Systems and methods for vascular intervention

Abstract

Various embodiments of an aspiration catheter configured for removing obstructions from a patient's blood vessel and associated methods are disclosed. The aspiration catheter comprises an elongate body having a reinforcing member extending along a first length of the elongate body. In some embodiments, the aspiration catheter comprises one or more of a deformer, such as a moveable deformer, a shaped distal end, and an obstruction gripper for efficiently and effectively holding and removing the obstruction to restore blood flow.

Description

[Technical Field]

[0001] (Cross-reference with related applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 212,514, filed on 18 June 2021 under 119(e) of the U.S. Patent Act, entitled “System and Method for Vascular Intervention,” which is incorporated herein by reference in its entirety. [Background technology]

[0002] Blood clots can be fatal and can lead to loss of limbs or cognitive function. Furthermore, the longer a blood clot remains in place, the greater the risk to the patient. For example, it is possible to dissolve blood clots using thrombolytic or anticoagulant drugs, but the use of such medications can cause serious complications in the patient, such as bleeding or stroke. Blood clots can also be removed using devices, but at least some of the thrombectomy devices currently available require several passes to capture and / or remove the clot.

[0003] For example, in acute ischemic stroke (AIS), time is crucial for patient outcomes because the longer the ischemic hemiinfiltration in the brain expands, the more likely it is to cause fatal damage to the patient. Therefore, the sooner a physician removes the thrombus from the neurovascular anatomical structure, the more the penumbra can be limited, leading to a better patient outcome. One limiting factor in this scenario is the number of passes required for a physician to completely remove the thrombus and fully recanalize the vessel. The more recanalizations required, the longer the penumbra expands. Devices and methods for safe and effective thrombectomy as quickly as possible can improve the prognosis of patients with occlusion. [Overview of the project]

[0004] The aspects of the present subject matter include various embodiments and related methods of suction catheters configured for removing thrombi from a patient's blood vessels. In one embodiment, the suction catheter may comprise an elongated body formed of a flexible material and having an inner lumen extending between a proximal body end and a distal body end. The inner lumen may be defined by an inner wall and may form a distal opening in the distal body portion. The suction catheter may further comprise a reinforcing member extending along a first length of the elongated body between a proximal reinforcing end and a distal reinforcing end. The distal reinforcing end may be positioned a second length from the distal body end of the elongated body. The suction catheter may comprise a deformer extending along a second length of the elongated body. The deformer may be coupled to a second length such that the distal opening has a first opening diameter when the deformer forms a first configuration and has a second opening diameter when the deformer forms a second configuration, with the second opening diameter being larger than the first opening diameter.

[0005] In some variations, one or more of the following features may be optionally provided in any feasible combination. The deformer may include an inflatable balloon. The inflatable balloon may extend spirally along a second length of an elongated body. The inflatable balloon may be twisted along a second length of an elongated body. The distal opening may form a first suction region when the inflatable balloon is in the first configuration and a second suction region when the inflatable balloon is in the second configuration. The second suction region may be larger than the first suction region. The first and second suction regions may each be defined by one or more of the diameter and cross-sectional area of ​​the distal opening. The inflatable balloon may deflate when in the first configuration and inflate when in the second configuration. The deformer may include a shape memory member. The shape memory member may include a nitinol material that migrates between the first and second configurations based on the temperature of the shape memory member. The shape memory member may include at least one nitinol wire extending longitudinally along the second length. The shape memory member may include a stent retriever. The elongated body may have a portion along a second length that is more flexible than the portion along a first length. The reinforcing member may include one or more of a Teflon® liner and a metal wire. The suction catheter may further include a plurality of LCP fibers extending along the second length of the elongated body. The first LCP fibers of the plurality of LCP fibers may be oriented longitudinally along the elongated body, and the second LCP fibers of the plurality of LCP fibers may be oriented circumferentially along the elongated body.

[0006] In another embodiment, the suction catheter may comprise an elongated body formed of a flexible material and having an inner lumen extending between a proximal body end and a distal body end. The inner lumen may be defined by an inner wall and may form a distal opening at the distal body end. The suction catheter may further comprise a reinforcing member extending along a first length of the elongated body between a proximal reinforcing end and a distal reinforcing end. The distal reinforcing end may be positioned a second length from the distal body end of the elongated body. The suction catheter may comprise a movable deformer slidably positioned along the inner lumen of the tubular elongated body. The movable deformer may be slidable along the first length of the elongated body. The movable deformer may form a folded configuration along the first length, allowing the distal opening to form a first opening diameter. The movable deformer may be movable to a second length to form an expanded configuration, allowing the distal opening to form a second opening diameter. The diameter of the second opening may be larger than the diameter of the first opening.

[0007] In some modifications, one or more of the following features may be optionally provided in any feasible combination. The movable deformer may include a nitinol material that transitions between a folded configuration and an expanded configuration based on the temperature of the movable deformer. The movable deformer may include a stent retriever. The movable deformer may include an expander. The suction catheter may further include a plurality of LCP fibers extending along a second length of an elongated body. The first LCP fibers of the plurality of LCP fibers may be oriented longitudinally along the elongated body, and the second LCP fibers of the plurality of LCP fibers may be oriented circumferentially along the elongated body.

[0008] In another embodiment, the suction catheter may comprise an elongated body formed of a flexible material and having an inner lumen extending between a proximal body end and a distal body end. The inner lumen may be defined by an inner wall and may form a distal opening at the distal body end. The distal opening may include a periphery extending along one or more planes, the periphery having a shape that extends longitudinally with respect to the longitudinal axis of the inner lumen. The suction catheter may further comprise a reinforcing member extending along the length of the elongated body.

[0009] In some modifications, one or more of the following features may be optionally provided in any feasible combination: The distal opening may have a suction area defined by the periphery of the distal opening. The shape of the periphery may include an angular or triangular shape. The shape of the periphery may include a rounded or sinusoidal shape. The suction catheter may further comprise a plurality of LCP fibers extending along an elongated body. The first LCP fibers of the plurality of LCP fibers may be oriented longitudinally along the elongated body, and the second LCP fibers of the plurality of LCP fibers may be oriented circumferentially along the elongated body.

[0010] In another embodiment, the suction catheter may comprise an elongated body formed of a flexible material and having an internal lumen extending between a proximal body end and a distal body end. The internal lumen may be defined by an inner wall and may form a distal opening at the distal body end. The suction catheter may further comprise a reinforcing member extending along a first length of the elongated body between a proximal reinforcing end and a distal reinforcing end. The distal reinforcing end may be positioned a second length from the distal body end of the elongated body. The suction catheter may comprise an occlusion-grasping portion extending along the inner wall of the elongated body for a second length. The occlusion-grasping portion may comprise an exposed coil configured to grasp a thrombus in order to hold the thrombus at least partially within the internal lumen.

[0011] In some modifications, one or more of the following features may be provided in any feasible combination. The suction catheter may further comprise a plurality of LCP fibers extending along a second length of an elongated body. The first LCP fibers of the plurality of LCP fibers may be oriented longitudinally along the elongated body, and the second LCP fibers of the plurality of LCP fibers may be oriented circumferentially along the elongated body. The portion of the elongated body along the second length may be more flexible than the portion along the first length. The reinforcing member may comprise one or more of a Teflon liner and a metal wire.

[0012] In another related embodiment of the present subject, a method for removing a thrombus from a patient's blood vessel includes the step of inserting the distal portion of a suction catheter into the blood vessel. The suction catheter may comprise an elongated body formed of a flexible material and having an inner lumen extending between a proximal body end and a distal body end. The inner lumen may be defined by an inner wall and may form a distal opening at the distal body end. The suction catheter may comprise a reinforcing member extending along a first length of the elongated body between a proximal reinforcing end and a distal reinforcing end. The distal reinforcing end may be positioned a second length from the distal body end of the elongated body. The suction catheter may further comprise a deformer extending along a second length of the elongated body. The deformer may be coupled to a second length such that the distal opening has a first opening diameter when the deformer forms a first configuration and the distal opening has a second opening diameter when the deformer forms a second configuration. The diameter of the second opening may be greater than the diameter of the first opening. The method may further include the steps of moving the deformer between a first configuration and a second configuration, and applying a vacuum to the elongated body to aspirate at least a portion of the thrombus into the distal opening having a second opening diameter.

[0013] In some variations, one or more of the following features may be provided in any feasible combination. The deformer may include an inflatable balloon. The inflatable balloon may extend spirally along a second length of an elongated body. The inflatable balloon may be twisted along a second length of an elongated body. The distal opening may form a first suction region when the inflatable balloon is in a deflated configuration and a second suction region when the inflatable balloon is in an inflated configuration. The second suction region may be larger than the first suction region. The first and second suction regions may each be defined by one or more of the diameter and cross-sectional area of ​​the distal opening. The inflatable balloon may be deflated when in the first configuration and inflated when in the second configuration. The deformer may include a shape memory member. The shape memory member may contain a nitinol material that migrates between the first and second configurations based on the temperature of the shape memory member. The shape memory member may include at least one nitinol wire extending longitudinally along the second length. The reinforcing member may comprise one or more of a Teflon liner and a metal wire. The suction catheter may comprise a plurality of LCP fibers extending along the second length of the elongated body. The first LCP fibers of the plurality of LCP fibers may be oriented longitudinally along the elongated body, and the second LCP fibers of the plurality of LCP fibers may be oriented circumferentially along the elongated body.

[0014] In another embodiment, a method for removing a thrombus from a patient's blood vessel includes the step of inserting the distal portion of a suction catheter into the blood vessel. The suction catheter may comprise an elongated body formed of a flexible material and having an inner lumen extending between a proximal body end and a distal body end. The inner lumen may be defined by an inner wall and may form a distal opening at the distal body end. The suction catheter may further comprise a reinforcing member extending along a first length of the elongated body between a proximal reinforcing end and a distal reinforcing end. The distal reinforcing end may be positioned a second length from the distal body end of the elongated body. The suction catheter may comprise a movable deformer slidably positioned along the inner lumen of the tubular elongated body. The movable deformer may be slidable along the first length of the elongated body. The movable deformer may form a folded configuration along the first length, allowing the distal opening to form a first opening diameter. The movable deformer may be movable to a second length to form an expanded configuration, allowing the distal opening to form a second opening diameter. The second opening diameter may be larger than the first opening diameter. The method may further include the steps of moving the deformer between the first and second configurations, and applying a vacuum to the elongated body to aspirate at least a portion of the thrombus into the distal opening having the second opening diameter.

[0015] In some modifications, one or more of the following features may be optionally provided in any feasible combination. The movable deformer may include a nitinol material that transitions between a folded configuration and an expanded configuration based on the temperature of the movable deformer. The movable deformer may include a stent retriever. The movable deformer may include an expander. The suction catheter may further include a plurality of LCP fibers extending along a second length of an elongated body. The first LCP fibers of the plurality of LCP fibers may be oriented longitudinally along the elongated body, and the second LCP fibers of the plurality of LCP fibers may be oriented circumferentially along the elongated body.

[0016] In another embodiment, a method for removing a thrombus from a patient's blood vessel includes the step of inserting the distal portion of a suction catheter into the blood vessel. The suction catheter may comprise an elongated body made of a flexible material and having an inner lumen extending between a proximal body end and a distal body end. The inner lumen is defined by an inner wall and may form a distal opening at the distal body end. The distal opening may include a periphery extending along one or more planes. The periphery may have a shape extending longitudinally with respect to the longitudinal axis of the inner lumen. The suction catheter may comprise a reinforcing member extending along the length of the elongated body. The method may also include the step of applying a vacuum to the elongated body to aspirate at least a portion of the thrombus into the distal opening and to form a suction seal between the periphery of the distal opening and the thrombus.

[0017] In some modifications, one or more of the following features may be provided in any feasible combination: The distal opening may include a suction area defined by the periphery of the distal opening. The shape of the periphery may include an angular or triangular shape. The shape of the periphery may include a rounded or sinusoidal shape. The suction catheter may include a plurality of LCP fibers extending along an elongated body. The first LCP fiber of the plurality of LCP fibers may be oriented longitudinally along the elongated body, and the second LCP fiber of the plurality of LCP fibers may be oriented circumferentially along the elongated body.

[0018] In another aspect, a method of removing a thrombus from a patient's blood vessel includes inserting a distal portion of a suction catheter into the blood vessel. The suction catheter may include an elongate body formed of a flexible material and having an inner lumen extending between a proximal body end and a distal body end. The inner lumen may be defined by an inner wall and may form a distal opening at the distal body end. The suction catheter may include a reinforcing member extending along a first length of the elongate body between a proximal reinforcing end and a distal reinforcing end. The distal reinforcing end may be disposed a second length from the distal body end of the elongate body. The suction catheter may further include an occlusion gripping portion extending along an inner wall of the second length of the elongate body. The occlusion gripping portion may include an exposed coil configured to grip the thrombus to at least partially hold the thrombus within the inner lumen. The method may further include applying a vacuum to the elongate body and suctioning the thrombus to the distal opening, and gripping the thrombus to at least partially hold the thrombus within the inner lumen.

[0019] In some variations, one or more of the following features may optionally be provided in any practicable combination. The suction catheter may further include a plurality of LCP fibers extending along a second length of the elongate body. A first LCP fiber of the plurality of LCP fibers may be longitudinally oriented along the elongate body, and a second LCP fiber of the plurality of LCP fibers may be circumferentially oriented along the elongate body. A portion of the elongate body along the second length may be more flexible than a portion along the first length. The reinforcing member may include one or more of a Teflon liner and a metal wire.

[0020] Details of one or more variations of the subject matter described in this specification are set forth in the accompanying drawings and the following description. Other features and advantages of the subject matter described in this specification will be apparent from the description and drawings, and from the claims.

Brief Description of the Drawings

[0021] [Figure 1] A diagram schematically showing normal forward cerebral circulation or intracranial circulation with thrombus occlusion of the left middle cerebral artery. [Figure 2] This is a diagram showing blood flow circulation after retrograde flow has been established using the retrograde flow system described in this specification. [Figure 3] This is a diagram showing a cerebrovascular system having an intervention device such as a mechanical thrombus removal device inserted through an exemplary arterial access device. [Figure 4] This is a diagram showing an alternative embodiment in which a secondary intervention device is advanced to the collateral middle cerebral artery through an arterial access device. [Figure 5] This is a diagram showing an exemplary embodiment of a vascular access and retrograde flow system used to establish retrograde flow during an intervention. [Figure 6] This is a diagram showing another exemplary embodiment of a vascular access and retrograde flow system used to establish retrograde flow during an intervention. [Figure 7] This is an enlarged view of the common carotid artery (CCA), internal carotid artery (ICA), and middle cerebral artery where an arterial access device and a thrombus removal device are disposed. [Figure 8A] This is a diagram showing an embodiment of an arterial access device or system useful in the methods and systems of the present disclosure. [Figure 8B] This is a diagram showing an embodiment of an arterial access device or system useful in the methods and systems of the present disclosure. [Figure 9A] This is a diagram showing an embodiment of an arterial access device or system useful in the methods and systems of the present disclosure. [Figure 9B] This is a diagram showing an embodiment of an arterial access device or system useful in the methods and systems of the present disclosure. [Figure 10A] [[ID=三十二]]This is a diagram showing another embodiment of an arterial access device. [Figure 10B] [[ID=三十五]]This is a diagram showing the structure of an additional arterial access device having a reduced-diameter distal end. [Figure 11A] This is a diagram showing a sheath stopper tube. [Figure 11B] This is a diagram showing a sheath stopper tube. [Figure 11C]This figure shows another embodiment of the sheath stopper tube. [Figure 11D] This figure shows another embodiment of the sheath stopper tube. [Figure 11E] This figure shows another embodiment of the sheath stopper tube. [Figure 11F] This figure shows another embodiment of the sheath stopper tube. [Figure 11G] This figure shows another embodiment of the sheath stopper tube. [Figure 12A] This figure shows the structure of an additional arterial access device equipped with an expandable occlusion member. [Figure 12B] This figure shows the structure of an additional arterial access device comprising an expandable occlusion member and a reduced-diameter distal end. [Figure 13] This figure shows a first embodiment of a venous return device useful in the methods and systems disclosed herein. [Figure 14A] This figure shows an alternative venous return device useful in the method and system disclosed herein. [Figure 14B] This figure shows an alternative venous return device useful in the method and system disclosed herein. [Figure 14C] This figure shows an alternative venous return device useful in the method and system disclosed herein. [Figure 15] This figure shows an example of a retroflow system, including a schematic diagram of a flow control assembly. [Figure 16A] This figure shows an embodiment of a variable flow resistance member useful in the method and system disclosed herein. [Figure 16B] This figure shows an embodiment of a variable flow resistance member useful in the method and system disclosed herein. [Figure 17] This figure shows an arterial access device with a stepped configuration. [Figure 18A] This figure shows a detailed cross-section of an exemplary Y-connector in an arterial access device. [Figure 18B] This figure shows a detailed cross-section of an exemplary Y-connector in an arterial access device. [Figure 19A] This figure shows an exemplary arterial occlusion system and method. [Figure 19B] This figure shows an exemplary arterial occlusion system and method. [Figure 19C] This figure shows an exemplary arterial occlusion system and method. [Figure 19D] This figure shows an exemplary arterial occlusion system and method. [Figure 20A] This is a side cross-sectional view of one embodiment of a suction catheter having an elongated body with an internal lumen. [Figure 20B] Figure 20A shows the distal end of the suction catheter. [Figure 21A] This is a side cross-sectional view of an embodiment of the distal end of a suction catheter, which has an inflatable balloon in a deflated configuration that extends along the expandable distal portion of an elongated body. [Figure 21B] This figure shows the distal end of the suction catheter in Figure 21A. [Figure 21C] Figure 21A is a side cross-sectional view of the suction catheter in its inflated balloon configuration. [Figure 21D] Figure 21C shows the distal end of the suction catheter. [Figure 22A] This is a side cross-sectional view of an embodiment of the distal end of a suction catheter, which has an inflatable balloon that extends spirally along the inflatable distal portion of an elongated body and is in a deflated configuration. [Figure 22B] Figure 22A shows the distal end of the suction catheter. [Figure 22C] Figure 22A is a side cross-sectional view of the suction catheter in its inflated balloon configuration. [Figure 22D] Figure 22C shows the distal end of the suction catheter. [Figure 23A] This is a side cross-sectional view of an embodiment of the distal end of a suction catheter, which has an inflatable balloon that is twisted along the length of the balloon, extends spirally along the inflatable distal portion of an elongated body, and is in a deflated configuration. [Figure 23B] Figure 23A shows the distal end of the suction catheter. [Figure 23C] Figure 23A is a side cross-sectional view of the suction catheter in its inflated balloon configuration. [Figure 23D] Figure 23C shows the distal end of the suction catheter. [Figure 24A] This is a side cross-sectional view of an embodiment of the distal end of a suction catheter, which has a deformer in an expanded configuration that extends longitudinally along the expandable distal portion of an elongated body. [Figure 24B] Figure 24A shows the distal end of the suction catheter. [Figure 24C] Figure 24A is a side cross-sectional view of the suction catheter in a folded configuration with a shape memory deformer. [Figure 24D] Figure 24C shows the distal end of the suction catheter. [Figure 25A] This is a side cross-sectional view of an embodiment of the distal end of a suction catheter, which includes a shape-memory deformer that extends along the expandable distal portion of an elongated body and is in an expanded configuration. [Figure 25B] Figure 24A shows the distal end of the suction catheter. [Figure 25C] Figure 25A is a side cross-sectional view of the suction catheter in a folded configuration with a shape memory deformer. [Figure 25D] Figure 25C shows the distal end of the suction catheter. [Figure 26A] This is a side cross-sectional view of an embodiment of the distal end of a suction catheter, which has a movable deformer positioned along the expandable distal portion of an elongated body and is in an expanded configuration. [Figure 26B] Figure 26A shows the distal end of the suction catheter. [Figure 26C] Figure 26A is a side cross-sectional view of the suction catheter, in which the movable deformer is located proximal to the expandable distal portion and is in a folded configuration. [Figure 26D] Figure 26C shows the distal end of the suction catheter. [Figure 27A]This is a side cross-sectional view of another embodiment of the distal end of a suction catheter, which has a movable deformer positioned along the expandable distal portion of an elongated body and is in an expanded configuration. [Figure 27B] Figure 27A shows the distal end of the suction catheter. [Figure 27C] Figure 27A is a side cross-sectional view of the suction catheter, in which the movable deformer is located proximal to the expandable distal portion and is in a folded configuration. [Figure 27D] Figure 27C shows the distal end of the suction catheter. [Figure 28A] This is a side cross-sectional view of an embodiment of the distal end of a suction catheter having an angled peripheral edge at the distal opening of an elongated body. [Figure 28B] This figure shows the distal end of the suction catheter in Figure 28A. [Figure 29A] This is a side cross-sectional view of the distal end of a suction catheter having a sinusoidal periphery at the distal opening of an elongated body. [Figure 29B] This figure shows the distal end of the suction catheter in Figure 29A. [Figure 30A] This is a side cross-sectional view of an embodiment of the distal end of a suction catheter having an obstruction-grasping portion. [Figure 30B] Figure 30A shows the distal end of the suction catheter. [Figure 31A] This is a side cross-sectional view of the distal end of an embodiment of a suction catheter having liquid crystal polymer (LCP) fibers. [Figure 31B] This figure shows the distal end of the suction catheter in Figure 31A. [Modes for carrying out the invention]

