancement of the 0.018 inch guidewire and/or inner tube too far during sheath insertion. After insertion of the sheath, the dilator, inner tube, and 0.018 inch guidewire were removed.

The operator may also form a large hole in the arterial wall and attach a tube 105 to provide a large access portion through which the sheath may be delivered, or for directly attaching the reflux system without the sheath.

Another arterial access device is shown in fig. 5D-5E. The manner in which this configuration is connected to the shunt is different from the version previously described with respect to fig. 5A-5B. Fig. 5D shows the components of the arterial access device 110, including the arterial access sheath 605, the sheath dilator 645, the tubing 105, and the sheath guidewire 611. Fig. 5E shows an arterial access device 110 to be assembled for insertion through a sheath guidewire 611 into a blood vessel, which may be the common carotid artery or another access site as described elsewhere herein. After the sheath is inserted, for example, through the tubing 105, in fluid communication with the artery, the sheath guidewire 611 and sheath dilator 645 (if used) are removed. In this configuration, the sheath has a sheath body 605, a proximal extension 610, and a proximal hemostasis valve 625 with an irrigation line 635 and a stopcock 640. The proximal extension 610 extends from the Y-adapter 660 to the hemostasis valve 625, with the flush line 635 connected at the hemostasis valve 625. Sheath body 605 is the portion that is sized for insertion into the carotid artery and actually inserted into the artery during use.

Instead of having a Y-connector terminating in a valve flow line connection, the sheath has a Y-adapter 660 that connects the distal portion of the sheath to the proximal extension 610. The Y-adapter may also include a valve 670, the valve 670 may be operated to open and close a fluid connection to a connector or hub 680, which connector or hub 680 may be removably connected to a flow line such as a diverter. The valve 670 is positioned immediately adjacent to the lumen of the adapter 660, which lumen of the adapter 660 communicates with the lumen of the sheath body 605. During preparation of the arterial sheath, the valve 670 closes the connector. The valve 670 is configured such that there is no possibility of air entrapment during preparation of the sheath. Once the shunt 120 is connected to the hub 680, the valve 670 opens to the connector and will allow blood to flow from the arterial sheath into the shunt. This configuration eliminates the need to prepare flush lines and flow lines, but rather allows preparation from a single flush line 635 and plug valve 640. This single point preparation is the same as the preparation of a conventional introducer sheath without a connection to the shunt line and is therefore more familiar and convenient to the user. Furthermore, the absence of a flowline over the sheath makes it easier to dispose of the arterial sheath when preparing and inserting the artery.

Referring again to fig. 5D, the sheath may also contain a more distal second connector 690 that is separated from the Y-adapter 660 by a length of tubing 665. The purpose of this second connector and tubing 665 is to allow the valve 670 to be positioned further proximal to the distal tip of the sheath while still limiting the length of the insertable portion of the sheath 605 and thus allowing for reduced user exposure to the level of radiation source, as the shunt is connected to the arterial sheath during the procedure. In one embodiment, the distal connector 690 contains a suture eyelet to help secure the sheath to the patient after positioning.

As an example method, the tubing 105 may be useful in a transcervical arterial blood flow reconstruction (TCAR) procedure. In this procedure, arterial sheath 605 may be inserted into the patient's Common Carotid Artery (CCA) either directly or through tubing 105. It should be appreciated that sheath 605 need not be inserted so far through conduit 105 that it is also inserted into the common carotid artery. As described elsewhere herein, to achieve reverse flow of blood, the CCA may be occluded to prevent antegrade blood flow from the aorta through the CCA. The flow through the CCA may be occluded with an external vascular ring or tape, a vascular clamp, an internal occlusion member (e.g., balloon), or other type of occlusion device (e.g., tourniquet 2105 shown in fig. 1A). When flow through the CCA is impeded, the natural pressure gradient between the Internal Carotid Artery (ICA) and the venous system will cause retrograde or reverse flow of blood from the cerebral vasculature. Blood from ICA and External Carotid Artery (ECA) flows in a retrograde direction, and the system described herein allows retrograde blood to flow into sheath 605, through flow controller 125, venous return device 115, and back to the femoral vein of the patient as described elsewhere herein. Loose embolic material may enter the arterial sheath 605 with retrograde blood flow.

The vascular clip 800, such as a Rummel tourniquet or a vascular ring positioned near the sheath insertion site, may be used to provide manual occlusion of the vessel V by a clinician at an occlusion location near the distal tip of the sheath 605 from outside the vessel V. The occluding device may be externally mounted to the vessel V about the sheath tip, e.g., an elastic ring, an inflatable cuff, or a mechanical clamp that may be tightened about the vessel and distal sheath tip. In a retrograde system, this type of vascular occlusion may minimize the creation of static blood flow regions, thereby reducing the risk of thrombosis. This also ensures that the sheath tip is axially aligned with the vessel V and avoids the vessel wall from partially or completely occluding the distal opening.

Fig. 6 shows an arterial sheath 605 inserted directly into a blood vessel V (e.g., the common carotid artery) or into another vascular access site exposed through an incision I. The vascular access site need not be an incision procedure, but may be percutaneous. The sheath guidewire 611 and arterial access sheath dilator 645 protrude from a distal opening near the distal region of the sheath 605. Sheath plug 705 may be used with sheath 605 to prevent over-insertion of distal arterial sheath 605 into an anatomical structure, as described in U.S. publication No.2019/0125512, which is incorporated herein by reference. Fig. 7 shows arterial sheath 605 extending distally of sheath plug 705 inside vessel V. The tubing 105 may be used to insert the arterial sheath 605 into a blood vessel without any sheath plug 705 or mechanical hard stop to establish the insertion length of the sheath 605 (e.g., where a deeper passageway of the sheath 605 is desired). The sheath 605 may be advanced through the common carotid artery distal to the bifurcation to the distal portion of the internal carotid artery or through the rock portion of the ICA. In this embodiment, sheath plug 705 may preferably be eliminated to provide a deeper passageway that is not limited by a mechanical stop. Other indications may benefit from the presence of a sheath plug, for example, where the sheath is preferably implanted proximal to the bifurcation.

The sheath plug 705 may be in the form of a tube that is coaxially received outside of the distal sheath 605. The sheath plug 705 is configured to prevent the sheath from being inserted too far into the vessel V. The sheath plug 705 is sized and shaped to be positioned over the sheath body 605 such that it covers a portion of the sheath body 605 and exposes a distal portion of the sheath body 605. Sheath plug 705 may have an expanded proximal end that engages adapter 620 and a distal end that abuts the exterior of vessel V. The length of the sheath plug 705 limits the introduction of the sheath 605 to the exposed distal portion of the sheath 605 such that the sheath insertion length is limited to the exposed distal portion of the sheath. In one embodiment, the sheath plug limits the exposed distal portion to a range between 2cm and 3 cm. In one embodiment, the sheath plug limits the exposed distal portion to 2.5cm. In other words, the sheath plug may limit the scope of insertion of the sheath into the artery to between about 2cm and 3cm or 2.5cm. Second, the sheath plug 705 may engage a pre-deployed puncture closure device (if present) disposed in the carotid wall to allow the sheath 605 to be withdrawn without moving the closure device. The sheath plug 705 may also be made of a flexible material or the sheath plug 705 may include portions that articulate or add flexibility so that it allows the sheath to flex in place after insertion into an artery as desired. The sheath plug may be plastically bendable such that it may be bent into a desired shape to retain that shape when released by a user. The distal portion of the sheath plug may be made of a stiffer material while the proximal portion may be made of a more flexible material. In one embodiment, the harder material is 85A durometer and the more pliable portion is 50A durometer. In one embodiment, the stiffer distal portion is 1cm to 4cm of the sheath plug 705. The sheath plug 705 may be removable from the sheath so if the user requires a longer sheath insertion length, the user may remove the sheath plug 705, clip the length (of the sheath plug), and reassemble the sheath plug 705 onto the sheath so as to protrude a longer length of insertable sheath length from the sheath plug 705.