[0022] Methods and apparatus for safely, quickly, and effectively retrieving and removing occlusions from a patient's blood vessels are disclosed. For example, various embodiments of a suction catheter are disclosed that can be used in combination with at least an arterial access device for accessing the occlusion (e.g., a thrombus) for removal. The systems and methods of the present disclosure having a suction catheter are configured for use in various blood vessels within a patient's body.

[0023] Furthermore, this specification discloses methods and apparatus that enable safe, rapid, and relatively short-duration access to at least cerebral arteries for introducing interventional devices to treat diseased or other conditions in the intracranial vascular system. The systems and methods of this disclosure are configured for use with at least cerebral arteries, the neurovascular system, and intracranial arteries, and these terms may be used interchangeably herein. Furthermore, the methods and apparatus of this disclosure are configured to more reliably close the access site to the cerebral arteries. The methods and apparatus include vascular access and retrograde flow systems that can be used safely and rapidly in neuro-interventional procedures.

[0024] The methods of this disclosure may be used in accordance with percutaneous or surgical access to the patient's vascular system. In embodiments, the location of access to the vascular system is within the neck region, such as the carotid arteries, including the common carotid, internal carotid, or external carotid arteries. The systems and methods of this disclosure use a neuroprotective system configured to generate retrograde flow (also called retrograde flow) through at least a portion of the carotid arteries. The neuroprotective system may also be configured to stagnate the flow in at least a portion of the carotid arteries. The extent to which retrograde flow is generated may be generated in a passive or active manner, as will be described in more detail below. The systems and methods of this disclosure may utilize suction in the intracranial arteries and / or carotid arteries.

[0025] The systems and methods of this disclosure may be used to treat any of the various intracranial and neurovascular conditions, such as stroke, acute stroke, great vessel occlusion, intracranial atherosclerosis (ICAD), multiple lesions, aneurysms, arteriovenous malformations (AVMs), arteriovenous fistulas, and acute and chronic total carotid artery occlusion, using various interventional devices, including some examples described herein. Furthermore, various occlusion devices and methods may be used with respect to occlusion of access sites to achieve hemostasis at the access site. The methods of this disclosure may be used in connection with or without the placement of an intraarterial stent.

[0026] In exemplary methods, the access location is provided or otherwise formed at the level of the neck, such as in the area of ​​the carotid arteries, including the internal carotid artery, external carotid artery, and / or common carotid artery. In one embodiment, the access location is within the common carotid artery. An arterial access sheath (also called an arterial access device), such as an arterial access device described herein, is then inserted into the artery through the access location. The sheath is inserted into the artery and passed through the artery until the distal end of the sheath is positioned at a desired location. In one embodiment, the distal end of the sheath is positioned within the internal carotid artery. In another embodiment, the distal end of the sheath is positioned within the external carotid artery or common carotid artery. A backflow condition is then optionally established, such as by clamping or occluding a portion of the carotid artery to achieve a pressure difference. The backflow condition allows blood to flow from the artery (such as the carotid artery) into the sheath, where it can be diverted or split to a return location such as an external container or into the vascular system (vein or artery). In another embodiment, an active flow condition may be achieved, such as by using a pump or syringe, as will be described in more detail below. Furthermore, as mentioned above, a stagnant flow state may also be achieved. The retrograde flow state acts as a neuroprotective system, as will be described in more detail below. An occlusion device may be applied to the access site to establish hemostasis, such as at the end of a therapeutic procedure, as will be discussed below. In one embodiment, the occlusion device is pre-positioned at the access site before introducing any device (such as a guidewire, sheath, or interventional device) into the artery through the access site.

[0027] Arterial access devices provide a passage for inserting interventional tools into the vascular system, allowing them to be routed to targeted therapeutic sites, such as cerebral blood vessels. In implantation, regurgitation is used in combination with interventional tools that include an aspiration catheter to aspirate material (such as thrombus) into the interventional device and / or arterial access sheath. In this regard, the interventional device and / or arterial access device may be inserted such that the distal tip of the device is located immediately proximal to the site to be aspirated or at any other location relative to the site to be aspirated. After the interventional tool has been used for treatment, the regurgitation or stagnant flow state is stopped to restore antegrade flow. During the procedure, the regurgitation state serves as neuroprotection, limiting or preventing the forward flow of material in the area of ​​intervention. As described below, an occlusion device may be placed at the access site during or after the procedure without removing the arterial access device from the access site or replacing the arterial access device with another device.

[0028] Figure 1 schematically illustrates normal forward cerebral circulation with an exemplary disease state (thrombotic occlusion 10) in the left middle cerebral artery (LMCA). It should be understood that other disease states requiring intervention are within the scope of this disclosure. The left middle cerebral artery (LMCA) branches from the left internal carotid artery (LICA). The middle cerebral artery is a large artery with tree-like branches that supply blood to the entire lateral surface of each hemisphere of the brain. The thrombotic occlusion 10 obstructs or restricts blood flow in the left middle cerebral artery. Thus, the blood supply to the brain is significantly interrupted by the presence of the thrombotic occlusion 10 in the left middle cerebral artery, resulting in an ischemic stroke.

[0029] Using the methods and systems described herein, a treatment method includes obtaining vascular access to a cerebral artery and establishing retrograde flow in at least a portion of the cerebral circulation and / or the carotid arteries to treat a thrombotic occlusion. In an exemplary procedure, an interventional device equipped with a mechanical thrombectomy device (such as a stentriever) is inserted into the cerebral vascular system to remove or otherwise treat the thrombotic occlusion under retrograde flow conditions, as described below. Figure 2 shows the blood flow circulation after retrograde flow has been established using the retrograde flow system described herein. The system comprises an arterial access device 110 that enters the left common carotid artery (LCCA) (or the right common carotid artery) and provides access to the cerebral vascular system. The artery may be clamped. Alternatively, an expandable occlusion member 129 on the arterial access device 110 may be used to occlude an artery in the cerebral vascular system and establish retrograde flow, as will be described more thoroughly below. For example, various arteries, including the common carotid artery, internal carotid artery, and / or vertebral artery, may be occluded. Exemplary embodiments of the system and its components are described in detail below.

[0030] Figure 3 shows a cerebrovascular system equipped with a mechanical thrombectomy device 15 inserted through an arterial access device 110. The thrombectomy device 15 comprises an elongated catheter that can be advanced through the arterial access device 110 to the location of the thrombotic occlusion 10. The thrombectomy device 15 has a distal region equipped with a thrombus engaging member 68 adapted to interact with and remove the thrombotic occlusion 10, as will be more fully described below. There are various types of thrombectomy devices. In another embodiment, the interventional device is a suction catheter positioned to interact with the target location via the arterial access device 110.

[0031] Figure 4 shows another embodiment in which a secondary interventional device, such as a balloon catheter 25, is advanced through an arterial access device 110 into a collateral cerebral artery, such as the anterior cerebral artery (ACA). The balloon catheter 25 comprises a balloon 30 that can be expanded within the collateral cerebral artery to occlude the artery. Occluding the collateral cerebral artery may promote aspiration and regurgitation through the cerebrovascular system.

[0032] Figure 5 shows an exemplary embodiment of a vascular access retrograde flow system 100 that can be used to establish retrograde flow during the removal of a thrombotic occlusion 10. The system 100 comprises an arterial access device 110, a vascular return device such as a venous return device 115, and a shunt 120 (which may be an extracorporeal shunt) that provides a passage for retrograde flow from the arterial access device 110 to the venous return device 115. A flow control assembly 125 interacts with the shunt 120. The flow control assembly 125 is configured to regulate and / or monitor the retrograde flow through the shunt 120, as will be described in more detail below. The flow control assembly 125 interacts with the outside of the flow path through the shunt 120, the inside of the flow path, or both. Figure 6 is another diagram of the vascular access retrograde flow system 100 coupled to a patient.

[0033] In one embodiment, as will be described in more detail below, the arterial access device 110 is inserted at least partially into the common carotid artery (CCA), and the venous return device 115 is inserted at least partially into a venous return site such as the femoral vein or internal jugular vein. The venous return device 115 may be inserted into the femoral vein (FV) via percutaneous puncture in the groin. The arterial access device 110 and the venous return device 115 are connected to both ends of the shunt 120 by connectors.

[0034] As shown in Figure 7, the distal end of the arterial access device 110 (with an optional occlusion member 129, if present) may be positioned in the ICA or other portion of the carotid artery. In situations where access to the ICA is extremely tortuous, it may be preferable to position the occlusion member closer to the common carotid artery. As previously mentioned, the ICA may also be clamped rather than occluded via an occlusion member. Thus, the artery may be occluded via external and / or internal locations. When flow through the internal carotid artery is blocked (using an occlusion member 129 or a clamp such as umbilical cord tape or a vascular loop), the natural pressure gradient between the internal carotid artery and the venous system causes blood to flow retrograde or in the reverse direction from the cerebrovascular system through the internal carotid artery and shunt 120 into the venous system. The flow control assembly 125 regulates, increases, assists, monitors, and / or otherwise adjusts the retrograde blood flow.

[0035] Subsequently, the interventional device (such as an aspiration catheter or other interventional device) is deployed through the arterial access device 110 and via the internal carotid artery to a target location such as the left middle cerebral artery. The distal region of the interventional device 15 is positioned within the middle cerebral artery due to interaction with thrombotic occlusion or other disease conditions. The proximal region of the interventional device protrudes from the access port within the arterial access device 110. This is explained in more detail with reference to Figure 7, which shows an enlarged view of the common carotid artery (CCA), internal carotid artery (ICA), and middle cerebral artery (MCA) with the arterial access device 110 and interventional device 15 deployed. The arterial access device 110 accesses the common carotid artery by a transcervical approach, such as direct intersection of the common carotid artery (CCA) or percutaneous puncture of the CCA. The interventional device 15 gains access to the internal carotid artery (ICA) by insertion through the medial lumen of the arterial access device 110, such as by insertion into the proximal opening that provides access to the arterial access device 110.

[0036] As discussed, the arterial access device 110 provides access to the anterior and middle cerebral arteries through the common carotid artery (CCA) using a transcervical approach. The transcervical access provides a short and uncurved route from the vascular access point to the target treatment site, thereby mitigating the time and difficulty of the procedure compared to, for example, a transfemoral approach. Furthermore, this access route reduces the risk of embolism occurring from navigating pathological, angular, or curvilinear aortic arch or common carotid artery tissue structures. In another embodiment, the arterial access device provides access to the basilar artery (BA) or posterior cerebral artery (PCA) by incision into the vertebral artery or percutaneous puncture of the vertebral artery.

[0037] In one embodiment, the arterial access device 110 accesses the common carotid artery (CCA) via a direct surgical transcervical approach. During the surgical approach, the common carotid artery may be clamped or occluded using a tourniquet or other device.

[0038] In another embodiment, transcervical access to the common carotid artery is achieved percutaneously by an incision or puncture in the skin into which the arterial access device 110 is inserted. If an incision is used, the incision is, for example, about 0.5 cm in length. An occlusion member 129, such as an inflatable balloon, may be used to occlude the internal carotid artery (ICA) or the common carotid artery (CCA) at a position proximal to the distal tip of the arterial access device 110. The occlusion member 129 may be located on the arterial access device 110 or on a separate device.

[0039] In another embodiment, the arterial access device 110 accesses the common carotid artery (CCA) via a transcervical approach, while the venous return device 115 accesses venous return sites other than the femoral vein, such as the internal jugular vein.

[0040] In another embodiment, the system provides retrograde flow from the carotid artery to an external container rather than a venous return site. The arterial access device 110 is connected to the container via a shunt 120. The shunt 120 communicates with a flow control assembly 125. The retrograde flow of blood is collected in the container 130. If necessary, the blood is filtered and returned to the patient. The pressure in the container 130 may be set to zero pressure (atmospheric pressure) or lower so that blood flows retrogradely from the cerebrovascular system to the container 130. Optionally, to achieve or enhance retrograde flow from the internal carotid artery, the flow from the external carotid artery may be blocked by placing a balloon or other occlusion device in the external carotid artery, typically directly above its bifurcation with the internal carotid artery.

[0041] In another embodiment, backflow may be replaced or enhanced by applying a suction source to a port (such as a stopcock) communicating with the flow shunt 120. Examples of suction sources include syringes, pumps, and the like. The system may also include an active pump as part of the flow control assembly 125, and control for pump flow and / or flow monitoring may be included in the assembly.

[0042] In yet another embodiment, the system may be used to perform intra-arterial thrombolysis, for example, through a side branch of the arterial access device 110. For example, the thrombolytic agent may be injected into the thrombus occlusion 10 through the arterial access device 110 via the flush line 635. In yet another embodiment, the system may be used to perform intra-arterial thrombolysis via a microcatheter inserted into the arterial access device 110. The microcatheter is delivered to the thrombus occlusion 10 for injection of the thrombolytic agent. The thrombolytic agent may be performed in conjunction with, or as an alternative to, mechanical thrombectomy, such as with a thrombectomy device 15.

[0043] In another embodiment, the system 100 may include means for perfusing the cerebral vascular system and ischemic brain tissue by a perfusion catheter delivered distal to the thrombotic occlusion 10, for example, via an arterial access device 110. The perfusion catheter is configured to deliver a perfusion solution to a desired location. The perfusion solution may be, for example, autologous arterial blood from the AV shunt 120 or another artery, an oxygenated solution, or other neuroprotective agent. The perfusion solution may also be cold to cool the brain tissue. This is another strategy that has been shown to minimize brain damage during ischemia. The perfusion catheter may also be used to deliver a bolus of intra-arterial thrombolytic agent in accordance with thrombolytic therapy. Typically, thrombolytic therapy takes 1-2 hours or more to clear the occlusion after bolus administration. Mechanical thrombectomy may also take 1-2 hours to fully reopen the occluded vessel. Distal perfusion of the ischemic area may minimize the level of brain damage during stroke treatment.

[0044] Another embodiment of System 100 comprises means for reperfusion of cerebral blood vessels during acute stroke treatment. Cerebral reperfusion, as described by Frazee et al., involves selectively cannulating and occluding the transverse sinus via the internal jugular vein and injecting blood into cerebral tissue via the superior sagittal sinus during the treatment of ischemic stroke. The following papers describing intracerebral retrograde perfusion are incorporated herein by reference in their entirety: Frazee, JG and X. Luo (1999) “Retrograde transvenous perfusion” Crit Care Clin 15(4):777-88,vii and Frazee, JG and X. Luo et al. (1998) “Retrograde transvenous nerve perfusion: backdoor treatment for stroke” Stroke 29(9):1912-6. This perfusion creates a retrograde flow gradient in the cerebral arteries, in addition to protecting the cerebral tissue. Retrograde perfusion members used with the retrograde flow system 100 may not only provide oxygen to the brain tissue but also assist in trapping embolic fragments within the retrograde shunt during the recanalization of the thrombotic occlusion 10.

[0045] Various interventional devices may be used. For example, the interventional device may be a thrombectomy device such as a stent retriever device. A stent retriever is, for example, a self-expanding mesh tube attached to a wire, which is guided into the vascular system via an arterial access device (and possibly a secondary catheter) so that the device can engage with a thrombus or other disease condition. The user guides the device through various blood vessels to a treatment site, such as a thrombus in the brain. The stent retriever is then used to grasp the thrombus, and when the user removes the catheter, the thrombus is extracted. In an exemplary embodiment, the interventional device is any device configured to treat by being delivered to a treatment site, delivering a substance to the site, removing a substance from the site, and / or interacting with the treatment site in any way. For example, a stent, balloon, coil, adhesive, liquid, solid, or gel may be delivered to the treatment site. The thrombectomy device may include or be connected to a microcatheter to assist in the delivery of the device into the distal vascular system.

[0046] It should be understood that the thrombectomy device 15 is not limited to a specific embodiment, and various embodiments of the thrombectomy device or therapeutic device may also be used. For example, the device may be an expandable cage, basket, snare, or gripper used to capture and remove thrombotic occlusions. Alternatively, the device may be a thrombus disruption device used to break up thrombi for easier aspiration and removal. The thrombus disruption device may be, for example, a mechanical disruptor for breaking up thrombi, a sound wave or ultrasonic energy source, another energy source, or a hydraulic or vortex energy source. The thrombectomy device may also be equipped with suction means for removing thrombotic occlusions.

[0047] Other means for providing flow through a thrombotic occlusion include, for example, recanalization means for delivering a balloon catheter to expand the passage through the occlusion, or means for positioning a stent through the thrombotic occlusion to form a lumen through the occlusion. The stent device may be a permanent implantable stent or a temporary stent for opening an occluded passage for a certain period until it is retrieved. The occlusion may be removed by the stent or by some other thrombectomy means. The thrombectomy and recanalization devices may be used in combination with the injection of a thrombolytic agent. Several exemplary stent-related devices and methods are described in U.S. Patents 5,964,773 and 5,456,667, which are incorporated herein by reference in their entirety.

[0048] Next, an example of the use of a vascular access retrograde flow system equipped with a thrombectomy device 15 will be described. The arterial access device 110 is introduced into the patient's common carotid artery (CCA) as shown in Figure 7 and positioned at least partially (e.g., the distal end of the distal sheath) in the distal common carotid artery or internal carotid artery. The thrombectomy device 15 is then advanced into the carotid artery through the arterial access device 110, with or without the microcatheter 60. Before further advancement of the thrombectomy device 15, the occlusion member 129 on the arterial access device 110 may be expanded to reduce or stop antegrade flow through the vessel. In another embodiment, retrograde flow is stopped by clamping the vessel from the outside. Stopping the flow within the vessel helps prevent the thromboembolism or a portion thereof from moving downstream by antegrade flow during the positioning of the thrombectomy device 15 or thrombus retrieval. Subsequently, the thrombectomy device 15 is further advanced into the vascular system via the microcatheter 60 or by itself within the arterial access device 110 to a proximal, internal, or distal location of the thrombus occlusion 10. During any part of the procedure, reflux is initiated in the blood vessel via a retrograde flow system (described below) and / or via active aspiration. In one embodiment, a gap exists between the outer diameter of the device 15 and the inner diameter of the arterial access device 110 at the position where the device 15 protrudes from the distal opening of the arterial access device. The gap is such that there is no seal between the outer diameter of the device 15 and the inner diameter of the arterial access device 110. This allows the refluxing blood to flow into the distal opening of the arterial access device from which the device 15 protrudes.

[0049] Subsequently, the thrombectomy device 15 is positioned to come into contact with the thrombus occlusion 10, and in some cases to penetrate the thrombus occlusion.

[0050] The thrombectomy device 15 may be used in any suitable manner to engage with the thrombotic occlusion. For example, the microcatheter 60 or sheath 65 may be advanced through the thrombotic occlusion and then retracted to expose the thrombectomy device 15. The thrombectomy device 15 is then retracted into the thrombotic occlusion to engage with it. The thrombectomy device 15 may be rotated as it moves into the thrombotic occlusion. Alternatively, the thrombectomy device 15 may be used to engage with the thrombotic occlusion by simply retracting the microcatheter 60 or sheath 65 while it is expanded within the thrombotic occlusion.

[0051] Another method to assist in the mechanical capture of thrombotic occlusions is to coat the device and its components with a substance that helps the thrombotic occlusions, particularly thrombi, adhere to the device or its components. This material may be, for example, fibrin or other suitable material.

[0052] It will be understood that other mechanical thrombectomy catheters may be used in a similar manner with the vascular access retrograde flow systems described above. Mechanical thrombectomy devices may comprise variations of the thrombus recovery devices described above, such as expandable cages, wire or filament loops, grippers, and brushes. These thrombus recovery devices may be equipped with a suction lumen to reduce the risk of embolic fragments causing ischemic complications. Furthermore, thrombus recovery devices may comprise thrombus disruption sections, such as fluid vortices, ultrasonic or laser energy sections, and balloons, connected to flushing and suction for thrombus removal. Several exemplary devices and methods are described in the following U.S. patents and patent publications, all of which are incorporated by reference in whole. U.S. Patent Nos. 6,663,650, 6,730,104, 6,428,531, 6,379,325, 6,481,439, 6,929,632, 5,938,645, 6,824,545, 6,679,893, 6,685,722, 6,436,087, 5,794,629, U.S. Patent Application Publication No. 2008 / 01772 Patent No. 45, U.S. Patent Application Publication No. 2009 / 0299393, U.S. Patent Application Publication No. 2004 / 0133232, U.S. Patent Application Publication No. 2020 / 183783, U.S. Patent Application Publication No. 2007 / 0198028, U.S. Patent Application Publication No. 2006 / 0058836, U.S. Patent Application Publication No. 2006 / 0058837, U.S. Patent Application Publication No. 2006 / 0058838, U.S. Patent Application Publication No. 2003 / 0212384, and U.S. Patent Application Publication No. 2002 / 0133111.

[0053] (An exemplary embodiment of a retrograde blood flow system) As discussed, system 100 comprises an arterial access device 110, a perfusion device 115, and a shunt 120 providing a passage for retrograde flow from the arterial access device 110 to the perfusion device 115. The system also comprises a flow control assembly 125 that interacts with the shunt 120 to regulate and / or monitor retrograde blood flow through the shunt 120. Exemplary embodiments of the components of system 100 are described here. The system may include a neurological intervention device or may be combined with a neurological intervention device.

[0054] (Arterial access device) Figures 8A and 8B show exemplary embodiments of the arterial access device 110. As shown in Figure 8B, the device comprises a distal sheath 605 (also called the sheath body 605), a proximal extension 610, and an adapter or Y-connector 620 that can be fluid-connected to a flow path such as a shunt 120. The arterial access device 110 may optionally include a sheath stopper 705 (further described below) and a guidewire 611.

[0055] The distal sheath 605 is the portion of the arterial access device 110 that is sized to be inserted into the carotid artery and is actually inserted into the artery during use. The distal sheath 605 is configured to be introduced by an incision or puncture in the wall of a typical carotid artery, such as an open surgical incision or percutaneous puncture made using the Seldinger technique. The length of the distal sheath may vary. In an unspecified example, the length is 18 cm or more. In another embodiment, the distal sheath may be in the range of 5 cm to 15 cm, for example, 10 cm to 12 cm. The inner diameter may be in the range of 7 Fr (1 Fr = 0.33 mm) to 10 Fr, for example, 8 Fr. In an unspecified example, the distal sheath 605 may be a 4 Fr sheath, a 6 Fr sheath, a 5 Fr sheath, or an 8 Fr sheath. In this embodiment, the distal sheath has an outer diameter of 4 Fr to 8 Fr, or up to 10.5 Fr, or up to 12 Fr.

[0056] When the sheath is introduced via a transcervical approach that is above the clavicle and below the carotid bifurcation, it is desirable that the sheath 605 have high flexibility while maintaining hoop strength to resist twisting and buckling. For this reason, the distal sheath 605 may be reinforced circumferentially with a blade, spiral ribbon, spiral wire, etc. In an alternative embodiment, the distal sheath is configured to be introduced into the target common carotid artery (CCA) via percutaneous puncture into the femoral artery, such as in the groin, ascending the aortic arch.

[0057] Figure 8A shows the components of an arterial access device 110 in a disassembled state, comprising an arterial access sheath 605, a sheath dilator 645, a sheath stopper 705, and a sheath guidewire 611. Figure 8B shows the arterial access device 110 assembled for insertion onto the sheath guidewire 611 into the carotid artery. After the sheath is inserted into the artery and during the procedure, the sheath guidewire 611 and the sheath dilator 645 are removed. A flush line 635 is connected to the arterial access device 110 and may have a stop valve 640 at its proximal end. The flush line 635 allows for the introduction of saline solution, contrast agent, etc., during the procedure. The flush line 635 may also allow for pressure monitoring during the procedure. In one embodiment, the dilator 645 has a distal region that protrudes 1.5 cm distally beyond the distal end of the sheath 605 when the dilator is positioned within the sheath.

[0058] The proximal extension 610 extends from the Y-adapter 620 to the proximal end of the arterial access device 110 (such as the location of the flush line 635, if present). The proximal extension 610 has an internal lumen that is in fluid communication with the internal lumen of the sheath 605. The embodiment in Figure 8A includes a proximal hemostatic valve 625 at the most proximal end of the arterial access device 110. In one embodiment described below with reference to Figure 9A (or in any embodiment described herein), the arterial access device 110 may not have a hemostatic valve, or may be detachably connected to one. The hemostatic valve may also be excluded from the embodiments in Figures 8A and 8B.

[0059] Referring further to Figure 8A, the Y-adapter 620 (also called a Y-connector) connects the proximal portion of the sheath 605 to the proximal extension 610. The Y-connector 620 may include a valve 670 that is operated to open and close a fluid connection to a connector or hub 680, which may be detachably connected to a flow path such as the shunt 120, or at least partially formed thereto. That is, the hub is connected to the retrograde shunt 120 (Figures 5 and 6) and forms at least a portion of it.

[0060] Valve 670 (such as a live valve) is positioned immediately adjacent to the inner lumen of the Y-adapter 620, which communicates with the inner lumen of the sheath body 605. Figures 18A and 18B show detailed cross-sections of an example of a Y-adapter 620 with valve 670 and hub 680. Figure 18A shows the valve closed to the connector. This is the position where the valve is present during pretreatment of the arterial sheath. The valve is configured to prevent air from being trapped during sheath pretreatment. Figure 18B shows the valve open to the connector. This position is used when the flow shunt 120 is connected to the hub 680, allowing blood flow from the arterial sheath to the shunt. This configuration eliminates the need to prepare both a flush line and a flow path, instead allowing preparation from a single flush line 635 and live valve 640. This single preparation is the same as the preparation of a conventional introduction sheath without a shunt line connection, making it more familiar and convenient for the user. Furthermore, because there are no flow channels on the sheath, handling the arterial sheath is easier during preparation and insertion into the artery.

[0061] Referring again to Figure 8A, the sheath body 605 may include a second distal connector 690 separated from the Y-adapter 620 by a segment of the tube 665. The purpose of this second distal connector and tube 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, thereby reducing the user's exposure level to the radiation source when the flow shunt is connected to the arterial sheath during the procedure. In one embodiment, the distal connector 690 has a suture eyelet to assist in securing the sheath to the patient when in position.

[0062] In alternative embodiments of any embodiment of the arterial access device 110 described herein, the arterial access device does not have a hemostatic valve at its proximal end. Rather, the arterial access device has an open proximal end without a hemostatic valve (such as a proximal opening that is not obstructive or completely blocked) to provide wider access than would be possible if a hemostatic valve were located therein. In one embodiment, the proximal opening is set to accommodate a catheter with an outer diameter of 0.071 inches, but this setting may be modified.

[0063] Figure 9A shows another embodiment of the arterial access device 110. This comprises a sheath body 605 having one or more depth markers 3205 that are dimensioned and spaced along the sheath body 605 to provide the user with an indication of the insertion depth of the sheath body 605 from the most distal end of the sheath body 605 to each depth marker 3205. In one embodiment, the depth markers are configured to provide an indication of depth up to at least 10 cm. In one embodiment, the sheath body 605 has a length of 18 cm, at least 18 cm, or less than 18 cm.

[0064] Referring further to Figure 9A, the proximal extension 610 extends from the Y-adapter 620 to the nearest end where a connector component 3210, such as a female Luer connector, is located. As previously mentioned, the hemostatic valve is not located at the nearest end. The connector component 3210 may be configured to be detachably attached to a corresponding connector on the proximal end of the arterial access dilator 645. As shown in Figure 9B, the connector component 3210 may be configured to be detachably attached to a rotary hemostatic valve (RHV) 3220 to achieve hemostasis. The RHV may include a Y-connector having a fluid line 3225 that communicates with the inner lumen of the arterial access device 110 when connected. The fluid line 3225 may function, for example, as a flush line used for flush fluid, and may include flow control members such as a stop valve. As previously mentioned, the shunt 120 may be detachably and fluidly connected to the arterial access device 110, as shown in Figure 9B. One or more suture eyelets may be placed at the proximal end of the distal sheath 605.

[0065] The distal tip of the distal sheath 605 may be made of a different material from the proximal portion of the sheath, such as a softer or more flexible material, either entirely or at least partially. The distal tip of the distal sheath 605 may define the most distal edge, which is positioned or aligned along a plane perpendicular to the longitudinal axis of the sheath. Alternatively, the distal tip of the distal sheath 605 may define the most distal edge, which is positioned or aligned along a plane that is at an angle to the longitudinal axis of the sheath (i.e., not normal). In one embodiment, the sheath 605 is a 6-French or 8-French sheath. In one embodiment, the sheath 605 has an inner diameter of 0.071 inches, 0.058 inches, or 0.045 inches, and a length of 58 cm, although these specifications may be modified.

[0066] Referring again to Figure 9A, the proximal extension 610 (if present) is detachably connected to the sheath 605 via at least one coupler or connector assembly 3215. The connector assembly 3215 may be located at the connection site immediately proximal to the proximal end of the sheath and distal to the Y-arm 620. In this embodiment, an additional hemostatic valve may be provided at the connection site of the proximal extension 610 to the Y-arm connector 620 so that hemostasis is maintained when the proximal extension is not attached. This allows the proximal extension 610 and the attached Y-connector 620 to be detached together from the distal sheath 605 at the location of the connector assembly 3215.

[0067] The connector assembly 3215 may comprise any of a wide variety of connector components that can be detachably attached. The arterial access device 110 may comprise a first connector component 3217 (located at the proximal end of the distal sheath 605) that is detachably attached to a second connector component 3219 located at the distal end of the Y-arm adapter 620 or the distal end of the proximal extension 610. The first connector component 3217 and the second connector component 3219 may be rotary joints connected to each other by a rotary mechanism such as a screw thread. In one embodiment, the connector component comprises one or more Luer connectors. At least one of the connector components may be a hemostatic valve or a hemostatic valve adapter. For example, the first connector component 3217 may be a hemostatic valve adapter configured to be detachably attached to the second connector component 3219. Alternatively, in one embodiment, the first connector component 3217 may be detachably attached to a hemostatic valve. This allows the second connector component 3219 to be detached from the first connector component 3217, thereby removing the Y-arm adapter 620 and the proximal extension 610. Subsequently, a hemostatic valve assembly may be attached to the first connector component 3217. In one embodiment, the first connector component 3217 and / or the second connector component 3219 are equipped with an auto-hemostatic member that automatically achieves hemostasis when the first connector component is detached from the second connector component. In an exemplary embodiment, the arterial access sheath has an overall length of less than 20 cm or less than 16 cm. In one embodiment, the arterial access sheath has a working length of 11 cm and an outer diameter of 10.5 Fr.

[0068] In one embodiment, the arterial access device 110 has an overall length of 32 cm or more. In an exemplary embodiment, the overall length of the distal sheath 605 is 16 cm, 20 cm, or other lengths less than 32 cm. A detachable proximal extension 610 (which also includes a detachable Y-arm connector or adapter 620 that connects to the shunt 120) allows for a reduction in the length of the arterial access device 110 when the proximal extension 610 is removed from the distal sheath 605. In an exemplary manner, the arterial access device 110 is used in accordance with a treatment method using the arterial access device 110, which is fully assembled to include both the proximal extension 610 and the attached distal sheath 605. In this configuration, the arterial access device 110 may be used for the introduction of one or more interventional devices into the vascular system by inserting the interventional device through the proximal opening at the proximal end of the proximal extension.

[0069] At some point in the method, such as after treatment via the interventional device is completed, the Y-arm adapter 620 and the proximal extension 610 are removed from the sheath 605 (by uncoupling the second connector component 2319 from the first connector component 3217), while the sheath 605 remains inserted into the artery without the Y-arm adapter 620 and the proximal extension 610. Thus, the sheath 605 provides a shorter access route into the artery compared to when the proximal extension 610 is attached to the sheath 605. The shorter access route can then be used to insert one or more devices for accessing and / or intervening in the artery without removing the entire arterial access device 110 and replacing it with the shorter access device. In one embodiment, the sheath 605 is used as an access route for inserting an occlusive delivery system into the artery, such as the occlusive delivery system described below in relation to Figures 19A and 19B. The occlusive device is then applied to achieve hemostasis at the access site. The sheath 605 is then removed. Alternatively, the proximal extension may be reconnected to the sheath 605 before removal. In one embodiment, a shorter access path allows for the insertion and use of one or more devices for accessing and / or intervening in an artery than when a longer access path having both the sheath and the proximal extension is attached.

[0070] Figures 10A and 10B show alternative embodiments of the arterial access device 110. The sheath 605 may optionally have a stepped configuration or other configuration with a reduced-diameter distal region 630, as shown in Figure 10B, which shows a magnified 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. The distal region 630 of the sheath typically has an inner diameter ranging from 2.16 mm (0.085 inches) to 2.92 mm (0.115 inches), while the remaining proximal region of the sheath has a larger outer diameter and lumen diameter. The inner diameter typically ranges from 2.794 mm (0.110 inches) to 3.43 mm (0.135 inches). The larger lumen diameter of the proximal region minimizes overall flow resistance through the sheath. In one embodiment, the reduced-diameter distal region 630 has a length of approximately 2 cm to 4 cm or 3 cm to 5 cm. In another embodiment, the reduced-diameter distal region 630 has a length of approximately 10 cm to 15 cm. The relatively short length of the reduced-diameter distal region 630 allows this section to be positioned within the common carotid artery (CCA) via a transcervical approach, while reducing the risk of the distal end of the sheath 605 contacting the bifurcation B. Furthermore, the reduced-diameter distal region 630 allows for a reduction in the size of the opening for introducing the sheath 605 into the artery, while having minimal impact on the level of flow resistance.

[0071] Referring again to Figure 10A, the proximal extension 610 has an internal lumen that is fluidly continuous with the internal lumen of the sheath 605. The lumens of the proximal extension 610 and the sheath 605 are connected by a Y-connector 620 that connects the lumen of the flow path 615 to the sheath. In the assembled system, the flow path 615 connects to the first leg of the retrograde shunt 120 (Figures 5 and 6) to form the first leg. In any embodiment, the proximal extension 610 may be long enough to position the proximal hemostatic valve 625 (or the proximal end of an arterial access device) away from the Y-connector 620 adjacent to the percutaneous or surgical insertion site. By positioning the hemostatic valve 625 away from the percutaneous insertion site, the physician can introduce an interventional system (such as a stent delivery system or other working catheter) into the proximal extension 610 and sheath 605 while it remains out of the fluoroscopic field when fluoroscopy is being performed.

[0072] To facilitate the introduction of the sheath 605 into the common carotid artery, a dilator 645 having a tapered distal end 650 may be provided. The dilator 645 may be introduced through a hemostatic valve 625 such that the tapered distal end 650 extends through the distal end of the sheath 605, as is most commonly seen in Figure 11A. The dilator 645 may have a central lumen for housing a guidewire. Typically, the guidewire is first positioned in the vessel, and the dilator / sheath combination moves over the guidewire as the guidewire is introduced into the vessel.

[0073] The length of the expander may be modified. In one embodiment, the expander has a length such that, when the expander is positioned within the inner lumen of the sheath 605, the tapered distal end 650 protrudes outward from the distal end of the sheath 605, similar to the distal region of the expander. In an exemplary embodiment, the length of the expander is 79 cm with a working length of 76 cm, but this length may be modified.