The sheath plug 705 may be deformed from a first shape (e.g., a straight shape) to a second shape that is different from the first shape, wherein the sheath plug retains the second shape until sufficient external force acts on the sheath plug to change its shape. The second shape may be, for example, a non-straight, curved, or other contour or irregular shape. The sheath plug 705 may have a plurality of curved portions and straight portions. The sheath plug 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 plug 705.

The sheath plug 705 may 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, especially if the sheath is inserted into the vessel at a steep angle. Even if the entry angle into the arteriotomy is relatively steep, the sheath plug can bend or otherwise deform into a shape that helps orient the sheath coaxially with the entering artery. The sheath plug may be shaped by the operator prior to insertion of the sheath into the patient. Alternatively, the sheath plug may be formed and/or reshaped in situ after insertion of the sheath into the artery.

In one embodiment, the sheath plug 705 is made of a malleable material or has an integral malleable member positioned on or in the sheath plug. In another embodiment, the sheath plug is configured to articulate using an actuator such as a concentric tube, a pull wire, or the like. The wall of the sheath plug may be reinforced with malleable wires or bands to help it retain its shape against external forces, such as when the sheath plug encounters an artery or an entry curve. Or the sheath plug may be constructed of a homogeneous malleable tube material comprising a metal and a polymer. The sheath plug body may also be at least partially composed of a reinforcing braid or coil capable of retaining its shape after deformation.

Another sheath plug embodiment is configured to facilitate adjustment of the sheath plug position (relative to the sheath), even after the sheath is positioned in the vessel. One embodiment of the sheath plug includes a tube having a slit along most or all of its length so that the sheath plug can be peeled off the sheath body, moved forward or backward as needed, and then repositioned along the length of the sheath body. The proximal end of the tube may have a tab or feature so that it can be grasped and peeled more easily.

In another embodiment, the sheath plug is a very short tube (e.g., a tether) or a ring located on the distal portion of the sheath body. The sheath plug may include features that can be easily grasped, for example with forceps, and pulled back or forth to a new position as needed to set the sheath insertion length to suit the procedure. The sheath plug may be secured to the sheath body by friction from the tube material or a clamp that may open or close against the sheath body. The clamp may be a spring loaded clamp that is typically clamped to the sheath body. To move the sheath plug, the user may open the clamp with his or her finger or instrument, adjust the position of the clamp, and then release the clamp. The design of the clamp does not interfere with the body of the sheath.

In another embodiment, the sheath plug includes features that allow suturing the sheath plug and sheath to patient tissue to improve fixation of the sheath and reduce the risk of sheath displacement. The feature may be a suture eyelet attached or molded into the sheath.

In another embodiment, as shown in fig. 6, the sheath plug 705 includes a distal flange that is sized and shaped to distribute the force of the sheath plug across a larger area on the vessel wall, thereby reducing the risk of vessel injury or accidental insertion of the sheath plug through an arteriotomy and into a vessel. The flange may have a rounded or other atraumatic shape that is large enough to distribute the force of the sheath plug across a large area on the vessel wall. In one embodiment, the flange is inflatable or mechanically expandable. For example, arterial sheaths and plugs may be inserted into the surgical field through a small puncture in the skin and then inflated prior to inserting the sheath into the artery.

The sheath plug may include one or more cuts or indentations along the length of the sheath plug that are patterned in a staggered configuration such that the indentations increase the flexibility of the sheath plug while maintaining axial strength to allow for the forward force of the sheath plug against the arterial wall. The indentations may also be used to facilitate securing the sheath to the patient by sutures to mitigate sheath displacement. The sheath plug may also include a connector element on the proximal end that corresponds to a feature on the arterial sheath such that the sheath plug may be locked or unlocked from the arterial sheath. For example, the connector element is a hub having generally L-shaped grooves that correspond to pins on the hub to create a bayonet-mounted connection. In this way, the sheath plug may be securely attached to the hub to reduce the likelihood that the sheath plug will be unintentionally removed from the hub unless it is unlocked from the hub.

Fig. 7 shows the distal end of arterial sheath 605 extending through sheath plug 705 within vessel V along a very steep approach angle. The angle between the axis of the vessel V and the axis of the sheath 605 (near the bend) is shown as about 50-60 degrees, but in some patient anatomies, the angle may be closer to 90 degrees to the axis of the vessel V. The distal-most tip of the sheath 605 extends toward the posterior wall of the vessel V, which, together with the steep angle, increases the risk of arterial dissection and perforation.

Unlike sheath plug 705, the distal-most end of tube 105 is configured to be secured to the vessel wall by suturing, thereby forming a leak-free connection with the vessel. The flexible tubing 105 may effectively become an extension of the vessel itself, just as a temporary anastomosis through which the arterial sheath 605 may be inserted.

The material of the tubing 105 as described elsewhere herein is inert, biocompatible, and strong. The material of the conduit 105 may be conformable, customizable, and relatively easy to handle. Preferably, the material of the tube 105 can be attached to the vessel wall by suturing, as opposed to another type of tube 105 that can only be inserted through a hole in the vessel sidewall. In some embodiments, the tubing 105 may be formed of polyethylene terephthalate (dacron), a polymer such as Polytetrafluoroethylene (PTFE), or a bioabsorbable material (e.g., PGA-PLA, PLGA, PCL, etc.). The tube 105 may be formed from one or more layers of material such as expanded polytetrafluoroethylene (ePTFE). Soft, resilient materials such as ePTFE are preferred, they can also carry fluids such as blood with little or no wall leakage. The softness and compliance of the material used to form the tubing 105 allows it to be relatively easily sutured, as the needle and suture may pass through the wall. Furthermore, the material is preferably tear resistant, which also makes it easier to suture than, for example, silicone tubing. The tubing 105 is preferably formed of a compliant material that is tear resistant and relatively fluid-tight and antithrombotic so that it can carry blood through its lumen and also form a leak-free seal at the tubing-vessel interface. ePTFE has all of these characteristics, making it particularly suitable for forming the tube 105. Other materials may have similar properties, such as tightly woven Dacron. If the tubing contains additional structural reinforcement to prevent tearing, a flexible elastomeric material, such as silicone, may be used. However, given the short term nature of the temporarily attached tubing 105, the reinforced silicone elastomer provides a more cost effective alternative to ePTFE.

The layer(s) of tubing 105 may be formed into a substantially cylindrical or tubular shape according to known techniques (e.g., extrusion, dip coating mandrels, etc.). The tubular shape may be tapered such that a first end of the tube 105 is smaller than an opposite end of the tube 105. The inner diameter of the tube 105 may be constant from the proximal end to the distal end, or may increase proximally near the coupler.

The tubing 105 may be designed for suturing to the vessel wall. The material of the tubular conduit 105 is configured to be penetrated by a needle and suture without snagging, tearing or ripping the wall of the conduit 105 while maintaining a substantial seal. The wall thickness of the tube 105 may be about 0.25mm to about 3.0mm. In some embodiments, the tube 105 has a gradual wall thickness such that at least one region has a reduced wall thickness for suturing. The reduced wall thickness segment of the tube 105 is at least 1mm long from the distal-most end. The sealing of the suture area allows tubing 105 to be used to transfer fluids into and out of the vessel lumen and through it to insert the device.

In some embodiments, the tube 105 may include an inner layer, an intermediate layer, and an outer layer of material. The inner layer may be heparinized to prevent platelet adhesion, and the middle layer may be elastic and configured to minimize post-suture leakage and suture hole bleeding.