[0074] (Sheath stopper) Optionally, a tubular sheath stopper 705 may be provided, coaxially received on the outside of the sheath 605, as shown in Figure 11A. The sheath stopper 705 is configured to function as a mechanical device to prevent the sheath from being inserted excessively into the blood vessel. The sheath stopper 705 is sized and shaped to be positioned on the sheath 605 so as to cover a portion of the sheath 605, leaving the distal portion of the sheath 605 exposed. The sheath stopper 705 may have a flared proximal end 710 that engages with the adapter 620 and a distal end 715. Optionally, the distal end 715 may be chamfered, as shown in Figure 11B.

[0075] The sheath stopper 705 can serve a variety of purposes. For example, the length of the sheath stopper 705 restricts the introduction of the sheath 605 to the exposed distal portion of the sheath 605, so that the insertion length of the sheath is limited to the exposed distal portion of the sheath. In one embodiment, the sheath stopper restricts the exposed distal portion to a range between 2 cm and 3 cm. In another embodiment, the sheath stopper restricts the exposed distal portion to 2.5 cm. In other words, the sheath stopper may restrict the insertion of the sheath into the artery to a range between approximately 2 cm and 3 cm, or to 2.5 cm. In another example, the sheath stopper 705 may engage with a puncture occlusion device (if present) pre-positioned on the carotid artery wall, allowing the sheath 605 to be withdrawn without removing the occlusion device.

[0076] The sheath stopper 705 may be made of a transparent material so that the sheath body is clearly visible beneath the sheath stopper 705. Alternatively, the sheath stopper 705 may be made of a flexible material and may have joints or sections with enhanced flexibility so that the sheath can be bent as needed at the appropriate position when inserted into the artery. The sheath stopper may be plastically bendable so that it can be bent into a desired shape so that it retains its shape when released by the user. The distal portion of the sheath stopper may be made of a harder material, and the proximal portion may be made of a more flexible material. In one embodiment, the harder material is 85A durometer, and the more flexible section is 50A durometer. In one embodiment, the harder distal portion is 1-4 cm of the sheath stopper 705. The sheath stopper 705 may be detachable from the sheath if the user desires a larger sheath insertion length. This allows the user to remove the sheath stopper 705, cut its length shorter, and reassemble the sheath stopper 705 onto the sheath so that the length of the insertable sheath protrudes from the sheath stopper 705.

[0077] Figure 11C shows another embodiment of a sheath stopper 705 positioned adjacent to a sheath 605 in which an expander 645 is located. The sheath stopper 705 in Figure 11C may be deformed from a first shape, such as a linear shape, to a second shape different from the first shape. The sheath stopper maintains the second shape until sufficient external force acts on it to change its shape. The second shape may be, for example, a non-linear, curved, or other shape with a contour, or an irregular shape. For example, Figure 11C shows a sheath stopper 705 having multiple bends as well as linear sections. Figure 11C is merely an example, and it should be understood that the sheath stopper 705 may be formed to have any amount of bends along its longitudinal axis. Figure 11D shows the sheath stopper 705 positioned on the sheath 605. The sheath stopper 705 has greater rigidity than the sheath 605 such that the sheath 605 has a shape or contour that conforms to the contour of the sheath stopper 705.

[0078] The sheath stopper 705 may be shaped according to the insertion angle of the sheath into the artery and the depth of the artery or the patient's physique. This feature reduces the force exerted by the tip of the sheath on the vessel wall, especially when the sheath is inserted into the vessel at a steep angle. The sheath stopper may be bent or deformed to a shape that helps direct the sheath coaxially with the artery into which it is being inserted, even when the entry angle into the arterial incision is relatively steep. The sheath stopper may be shaped by the operator before inserting the sheath into the patient. Alternatively, the sheath stopper may be shaped and / or reshaped in situ after the sheath has been inserted into the artery. Figures 11E and 11F illustrate examples of the use of a malleable sheath stopper 705. Figure 11E shows the sheath stopper 705 positioned on the sheath 605 in a linear shape. The sheath 605 takes the straight shape of the sheath stopper 705 and enters artery A at a relatively steep angle so that the distal tip of the sheath 605 is in contact with or facing the wall of the artery. In Figure 11F, the user bends the sheath stopper 705 to adjust the entry angle of the sheath 605 so that the longitudinal axis of the sheath 605 is more aligned with the axis of artery A. In this way, the sheath stopper 705 is formed by the user to assist in aligning the sheath 605 away from the opposing wall of artery A and in a direction more coaxial with the axis of artery A, relative to the shape in Figure 11E.

[0079] In one embodiment, the sheath stopper 705 is made of a malleable material or has an integral malleable component located on or inside the sheath stopper. In another embodiment, the sheath stopper is configured to articulate using actuators such as concentric tubes or pull wires. The walls of the sheath stopper may be reinforced with ductile wires or ribbons to help maintain their shape against external forces, such as when the sheath stopper encounters a bend in an artery or inlet. Alternatively, the sheath stopper may be made of a homogeneous malleable tubular material containing metal and polymer. The sheath stopper body may also be made of a reinforced braid or coil that can retain its shape after deformation, at least in part.

[0080] Another embodiment of the sheath stopper is configured to allow easy adjustment of the position of the sheath stopper (relative to the sheath) even after the sheath has been placed in the container. One embodiment of the sheath stopper comprises a tube having a slit along most or all of its length so that the sheath stopper can be detached from the sheath body, moved forward or backward as necessary, and then repositioned along the length of the sheath body. The tube may have a tab or feature at its proximal end to allow for easier gripping and detachment.

[0081] In another embodiment, the sheath stopper is a very short tube (such as a band) or ring located in the distal section of the sheath body. The sheath stopper may be easily grasped, for example, by forceps, and may be pulled back to a new position or pulled forward as needed to set the sheath insertion length to suit the procedure. The sheath stopper may be secured to the sheath body by friction from the tubular material or by a clamp that can be opened and closed relative to the sheath body. The clamp may be a spring-loaded clamp that is typically clamped to the sheath body. To move the sheath stopper, the user may open the clamp with their fingers or an instrument, adjust the position of the clamp, and then release the clamp. The clamp is designed not to interfere with the sheath body.

[0082] In another embodiment, the sheath stopper has features that allow the sheath stopper and the sheath to be sutured to the patient's tissue in order to improve the fixation of the sheath and reduce the risk of the sheath coming loose. These features may be suture eyelets attached to or molded into the tube of the sheath stopper.

[0083] In another embodiment, as shown in Figure 8A, the sheath stopper 705 includes a distal flange 710 having a size and shape that distributes the force of the sheath stopper over a larger area on the vessel wall, thereby reducing the risk of vessel injury or accidental insertion of the sheath stopper into the vessel through the arterial incision. The flange 710 may have a sufficiently large rounded shape or other non-traumatic shape to distribute the force of the sheath stopper over a wide area on the vessel wall. In embodiments, the flange is inflatable or mechanically expandable. For example, the arterial sheath and sheath stopper may be inserted into the surgical site through a small puncture of the skin and then expanded before inserting the sheath into the artery.

[0084] The sheath stopper may have one or more notches or recesses 720 along its length, patterned in a zigzag structure, to increase the flexibility of the sheath stopper while maintaining axial strength that allows the sheath stopper to advance against the arterial wall. The recesses may also be used to facilitate the fixation of the sheath to the patient with sutures and to reduce sheath movement. The sheath stopper may also be provided with a connector member 730 at its proximal end that corresponds to a feature on the arterial sheath, so that the sheath stopper can be locked or unlocked from the arterial sheath. For example, the connector member is a hub having a generally L-shaped slot 740 corresponding to a pin 750 on the hub to create a bayonet-mount type connection. In this way, the sheath stopper may be securely attached to the hub, reducing the possibility of the sheath stopper being unintentionally removed from the hub unless it is unlocked from the hub.

[0085] The distal sheath 605 may be configured to establish a curved transition from a generally anterior-posterior approach over the common carotid artery to a generally axial, lumen-oriented transition within the common carotid artery. Arterial access through the arterial wall of the common carotid artery, whether from a straight surgical venotomy or percutaneous access, may generally require a larger access angle than other sites of arterial access. This is due to the fact that the insertion site in the common carotid artery is much closer to the treatment site (i.e., the carotid bifurcation) than other access points. A larger access angle may be required to increase the distance from the insertion site to the treatment site so that the sheath can be inserted at an appropriate distance without the distal tip of the sheath reaching the carotid bifurcation. For example, in access to the femoral artery, the insertion angle of the sheath is 15-20 degrees, but in access to the carotid artery, the insertion angle of the sheath is usually 30-45 degrees or even greater. Therefore, the sheath must bend more than an introducer sheath, without twisting and without applying excessive force to the opposing arterial wall. Furthermore, it is desirable that the tip of the sheath be designed in a way that restricts the flow into the sheath so that it does not abut or come into contact with the arterial wall after insertion. The sheath insertion angle is defined as the angle between the lumen axis of the artery and the longitudinal axis of the sheath.

[0086] The sheath body 605 may be formed in various ways to allow for the large bends required by the access angle. For example, the sheath and / or expander may have a combined flexible bending stiffness lower than that of a typical introducer sheath. In one embodiment, the sheath / expander combination (i.e., a sheath with an expander positioned inside) has a stiffness of about 80 to 100 N-m 2 ×10 -6 Composite flexible stiffness in the range (E * I) is the elastic modulus, where E is the elastic modulus and I is the moment of inertia of the device. The sheath alone has an elasticity of approximately 30-40 N-m. 2 ×10 -6 The expander has a bending rigidity in the range of approximately 40-60 N-m. 2 ×10-6 It may have a bending stiffness within the range of. The typical bending stiffness of a sheath / dilator is 150 - 250 N-m 2 ×10 -6 in the range of. Greater flexibility may be achieved by material selection or the design of the reinforcement. For example, the sheath may include a stainless steel ribbon coil reinforcement having dimensions of 0.002 inches to 0.003 inches in thickness and 0.005 inches to 0.015 inches in width, and an outer coating hardness between 40 and 55 D. In one embodiment, the coil ribbon is 0.003 inches × 0.010 inches and the outer coating hardness is 45 D. In one embodiment, the sheath 605 may be pre-formed to have a curve or angle at a set distance from the tip, typically 0.5 - 1 cm. The pre-formed curve or angle may typically provide a turn within the range of 5° - 90°, preferably 10° - 30°. For the initial introduction, the sheath 605 may be straightened with an occluder or other linear instrument such as a dilator 645 disposed within its lumen. After the sheath 605 has been at least partially introduced through a percutaneous or other arterial wall penetration, the occluder may be withdrawn to allow the sheath 605 to re-capture its pre-molded configuration within the arterial lumen. To maintain the curved or angled shape of the sheath body after being straightened during insertion, the sheath may be heat-set in an angled or curved shape during manufacture. Also, the reinforcement structure may be composed of nitinol and heat-formed into a curved or angled shape during manufacture. Also, an additional spring member may be added to the sheath body. For example, a strip of spring steel or nitinol having an exact shape may be added to the reinforcement layer of the sheath

[0087] Other sheath configurations have a deflection mechanism that positions the sheath and deflects the catheter in place to a desired deployment angle. In yet another configuration, the catheter has a non-rigid configuration when positioned within the lumen of the common carotid artery. Once positioned, a pull wire or other stiffening mechanism may be deployed to mold and stiffen the sheath to its desired configuration. One particular example of such a mechanism is commonly known as a “shape-lock” mechanism, as is frequently described in medical patent literature.

[0088] Other sheath configurations include a curved dilator inserted into a straight but flexible sheath, with the dilator and sheath bending during insertion. The sheath is flexible enough to conform to the tissue structure after the dilator is removed.

[0089] Other embodiments of the sheath have one or more flexible distal sections so that, once inserted and in an angled configuration, the sheath can bend at a large angle without twisting and without applying excessive force to the opposing arterial wall. In one embodiment, there is a sheath body 605 with a more flexible distal section than the rest of the sheath body. For example, the bending stiffness of the distal section is half to one-tenth of the bending stiffness of the rest of the sheath body 605. In one embodiment, the distal section has a bending stiffness of 30-300 N-mm 2 It has a bending rigidity in the range of 500-1500 N-mm², and the rest of the sheath body 605 has a bending rigidity of 500-1500 N-mm². 2It has a bending stiffness in the range of . For a sheath configured for a CCA access site, the flexible distal section constitutes a significant part of the sheath body, which can be expressed as a ratio. In one embodiment, the ratio of the length of the flexible distal section to the total length of the sheath body is at least one-tenth and at most one-half of the total length of the sheath body. This variation in flexibility may be achieved in various ways. For example, the outer covering may have varying hardness and / or material in different sections. Also, the reinforcing structure or material may vary over the length of the sheath body. In one embodiment, the flexible distal section is in the range of 1 cm to 3 cm. In one embodiment having one or more flexible sections, the less flexible section (relative to the distal section) may be in the range of 1 cm to 2 cm from the distal section. In one embodiment, the flexible distal section is about 30 to 50 N-mm 2 ×10 -6 It has a bending stiffness in the range of approximately 50-100 N-mm², and the less flexible section has a bending stiffness of approximately 50-100 N-mm². 2 ×10 -6It has a bending stiffness in the range of . In another embodiment, a more flexible section is positioned between 0.5 and 1.5 cm for a length of 1 to 2 cm, forming an articulated section that allows the sheath to enter the artery obliquely but allows the distal section of the sheath to align more easily with the vascular axis. These configurations with a variable flexible section may be manufactured in several embodiments. For example, a reinforced, less flexible section may vary such that it has a stiffer reinforcement in the proximal section and a more flexible reinforcement in the distal or articulated section. In one embodiment, the outermost covering material of the sheath has a hardness of 45D to 70D in the proximal section and a hardness of 80A to 25D in the distal section of the outermost layer. In one embodiment, the flexibility of the sheath varies continuously along the length of the sheath body. Figure 11G shows such a sheath inserted into an artery. The flexible distal section allows the sheath body to bend, so that the distal tip roughly coincides with the vascular lumen. In one embodiment, the distal section is fabricated with a more flexible reinforcement structure by varying the pitch of the coil or blades, or by incorporating a subcutaneous tube having a different cutting pattern. Furthermore, the distal section has a different reinforcement structure than the proximal section.

[0090] In one embodiment, the tapered tip of the distal sheath is made of a material harder than the distal sheath body. The purpose of this is to facilitate sheath insertion by allowing a smooth taper on the sheath and to reduce changes in distortion or ellipsification of the sheath tip during and after insertion into the blood vessel. In one embodiment, the distal tapered tip member is made of a material with higher hardness, such as 60-72D Shore material. In another example, the distal tip is made of a different material, such as HDPE, stainless steel, or other suitable polymer or metal. In an additional embodiment, the distal tip is made of a radiopaque material, such as an additive to a polymer material such as tungsten or barium sulfate, or as an inherent property of the material (as in the case of most metallic materials).

[0091] In another embodiment, the dilator 645 may have variable stiffness. For example, to minimize the risk of vascular damage when the sheath and dilator are inserted into an artery, the tapered distal end 650 of the dilator may be made of a material that is more flexible than the proximal portion of the dilator. In one embodiment, the flexible distal section is approximately 45-55 N-m 2 ×10 -6 The bending stiffness is in the range of 60-90 N-m, with the less flexible proximal section having a bending stiffness of approximately 60-90 N-m. 2 ×10 -6 It has a bending stiffness in the range of [range]. Furthermore, the tapered shape of the dilator may be optimized for transcarotid artery access. For example, to limit the amount of sheath and dilator tip entering the artery, the length of the taper and the amount of dilator extending beyond the sheath are preferably shorter than those of a typical introducer sheath. For example, the length of the taper may be 1 to 1.5 cm and may extend 1.5 to 2 cm from the end of the sheath body. In one embodiment, the dilator has a radiopaque marker at its distal tip so that the position of the tip is easily visible under fluoroscopy.

[0092] In another embodiment, the introducer guidewire is optimally configured for transcarotid artery access. Typically, when inserting the introducer sheath into a vessel, the introducer guidewire is inserted into the vessel first. This may be done by either a micropuncture technique or a modified Seldinger technique. Usually, in the direction from which the sheath is inserted, there are long vessels into which the introducer guidewire may be inserted, such as the femoral artery. In this case, the user may introduce 10 to 15 cm or more of the guidewire into the vessel before inserting the sheath. The guidewire is designed so that the distal section is flexible so as not to damage the vessel when introduced into the artery. The flexible section of the introducer sheath guidewire is usually 5 to 6 cm, gradually transitioning to a rigid section. Inserting the guidewire 10 to 15 cm means that the rigid portion of the guidewire is positioned in the puncture area, providing stable support for the subsequent insertion of the sheath and dilator into the vessel. However, in the case of transcarotid sheath insertion into the common carotid artery, there is a limit to the amount of guidewire that can be inserted into the carotid artery. When there is carotid artery disease in the bifurcation or internal carotid artery, it is desirable to insert the wire into the external carotid artery (ECA) to minimize the risk of embolism, so the guidewire insertion amount can be about 5-7 cm, or about 3-5 cm if stopped before reaching the bifurcation. Therefore, the transcarotid sheath guidewire may have a distal section that is flexible for 3-4 cm and / or a shorter transition section to a stiffer section. Alternatively, the transcarotid sheath guidewire may have a non-traumatic tip section but a very distal and short transition section to a stiffer section. For example, the flexible tip section may be 1.5-2.5 cm, followed by a transition section of 3-5 cm in length, followed by a stiff proximal section that makes up the remainder of the wire.

[0093] In another embodiment, the sheath dilator is configured to be inserted on a 0.018-inch guidewire for percutaneous access. Standard sheath insertion using a micropuncture kit requires first inserting a 0.018-inch guidewire through a 22Ga needle, then replacing the guidewire with a 0.035-inch or 0.038-inch guidewire using a micropuncture catheter, and finally inserting the sheath and dilator on the 0.035-inch or 0.038-inch guidewire. A 0.014-inch guidewire may also be used. There are also sheaths that can be inserted on a 0.018-inch guidewire, eliminating the need for wire replacement. These sheaths are designed for insertion into the radial artery and are therefore usually labeled "transradial," and typically have a long dilator taper to ensure sufficient diameter from the 0.018-inch wire to the sheath body. Unfortunately, these existing sheaths are not suitable for transcarotid access due to limitations in the insertion length of the sheath and dilator. Another drawback is that a 0.018-inch guidewire may not have the necessary support to insert a sheath with a sharper angle into the carotid artery. In the embodiments disclosed herein, the transcarotid sheath system comprises a sheath body, a sheath dilator, and an inner tube that is slidably fitted within the sheath dilator and has a tapered distal end capable of accommodating a 0.018-inch guidewire.

[0094] To use this embodiment of the sheath system, a 0.018-inch guidewire is first inserted into the blood vessel through a 22Ga needle. The coaxially assembled sheath system is inserted on the 0.018-inch wire. The inner tube is first advanced on the 0.018-inch wire. The wire essentially deforms the inner tube into the equivalent of a 0.035-inch or 0.038-inch guidewire in both outer diameter and mechanical support. The inner tube is secured to the 0.018-inch wire at its proximal end. The sheath and dilator are inserted into the blood vessel via the 0.018-inch wire and inner tube. This configuration eliminates the need for a longer dilator taper, as in current transradial sheaths, and allows for the elimination of the wire change procedure with the same guidewire support as a standard introducer sheath. As described above, this configuration of the sheath system may include a stopper function to prevent accidental advancement of the 0.018-inch guidewire and / or inner tube during sheath insertion. Once the sheath is inserted, the dilator, inner tube, and 0.018-inch guidewire are removed.

[0095] Figure 12A shows another embodiment of the arterial access device 110. This embodiment is substantially the same as the embodiment shown in Figure 8A, except that the distal sheath 605 includes an occlusion member 129 for occluding flow, for example, through the common carotid artery. Any embodiment of the arterial access device may include an occlusion member. If the occlusion member 129 is an inflatable structure such as a balloon, the sheath 605 may include an inflation lumen communicating with the occlusion member 129. The occlusion member 129 may be an inflatable balloon, an inflatable cuff, a conical or other circumferential member that flares outward to engage with the inner wall of the common carotid or internal carotid artery to block the flow beyond, a membrane-coated blade, a slotted tube that expands radially when compressed axially, or a similar structure deployable by mechanical means. In the case of balloon occlusion, the balloon may have various properties such as compliant, non-compliant, elastic, reinforced, or others. In one embodiment, the balloon is an elastic balloon that is tightly received, covering the outside of the distal end of the sheath before inflation. When inflated, the elastic balloon can expand and conform to the inner wall of the common carotid artery. In one embodiment, the elastic balloon can expand to a diameter at least twice that of the unexpanded configuration, can frequently expand to a diameter at least three times that of the unexpanded configuration, and more preferably expand to at least four times, or larger, that of the unexpanded configuration.

[0096] As shown in Figure 12B, the distal sheath 605 with the occlusion member 129 may have a stepped or other configuration with a reduced-diameter distal region 630. The distal region 630 may be sized for insertion into a carotid artery where the remaining proximal region of the sheath 605 has a larger outer diameter and lumen diameter. The inner diameter is typically in the range of 2.794 mm (0.110 inches) to 3.43 mm (0.135 inches). The larger lumen diameter of the proximal region minimizes the overall flow resistance of the sheath. In one embodiment, the reduced-diameter distal section 630 has a length of about 2 cm to 4 cm or 3 cm to 5 cm. In another embodiment, the length of the reduced-diameter distal section 630 is about 10 cm to 15 cm. The relatively short length of the reduced-diameter distal section 630 reduces the risk of the distal end of the sheath 605 contacting bifurcation B, allowing this section to be placed in the common carotid artery (CCA) via a transcervical approach. In another embodiment shown in Figure 28, the reduced-diameter distal section 630 is tapered or stepped and has a length of about 10 cm to 15 cm such that its distal tip is positioned in the internal carotid artery (ICA).

[0097] In situations involving a sharp sheath insertion angle and / or a short length of sheath inserted into an artery, such as in transcarotid artery access procedures, the distal tip of the sheath is likely to be partially or completely positioned relative to the vessel wall, thereby restricting flow into the sheath. In one embodiment, the sheath is configured so that its tip is centered within the lumen of the vessel. Such an embodiment includes a balloon, such as the occlusion member 129 described above. In another embodiment, the balloon may be centered away from the vessel wall at the tip of the sheath, such as an inflatable bumper, even if it is not occluding to the flow. In another embodiment, an expandable feature is located at the tip of the sheath and is mechanically expanded when the sheath is in place. Examples of mechanically expandable features include braided or helical structures, or longitudinal struts that expand radially when shortened.

[0098] In one embodiment, occlusion of a vessel adjacent to the distal tip of the sheath may be performed from the outside of the vessel, such as by a Rummel tourniquet or a vascular loop adjacent to the sheath insertion site. In an alternative embodiment, the occlusion device may be fitted externally to the vessel around the sheath tip, such as an elastic loop, an inflatable cuff, or a mechanical clamp that tightens around the vessel and the distal tip of the sheath. In a flow reversal system, this method of occluding a vessel minimizes the area of ​​static blood flow, thereby reducing the risk of thrombus formation, and ensures that the sheath tip is axially aligned with the vessel and not partially or completely blocked by the vessel wall.

[0099] In one embodiment, the distal portion of the sheath body may have side holes so that flow to the sheath is maintained even if the tip of the sheath is partially or completely blocked by the arterial wall.

[0100] (Venous return device) Referring here to Figure 13, the venous return device 115 comprises a distal sheath 910 and a channel 915 that connects to and forms a leg of the shunt 120 when the system is in use. The distal sheath 910 is adapted to be introduced through an incision or puncture into a venous return site such as a jugular or femoral vein. The distal sheath 910 and channel 915 may be permanently attached or attached using conventional Luer connectors as shown in Figure 13. Optionally, the sheath 910 may be joined to the channel 915 by a Y-connector 1005 as shown in Figure 14A. The Y-connector 1005 may include a hemostatic valve 1010 that allows insertion of a dilator 1015 to facilitate the introduction of the venous return device into the internal jugular vein or other vein. Similar to the arterial access dilator 645, the venous dilator 1015 has a central guidewire lumen, so the combination of the venous sheath and dilator may be positioned on the guidewire. Optionally, the venous sheath 910 may include a flush line 1020 having a live valve 1025 at its proximal or distal end.

[0101] Figures 14B and 14C show alternative configurations. Figure 14B shows the components of a venous return device 115 comprising a venous return sheath 910, a sheath dilator 1015, and a sheath guidewire 611. Figure 14C shows the venous return device 115 as assembled for insertion onto the sheath guidewire 611 into a central vein. 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 channel 915. A stop valve 1025 provided at the end of the flow channel allows the venous sheath to be flushed through the flow channel before use. This configuration allows the sheath to be prepared from a single point, similar to a conventional introducer sheath. Connection to the flow shunt 120 is made using a connector 1030 (such as a hemostatic valve) provided on the stop valve 1025. The venous return device 115 may be equipped with one or more eyelets that can be used to attach to sutures for securing the venous return device 115 to the patient.

[0102] To reduce the overall flow resistance of the system, the arterial access channel 615, Y-connector 620 (Figure 8A), venous return channel 915, and Y-connector 1005 (Figure 13 or 14) may each have a relatively large flow lumen inner diameter, typically ranging from 2.54 mm (0.100 inches) to 5.08 mm (0.200 inches), and a relatively short length, typically ranging from 10 cm to 20 cm. Low flow resistance of the system is desirable because it allows for maximum fluid flow in the part of the procedure where the risk of embolism is greatest. Low flow resistance of the system also allows for the use of variable flow resistance to control the flow rate within the system, as will be described in more detail below. The dimensions of the venous return sheath 910 may be approximately the same as those described above for the arterial access sheath 605. In the venous return sheath, an extension for the hemostatic valve 1010 is not necessary.

[0103] (Retrograde shunt or flow path) The shunt 120 may be formed as a single tube or multiple connected tubes that provide fluid communication between the arterial access catheter 110 and the venous return catheter 115, providing a pathway for retrograde blood flow between them. As shown in Figures 5 and 6, one end of the shunt 120 is connected to the flow path 615 of the arterial access device 110, and the other end is connected to the flow path 915 of the venous return catheter 115.

[0104] In one embodiment, the shunt 120 may be formed of at least one tube communicating with a 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 multiple lumens. The shunt 120 may be detachably attached to the flow control assembly 125, the arterial access device 110, and / or the venous return device 115. Before use, the user may select the shunt 120 having the length most appropriate for use at the arterial access site and the venous return site. In one embodiment, the shunt 120 may include one or more extension tubes that can be used to change the length of the shunt 120. The extension tubes may be modularly attached to the shunt 120 to achieve the desired length. The modular aspect of the shunt 120 allows the user to lengthen the shunt 120 as needed, 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 in this area may be higher than in some other areas due to its proximity to other tissue structures. Furthermore, a hematoma in the neck can cause airway obstruction and cerebrovascular complications. Therefore, for such patients, it may be desirable to locate the venous return site in a site other than the internal jugular vein (IJV), such as the femoral vein. Femoral vein return has a lower risk of serious complications, can be achieved percutaneously, and can provide alternative venous access to a central vein when the internal jugular vein (IJV) is unavailable. In addition, femoral vein return modifies the layout of the reflux shunt so that the shunt control unit can be located closer to the interventional "working area" where the device is introduced and the contrast agent injection port is located.

[0105] In one embodiment, the shunt 120 has an inner diameter of 4.76 mm (3 / 16 inch) and a length of 40 to 70 cm. As mentioned above, the length of the shunt can be adjusted and may differ from that described herein.

[0106] In one embodiment, the shunt may have a port that can be connected to a suction source such as a syringe or a suction pump.

[0107] In an additional embodiment, the shunt may include a component that connects to an active pump, such as a peristaltic pump, diaphragm pump, impeller pump, or syringe pump.

[0108] (Flow control assembly - regulation and monitoring of backflow) The flow control assembly 125 interacts with the retrograde shunt 120 to regulate and / or monitor retrograde flow from the common carotid artery to a venous return site such as the internal jugular vein or to an external container. In this regard, the flow control assembly 125 allows the user to achieve a higher maximum flow rate than existing systems and to selectively adjust, set, or otherwise regulate retrograde flow. Various mechanisms may be used to regulate retrograde flow, as will be more fully described below. The flow control assembly 125 allows the user to configure retrograde blood flow in a manner suitable for various treatment regimens, as will be described below.

[0109] Generally, the ability to control continuous retrograde flow allows physicians to tailor protocols to individual patients and stages of treatment. Retrograde blood flow is typically controlled across a range from low to high rates. High rates are at least twice as high as low rates, typically at least three times higher, often at least five times higher, or even higher. In one embodiment, high rates are at least three times higher than low rates. In another embodiment, high rates are at least six times higher than low rates. While high retrograde blood flow is generally desirable to maximize the extraction of embolus from the carotid artery, patients' tolerance for retrograde flow varies. Therefore, having systems and protocols with easily adjustable retrograde blood flow allows the treating physician to determine when the flow exceeds the patient's tolerance level and adjust the retrograde blood flow accordingly. For patients who cannot tolerate continuous high retrograde flow, the physician can choose to turn on high flow only for short, critical portions of the procedure where the risk of embolic material is highest. At short intervals, for example between 15 seconds and 1 minute, the patient's tolerance limit is usually not a contributing factor.

[0110] In certain embodiments, the continuous retrograde blood flow may be controlled at a baseline flow rate in the range of 10 ml / min to 200 ml / min, typically 20 ml / min to 100 ml / min. These flow rates are acceptable for the majority of patients. For most of the procedure, the flow rate is maintained at the baseline, but when the risk of embolic discharge increases, the flow rate may be increased above the baseline for a short period to improve the ability to capture such emboli. For example, the retrograde blood flow rate may be increased above the baseline during stent catheter introduction, stent deployment, before and after stent expansion, and during removal of common carotid artery occlusion.

[0111] The flow control system may cycle between relatively low and relatively high flow rates to “flush” the carotid artery in the carotid bifurcation region before re-establishing antegrade flow. Such cycles may be established at high flow rates that are approximately 2 to 6 times greater than low flow rates, typically about 3 times greater. These cycles typically range in length from 0.5 to 10 seconds, usually from 2 to 5 seconds. The total duration of the cycles ranges from 5 to 60 seconds, usually from 10 to 30 seconds.

[0112] Figure 15 shows an example of a system 100 having a schematic diagram of a flow control assembly 125 positioned along a shunt 120 such that retrograde blood flow passes through or communicates with at least a portion of the flow control assembly 125. The flow control assembly 125 may include various controllable mechanisms for regulating and / or monitoring the retrograde flow. These mechanisms may include various means for controlling the retrograde flow, including one or more pumps 1110, valves 1115, syringes 1120, and / or variable resistance elements 1125. The flow control assembly 125 may be manually controlled by a user and / or automatically controlled via a controller 1130 to change the flow through the shunt 120. For example, the retrograde blood flow through the shunt 120 may be controlled by changing the flow resistance. The controller 1130, which will be described in more detail below, may be integrated into the flow control assembly 125 or may be a separate component that communicates with components of the flow control assembly 125.

[0113] Furthermore, the flow control assembly 125 may include one or more flow sensors 1135 and / or tissue data sensors 1140 (detailed below) that detect one or more modes of retrograde flow. A filter 1145 may be positioned along the shunt 120 to remove embolus before blood is returned to the venous return site. If the filter 1145 is positioned upstream of the controller 1130, the filter 1145 can reduce the possibility of embolus entering the controller 1130 and clogging the variable flow resistance element 1125. It should be understood that the various components of the flow control assembly 125 (including the pump 1110, valve 1115, syringe 1120, variable resistance element 1125, sensors 1135 / 1140, and filter 1145) may be positioned at various locations along the shunt 120, in various upstream or downstream positions relative to each other. The components of the flow control assembly 125 are not limited to the positions shown in Figure 15. Furthermore, the flow control assembly 125 does not necessarily have to include all components, but may include various partial combinations of components. For example, a syringe may optionally be used within the flow control assembly 125 for the purpose of regulating flow, or it may be used outside the assembly for purposes other than flow regulation, such as introducing a fluid, such as a radiopaque contrast agent, forward into an artery via the shunt 120.

[0114] Both the variable resistance element 1125 and the pump 1110 may be coupled to the shunt 120 to control the retrograde flow rate. The variable resistance element 1125 controls the flow resistance, while the pump 1110 provides active replacement of blood through the shunt 120. Thus, the pump may be operated to drive retrograde flow without relying on the perfusion trunk pressure and venous pressure of the ECA and ICA. The pump 1110 may be any type of pump, including a peristaltic tube pump or a positive displacement pump. The pump 1110 may be operated and stopped (manually or automatically via the controller 1130) to selectively realize the displacement of blood through the shunt 120 and to control the flow rate through the shunt 120. Alternatively, the displacement of blood through the shunt 120 may be achieved by other means, including the use of a suction syringe 1120. Or, a suction source such as a vacuum inlet, a vacuum syringe, or wall aspiration may be used. The pump 1110 may communicate with the controller 1130.

[0115] One or more flow control valves 1115 may be arranged along the shunt path. The valves may be manually operated or automatically (via the controller 1130). The flow control valves 1115 may be, for example, one-way valves that restrict antegrade flow in the shunt 120, check valves, or high-pressure valves that occlude the shunt 120 during high-pressure contrast agent injection (intended to enter the arterial vascular system in a antegrade direction).

[0116] The controller 1130 communicates with components of system 100, including the flow control assembly 125, to enable manual and / or automatic adjustment and / or monitoring of retrograde flow through the components of system 100 (e.g., the shunt 120, arterial access device 110, venous return device 115, and flow control assembly 125). For example, a user may manually control the components of the flow control assembly 125 by operating one or more actuators on the controller 1130. The manual control unit may include switches, dials, or similar components located directly on the controller 1130, or components located away from the controller 1130, such as a foot pedal or similar device. Alternatively, the controller 1130 may automatically control the components of system 100 without requiring input from the user. In one embodiment, a user may program software within the controller 1130 to enable such automatic control. The controller 1130 may control the operation of the mechanical parts of the flow control assembly 125. The controller 1130 may include circuitry or programming for interpreting signals generated by sensors 1135 / 1140 so that the controller 1130 can control the operation of the flow control assembly 125 in response to such signals generated by the sensors.

[0117] The flow control assembly 125 may include active pump actuators that interface with components within the shunt to enable active retrograde pumping of blood, such as a pump head for a roller pump or a rotary motor for an impeller pump. The controller 1130 will provide control of the pump speed.

[0118] The representation of the controller 1130 in Figure 15 is illustrative only. It should be understood that the appearance and structure of the controller 1130 are modifiable. In Figure 15, the controller 1130 is shown as being integrated into a single housing. This allows the user to control the flow control assembly 125 from a single location. It should be understood that any component of the controller 1130 may be separated into separate housings. Furthermore, Figure 15 shows the controller 1130 and the flow control assembly 125 as separate housings. It should be understood that the controller 1130 and the flow control regulator 125 may be integrated into a single housing or divided into multiple housings or components.

[0119] (Flow status indicator) The controller 1130 may include one or more indicators that provide the user with visual and / or audible signals regarding the state of the backflow. Audible indication is advantageous for reminding the user of the flow state without requiring the user to visually confirm the flow controller 1130. The indicators may include a speaker 1150 and / or light 1155, or any other means for communicating the state of the backflow to the user. The controller 1130 may communicate with one or more sensors in the system to control the operation of the indicators. Alternatively, the operation of the indicators may be directly linked to the user operating one of the flow control actuators 1165. The indicators do not have to be speakers or light. The indicators may be simply buttons or switches that visually indicate the state of the backflow. For example, a button in a certain state (such as pressed or lowered) may visually indicate that the backflow is high. Alternatively, a switch or dial pointing to a specific labeled flow state may visually indicate that the backflow is in the labeled state.

[0120] The indicator may provide a signal indicating one or more states of the backflow. In one embodiment, the indicator identifies only two distinct states: a "high" flow rate state and a "low" flow rate state. In another embodiment, the indicator identifies more than two flow rates, including "high" flow rate, "medium" flow rate, and "low" flow rate. The indicator may be configured to identify any amount of any of the distinct states of the backflow, or it may identify a scale signal corresponding to the state of the backflow. In this regard, the indicator may be a digital or analog meter 1160 that displays a value of the backflow flow rate, such as ml / min or any other unit.

[0121] In one embodiment, the indicator is configured to show the user whether the backflow rate is in a "high" or "low" flow rate state. For example, the indicator may illuminate in a first mode (e.g., a brightness level) and / or emit a first audible signal when the flow rate is high, and then change to a second mode of illumination and / or emit a second audible signal when the flow rate is low. Alternatively, the indicator may illuminate and / or emit an audible signal only when the flow rate is high, or only when the flow rate is low. Considering that some patients cannot tolerate high flow rates, or cannot tolerate high flow rates for extended periods, it may be desirable for the indicator to notify the user when the flow rate is high. This would serve as a fail-safe function.

[0122] In another embodiment, the indicator provides a signal (audio and / or visual) when the flow rate changes state, such as when the flow rate changes from high to low and / or vice versa. In another embodiment, the indicator provides a signal when there is no backflow, such as when the shunt 120 is blocked or when one of the valves in the shunt 120 is closed.

[0123] (Flow actuator) The controller 1130 may include one or more actuators that can be pressed, switched, operated or otherwise actuated by the user to adjust and / or monitor the backflow rate. For example, the controller 1130 may include a flow control actuator 1165 (one or more buttons, knobs, dials, switches, etc.) that can be actuated by the user to selectively change the backflow pattern. For example, in the illustrated embodiment, the flow control actuator 1165 is a knob rotatable to various distinct positions on the controller 1130, each corresponding to causing the system 100 to achieve a specific backflow state. These states include, for example, (a) off, (b) low flow rate, (c) high flow rate, and (d) suction. The states described above are merely illustrative, and it should be understood that different states or combinations of states may be used. The controller 1130 achieves various backflow states by interacting with one or more components of the system, including sensors, valves, variable resistance elements, and / or pumps. Furthermore, it should be understood that the controller 1130 may also include circuits and software to adjust and / or monitor the backflow rate, so that the user does not need to actively operate the controller 1130.