The outer surface of the tube 105 may have one or more visual indicia to identify the length of the tube 105 from the proximal coupler. Visual indicia may provide guidance to a user attempting to customize the length of the conduit 105 prior to use. For example, the length of tubing 105 may be at least about 20cm from the coupler to the distal-most end. The tubing 105 may have visual indicia from the coupler to the distal-most end one per 5cm, so that the 20cm length of the tubing 105 may be more easily modified to 15cm, 10cm, or 5cm lengths. The visual indicia may provide any of a variety of graduations to identify length.

Fig. 8A-8C show a sheath 605 extending through the coupler 107 of the tube 105, the distal end of the tube 105 being attached to the wall of the vessel V. Sheath 605 may be inserted through coupler 107 on the proximal end of tube 105. Fig. 8A shows that the distal end of the sheath 605 may extend completely through the conduit 105 and out the distal end such that the distal end of the sheath 605 is positioned within the vessel V. Fig. 8B shows the distal end of sheath 605 remaining within the lumen of tubing 105 and not entering the vessel V-lumen. In this embodiment, the distal end of the sheath 605 remains outside the vessel and reduces the risk of dissection or perforation. In still further embodiments, the arterial access device does not have a distal sheath 605 inside the tube 105 (see fig. 5F), and the coupler 107 on the proximal end of the tube 105 is directly operably coupled with the distal coupler 690 of the arterial access device. The lumen of the tube 105 maintains its maximum size without any flow resistance due to the presence of smaller tubes within its lumen.

Fig. 8C shows the tubing 105 coupled directly to the blood vessel and having a coupler 107 at the proximal end, the coupler 107 being couplable to an arterial access device 110 of a retrograde system. As discussed elsewhere herein, the tubing 105 may be part of a retrograde shunt loop without any sheath extending within its lumen. The tubing 105 may thus replace the access sheath and be directly connected to the reflux circuit, and is also configured to insert the interventional device into a blood vessel without the use of a conventional access sheath (e.g., an 8Fr sheath). The coupler 107 of the tubing 105 may be a simple luer fitting (see fig. 5C), or the coupler 107 may be a multi-port device with a rotary hemostatic valve 670 at each port (see fig. 8C). Any of a variety of hemostatic coupling configurations are contemplated herein to provide fluid communication between the reverse flow shunt circuit and the lumen of the tube 105 such that reverse flow through the CCA may be directed out through the system 110 and such that one or more devices or fluids may be provided to the CCA and elsewhere.

The hemostatic Valve 670 (e.g., tuohy Valve, passive Valve) may be configured as an integrated hub or hemostatic Valve 670. The hemostatic valve 670 provides hemostasis without the need to insert a specific sheath into the tube 105. An integrated hub or hemostasis valve 670 may also provide hemostasis with the clamp during insertion and removal of the heavy gauge tool. A main port with an insert or small bore adaptor 1155 for small bore access may be used to increase the utility of the assembly in small bore applications. Auxiliary ports (e.g., Y-port 1120) may provide additional opportunities for retrograde blood flow or use of other surgical tools. The integrated hub or hemostasis valve 670 may be directly attached to the tubing 105. The integrated hub or hemostasis valve 670 can be attached to the distal tubular body 1605 by adhesive and/or over-molding. The integrated hub or hemostasis valve 670 may be a passive hemostasis valve with a self-sealing polymer valve. The integrated hub or hemostasis valve 670 may be an active Tuohy valve, for example, to allow passage of delivery devices and/or sheaths having the potential to restrict blood flow. The integrated hub or hemostasis valve 670 may be a combination of active and/or passive valves. The integrated hub or hemostasis valve 670 may be coated with silicone, or with another suitable polymer or plastic. The integrated hub or hemostasis valve 670 may include a second port 1120, such as for purging, venting, back flow, or other applications. The integrated hub or hemostasis valve 670 may have an insert, such as a hub-bearing insert or small bore adapter 1155, to facilitate small bore access as well as sheath/pigtail and wire delivery. The second port 1120 may be configured as a "Y" port.

Venous return device

Referring now to fig. 9A-9D, venous return device 115 may include a distal sheath 910 and a flow line 915 that connects and branches off of shunt 120 when the system is in use. The distal sheath 910 is adapted to be introduced into a venous return site, such as the jugular vein or femoral vein, by incision or puncture. The distal sheath 910 and the flow line 915 may be permanently affixed, or may be connected using a conventional luer fitting, as shown in fig. 9A. Alternatively, as shown in fig. 9B, sheath 910 may be coupled to flow line 915 by Y-connector 1005. The Y-connector 1005 may include a hemostasis valve 1010. The venous return device also includes a venous sheath dilator 1015 and an introducer guidewire 611 to facilitate introduction of the venous return device into the internal jugular vein or other vein. As with arterial access dilator 645, venous dilator 1015 includes a central guidewire lumen, so a venous sheath and dilator combination may be placed over guidewire 611. Alternatively, venous sheath 910 may include an irrigation line 1020 with a stopcock 1025 at its proximal or distal end.

Another configuration is shown in fig. 9C and 9D. Fig. 9C shows components of venous return device 115 including venous return sheath 910, sheath dilator 1015, and sheath guidewire 611. Fig. 9D shows the venous return device 115 to be assembled for insertion into the central vein through the sheath guidewire 611. Once the sheath is inserted into the vein, the dilator and guidewire are removed. The venous sheath may include a hemostatic valve 1010 and a flow line 915. A stopcock 1025 at the end of the flowline allows the venous sheath to be flushed through the flowline prior to use. This configuration allows the sheath to be prepared from a single point, as is done with conventional introducer sheaths. A connector 1030 on the plug valve 1025 is used to connect to the shunt 120.

To reduce the flow resistance of the overall system, arterial access flow line 615 (fig. 5A) and venous return line 915, and Y-connectors 620 (fig. 5A) and 1005 (fig. 9B) may each have a relatively large flow lumen inner diameter, typically in the range of 2.54mm (0.100 inch) to 5.08mm (0.200 inch), and may each have a relatively short length, typically in the range of 10cm to 20 cm. Low system flow resistance is desirable because it allows for maximizing flow during part of the procedure when the risk of embolism is greatest. The low system flow resistance also allows for the use of variable flow resistance to control flow in the system, as described in more detail below. The dimensions of venous return sheath 910 may be substantially the same as those described above for arterial access sheath 605. In the venous return sheath, an extension of hemostasis valve 1010 is not required.

Retrograde flow splitting

The shunt 120 may be formed of a single tube or a plurality of 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 therebetween. As shown in fig. 1A, the shunt 120 is connected at one end (via connector 127 a) to the flow line 615 of the arterial access device 110 and at the opposite end (via connector 127 b) to the flow line 915 of the venous return catheter 115.

In one embodiment, the flow splitter 120 can be formed from at least one tube in communication with the flow control assembly 125. The shunt 120 may be any structure that provides a fluid path for blood flow. The shunt 120 may have a single lumen or it may have multiple lumens. The shunt 120 may be removably attached to the flow control assembly 125, tubing 105, arterial access device 110, and/or venous return device 115. Prior to use, the user may select a shunt 120 having a length most suitable for use with arterial access locations and venous return locations. In embodiments, the shunt 120 may include one or more extension tubes that may be used to vary the length of the shunt 120. The extension tube may be modularly attached to the shunt 120 to achieve a desired length. The modular aspect of the shunt 120 allows the user to lengthen the shunt 120 as desired depending on the venous return site. For example, in some patients, the internal jugular vein IJV is small and/or tortuous. The risk of complications at this site may be higher than at other sites due to the proximity to other anatomical structures. Furthermore, cervical hematomas may lead to airway obstruction and/or cerebrovascular complications. Thus, for such patients, it may be desirable to locate the venous return site at a location other than the internal jugular vein IJV, such as the femoral vein. The femoral reflux site can be done percutaneously with less risk of serious complications and can also provide alternative venous access to the central vein if the internal jugular vein IJV is not available. In addition, femoral venous return alters the placement of the reflux diverter so that the diverter control device can be positioned closer to the "working area" of the intervention, i.e., where the introduction device and contrast media injection port are located.

In one embodiment, the shunt 120 has an inner diameter of 4.76mm (3/16 inch) and a length of 40-70cm. As previously mentioned, the length of the shunt may be adjustable. In one embodiment, the connector between the shunt and the arterial and/or venous access device is configured to minimize flow resistance. In one embodiment, arterial access sheath 110, retrograde shunt 120, and venous return sheath 115 are combined together to form a low flow blocking venous AV shunt, as shown in fig. 1A-1D. As mentioned above, the connections and flow lines of all these devices are optimized to minimize or reduce the flow resistance. In one embodiment, the AV shunt has a flow resistance that enables a flow of up to 300 milliliters per minute when no device is 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 vary depending on whether a check valve or filter is present or the length of the shunt, and may result in a flow rate between 150 and 300 ml/min.

When a device such as a stent delivery catheter is present in the arterial sheath, a portion of the arterial sheath has an increased flow resistance, which in turn increases the flow resistance of the overall AV shunt. This increase in flow resistance correspondingly reduces flow. In one embodiment, a Y-arm 620 as shown in fig. 5A connects the arterial sheath body 605 to a flow line 615 that is a distance from a hemostasis valve 625 where a catheter is introduced into the sheath. This distance is set by the length of proximal extension 610. Thus, the portion of the arterial sheath that is constrained by the catheter is constrained to the length of the sheath body 605. The actual flow restriction will depend on the length and inner diameter of the sheath body 605 and the outer diameter of the catheter. As described above, the sheath body 605 may range in length from 5cm to 15cm, typically from 10cm to 12cm, and the inner diameter typically ranges from 7Fr (1fr=0.33 mm) to 10Fr, typically 8Fr. The stent delivery catheter may range from 3.7Fr to 5.0 or 6.0Fr depending on the size and manufacturer of the stent. This limitation can be further reduced if the sheath body is designed to increase the inner diameter of the portion not in the blood vessel (stepped sheath body), as shown in fig. 5B. Since the flow restriction is proportional to the fourth power of the lumen distance, a small increase in lumen or annular area results in a large decrease in flow resistance.

The presence of the tubing 105 further reduces the flow resistance of the system 100, particularly if the tubing 105 is directly coupled to the distal coupler 690 of the arterial access system 110 and the arterial access system 110 has no distal sheath 605 or wherein the tubing 105 is directly coupled to the reverse flow shunt without any arterial access system 110. As discussed elsewhere herein, the inner diameter of the tubing 105 can be very large (e.g., between about 5-6 mm) compared to the inner diameter of an interventional device such as a stent delivery catheter or even an arterial access sheath designed for access to a vessel lumen (e.g., between 2.3mm and 3.0 mm). This size range of tubing 105 may promote a fairly rapid anastomosis time and provide sufficient inner diameter for delivery of devices having various sizes. The tubing 105 significantly reduces the flow resistance through the reverse flow circuit compared to an 8Fr or even 10Fr arterial sheath. The internal dimensions of the flow path near the tubing 105 may also be enlarged, resulting in a substantial increase in retrograde flow through the system, while increasing patient safety that is challenging for sheath insertion into anatomy.

The flow control assembly and regulation and monitoring of retrograde flow through the system is described in detail in U.S. publication No.2019/0125512, which is incorporated herein by reference.

Exemplary methods of use

Access to the common carotid CCA may be through a surgical incision through the carotid access. The tube 105 may be provided with a coupler 107 integral with the proximal end of the tube 105, or the coupler 107 may be attached to the proximal end of the tube 105 at the time of surgery. The tube 105 may be attached to the CCA using any of a variety of standard surgical techniques to perform end-to-side joining or anastomosis as discussed elsewhere herein. The tube 105 may be prepared by cutting the distal region to a desired overall length. The cut through the distal region of the tube 105 may be angled, e.g., beveled, relative to a longitudinal axis through the lumen of the tube 105, thereby forming a toe and a heel at the distal end of the tube 105. An arteriotomy can be performed on the exposed CCA wall at the target site to create a hole of the desired size. The length of the arteriotomy can be one and one half times the diameter of the tube 105. In other embodiments, an incision may be made in the vessel wall and the incision enlarged to create a hole. In one embodiment, the aperture may be about 5mm to 6mm along its largest dimension. Any of a variety of suturing techniques may be used to suture the distal end of the tube 105 to the vessel wall surrounding the aperture to form a sealed connection between the distal end of the tube 105 and the vessel wall. As described above, an arteriotomy can be formed by the tube 105 that has been attached to the vessel wall to provide a blood-free/clip-free anastomosis. The suture used to couple the tube 105 to the vessel may be pre-placed and/or may include one or more attachment features, such as a shield, washer, suture ring, or other distal features on the tube, for promoting a faster anastomosis and reducing bleeding.

10A-10E, flow through the carotid bifurcation at various stages of the method of the present disclosure will be described. The distal sheath 605 of the arterial access device 110 may be introduced or placed in fluid communication with the common carotid artery CCA through the tubing 105. In some embodiments, the distal end of the distal sheath 605 is inserted through the coupler 107 and into the lumen of the tube 105. The distal end of the distal sheath 605 may be inserted beyond the distal end of the tube. Preferably, the distal end of sheath 605 does not leave the distal end of tube 105 to enter the lumen of the blood vessel but resides within tube 105. In other embodiments, the arterial access device 110 does not have a distal sheath 605 and is coupled directly to the coupler 107 without any tubular feature extending into the lumen of the tube 105. After the arterial access device 110 has been placed in fluid communication with the common carotid artery CCA through the tubing 105, blood flow will continue in the antegrade direction AG from the common carotid artery into the internal carotid artery ICA and external carotid artery ECA, as shown in fig. 10A. In still further embodiments, no arterial access device 110 is incorporated into the system. The distal end of the tube 105 is directly coupled to the vessel, while the proximal end of the tube 105 is attached to the reverse flow circuit, for example, by a coupler 107. This embodiment maximizes the overall loop cavity size.

The venous return device 115 is then inserted into a venous return site, such as the internal jugular vein IJV (not shown in FIGS. 10A-10E) or the femoral vein. The shunt 120 is used to connect the flow lines 615 and 915 of the arterial access device 110 (or the coupler 107 of the tubing 105 in embodiments without an arterial access device 110) and the venous return device 115 (as shown in fig. 1A), respectively. In this way, the shunt 120 provides a passageway for the reverse flow from the tubing 105, arterial access device 110 (if present) to venous return device 115. In another embodiment, the shunt 120 is connected to the external reservoir 130 rather than to the venous return device 115, as shown in fig. 1C.