[0124] The off state corresponds to a state in which there is no retrograde blood flow through the shunt 120. When the user sets the flow control actuator 1165 to off, the controller 1130 stops the retrograde flow by tightening a valve in the shunt 120 or closing a stop valve. The low flow state and high flow state correspond to low retrograde flow and high retrograde flow, respectively. When the user sets the flow control actuator 1165 to low flow or high flow, the controller 1130 interacts with the components of the flow control regulator 125, including the pump 1110, valve 1115 and / or variable resistance element 1125, to increase or decrease the flow rate as appropriate. Finally, the suction state corresponds to opening the circuit to a suction source, such as a vacuuminer or suction unit, when active retrograde flow is desired. The suction source may be connected to any part of the circuit including the shunt 120 or the arterial access device 110.

[0125] The system may be used to change blood flow between various states, including active, passive, suction, and off states. The active state corresponds to a system that uses means to actively drive retrograde blood flow. Such active means include, for example, pumps, syringes, and vacuum sources. The passive state corresponds when retrograde blood flow is driven by perfusion trunk pressure of the ECA and ICA and possibly venous pressure. The suction state corresponds to a system that uses a suction source, such as a vacuuminer or suction unit, to drive retrograde blood flow. The off state corresponds to a system where retrograde blood flow is zero, such as as a result of closing a stop valve or valve. Low flow rate and high flow rate may be either passive or active flow states. In one embodiment, a specific value (such as ml / min) for either the low flow rate and / or the high flow rate may be pre-set and / or pre-programmed in the controller so that the user does not actually set or input the value. Rather, the user simply selects "high flow rate" and / or "low flow rate" (for example, by pressing an actuator such as a button on the controller 1130), and the controller 1130 interacts with one or more components of the flow control assembly 125 to cause the flow rate to achieve a predetermined high flow rate or low flow rate value. In another embodiment, the user sets or inputs the low flow rate and / or high flow rate values, for example, to the controller. In another embodiment, the low flow rate and / or high flow rate are not actually set. Rather, external data (such as data from the tissue data sensor 1140) is used as a criterion that influences the flow rate.

[0126] The flow control actuator 1165 may consist of multiple actuators, such as one actuator, like a button or switch, for switching the state from low to high flow rate, and another actuator, for example, for closing the flow loop and turning it off during contrast agent injection, where the contrast agent is directed forward into the carotid artery. In one embodiment, the flow control actuator 1165 may include multiple actuators. For example, one actuator may be operated to switch the flow rate from low to high, another actuator may be operated to temporarily stop the flow, and a third actuator (such as a stop valve) may be operated to perform aspiration using a syringe. In another example, one actuator may be operated to switch to a low flow rate, and another actuator may be operated to switch to a high flow rate. Alternatively, the flow control actuator 1165 may include multiple actuators for switching the state from low to high flow rate, and additional actuators for fine-tuning the flow rate within the high flow rate and low flow rate states. When switching between low and high flow rates, these additional actuators may be used to fine-tune the flow rate within those states. Thus, it should be understood that within each state (i.e., high-flow and low-flow states), various flow rates may be fine-tuned by turning a dial. Control of the flow state may be achieved using a wide variety of actuators.

[0127] The controller 1130 or its individual components may be positioned in various locations relative to the patient and / or other components of the system 100. For example, the flow control actuator 1165 may be positioned near the hemostatic valve through which any interventional tool is introduced to the patient to facilitate access to the flow control actuator 1165 during tool introduction. This position may be modified, for example, based on whether a transfemoral or transcervical approach is used. The controller 1130 may have wireless and / or adjustable-length wired connections to the rest of the system 100 to enable remote control of the system 100. The controller 1130 may also have wireless and / or adjustable-length wired connections to enable remote control of the flow control regulator 125. Alternatively, the controller 1130 may be integrated with the flow control regulator 125. If the controller 1130 is mechanically connected to a component of the flow control assembly 125, a tether having mechanical actuation capability may connect the controller 1130 to one or more of the components. In one embodiment, the controller 1130 is positioned at a sufficient distance from the system 100 to allow the controller 1130 to be placed outside the radiation field when fluoroscopy is being used.

[0128] The controller 1130 and any of its components may interact with other components of the system (such as pumps, sensors, and shunts) in various ways. For example, any of various mechanical connections may be used to enable communication between the controller 1130 and the components of the system. The controller 1130 may also communicate with the components of the system electrically or magnetically. Electromechanical connections may also be used. The controller 1130 may include control software that enables the controller to perform functions that control the components of the system. The controller itself may be a mechanical, electrical, or electromechanical device. The controller may be mechanically, pneumatically, or hydraulically actuated, or electromechanically actuated (for example, in the case of solenoid operation in flow control conditions). The controller 1130 may include a computer, computer processor, and memory, in addition to data storage functions.

[0129] (sensor) As described above, the flow control assembly 125 may include or interact with one or more sensors that communicate with the system 100 and / or the patient's tissue structure. Each sensor may be configured to respond to physical stimuli (including, for example, heat, light, sound, pressure, magnetism, motion, etc.) and transmit a result signal for measurement or display or for operating the controller 1130. In one embodiment, the flow sensor 1135 interacts with the shunt 120 to detect the mode of flow through the shunt 120, such as blood flow velocity or volumetric flow rate. The flow sensor 1135 may be directly connected to a display that directly displays the value of volumetric flow rate or flow velocity. Alternatively, the flow sensor 1135 may supply data to the controller 1130 for display of volumetric flow rate or flow velocity.

[0130] The type of flow sensor 1135 may be modified. The flow sensor 1135 may be a mechanical device such as a paddle wheel, a flapper valve, a rotating ball, or any mechanical component that responds to the flow through the shunt 120. The movement of the mechanical device that responds to the flow through the shunt 120 can serve as a visual representation of the fluid flow and can also be used to calibrate a scale as a visual representation of the fluid flow rate. The mechanical device may be coupled to an electrical component. For example, a paddle wheel may be placed in the shunt 120 such that the fluid flow rotates the paddle wheel. As the velocity of the fluid flow increases, the rotational speed of the paddle wheel increases. The paddle wheel may be magnetically coupled to a Hall effect sensor to detect the rotational speed indicating the fluid flow rate through the shunt 120.

[0131] In one embodiment, the flow sensor 1135 is an ultrasonic or electromagnetic flowmeter capable of measuring blood flow without contacting the blood through the walls of the shunt 120. The ultrasonic or electromagnetic flowmeter may be configured so as not to require contact with the inner lumen of the shunt 120. In one embodiment, the flow sensor 1135 includes at least partially a Doppler flowmeter, such as a transonic flowmeter, for measuring the fluid flow through the shunt 120. It should be understood that any of the wide variety of sensor types, including ultrasonic flowmeters and transducers, may be used. Furthermore, the system may comprise multiple sensors.

[0132] The system 100 is not limited to using a flow sensor 1135 located within the shunt 120, or a sensor that interacts with a venous return device 115 or an arterial access device 110. For example, a tissue data sensor 1140 may communicate with or interact with patient tissue structures, such as the patient's nerve tissue structures. In this embodiment, the tissue data sensor 1140 may detect measurable tissue characteristics directly or indirectly related to the velocity of retrograde flow from the carotid artery. For example, the tissue data sensor 1140 may measure blood flow conditions in the brain (e.g., flow velocity in the middle cerebral artery) and transmit such conditions to a display and / or controller 1130 to adjust the retrograde flow velocity based on predetermined criteria. In one embodiment, the tissue data sensor 1140 includes transcranial Doppler ultrasound (TCD), which is an ultrasound examination that uses reflected sound waves to evaluate blood flow in the brain. The use of TCD results in TCD signals that are transmitted to a controller 1130 for controlling retrograde flow to achieve or maintain a desired TCD profile. The tissue data sensor 1140 may be based on any physiological measurement, including regurgitation velocity, blood flow through the middle cerebral artery, TCD signal of embolic particles, or other neuromonitoring signals.

[0133] In one embodiment, system 100 constitutes a closed-loop control system. In the closed-loop control system, one or more sensors (such as a flow sensor 1135 or a tissue data sensor 1140) detect or monitor a predetermined aspect of system 100 or tissue (e.g., retrograde flow and / or nerve monitoring signals). The sensors supply relevant data to a controller 1130, which continuously adjusts the system's characteristics as needed to maintain a desired retrograde flow. The sensors transmit feedback to the controller 1130 about how system 100 is operating, which translates the data to activate components of the flow control regulator 125 to dynamically compensate for disturbances in the retrograde flow. For example, the controller 1130 may include software that causes the controller 1130 to signal components of the flow control assembly 125 to adjust the flow so that the flow rate remains constant despite varying blood pressure from the patient. In this embodiment, the system 100 does not need to rely on the user to determine when, for how long, and / or by what value to set the backflow rate to either a high or low state. Rather, software within the controller 1130 may control such factors. In a closed-loop system, the controller 1130 may control components of the flow control assembly 125 to establish a level or state of backflow (either an analog level or a specific state such as high, low, baseline, or intermediate) based on the backflow rate detected by the sensor 1135.

[0134] In one embodiment, a tissue data sensor 1140 (which measures physiological measurements of the patient) transmits a signal to a controller 1130, which adjusts the flow rate based on the signal. For example, the physiological measurements may be based on flow velocity through the MCA, a TCD signal, or other cerebral vascular signals. In the case of a TCD signal, the TCD may be used to monitor changes in cerebral flow and detect microembolus. The controller 1130 may adjust the flow rate to maintain the TCD signal within a desired profile. For example, the TCD signal may indicate the presence of a microembolus ("TCD hit"), and the controller 1130 may adjust the retrograde flow rate to keep the TCD hit below a hit threshold.

[0135] In the case of MCA flow, the controller 1130 may set the retrograde flow rate to the "maximum" flow rate acceptable to the patient, as assessed by perfusion to the brain. Thus, the controller 1130 may control the retrograde flow rate to optimize the level of protection for the patient without relying on user intervention. In another embodiment, the feedback is based on the state of the device or interventional tool being used within the system 100. For example, when the system 100 is in a high-risk state (e.g., when the interventional catheter is positioned in the sheath 605), the sensor may notify the controller 1130. The controller 1130 then adjusts the flow rate to compensate for such a state.

[0136] Controller 1130 may be used to selectively increase retrograde flow in various ways. For example, it has been observed that increased retrograde flow results in a greater decrease in blood flow to the brain. Here, the most important point is that the ipsilateral MCA may not be adequately compensated for by collateral flow from the Circle of Willis. Therefore, if high retrograde flow persists for a long time, the patient's brain may not receive sufficient blood flow, potentially leading to intolerance in the patient, as manifested by neurological symptoms. Studies have shown that MCA blood flow velocities of less than 10 cm / sec are a threshold at which patients are at risk of neurological blood deficiency. Other indicators, such as EEG (electroencephalography) signals, are used as indicators to monitor adequate perfusion to the brain. However, high flow may be acceptable even to the point of complete cessation of MCA flow for short periods ranging from about 15 seconds to 1 minute.

[0137] Thus, the controller 1130 can optimize the capture of embolic fragments by automatically increasing retrograde flow only during limited periods corresponding to periods of high risk of embolism during the procedure. These high-risk periods include the period during which an interventional device (such as a thrombectomy device 15) crosses the thrombotic occlusion 10. During low-risk periods, the controller may return the retrograde flow to a lower baseline level. This lower level may correspond to low retrograde flow in the ICA or slight antegrade flow in the patient with a high perfusion pressure ratio of the ICA to the ECA.

[0138] In a flow control system where the user manually sets the flow state, there is a risk that the user may not pay attention to the backflow state (high or low) and inadvertently maintain the circuit at a high flow rate. This can lead to adverse reactions in patients. In one embodiment, as a safety mechanism, the initial flow rate is low. This serves as a fail-safe measure for patients who cannot tolerate high flow rates. In this regard, the controller 1130 may be biased back to the initial flow rate so that the system returns to a low flow rate after a predetermined period of time at a high flow rate. The bias to a low flow rate may be achieved by electronic equipment or software, or by using mechanical components or a combination thereof. In one embodiment, the valve 1115 and / or pump 1110 of the flow control actuator 1165 and / or flow control regulator 125 of the controller 1130 are spring-loaded towards a state that achieves a low flow rate. The controller 1130 is configured so that the user has priority over the controller 1130 so that the system can be manually returned to a low flow rate state if necessary.

[0139] In another safety mechanism, the controller 1130 includes a timer 1170 (Figure 15) that records the time during which the flow rate was high. The controller 1130 may be programmed to automatically return the system 100 to a low flow rate after a predetermined period of time has elapsed at a high flow rate (e.g., 15, 30, or 60 seconds or more). After the controller has returned to a low flow rate, the user may, if necessary, start another predetermined period of high flow rate. Furthermore, the user may override the controller 1130 to transition the system 100 to a desired low (or high) flow rate.

[0140] In an exemplary procedure, the capture of embolic fragments is optimized while avoiding patient tolerance issues by initially setting the retrograde flow level to a low flow rate and then switching to a high flow rate only for individual periods during critical stages of the procedure. Alternatively, the flow rate is initially set to a high flow rate, and then the patient's tolerance to that level is checked before proceeding with the remainder of the procedure. If the patient shows signs of intolerance, the retrograde flow rate is reduced. The patient's tolerance may be determined automatically by the controller based on feedback from the tissue data sensor 1140, or it may be determined by the user based on observations of the patient. The adjustment of the retrograde flow rate may be performed automatically by the controller or manually by the user. The user may also monitor the flow velocity through the middle cerebral artery (MCA) using, for example, a TCD, and set the maximum level of retrograde flow to maintain the MCA flow velocity above a threshold. In this case, the entire procedure may be performed without changing the flow velocity. If the MCA flow velocity changes or the patient develops neurological symptoms during the procedure, adjustments may be made as appropriate.

[0141] (An example mechanism for regulating backflow) System 100 is configured to regulate backflow in various ways. Any combination of the pump 1110, valve 1115, syringe 1120, and / or variable resistance element 1125 may be manually controlled by the user or automatically controlled by the controller 1130 to regulate backflow. This allows System 100 to regulate backflow in various ways, such as controlling active flow components (e.g., pump, syringe, etc.), reducing flow limiting, switching to a suction source (pre-configured backclock syringe, vacuum container, suction system, etc.), or any combination thereof.

[0142] In situations where an external container or reservoir is used, retrograde flow may be increased in various ways. The reservoir has a head height consisting of the height of the blood in the reservoir and the height of the reservoir relative to the patient. Retrograde flow into the reservoir may be regulated by setting the height of the reservoir to increase or decrease the amount of pressure gradient from the CCA to the reservoir. In one embodiment, the reservoir is raised to increase the reservoir pressure to a pressure greater than the venous pressure. Alternatively, the reservoir may be positioned below the patient, such as at floor level, to reduce the reservoir pressure to a pressure lower than the venous pressure or atmospheric pressure.

[0143] The variable flow resistance within the shunt 120 may be provided in a wide variety of ways. In this regard, the flow resistance element 1125 may change the size or shape of the shunt in order to change the flow conditions and thereby change the flow rate. Alternatively, the flow resistance element 1125 may divert the blood flow to an alternative path through one or more alternative channels within the shunt in order to change the flow conditions. Hereinafter, some exemplary embodiments of the flow resistance element 1125 will be described.

[0144] In a non-limiting embodiment, the flow resistance through the shunt 120 may be modified by providing two or more alternative flow paths. As shown in Figures 16A and 16B, the flow through the shunt 120 passes through not only the main lumen 1700 but also the secondary lumen 1705. The secondary lumen 1705 is longer and / or has a smaller diameter than the main lumen 1700. Thus, the secondary lumen 1705 has a higher flow resistance than the main lumen 1700. By passing blood through both of these lumens, the flow resistance is minimized. The blood can flow through both lumens 1700,1705 due to the pressure loss that occurs in the main lumen 1700 across the inlet and outlet of the secondary lumen 1705. This has the advantage of reducing blood stagnation. As shown in Figure 20B, by blocking the flow through the main lumen 1700 of the shunt 120, the flow can be completely diverted to the secondary lumen 1705, thereby increasing the flow resistance and reducing the blood flow rate. It should also be understood that additional flow lumens may be provided in parallel to allow for three, four, or more individual flow resistances. The shunt 120 includes a valve 1710 that controls the flow to the main lumen 1700 and the secondary lumen 1705, and the valve 1710 may be controlled by a controller 1130 or manually controlled by the user. The embodiments in Figures 16A and 16B are advantageous in that they do not require reducing the lumen size to achieve the desired backflow rate, as is the case with other embodiments of variable flow resistance mechanisms. This is advantageous in that a larger lumen size is less likely to clog and cause thrombosis than a smaller lumen size in a blood flow line.

[0145] (Obstruction) Before withdrawing the sheath 605 at the end of the procedure, any type of occlusion member, including a self-occluding member, may be positioned around the penetration in the wall of the common carotid artery. The occlusion member may be positioned at or near the start of the procedure, but optionally, the occlusion member may be positioned when the sheath is withdrawn and released from the distal end of the sheath onto the wall of the artery (such as the common carotid artery) from which the penetration originates. The use of a self-occluding member is advantageous because it substantially affects the rapid occlusion of the penetration in the common carotid artery as the sheath is withdrawn. Such rapid occlusion can reduce or eliminate unintended blood loss at the end of the procedure or while the sheath is accidentally dislodged. Furthermore, such a self-occluding member can reduce the risk of arterial wall dissection during access. In addition, the self-occluding member may be configured to exert a frictional or other retaining force on the sheath during the procedure. Such a retaining force is advantageous and can reduce the likelihood of the sheath accidentally dislodging during the procedure. The self-occluding device eliminates the need for surgically occluding the artery with sutures after sheath removal, reduces the need for a wide surgical field, and significantly reduces the surgical skills required for the procedure.