Once all the components of the system are in place and connected, flow through the common carotid CCA is stopped, typically by occluding the common carotid CCA using tourniquet 2105 or other external vascular occlusion device. The retrograde flow RG from the external carotid artery ECA and internal carotid artery ICA will then begin and will flow through the tubing 105 (sheath 605, if present), the flow line 615 (if present), the shunt 120 (if present), and into the venous return device 115 via the flow line 915. The flow control assembly 125 regulates retrograde flow as described above. Fig. 10B shows the occurrence of retrograde flow RG. While retrograde flow is maintained, an interventional tool 2110 may be introduced into the vessel, as shown in fig. 10C. The tool 2110 may be introduced through the hemostatic valve 615 and proximal extension 610 (not shown in fig. 10A-10E) of the arterial access device 110. The tool 2110 may be introduced through the coupler 107 of the tubing 105 and directly into the blood vessel without insertion through the arterial access device 110. Fig. 10D shows the interventional tool 2110 being a stent delivery catheter advanced into the internal carotid artery ICA and a stent 2115 deployed at bifurcation B. The interventional tool may also be an angioplasty catheter, a suction catheter, or any of a variety of interventional devices for treating the carotid artery, the internal carotid artery, or any of a variety of cerebral vessels. The tubing 105 may provide an access port for procedures other than TCAR and neurovascular procedures. For example, tubing 105 may be attached to the CCA to facilitate guiding device delivery to the proximal CCA, into the aorta and elsewhere for treatment of innominate orifice lesions, delivery of stent implants (TEVAR) in the aorta, delivery of valves to the aortic root (TAVR), and the like. These procedures typically involve larger devices that would benefit from accessing the vessel through a tube, rather than the traditional 8Fr access sheath. The tubing provides a safer pathway that may be more efficient and easier to access the proximal CCA, the innominate artery, the aorta, and other locations. The larger size of the direct access to the blood vessel provides particular advantages for inserting catheters and instruments that tend to be larger and prevent flow through conventionally sized sheaths, which makes retrograde flow embolic protection less effective.

The rate of retrograde flow may be increased during periods of higher risk of embolic generation, such as when introducing the stent delivery tube 2110 and optionally when deploying the stent 2115. Retrograde flow rates may also be increased during placement and expansion of the balloon for expansion either before or after stent deployment. Atherectomy may also be performed prior to retrograde flow stent placement. The tubing 105 may improve the fluid dynamics for deploying such devices by providing a larger internal dimension than conventional access sheaths.

Still further alternatively, after the stent 2115 has been expanded, the bifurcation B may be flushed by circulating retrograde flow between low and high flow rates. The intra-carotid area, where the stent has been deployed or other procedure is performed, may be flushed with blood before normal blood flow is reestablished. In particular, while the common carotid artery remains occluded, a balloon catheter or other occlusion element may be advanced into the internal carotid artery and expanded to fully occlude the artery. An external occlusion mechanism, such as tourniquet 2105, may also be used to occlude the common carotid artery. The same procedure may also be used to perform post-deployment stent expansion, which is typically performed in current self-expanding stent procedures. Flow from the common carotid artery into the external carotid artery may then be reestablished by temporarily opening the occluding device present in the artery. The resulting flow will thus be able to flush the common carotid artery, which sees a slow, turbulent or stagnant flow during carotid occlusion, into the external carotid artery. In addition, the same balloon may be positioned distally of the stent during retrograde and forward flow, and then established by temporarily unblocking and flushing the common carotid artery. Thus, a flushing action occurs in the stented region to help remove loose or loosely attached embolic debris in that region.

Optionally, as flow from the common carotid artery continues and the internal carotid artery remains occluded, steps may be taken to further loosen emboli in the treatment area. For example, mechanical elements may be used to clean or remove loose or loosely attached plaque or other potential embolic debris within the stent, thrombolytic or other fluid delivery catheters may be used to clean the area, or other procedures may be performed. For example, a balloon, atherectomy, or more stents may be used in retrograde flow to treat restenosis within the stent. In another example, the occlusion balloon catheter may include a flow or aspiration lumen or channel that opens proximally to the balloon. Saline, thrombolytic agents, or other fluids may be infused into and/or blood and debris drawn into or from the treatment area without the need for additional devices. While the emboli thus released will flow into the external carotid artery, the external carotid artery is generally less susceptible to embolic release than the internal carotid artery. By prophylactically removing residual potential emboli, the risk of embolic release is even further reduced when flow to the internal carotid artery is reestablished. The emboli may also be released in retrograde flow such that the emboli flow through shunt 120 to venous system, filter or container 130 in shunt 120.

After the bifurcation is cleared of the plug, the tourniquet 2105 (or the occlusion element 129 on the sheath 605, if applicable) may be released, reestablishing the antegrade flow, as shown in fig. 10E. Sheath 605 may then be removed from tube 105 or if sheath 605 is not used in the system, proximal coupler 660 is decoupled from coupler 107 on tube 105. The tube 105 may be removed from the vessel after use, for example by removing sutures attaching the distal end of the tube 105 to the vessel wall and closing the hole through the vessel wall with the sutures or another closing method. The vessel may be temporarily clamped proximally and distally of the aperture in the vessel to stop blood flow when the aperture in the vessel is closed. Alternatively, the tube 105 may be closed, for example, using a suture closure technique, such as by a pre-placed/pre-stitched suture positioned near the distal region of the tube 105.

The tubing 105 may provide an access port for procedures other than stenting. For example, the tubing 105 may be attached to the CCA to facilitate delivery of the device for stent graft in the aorta (TEVAR) or in combination with retrograde delivery of the valve to the aortic root (TAVR). The neuroprotective system can be directly attached to the tubing 105 such that the total flow resistance is much lower than if an access sheath were used to deliver the device for the procedure.

Fig. 11 illustrates a correlated embodiment of a large caliber delivery system 1100, which may be adapted for retrograde or countercurrent blood circulation as described elsewhere herein. The large bore delivery system 1100 (as the access system described in detail elsewhere herein) is further configured for use with a larger bore sheath or delivery system, such as for certain carotid procedures. As previously mentioned, some carotid artery patients or procedures (e.g., short/deep vascular procedures, ill patients, dissection, scar tissue patients, etc.) may require a larger mouth sheath or delivery system, and thus a larger access point for the carotid artery. Such patients and procedures would benefit from the use of large bore tubing (e.g., as part of large bore delivery system 1100).

An embodiment of a large caliber delivery system 1100 is shown in fig. 11-12E. The heavy caliber delivery system 1100 includes a conduit 105, which may be a polymer, fabric, graft, or other material, as described elsewhere herein. The tubing 105 may be coupled at a proximal end to a distal tubular body 1605 by a coupler 107. The distal tubular body 1605 may be a distal sheath 605 as described in further detail elsewhere herein, or may be a length of tubing that may include a polymeric material or other inorganic material. The length of the tube may be rigid or flexible. The distal tubular body 1605 may include at least a portion of a transparent or translucent material, for example, to visualize the contents of the distal tubular body 1605. The distal end of the distal tubular body 1605 is coupled to the tubing 105, and at least a portion of the proximal end of the distal tubular body 1605 is inserted into the hub assembly 1635. Hub assembly 1635 may include a hub 1135 having a side port 1134, a hemostatic valve 670 such as a Tuohy valve, a Tuohy knob 1140, and a strain relief connector 1130.

Referring now to fig. 12A-12E, the components of the heavy caliber delivery system 1100 are described in more detail. As shown in fig. 12A, a conduit 105 is included, which may include an inorganic material or a graft material, as described in further detail elsewhere herein. As previously described, the use of the heavy gauge delivery system 1100 may improve the surgical outcome because there is no need to manipulate the tissue surrounding the heavy gauge device to control the access site. The tubing 105 may be coupled to the distal tubular body 1605 by a coupler 107 as described above. The coupler 107 may be a pass-through pipe coupler, as shown in fig. 12A and 12E. Alternatively, coupler 107 may be any suitable coupler or connector (e.g., threaded or unthreaded coupler, non-female coupler, flange coupler, clip, clamp, etc.). The coupler 107 may be constructed of any suitable material, such as metal, plastic, polymer, bioabsorbable material, combinations of the foregoing, and the like. The tubing 105 may also provide increased certainty in the integrity of the material used for surgical site closure (i.e., tubing/graft material having better structural integrity than patient tissue).

Fig. 12A shows an exploded view of a large bore delivery system 1100, including tubing 105, coupler 107, and distal tubular body 1605, which may be connected as described above. Fig. 12A further illustrates an exploded view of hub assembly 1635. Hub assembly 1635 may include a strain relief connector 1130, a hub 1135 having a side port 1134, a hemostatic valve 670 such as a silicone Tuohy valve and Tuohy knob 1140, and a small bore adapter 1155. The small bore adapter 1155 is configured to allow the large bore delivery system 1100 to be connected to a small bore sheath or device. The coupling 107 may be configured as a pipe/polymeric tubing connector, as shown in fig. 12A. The coupler 107 provides a seamless transition between the tubing 105 and the distal tubular body 1605. Fig. 12E is a close-up view of the coupling 107 configured as a pass-through pipe coupling. As shown in fig. 12E, the coupler 107 has a distal end 1104 and a proximal end 1109. The coupler 107 may have a suture tab 1108 located at a point between the distal end 1104 and the proximal end 1109. The coupler 107 has an orifice 1103 with a lumen that places the tubing 105 in fluid connection with the distal tubular body 1605 when they are coupled via the coupler 107. The suture tab 1108 is perpendicular to the aperture 1103 and further includes a hole 1102 for connecting the suture tab 1108 to a blood vessel.

In some cases, such as shown in fig. 14A, the coupler 107 may also include a side port 1134 for a small bore passage. For example, side ports 1134 for small bore access may provide greater access site utility, including points for flashback. The transition of the seamless tubing 105 to the distal tubular body 1605 allows, for example, the overall length of the distal tubular body 1605 to be customized using less expensive materials (e.g., polymers). The distal tubular body 1605 may also help improve attachment to the hub 1135 or the hemostasis valve 1670. The suture tabs may provide an auxiliary location to stabilize the tubing 105 assembly. The coupler 107 may provide a transition from the tubing 105 to the distal tubular body 1605 or to the hemostatic valve 1670. Coupler 107 may include a side port 1134 with a hub 1135 and a hemostatic valve or Tuohy valve 1670, such as for a small bore adapter 1155 passageway (e.g., 4-8F sheath, pigtail catheter, or other device). The side ports 1134 may also be used for retrograde flow or for providing distal occlusion. As previously described, the coupler 107 may include suture tabs 1108 for securing the heavy gauge delivery system or assembly 1100 to a blood vessel.

The distal tubular body 1605, which may comprise, for example, a soft polymer, provides an alternative site for placement of a primary or secondary clip (e.g., clamp) to control blood flow to the heavy gauge delivery system 1100, such as to initiate retrograde flow, as described elsewhere herein. The distal tubular body 1605 may comprise a plastic or polymer that acts as a modified substrate for adhesive bonding to the hemostatic valve 670 or hub 1135. For example, the distal tubular body 1605 provides a length of tubing that is attached to the hemostatic valve 670 or hub 1135, such as by an adhesive, and the access device 110 may be inserted into the distal tubular body 1605 rather than directly attaching the access device 110 to the hemostatic valve 670 or hub 1135. The distal tubular body 1605 may be formed of a soft polymer and may include primary and/or secondary clamps, such as clips, tubes, or ratcheting clamps, as described above, for controlling blood flow to the heavy gauge delivery system 1100. The distal tubular body 1605 may be lined with a secondary polymer, such as PTFE liner, to provide better lubricity, or may be provided with a secondary reinforcement, such as by a braid or coil, to improve kink resistance. The secondary polymer may be any polymer composition suitable for providing improved lubrication. The auxiliary reinforcement may comprise a rigid or flexible plastic or polymer, a metal or metal alloy, or a combination of metal and polymer or plastic.

Fig. 12B is a transparent representation of hub 1135 with side ports 1134.

Fig. 12C is a perspective view of a small bore adapter 1155. The small bore adaptor 1155 includes a distal end 1156 and a proximal end 1157. The distal end 1156 is coupled to a large caliber delivery system 1100, while the proximal end 1157 is connected to a small caliber sheath or device. Fig. 12D is a close-up view of the proximal end 1157 of the small bore adapter 1155, which includes a coupling channel 1158, the small bore adapter 1155 being coupled to a small bore sheath or device at the coupling channel 1158. For example, the diameter of the arterial access device 110 may be smaller than the diameter of the distal tubular body 1605 such that the arterial access device 110 cannot be coupled to the distal tubular body 1605. The small bore adapter 1155 has an inner orifice that tapers from a smaller diameter at the proximal end 1157 to a larger diameter at the distal end 1156, thereby providing fluid communication between the small bore sheath or device and the distal tubular body 1605.

As discussed elsewhere herein, the conduit 105 may be formed of an inorganic material (e.g., a polymer or plastic). The conduit 105 may also be formed of a graft material formed of tissue such as the patient's own tissue. Fig. 13A-13B illustrate interrelated embodiments of a large bore delivery system 1300 that include a conduit 105 that may be formed of a graft material. As described above, the tubing 105 may be coupled to the distal tubular body 1605 by the coupler 107. The graft material may be formed of tissue and/or an inorganic material such as a polymer or plastic. The tubing 105 may be formed of polyethylene terephthalate (dacron), a polymer, or a bioabsorbable material. The tubing 105 may be coiled over a straight graft for attachment to a vessel or structure to which the heavy gauge delivery system 1300 is approximated. The distal tubular body 1605 is also coupled to a hemostatic valve 670, such as the passive hemostatic valve shown in fig. 13A and 13B. Fig. 13B shows another angle of the large bore delivery system 1300, showing the tubing 105 connected to the distal tubular body 1605 by the coupler 107.

Referring to fig. 14A-14B, an embodiment of a coupler 107 is shown. The coupler 107 may be a polymeric through pipe connector as shown at the bottom of fig. 14A and as shown in fig. 12E, or may be configured as a connector with a side port 1176 as shown at the top of fig. 14A. The connector with side port 1176 may be configured as a small bore access port that allows for the introduction of a small bore device into the large bore delivery system 1100. A connector having a side port 1176 is used to introduce another device, tool or substance into the heavy calibre delivery system 1100. Fig. 14B shows a transparent perspective view of hub 1135 with side ports 1134. Hub 1135 with side ports 1134 may be configured for large or small bore access.

Fig. 15A-15B and fig. 17A-17C illustrate an embodiment of a vascular ring controller 1165. The vascular ring controller 1165 is used to manage the vascular rings 1168 (see fig. 17A-17C). The vascular ring 1168 may be a disposable, single-use vascular ring for occluding, retracting, and/or identifying vessels, veins, or nerves and tendons during various medical procedures (such as those described herein). In some embodiments, one or more vascular rings 1168 are attached to the mechanism 1565 for actuation. For example, the blood vessel ring 1168 can be circumferentially wrapped around at least a portion of the distal tubular body 1605. Actuation of the blood tube ring 1168 may tighten the distal tubular body 1605, such as completely stopping blood flow, establishing retrograde flow, or stabilizing or "locking" the positioning of the device. The blood vessel loop 1168 may also be used to control bleeding through the complete seal or around the seal. In an embodiment, a knob such as Tuohy knob 1140 or other mechanism may be used to actuate the vascular ring 1168 (e.g., crank, motor, slider, pulling device, etc.). In some embodiments, the blood vessel ring 1168 may be formed of an elastomeric material (e.g., silicone, etc.) that does not elastically deform over the range of travel of the blood vessel ring 1168. The vascular ring controller 1165 may be attached to the tubing 105, for example, at the location of the coupler 107. The tube 105 may extend through an aperture 1510 in the controller 1165 such that the knob 1140 is located above the tube 105. The coupler 107 may be configured as a reversible clip or clamp for reversibly attaching the vascular ring controller 1165 or hub 1135 to the tubing 105 or graft material and placing the vascular ring controller 1165 in fluid communication with the tubing 105 or graft material. The vascular ring controller 1165 may then be used to introduce the vascular ring 1168 into the large caliber delivery system 1100. The coupling 107, when reversible, provides a means of temporarily securing the vascular ring controller 1165 or hub 1135 to the tubing 105 or graft material.