[0146] The systems and methods of this disclosure may use a wide variety of occluding members, including mechanical members that include an anchor portion and an occluding portion such as a self-occluding portion. The anchor portion may include a hook, pin, staple, clip, tooth, suture, etc., which engage with the outer surface of the common carotid artery around the penetration to secure the self-occluding member when the penetration is fully open. The self-occluding member may also include a spring-like or other self-occluding portion that closes the anchor portion to provide occlusion by pulling together the arterial wall tissue when the sheath is removed. Typically, this occlusion is sufficient so that no further measures are needed to close or seal the penetration. However, optionally, it may be desirable to provide an auxiliary seal of the self-occluding member after the sheath has been withdrawn. For example, the self-occluding member and / or the tissue canal within the area of ​​the member may be treated with a hemostatic material such as a bioabsorbable polymer, collagen plug, adhesive, sealant, coagulation factor, or other coagulation accelerator. The tissue or self-occluding member may also be sealed using other sealing protocols such as electrocautery, suturing, clipping, stapling, etc. Alternatively, the self-occluding member may be a self-sealing membrane or gasket material attached to the outer wall of a blood vessel by clips, adhesives, bands, or other means. The self-sealing membrane may have an internal opening, such as a slit or crosscut, which normally closes in response to blood pressure. These self-occluding members may be designed to be placed in an open surgical procedure or to be deployed percutaneously. The occlusion examples described below may be modified to deliver an expandable collagen plug that expands or dilates when placed in an artery to fill the arterial opening and achieve hemostasis.

[0147] In one embodiment, the occlusion member is a suture-based vascular occlusion device that can dilate an arterial incision puncture, thereby eliminating the need for prior dilation of the arterial incision puncture by another device or a procedural sheath dilator. The suture-based vascular occlusion device may have one or more sutures placed across the vascular access site so that the sutures provide hemostasis to the access site when the suture ends are tied after sheath removal. The sutures may be applied before inserting the procedural sheath through the arterial incision or after removing the sheath from the arterial incision. The device can maintain temporary hemostasis at the arterial incision site after suture placement, before and during placement of the procedural sheath, and can also maintain temporary hemostasis after withdrawal of the procedural sheath and before tying the sutures. Several exemplary suture-based vascular occlusion devices are described in U.S. Patent Nos. 7,001,400 and 7,004,952, which are incorporated herein by reference in their entirety.

[0148] In one embodiment described with reference to Figures 19A to 19D, a system and method for stopping bleeding at a puncture site in an artery, such as the carotid artery, is shown, using a hemostatic delivery device 1902, which is an elongated body configured to deploy a device configured to achieve hemostasis. The user places an introducer sheath 1905 (which may be a separate sheath or may be an arterial access device 110) at an access site in an artery, such as in the neck. The introducer sheath may be deployed percutaneously into the artery. The access site may extend through the skin 1910 and the outer wall of the carotid artery CA. The distal end of the sheath 1905 is positioned in the lumen 1915 of the carotid artery CA. The user then inserts the hemostatic delivery device 1902 through the introducer sheath 1905, which has a hemostatic member connected to the distal end or distal region of the hemostatic delivery device, as shown in Figure 19B. The hemostatic member may be, for example, an inflatable hemostatic member 1920. The hemostatic delivery device 1902 is deployed through the sheath 1905 such that the hemostatic member 1920 is positioned outside the distal tip of the sheath 1905 and within the lumen 1915.

[0149] Referring here to Figures 19C and 19D, the hemostatic member 1920 is deployed. After the hemostatic member 1920 is deployed outward, the hemostatic device 1902 may be pulled proximal to engage the hemostatic member 1920 with the wall of the artery. The introducer sheath 1905 may then be removed, leaving the expandable hemostatic member 1920 seated at position 1925, forming an entrance into the carotid artery CA, thereby achieving hemostasis. To maintain tension to hold the expandable hemostatic member 1920 in place, an external tensioning member, such as a clip 1920, may be placed on the skin surface. An exemplary occlusion system is described in U.S. Patent No. 7,993,366, incorporated by reference.

[0150] (Interventional device - suction catheter) A wide variety of interventional devices may be used in combination with the systems of this disclosure, such as insertion via an arterial access device 110. For example, the interventional device may constitute a suction catheter formed of an elongated body, having an arbitrary proximal and distal end, with at least one opening formed at or near the proximal end, and at least one opening formed at or near the distal end, with a lumen through them. In an unspecified example, the suction catheter has an inner diameter in the range of 0.071 inches, 0.058 inches, 0.045 inches, or so. In another unspecified example, the suction catheter has a length of 58 centimeters or about 58 centimeters. The suction catheter may have an overall length of about 67 cm or about 63 cm and / or a working length of about 62 cm or 58 cm. The suction catheter may have an outer diameter of about 0.069 inches or about 0.082 inches. In one embodiment, the interventional device is a catheter with an inner lumen of 0.088 inches. The distal sheath 605 of the arterial access device 110 may have an inner diameter of 0.088 inches or 0.058 inches. Alternatively, in a non-limiting example, the inner diameter may be in the range of 0.07x inches.

[0151] Various interventions can be used with the system of this disclosure, such as inserting an interventional device through the arterial access device 110 to perform treatment. For example, the interventional device may include a suction catheter for local aspiration distal to the sheath 605 of the arterial access device 110, for example, to capture and remove a thrombus in a blood vessel. For example, the suction catheter may be sized and shaped, or otherwise configured, to be inserted into the hemostatic valve 625, as well as the proximal extension 610 and the sheath 605, to access the treatment site in the blood vessel. The suction catheter may use a previously positioned guidewire or other device to facilitate the positioning of the distal opening of the suction catheter near the occlusion. Once the distal opening of the suction catheter is positioned at or near the treatment site, the suction catheter can be used to aspirate the thrombus, capture it, and remove it from the patient. For example, the suction catheter may be connected to a suction source such as a pump or syringe.

[0152] In some embodiments, the arterial access device 110 and the suction catheter may be configured to access any number of different blood vessels, including the common carotid artery (CCA) and / or the femoral artery. For example, the suction catheter may be introduced into the vascular system from either the carotid artery access site or the femoral artery access site for the retrieval of occlusions (e.g., thrombi). As described above, the arterial access device 110 may comprise a flow control assembly 125 and a shunt 120 connectable to a mechanism for passive or active regurgitation. For example, regurgitation can be performed while suctioning occlusions using any of the embodiments of the suction catheter described herein.

[0153] Figures 20A and 20B show embodiments of a suction catheter 2100 having an elongated body 2110 and an internal lumen 2112 extending between the distal body end 2114 and the proximal body end 2116 of the elongated body 2110. In some embodiments, the elongated body 2110 is formed of a flexible material. The proximal body end 2116 may be configured to connect to a suction source such as an active or passive suction mechanism (e.g., a pump, syringe). The internal lumen 2112 may be defined by an internal wall 2126. The distal body end 2114 has a distal opening 2120 that is at least partially defined by the internal lumen 2112. The distal opening 2120 can provide local suction at the distal position of the most distal end of the arterial access device 110, for example, to capture and remove a thrombus from a blood vessel.

[0154] As shown in Figures 20A and 20B, the distal opening 2120 has a suction region 2122 for fluid communication with a suction source and for applying suction force to occluding objects such as thrombi in order to capture and remove the occluding material. For example, the suction region 2122 is defined as the cross-sectional area of ​​the inner lumen 2112 at the distal body end 2114. Thus, the suction region 2122 may be determined based on the diameter of the distal opening 2120 and / or the periphery 2124 of the inner lumen 2112 at the distal body end 2114. The inner lumen 2112 may be defined by the inner wall 2126.

[0155] For example, as the peripheral portion 2124 defining the distal opening 2120 increases, the suction area 2122 increases, thereby increasing the amount of suction force that can be applied to the thrombus. The greater the suction force of the suction catheter 2100, the more efficient and effective the retrieval and removal of the thrombus by the suction catheter 2100 becomes. Reliably capturing and removing the thrombus is important for restoring blood flow to the vessel and mitigating the adverse effects on the body caused by the occlusion. At least some of the current occlusion retrieval / removal devices require at least two attempts to capture the occlusion for removal. If attempts to remove the occlusion are unsuccessful, the time that blood flow is stopped along part of the body increases, which is likely to result in adverse physical and / or cognitive effects. However, while increasing the suction area 2122 can improve occlusion treatment and patient outcomes, the size and shape of the suction catheter 2100 with its distal body end 2114 may be limited by the arterial access device 110 and one or more vessels along which the suction catheter 2100 travels for occlusion treatment.

[0156] The following describes various embodiments of a suction catheter 2100 having various distal features (e.g., deformers, distal opening periphery, occlusion grasping portion) that provide an improved suction area 2122 and / or capture / removal of occlusions in order to achieve more efficient and effective aspiration of thrombi and restoration of blood flow along one or more affected blood vessels. As will be described in more detail below, some embodiments of the suction catheter 2100 have an expandable distal portion, such as when placed in a therapeutic position. Expansion of such a distal portion can increase the suction area 2122 provided by the suction catheter 2100 in the therapeutic position in order to achieve greater suction force. As a result, the diameter of the suction catheter for insertion into one or more blood vessels and movement along those vessels can be reduced, while thrombi can be efficiently and effectively captured and removed from the patient. In some embodiments, the suction catheter 2100 has a distal end (e.g., distal body end 2114) having a shape that increases the length of the peripheral portion 2124 of the distal opening 2120, thereby forming a larger suction area 2122 without changing the diameter of the distal opening 2120. Various suction catheters 2100 having other features and functions, such as an occluding portion, are described herein.

[0157] In some embodiments, the suction catheter 2100 has at least one reinforcing member along at least a portion of the elongated body 2110 to reduce flexibility and increase structural strength in order to assist in the advancement and positioning of the suction catheter 2100. For example, the reinforcing member may extend along a first length of the elongated body 2110 between a proximal reinforcing end and a distal reinforcing end. For example, the proximal reinforcing end may be located at or adjacent to the proximal body end 2116 of the elongated body 2110. Furthermore, the distal reinforcing end may be located a second length from the distal body end 2114 of the elongated body 2110. Thus, in some embodiments, the second length of the elongated body 2110 may define an expandable distal portion of the elongated body 2110, while maintaining flexibility, as will be described in more detail below.

[0158] For example, the expandable distal portion may be expanded in or adjacent to the occlusion to increase the diameter of the distal opening 2120, thereby increasing the suction area 2122 that can be applied to the occlusion in order to efficiently and effectively capture and remove the occlusion. Such capture of the occlusion may include activating a suction source to apply a vacuum to the distal opening 2120. Capture of the occlusion by the suction device 2100 may include holding the occlusion in and / or within the distal opening 2120 (e.g., using a suction and / or occlusion capture function). For example, the occlusion may be captured in or within the distal opening 2120 and / or the distal portion. The suction catheter 2100 may then be withdrawn once the occlusion has been sufficiently removed and / or captured and blood flow has returned to the affected vessel.

[0159] Embodiments of the suction catheter 2100 described herein may be made of one or more different materials, including various materials to achieve desired properties. For example, one or more reinforcing members may be made of metal wire and / or Teflon material. In some embodiments, at least the distal portion of the elongated body 2110 of the suction catheter 2100 may be made of a flexible material such as a tie layer. For example, the flexible material forming at least a portion of the expandable distal portion may be elastic to allow circumferential expansion at the distal opening 2120.

[0160] In some embodiments, at least the distal portion of the elongated body 2110 may contain one or more liquid crystal polymer (LCP) fibers that can enhance wall strength without significantly affecting flexibility. Various embodiments of the suction catheter 2100 for achieving improved capture and / or removal of occlusions to efficiently and effectively restore blood flow are described in more detail below.

[0161] Figures 21A to 21D show embodiments of a suction catheter 2200 comprising an elongated body 2110 having an expandable distal portion 2230. The suction catheter 2200 in Figures 21A to 21D may have the same or similar features and functions as described above with respect to the suction catheter 2100 in Figures 20A to 20B. Furthermore, the expandable distal portion 2230 of the elongated body 2110 may be flexible and deformable so as to increase the diameter of the distal opening 2120, thereby increasing the suction area 2122 of the distal opening 2120, as will be described in more detail below.

[0162] As shown in Figure 21A, the suction catheter 2200 may include one or more reinforcing members 2240 extending along a first length 2250 of the elongated body 2110. For example, the reinforcing member 2240 may include a metal wire 2241 that extends spirally along the inner wall 2126 of the first length 2250 of the elongated body 2110. Furthermore, the reinforcing member 2240 may include a Teflon liner 2242 that extends along the inner diameter of the spiral metal wire 2241, as shown in Figures 21A and 21C. For example, the reinforcing member 2240 may extend along the first length 2250 of the elongated body 2110 between a proximal reinforcing end and a distal reinforcing end. For example, the proximal reinforcing end may be located at or adjacent to the proximal body end 2116 of the elongated body 2110. The distal reinforcing end may be positioned at a distance of a second length 2255 from the distal body end 2114 of the elongated body 2110. In this way, the second length 2255 can maintain flexibility and define at least a portion of the expandable distal portion 2230 of the elongated body 2110. Furthermore, each of one or more reinforcing members 2240 may extend along various lengths of the elongated body 2110 adjacent to the second length 2255 without departing from the scope of this disclosure.

[0163] In some embodiments, one or more LCP fibers may extend along the flexible second length 2255 of the elongated body 2110 and help increase wall strength without significantly affecting the flexibility of the elongated body 2110 along the second length.

[0164] As shown in Figures 21A to 21D, the suction catheter 2200 may include a deformer such as an inflatable balloon 2260 connected to a second length 2255 of an elongated body 2110 and extending along the second length. For example, the inflatable balloon 2260 may extend along the longitudinal axis of the elongated body 2110 and along the outer wall of the elongated body 2110. For example, the inflatable balloon 2260 may be held (e.g., attached) to the elongated body 2110 at one or more positions, such as the distal end and / or proximal end of the second length 2255. In some embodiments, the inner diameter of the inflatable balloon 2260 may be approximately the same as the outer diameter of the elongated body 2110 (e.g., along the second length). As shown in Figure 21A, the inflatable balloon 2260 can form a deflated configuration. Also, as shown in Figure 21C, the inflatable balloon 2260 can form an inflated configuration. In the inflated configuration, the expandable distal portion 2230 (for example, the second length 2255 of the elongated body 2110) can deform distally to increase its diameter, thereby increasing the diameter of the distal opening 2120 compared to when the inflatable balloon 2260 is in a deflated configuration.

[0165] As shown in Figures 21A and 21C, the inflatable balloon 2260 can be fluid-connected to a filling line 2262 extending from the proximal end of the elongated body 2110, allowing fluid (e.g., saline solution, contrast agent solution) to be supplied to the inflatable balloon 2260 to enable it to form an inflated configuration. The filling line 2262 can also provide a fluid passage for discharging fluid to enable the inflatable balloon 2260 to form a deflated configuration.

[0166] For example, as shown in Figure 21B, when the inflatable balloon 2260 is in a deflated configuration, the distal opening 2120 forms a first suction region 2122a, which has a diameter approximately the same as the diameter of the elongated body 2110 along the first length 2250. As shown in Figure 21D, in an inflated configuration, the inflatable distal portion 2230 may increase in diameter such that the distal opening 2120 forms a second suction region 2122b (e.g., having a second opening diameter) which is larger than the first suction region 2122a (e.g., having a first opening diameter). For example, as the filling line supplies fluid to the inflatable balloon 2260 and the inflatable balloon 2260 expands, the inflatable balloon 2260 may expand radially, thereby deforming and expanding the inflatable distal portion 2230 radially. Radial expansion of the expandable distal portion 2230 results in a larger diameter distal opening 2120 (for example, the diameter of the second opening is larger than the diameter of the first opening) and a larger suction area 2122 (compared to when the balloon 2260 is in a deflated configuration), allowing the suction catheter 2200 to apply greater suction force to retrieve the occlusion. Suction force may be activated when the balloon 2260 is in an inflated configuration to capture the occlusion, either in or within the expandable distal portion 2230 for removal from the blood vessel.

[0167] Figures 22A to 22D show another embodiment of the suction catheter 2300 having an inflatable distal portion 2230. The suction catheters of Figures 22A to 22D may have the same or similar features and functions as described above with respect to the suction catheter 2200 of Figures 21A to 21D. Furthermore, as shown in Figures 22A and 22C, the inflatable balloon 2360 of the suction catheter 2300 may extend spirally around and along the second length 2255. Thereafter, the inflatable balloon 2360 of Figures 22A to 22D may have a smaller diameter and a longer length compared to the inflatable balloon 2260 of Figures 21A to 21D.

[0168] As shown in Figure 22B, when the inflatable balloon 2360 is in a deflated configuration, the distal opening 2120 can form a first suction region 2122a, which has a diameter approximately the same as the diameter of the elongated body 2110 along the first length 2250. In the inflated configuration, as shown in Figures 22C and 22D, the inflatable distal portion 2230 may deform distally and increase in diameter as a result of the inflatable balloon 2360 forming the inflated configuration, such that the distal opening 2120 forms a second suction region 2122b which is larger than the first suction region 2122a.

[0169] Figures 23A to 23D show another embodiment of the suction catheter 2400, comprising an elongated body 2110 having an expandable distal portion 2230. The suction catheter 2400 of Figures 23A to 23D may have the same or similar features and functions as those described above with respect to the suction catheter 2100 of Figures 21A to 21D. Furthermore, the inflatable balloon 2460 of the suction catheter 2400 shown in Figures 23A to 23D may extend spirally around and along the second length 2255, and may be twisted along at least a portion of the length of the balloon 2460 that extends spirally around the second length 2255. Thus, the inflatable balloon 2460 of Figures 23A to 23D may have a smaller diameter and a longer length compared to the inflatable balloon 2260 of Figures 21A to 21D. Furthermore, due to the twisting of the inflatable balloon 2460, the inflatable balloon 2460 in Figures 23A to 23D can have a longer length compared to the inflatable balloon 2260 in Figures 22A to 22D. For example, the longer the balloon, the greater the expansion of the expandable distal portion 2230 to form a larger suction area 2122, such as when the inflatable balloon 2460 is in an expanded configuration, as shown in Figures 23C and 23D. Figures 23A and 23D show the inflatable balloon 2460 in an expanded configuration, twisted and spirally extending around a second length 2250.

[0170] In some embodiments, the second length 2255 may be about 1 millimeter (mm) to about 5 mm in length. In some embodiments, the second length 2255 may be about 0.5 to 2 times the diameter of the elongated body 2110. In some embodiments, the inflatable balloon may be spirally wound about 1 to 5 times around the second length 2255 of the elongated body 2110. The inflatable balloon may be made of a variety of materials, such as one or more biocompatible or compliant materials such as polyurethane or silicone.

[0171] In some embodiments of the suction catheter, a balloon is not used to deform (e.g., expand) the expandable distal portion 2230, as will be discussed in more detail below. For example, the suction catheter may include a deformer having a shape memory deformer positioned along and / or coupled to the second length 2255. For example, the shape memory deformer may be configured to form a folded configuration and an expanded configuration, such as to form a larger suction area 2122 when the shape memory deformer is in an expanded configuration. For example, when the shape memory deformer is in a folded configuration along the second length 2255, the distal opening 2120 can form a first suction area 2122a, having a diameter approximately the same as the diameter of the elongated body 2110 along the first length 2250. In the expanded configuration, the shape memory deformer can deform the expandable distal portion 2230 to increase its diameter so that the distal opening 2120 forms a second suction area 2122b, which is larger than the first suction area 2122a.