Fig. 16 shows one embodiment of a primary integrated clamp 1127. The primary integrated clamp 1127 is located on the tubing 105 or graft material and allows the physician to completely stop blood flow during device introduction and removal, thereby minimizing blood loss and establishing retrograde flow. Moving the position of the clamp from the conventional position of the patient's neck (proximal vessel) to a position on the tube 105 increases patient comfort and reduces the risk of arterial injury or the generation or release of embolic material upon occurrence of a disease in the artery. In some embodiments, a partially actuated clamp may be used, for example, to stabilize the position of the delivery system within the tube 105 for therapeutic device delivery. In some embodiments, the primary integrated clamp 1127 may be pre-positioned on the tubing 105 or distal tubular body 1605 to prevent blood flow through the tubing 105 assembly during device replacement. In some embodiments, the primary integrated clamp 1127 may be used to clamp the tubing 105 or distal tubular body 1605 partially to a sheath or delivery system, for example, to provide increased stability. The primary integrated clamp 1127 may construct a Cheng Luer fitting, as shown in fig. 16, or any other suitable clamp (e.g., spring clip, tube clamp, ratchet clip, vascular ring, tube clamp, etc.).

Referring now to fig. 17A, another embodiment of a large caliber delivery system 1700 is shown that includes a vascular ring controller 1165 as described above. The large bore delivery system 1700 is sized to accommodate a delivery device 1710, such as a TAVR delivery device. The system 1700 can include a hub 1135 having a side port 1134, a distal tubular body 1605, and an irrigation tube 1611. In some embodiments, side port 1120 of hub 1135 with side port 1134 is optional and tubing hub 1136 is used. The delivery device 1710 is inserted into the proximal end of a hub 1135 with a side port 1134. A hub 1135 with a side port 1134 is distally connected to the distal tubular body 1605. At the distal point of hub 1135 with side port 1134, the distal end near hub 1135 with side port 1134 is the connection point of irrigation tubing 1611. The flush tube 1611 may facilitate removal of liquid or gas from the heavy gauge delivery system 1700. The distal tubular body 1605 may then be connected to a hub at its distal end, for example, at a vascular ring controller 1165. The conduit hub 1136 may provide a secondary seal or mechanism to provide hemostasis. In some embodiments, the secondary seal or mechanism for hemostasis may be of passive design, such as a cross-cut silicone seal or a series of seals. Alternatively, the seal may be an active seal, such as a Tuohy valve or the like. Other possible features include a hub 1135 with a side port 1134 or small-bore adapter 1155 for delivering a small-bore device or sheath, or insertion into a primary hemostatic mechanism that allows the small-bore device to be delivered.

The distal tubular body 1605 is configured to attach to a vascular ring controller 1165 and may provide bridging between the conduit hub 1136 and the conduit 105, which may be a graft. In some embodiments, the distal tubular body 1605 has a hardness of about 15 shore a to about 80 shore a. In practice, the distal tubular body 1605 may have a hardness of about 10 shore a to about 100 shore a. In an embodiment, the distal tubular body 1605 may have a hardness of about 20 shore a to about 90 shore a. In an embodiment, the distal tubular body 1605 may have a hardness of about 30 shore a to about 80 shore a. In an embodiment, the distal tubular body 1605 may have a hardness of about 40 shore a to about 70 shore a. In embodiments, the distal tubular body 1605 may have a hardness of about 50 shore a to about 60 shore a. In some embodiments, the portion of the distal tubular body 1605 where the blood vessel ring 1168 is located after insertion may have a reduced wall thickness to facilitate actuation of the blood vessel ring 1168 in these regions. In some embodiments, the distal tubular body 1605 may be press fit onto the conduit hub 1136. In some embodiments, the distal tubular body 1605 may have a clamp or other connector for attachment to the conduit hub 1136 and/or graft material. In some embodiments, an adhesive or thermal bonding agent may also be employed to attach the distal tubular body 1605 to the conduit hub 1136 and/or the graft material. In some embodiments, the length of the distal tubular body 1605 between the tubing hub 1136 and the vascular ring controller 1165 can be used to remove air bubbles, i.e., outgassing, from the implant prior to delivery of the implant. This design may eliminate the loading tube and other features typically used with balloon inflation valves and other conventional interventions. This distal tubular body 1605 region also allows the user to pull the delivery device 1710 and/or sheath into the distal tubular body 1605 region, then fully close the vascular ring, and remove the delivery device 1710 and/or sheath to prevent blood loss during removal.

Fig. 17B shows a large bore delivery system 1700 comprising a tubing 105 and clamp 1116, a vascular ring controller 1165, a hub 1135 with a side port 1134, and a distal tubular body 1605. The tube 105 may be formed of Dacron or other suitable materials described elsewhere herein. The clamp 1116 is configured to couple the tubing 105 to the vascular ring controller 1165. The clamp 1116 may be any clip or clamp, permanent or reversible, suitable for connecting the tubing to the vascular ring controller 1165. Fig. 17C is a close-up view of the distal tubular body 1605 with the delivery device 1710 inserted therein. A portion of the distal tubular body 1605 may act as a window such that a user may view the delivery device 1710 within the distal tubular body 1605. Further, the user may perform blood flow control or remove air from the large bore delivery system 1700 when the delivery system is within the flexible tubing portion forming the window 1610.

In various embodiments, the description is with reference to the accompanying drawings. However, certain embodiments may be practiced without one or more of these specific details or in combination with other known methods and configurations. In the description, numerous specific details are set forth, such as specific configurations, dimensions, and procedures, in order to provide a thorough understanding of the embodiments. In other instances, well-known processes and manufacturing techniques have not been described in particular detail so as not to unnecessarily obscure the description. Reference throughout this specification to "one embodiment," "an embodiment," "one implementation," "an implementation," etc., means that a particular feature, structure, configuration, or characteristic described is included in at least one embodiment or implementation. Thus, the appearances of the phrases "one embodiment," "an embodiment," "one implementation," "an embodiment," and the like in various places throughout this specification are not necessarily referring to the same embodiment or implementation. Furthermore, the particular features, structures, configurations, or characteristics may be combined in any suitable manner in one or more embodiments.

Related terms used throughout the description may refer to relative positions or directions. For example, "distal" may indicate a first direction away from a reference point. Similarly, "proximal" may indicate a position in a second direction opposite to the first direction. However, these terms are provided to establish a relative frame of reference and are not intended to limit the use or orientation of the catheter and/or delivery system to the particular configuration described in the various embodiments.

The term "about" refers to a range of values including the stated value, which one of ordinary skill in the art would consider reasonably similar to the stated value. In an embodiment, approximately means within standard deviation using measurements generally acceptable in the art. In an embodiment, a range extending to +/-10% of the specified value is indicated. In an embodiment, the specified value is approximately included.

While this specification contains many specifics, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination and the claimed combination may be directed to a subcombination or variation of a subcombination. Similarly, although operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Only a few examples and embodiments are disclosed. Variations, modifications, and enhancements to the described examples and embodiments, as well as other embodiments, may be made based on the disclosure.

In the description above and in the claims, phrases such as "at least one" or "one or more" may appear after a connected list of elements or features. The term "and/or" may also occur in a list of two or more elements or features. Such phrases are intended to mean any element or feature listed alone or in combination with any other listed element or feature unless implicitly or explicitly contradicted by context in which such phrase is used. For example, at least one of the phrases "a and B; one or more of "" "A and B; "" A and/or B "means" A alone, B alone or A and B together ". Similar explanations apply to lists containing three or more items. For example, at least one of the phrases "A, B and C; one or more of "" "A, B and C; "" A, B and/or C "each means" A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together. "

The use of the term "based on" in the foregoing and claims is intended to mean "based, at least in part, on" such that unrecited features or elements are also permitted.

Claims

1. A system for accessing an artery through a transcervical access, comprising:

an arterial access device comprising a distal connector, a lumen, and a hemostatic valve spaced apart from the distal connector by the lumen; and

a tube having a lumen extending between a proximal end and a distal end and a coupler at the proximal end, the distal end of the tube configured for end-to-side coupling with a blood vessel,

wherein the distal connector of the arterial access device is configured to operably couple with a coupler at the proximal end of the tube to place the lumen of the arterial access device in fluid communication with the lumen of the tube.

2. The system of claim 1, wherein the conduit is a flexible tubular structure formed of a biological fabric.

3. The system of claim 1, wherein the conduit is a vascular graft.

4. The system of claim 1, wherein the vascular graft is formed from a substrate selected from the group consisting of polyethylene terephthalate, polyester, nylon, expanded polytetrafluoroethylene, heparin-bonded ePTFE, cap PTFE, ring-reinforced ePTFE, and nylon-ePTFE woven mixtures.

5. The system of claim 1, wherein the conduit lumen has a diameter of greater than about 2mm up to about 10 mm.

6. The system of claim 1, wherein the conduit lumen has a diameter between about 6mm and about 16 mm.

7. The system of claim 1, wherein the conduit lumen has a diameter between about 8mm and about 10 mm.

8. The system of claim 5, wherein the arterial access device further comprises a distal sheath coupled to and extending distally from the distal connector, the distal sheath comprising a sheath lumen.

9. The system of claim 8, wherein the sheath lumen has a size of 7Fr to 10Fr.

10. The system of claim 8, wherein the sheath lumen has a size of 12Fr to 36Fr.

11. The system of claim 8, wherein the sheath lumen has a size of 14Fr to 20Fr.

12. The system of claim 8, wherein a length of the tubing between the proximal end and the distal end is longer than a length of the distal sheath such that the distal end of the distal sheath remains within the lumen of the tubing and proximal of the distal end of the tubing as the distal sheath extends through the lumen of the tubing.

13. The system of claim 12, wherein the length of the tubing is 5cm to 30cm, and wherein the length of the distal sheath is 4cm to 29cm.

14. The system of claim 1, wherein the blood vessel is the common carotid artery, the femoral artery, the radial artery, the brachial artery, the ulnar artery, or the subclavian artery.

15. The system of claim 1, further comprising a shunt fluidly connected to the arterial access device, wherein the shunt provides a path for blood to flow from the arterial access device to a return site.

16. The system of claim 15, further comprising a flow control assembly coupled to the shunt and adapted to regulate blood flow through the shunt.

17. The system of claim 15, further comprising a suction device coupled to a port on the shunt.

18. The system of claim 17, wherein the aspiration device is a syringe or pump.

19. The system of any of the preceding claims, wherein the system further comprises a distal adapter coupled to and extending distally from the distal sheath.

20. A system for accessing an artery through a transcervical access, comprising:

A tube having a lumen extending between a proximal end and a distal end, the distal end of the tube configured for operative end-to-side coupling with a blood vessel;

a coupler located at a proximal end of the tube; and

a shunt fluidly connected to the coupler such that an inner lumen of the conduit is coupled to a lumen of the shunt, the lumen of the shunt providing a path for blood from the conduit, through the shunt and to a return site.

21. The system of claim 20, further comprising a port in fluid communication with the shunt, wherein the port is configured to connect a suction device to the shunt, wherein a distal connector of the arterial access device is configured to operably couple with the coupler at a proximal end of the tube, thereby fluidly communicating a lumen of the arterial access device with an inner lumen of the tube.

22. The system of claim 20, wherein the conduit is a flexible tubular structure formed of a biological fabric.

23. The system of claim 20, wherein the conduit is a vascular graft.

24. The system of claim 23, wherein the tubing provides an access port for procedures in the innominate arterial orifice, aorta, aortic root, carotid artery, or cerebral vessel.

25. A method for treating a patient, the method comprising:

attaching a tube to a wall of a blood vessel, the tube having a lumen extending between a proximal end and a distal end, a distal end of the tube being attached to the wall;

forming an arteriotomy in a wall of the blood vessel;

inserting a device through the lumen of the tube and into the blood vessel; and

treatment is performed with the device.

26. The method of claim 25, wherein the proximal end of the tube comprises a coupler, wherein the device is inserted into the lumen of the tube through the coupler.

27. The method of claim 25, wherein attaching the conduit to the wall further comprises suturing the conduit to the wall with a suture.

28. The method of claim 27, further comprising cinching the suture after performing the treatment to perform a primary closure of the vessel.

29. The method of claim 25, wherein the distal end of the tube includes a mechanical element to facilitate attachment of the tube to the vessel.

30. The method of claim 29, wherein the mechanical element comprises a cap, a washer, or a sewing ring.

31. The method of claim 25, wherein forming the arteriotomy comprises forming the arteriotomy through a lumen of a tube attached to a wall of the blood vessel.

32. The method of claim 25, further comprising reversing blood flow through the blood vessel while the treatment is being performed.

33. The method of claim 32, wherein the blood vessel comprises the common carotid artery.

34. The method of claim 33, further comprising advancing the device through the common carotid artery to a innominate artery, aortic arch, descending aorta, ascending aorta, aortic root, coronary artery, internal carotid artery, external carotid artery, or intracranial vessel.

35. The method of claim 34, wherein the device comprises a balloon catheter, a stent delivery catheter, or an aspiration catheter.

36. The method of claim 25, wherein the treatment comprises one or more of stent delivery, angioplasty expansion, stent graft delivery, valve delivery, aspiration embolectomy, and combinations thereof.

37. The method of claim 25, wherein the lumen of the tube has a diameter between about 6mm and about 16 mm.

38. The method of claim 25, wherein the lumen of the tube has a diameter of between about 8mm and about 10 mm.

39. A method for treating a patient having atypical anatomy, the method comprising:

forming an arteriotomy in a wall of the blood vessel;

inserting a device through the lumen of the tube and into the blood vessel; and

treatment is performed with the device.

40. The method of claim 39, wherein the proximal end of the tube comprises a coupler, wherein the device is inserted into the lumen of the tube through the coupler.

41. The method of claim 39, wherein attaching the conduit to the wall further comprises suturing the conduit to the wall with a suture.

42. The method of claim 41, further comprising cinching the suture after performing the treatment to perform a primary closure of the vessel.

43. The method of claim 39, wherein the distal end of the tube includes a mechanical element to facilitate attachment of the tube to the vessel.

44. The method of claim 43, wherein the mechanical element comprises a cap, a washer, or a sewing ring.

45. The method of claim 39, wherein forming the arteriotomy comprises forming the arteriotomy through a lumen of a tube attached to a wall of the blood vessel.

46. The method of claim 39, further comprising reversing blood flow through a blood vessel while performing the treatment.

47. The method of claim 46, wherein the blood vessel comprises a vein, left ventricular apex, axillary artery, or aorta.

48. The method of claim 47, further comprising advancing the device through a vein, left ventricular apex, axillary artery, or aorta to an innominate artery, aortic arch, descending aorta, ascending aorta, aortic root, coronary artery, internal carotid artery, external carotid artery, or intracranial vessel.

49. The method of claim 39, wherein the device comprises a balloon catheter, a stent delivery catheter, a vascular ring, or an aspiration catheter.

50. The method of claim 39, wherein the treatment comprises one or more of stent delivery, angioplasty expansion, stent graft delivery, valve delivery, aspiration embolectomy, and combinations thereof.

51. The method of claim 39, wherein the lumen of the tube has a diameter between about 6mm and about 16 mm.

52. The method of claim 39, wherein the lumen of the tube has a diameter of between about 8mm and about 10 mm.

53. The method of claim 39, wherein the conduit further comprises a vascular ring controller located at a proximal end of the conduit opposite the blood vessel, wherein the vascular ring controller is configured to actuate one or more vascular rings.