[0172] In some embodiments, the shape memory deformer may include a nitinol material, such as at least one nitinol wire extending along a second length 2255. For example, the nitinol wire may be configured to form a folded configuration when the nitinol wire is below a first temperature (e.g., body temperature), and to form an expanded configuration when the nitinol wire reaches and / or exceeds the first temperature. Other temperatures may be preset to cause the nitinol wire to form the folded and expanded configurations. For example, some embodiments of a suction catheter may include a thermally conductive and / or electrically conductive wire that can extend between the shape memory deformer and a power source. Thereafter, in some embodiments, an electric current may be supplied along the conductive wire to raise the temperature of the nitinol wire to transition it into the expanded configuration. Other shape memory members and formations of nitinol materials are within the scope of this disclosure.

[0173] Figures 24A to 24D show another embodiment of the suction catheter 2500, which comprises an elongated body 2110 having an expandable distal portion 2230. The suction catheter 2500 of Figures 24A to 24D has the same or similar features and functions as described above with respect to the suction catheter 2100 of Figures 21A to 21D. However, the suction catheter 2500 of Figures 24A to 24D includes a shape memory deformer 2570 that can transition between a folded configuration, as shown in Figures 24C to 24D, and an expanded configuration, as shown in Figures 24A to 24B, instead of an inflatable balloon 2260 extending along a second length 2255 to deform (e.g., expand) the expandable distal portion 2230.

[0174] For example, the shape memory deformer 2570 may include at least one nitinol wire 2572 extending longitudinally along a second length 2255 of the elongated body 2110. As shown in Figures 24A to 24D, the nitinol wire 2572 may extend longitudinally at multiple radial positions along the second length 2255. In some embodiments, the nitinol wire 2572 may extend along the inner wall 2126 of the inner lumen 2112 of the elongated body 2110 and / or along the outer wall of the elongated body 2110. An additional material sheath 2574 may extend over the nitinol wire 2572 so as to position the nitinol wire 2572 between the material sheath 2574 and the second length 2255 of the elongated body 2110. As described above, the shape memory deformer 2570 may transition between a folded configuration and an extended configuration based on the temperature of the shape memory deformer 2570. In some embodiments, the nitinol wire 2572 may be bent radially outward and expanded when it reaches body temperature, as shown in Figures 24A and 24B.

[0175] For example, when the shape memory deformer 2570 is in a folded configuration along the second length 2255, as shown in Figures 24C and 24D, the distal opening 2120 can form a first suction region 2122a, which has a diameter approximately the same as the diameter of the elongated body 2110 along the first length 2250. In the expanded configuration, the shape memory deformer 2570 can increase the diameter by deforming the expandable distal portion 2230 such that the distal opening 2120 forms a second suction region 2122b, which is larger than the first suction region 2122a.

[0176] Figures 25A to 25D show another embodiment of the suction catheter 2600, comprising an elongated body 2110 having an expandable distal portion 2230. The suction catheter 2600 of Figures 25A to 25D has the same or similar features and functions as any one of the embodiments of the suction catheter disclosed herein. For example, the suction catheter 2600 may comprise an embodiment of a shape memory deformer 2670 that can transition between a folded configuration, as shown in Figures 25C to 25D, and an expanded configuration, as shown in Figures 25A to 25B.

[0177] As shown in Figures 25A to 25D, the shape memory deformer 2670 may include a stent retriever 2675 positioned along a second length 2255, such as embedded between the inner wall 2126 of the elongated body 2110 and the material sheath 2574. For example, the stent retriever 2675 may include at least one nitinol wire 2572 extending in one or more directions and at one or more angles with respect to the longitudinal axis of the inner lumen 2112. As shown in Figures 25A and 25C, the stent retriever 2675 may include braided or woven nitinol wire 2572. As described above, the shape memory deformer 2670 can transition between a folded configuration and an extended configuration based on the temperature of the shape memory deformer 2670. For example, the braided nitinol wire 2572 of the stent retriever 2675 can move closer to parallel with the longitudinal axis of the inner lumen 2112 when moving to the folded configuration, as shown in Figure 25C. Furthermore, the nitinol wire 2572 of the stent retriever 2675 can move to a greater angle with respect to the longitudinal axis when moving to the extended configuration, as shown in Figure 25A, such as when the nitinol wire 2572 reaches a preset temperature (e.g., body temperature).

[0178] For example, when the shape memory deformer 2670 is in a folded configuration along the second length 2255, the distal opening 2120 can form a first suction region 2122a, which has a diameter approximately the same as the diameter of the elongated body 2110 along the first length 2250. In the expanded configuration, the shape memory deformer 2670 can increase its diameter by deforming the expandable distal portion 2230 such that the distal opening 2120 forms a second suction region 2122b, which is larger than the first suction region 2122a.

[0179] Figures 26A to 26D show another embodiment of a suction catheter 2700 having an expandable distal portion 2230 of an elongated body 2110. The suction catheter 2700 of Figures 26A to 26D has the same or similar features and functions as any one of the embodiments of suction catheters disclosed herein. Furthermore, the suction catheter 2700 of Figures 26A to 26D includes a movable deformer 2770 that is movable relative to the elongated body 2110. For example, when the movable deformer 2770 is positioned along a first length 2250 (equipped with a reinforcing member 2240) of the elongated body 2110, it can form a folded configuration as shown in Figures 26C to 26D, and when positioned along a flexible second length 2255 having the expandable distal portion 2230 of the elongated body 2110, it can form an expanded configuration as shown in Figures 26A to 26B.

[0180] For example, the movable deformer 2770 may include a movable stent retriever 2775 that can be positioned along a first length 2250 and / or a second length 2255 to be slidably controlled by a physician (e.g., via a connecting function 2776). For example, the movable stent retriever 2775 may include at least one nitinol wire 2572 extending in one or more directions and one or more angles with respect to the longitudinal axis of the inner lumen 2112. As shown in Figures 26A and 26C, the movable stent retriever 2775 may include a radially expandable braided or woven nitinol wire 2572 (e.g., formed in an expandable basket) so that when the movable stent retriever 2775 is positioned along the flexible second length 2255, the movable stent retriever 2775 can expand radially to enlarge the distal opening 2120 and form a larger suction area 2122. For example, the movable stent retriever 2775 may form an extended configuration when it reaches a preset temperature (e.g., body temperature). The retrieval and removal of the obstruction (using suction) can be performed with the stent retriever positioned along the second length 2255.

[0181] Figures 27A to 27D show another embodiment of a suction catheter 2800 having an expandable distal portion 2230 of an elongated body 2110. The suction catheter 2800 of Figures 27A to 27D has the same or similar features and functions as any one of the embodiments of suction catheters disclosed herein, comprising a movable deformer 2870 that is translatable relative to the elongated body 2110. For example, when the movable deformer 2870 is positioned along a first length 2250 (with reinforcing members 2240) of the elongated body 2110, it can form a folded configuration as shown in Figures 27C to 27D, and when positioned along a second length 2255 of the elongated body 2110, it can form an expanded configuration as shown in Figures 27A to 27B.

[0182] For example, the movable deformer 2870 may include a movable expander 2877 that can be positioned to be slidably controlled by a physician within the inner wall 2126 of an elongated body 2110 along a first length 2250 and / or a second length 2255. For example, the movable expander 2877 may include a tubular body having a plurality of longitudinal slits 2878 that form a distal extension 2879. At least the distal end of the movable expander 2877 having the distal extension 2879 may be formed of a shape memory material (e.g., nitinol) such that when the distal extension 2879 is positioned along the flexible second length 2255, as shown in Figures 27A and 27B, the slits 2878 cause the distal extension 2879 to expand radially, thereby expanding the distal opening 2120 to form a larger suction area 2122. For example, the movable expander 2877 may form an expanded configuration when the movable expander 2877 reaches a preset temperature (e.g., body temperature). The retrieval and removal of the obstruction (using suction) may be performed with the movable expander 2877 positioned along the second length 2255.

[0183] For example, when the movable deformer 2870 is positioned along a second length 2255 (e.g., non-expandable / non-deformable), its deformation (e.g., expansion) may be limited, and when positioned along a first length 2250 (e.g., expandable / deformable) after reaching a preset temperature, its deformation (e.g., expansion) may be permitted. This allows the user to wait to move the movable deformer (e.g., expandable movable deformer 2770 and / or 2870) to a position along the second length 2255 when deformation and expansion of the expandable distal portion 2230 is desired. A vacuum source can be applied along the elongated body and / or along the movable deformer (e.g., expandable deformer 2770 and / or 2870) to draw at least a portion of the blockage into the movable deformer in the expanded configuration.

[0184] Figures 28A and 28B show another embodiment of the suction catheter 2900 having a distal opening 2120 with a fixed diameter and that does not expand. Furthermore, the suction catheter 2900 of Figures 28A and 28B has the same or similar features and functions as any one of the embodiments of the suction catheter disclosed herein, including comprising one or more reinforcing members 2240 along at least a portion of the elongated body 2110. However, instead of having an expandable distal portion to form a larger suction area 2122, the suction catheter 2900 of Figures 28A and 28B comprises a molded distal end 2980. The molded distal end 2980 has a periphery 2124 that forms a suction seal between the periphery 2124 and the occlusion so that a vacuum is applied to the elongated body 2110 to suction at least a portion of the occlusion into the distal opening 2120. The peripheral portion 2124 may extend outward from a single plane, such as forming a plurality of angled shapes 2981 (e.g., triangles) that extend longitudinally with respect to the longitudinal axis of the inner lumen 2112, as shown in Figure 28A.

[0185] For example, the periphery 2124 may have at least four angled shapes 2981 arranged at approximately equal intervals along the periphery 2124. Such multiple angled shapes 2981 along the periphery 2124 increase the length of the periphery 2124 compared to, for example, the case where the periphery 2124 extends along a single plane. The longer the length of the periphery 2124 of the distal opening 2120, the larger the three-dimensional suction area 2122 can be formed compared to a distal opening 2120 having a periphery 2124 that extends along a single plane (e.g., a two-dimensional suction area 2122). As described above, by increasing the suction area 2122 of the distal opening 2120, a greater suction force can be applied to the occlusion, thereby enabling more efficient and effective retrieval and removal of the occlusion (and restoration of blood flow). Various shapes can be formed along the peripheral edge 2124 of the distal opening 2120 to increase the length of the peripheral edge 2124 and the suction area 2122.

[0186] Figures 29A and 29B show another embodiment of the suction catheter 3100 having a distal opening 2120 with a fixed diameter (non-expandable) and a molded distal end 2980. As described above, the molded distal end 2980 has a periphery 2124 that forms a suction seal between the periphery 2124 and the occlusion so that a vacuum is applied to the elongated body 2110 to suction at least a portion of the occlusion into the distal opening 2120. The periphery 2124 may extend outward from a single plane, such as forming a plurality of rounded shapes 3181 (e.g., circular, sinusoidal) that extend longitudinally with respect to the longitudinal axis of the inner lumen 2112, as shown in Figure 29A.

[0187] For example, the periphery 2124 may have at least four rounded shapes 3181 arranged at approximately equal intervals along the periphery 2124. Such multiple rounded shapes 3181 along the periphery 2124 increase the length of the periphery 2124 compared to, for example, a periphery 2124 extending along a single plane. The longer the length of the periphery 2124 of the distal opening 2120, the larger the three-dimensional suction area 2122 can be formed compared to a distal opening 2120 having a periphery 2124 extending along a single plane (e.g., a two-dimensional suction area 2122). As described above, by increasing the suction area 2122 of the distal opening 2120, a greater suction force can be applied to the occlusion, thereby enabling more efficient and effective retrieval and removal of the occlusion (and restoration of blood flow). Without departing from the scope of this disclosure, other shapes and configurations may be formed along the periphery 2124 of the distal opening 2120 to increase the length of the periphery 2124 and the suction area 2122. Furthermore, although the elongated body 2110 is shown having a circular cross-section, it may have other shapes such as an ellipse. Thus, the periphery 2124 and / or the distal opening 2120 may have circular, elliptical, or other shapes without departing from the scope of this disclosure.

[0188] Figures 30A and 30B show another embodiment of a suction catheter 3200 having a distal opening 2120 with a fixed diameter (non-expandable) and an occlusion grasping section 3290. As shown in Figure 30A, a first length 2250 of the elongated body 2110 includes a reinforcing member 2240, such as a spiral metal wire 2241 embedded in the inner wall 2126 of the elongated body 2110. As also shown in Figure 30A, a second length 2255 extending along the distal end of the elongated body 2110 may include an occlusion grasping section 3290 having an internally exposed coil 3292 that extends along the inner wall 2126 and is configured to engage and capture a thrombus, such as by rotating the suction catheter 3200 to capture and remove the thrombus. In some embodiments, the internally exposed coil 3292 has the same or similar material and / or construction as the reinforcing member 2240 extending along the first length 2250. For example, the internally exposed coil 3292 may be made of one or more of stainless steel and nitinol. In some embodiments, the internally exposed coil 3292 extends along the second length 2255 from about 1 centimeter (cm) to about 2 centimeters. In some embodiments, LCP fibers extend along the second length 2255 to provide further wall strength.

[0189] For example, during use of the suction catheter 3200, suction force can be applied to the elongated body 2110, thereby pulling an adjacent thrombus at least partially through the distal opening 2120. The suction catheter 3200 can then be rotated so that the internally exposed coil 3292 of the occlusion-grasping section 3290 can break the thrombus into smaller fragments for aspiration and / or capture a portion of the thrombus to enable reliable removal of the thrombus from the vascular system.

[0190] Any one of the suction catheters described herein may include LCP fibers along at least a second length 2255 to enhance wall strength without significantly reducing the flexibility of the elongated body 2110 along the second length 2255. For example, the wall strength of a suction catheter is important for efficiently and effectively moving the suction catheter along one or more different blood vessels to reach a thrombus. Furthermore, while a suction catheter may have a thin wall thickness to achieve a desired size and flexibility, such a thin wall may adversely affect the suction catheter's ability to withstand high-pressure injection. For this reason, by adding one or more layers of LCP fibers along at least the portion of the elongated body 2110 that does not contain reinforcing members, the LCP fibers can provide structural support without significantly reducing flexibility or increasing wall thickness.

[0191] Furthermore, as the catheter diameter increases, the strength of the catheter wall cross-section increases, and structural support may be required. Increasing the thickness of the catheter wall increases structural support, but it also increases the rigidity of the catheter, which may reduce the diameter of the inner lumen 2112. For this reason, LCP fibers can be added to at least a portion of the aspiration catheter without significantly affecting the flexibility of the catheter along that portion. The LCP fibers can extend in various directions and configurations, including longitudinally and / or at angles to the longitudinal axis of the inner lumen 2112.

[0192] Figures 31A and 31B show another embodiment of a suction catheter 3300 including a plurality of LCP fibers 3395 extending along the length of an elongated body 2110. For example, the LCP fibers 3395 include at least one longitudinally oriented LCP fiber 3395a and at least one circumferentially oriented LCP fiber 3395b, as shown in Figure 31A. The LCP fibers can form at least one layer along the length of the elongated body 2110. For example, the first layer includes the circumferentially oriented LCP fiber 3395b, and the second layer includes the longitudinally oriented LCP fiber 3395a. The number of various layers of LCP fibers 3395 oriented in one or more directions is within the scope of this disclosure.

[0193] For example, LCP fibers 3395a oriented longitudinally can provide additional tensile strength, and LCP fibers 3395b oriented circumferentially can increase burst strength. Such additional increases in tensile and burst strength can be achieved at least along the portion of the elongated body 2110 on which the LCP fibers extend. In some embodiments, the LCP fibers may extend along the length of the elongated body 2110, which includes one or more reinforcing members 2240, such as metal wires 2241, as shown in Figure 31A.

[0194] Although this specification contains many specific details, these should not be interpreted as limiting the scope of the claimed or potentially claimed invention, but rather as descriptions of features specific to particular embodiments. Certain features described herein in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may be implemented separately or in any suitable partial combination in multiple embodiments. Furthermore, although features are described above as acting in a particular combination, and may initially be claimed as such, one or more features from a claimed combination may be removed from the combination, and the claimed combination may be directed towards a partial combination or a variation of a partial combination. Similarly, although actions are depicted in the drawings in a particular order, this should not be understood as requiring such actions to be performed in a specific order, a sequential order, or all illustrated actions in order to achieve a desired result.

[0195] While various embodiments of the methods and apparatus are described in detail herein with reference to specific versions, it should be understood that other versions, embodiments, methods of use, and combinations thereof are also possible. Accordingly, the spirit and scope of the appended claims should not be limited to the embodiments described herein.

Claims

1. A suction catheter configured to remove a blood clot from a patient's blood vessel, An elongated body formed of a flexible material, having an inner lumen extending between a proximal body end and a distal body end, wherein the inner lumen is defined by an inner wall and forms a distal opening at the distal body end, A reinforcing member extending along a first length of the elongated body between a proximal reinforcing end and a distal reinforcing end, wherein the distal reinforcing end is positioned a second length from the distal end of the elongated body, A deformer extending along the second length of the elongated body, wherein the distal opening has a first opening diameter when the deformer forms a first configuration, and the second opening diameter has a second opening diameter when the deformer forms a second configuration, and the second opening diameter is larger than the first opening diameter, and the deformer is coupled to the second length. Equipped with, The deformation device comprises an inflatable balloon, When the inflatable balloon is in the first configuration, the distal opening forms a first suction region having a first length and a substantially constant inner diameter. A suction catheter in which, when the inflatable balloon is in the second configuration, the distal opening forms a second suction region having a second length and substantially constant inner diameter, wherein the second suction region is larger than the first suction region.

2. The suction catheter according to claim 1, wherein the inflatable balloon extends spirally along the second length of the elongated body.

3. The suction catheter according to claim 1, wherein the inflatable balloon is twisted along the second length of the elongated body.

4. The suction catheter according to claim 1, wherein the first suction region and the second suction region are each defined by one or more of the diameter and cross-sectional area of ​​the distal opening.

5. The suction catheter according to claim 1, wherein the inflatable balloon deflates when in the first configuration and inflates when in the second configuration.

6. The suction catheter according to claim 1, wherein the deformation device comprises a shape memory member.

7. The aspiration catheter according to claim 6, wherein the shape memory member includes a nitinol material that migrates between the first and second configurations based on the temperature of the shape memory member.

8. The suction catheter according to claim 6, wherein the shape memory member comprises at least one nitinol wire extending longitudinally along the second length.

9. The suction catheter according to claim 6, wherein the shape memory member comprises a stent retriever.

10. The suction catheter according to claim 1, wherein the elongated body has a portion along the second length that is more flexible than the portion along the first length.

11. The suction catheter according to claim 1, wherein the reinforcing member comprises one or more of a Teflon liner and a metal wire.

12. The suction catheter according to claim 1, further comprising a plurality of LCP fibers extending along the second length of the elongated body.

13. The aspiration catheter according to claim 12, wherein the first LCP fibers of the plurality of LCP fibers are oriented longitudinally along the elongated body, and the second LCP fibers of the plurality of LCP fibers are oriented circumferentially along the elongated body.

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