Devices and methods for removing occlusive substances from intravascular sites

Abstract

The present invention relates to a system or device and method for removing occlusive material from an intravascular site. The system includes an elongate flexible tubular body having a proximal end, a distal end, and a tubular sidewall defining at least one lumen extending axially therethrough; the axial constraint piece is carried by the side wall and is exposed to the inner cavity; a rotatable core wire extendable through the lumen, the core wire having a distal end; a restraining member carried by the core wire, the restraining member having a bearing surface for rotatably engaging the restraining member; and an agitator tip on the distal end of the core wire. The restricting member and the constraining member are engageable to permit rotation of the core wire but restrict distal advancement of the tip relative to the tubular body.

Description

[0001] This application is a divisional application of a Chinese invention patent application filed on April 29, 2019, with application number 201980029625.1 and invention name “Device and method for removing occlusive substances from intravascular sites”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Application No. 62 / 665,369, filed May 1, 2018, the entirety of which is hereby incorporated by reference herein. Background Art

[0004] Stroke is the third most common cause of death in the United States and the most disabling neurological disease. Approximately 700,000 patients suffer from stroke each year. Stroke is a syndrome characterized by acute onset of neurological deficits lasting at least 24 hours, reflecting focal involvement of the central nervous system and the result of cerebral circulation disorders. Its incidence increases with age. Risk factors for stroke include systolic or diastolic hypertension, hypercholesterolemia, smoking, alcohol abuse, and oral contraceptives.

[0005] Hemorrhagic stroke accounts for 20% of the annual stroke population. Hemorrhagic stroke often occurs due to aneurysm rupture or arteriovenous malformation that bleeds into the brain tissue, causing cerebral infarction. The remaining 80% of the stroke population is ischemic stroke, which is caused by vascular occlusion that deprives the brain of oxygen-carrying blood. Ischemic stroke is often caused by emboli or thrombotic tissue fragments that fall off from other parts of the body or from the cerebral blood vessels themselves and cause occlusion in narrow cerebral arteries more distally. When patients present with neurological symptoms and signs that completely resolve within 1 hour, the term transient ischemic attack (TIA) is used. In etiology, TIA and stroke have the same pathophysiological mechanism, and therefore represent a continuum based on symptom persistence and ischemic injury degree.

[0006] During an arrhythmia, emboli occasionally form around heart valves or in the left atrial appendage, then break off and follow the bloodstream into distal areas of the body. These emboli can travel to the brain and cause embolic strokes. As will be discussed below, many such occlusions occur in the middle cerebral artery (MCA), although this is not the only site where emboli lodge.

[0007] When a patient presents with a neurologic deficit, a diagnostic hypothesis for the cause of the stroke can be generated based on the patient's history, a review of stroke risk factors, and a neurologic examination. If an ischemic event is suspected, the clinician can tentatively evaluate the patient for cardioembolic sources, extracranial or intracranial disease of the large arteries, intraparenchymal disease of the small arteries, or hematologic or other systemic disease. A CT scan of the head is often performed to determine whether the patient has an ischemic or hemorrhagic injury. Blood will be seen on a CT scan in the presence of a subarachnoid hemorrhage, intraparenchymal hematoma, or intraventricular hemorrhage.

[0008] Traditionally, the emergency management of acute ischemic stroke has mainly consisted of general supportive care such as hydration, monitoring of neurological status, blood pressure control, and / or antiplatelet or anticoagulant therapy. In 1996, the (U.S.) Food and Drug Administration approved the use of Genentech's thrombolytic drugs, tissue plasminogen activator (t-PA) or To treat acute stroke. A randomized, double-blind trial of t-PA by the National Institute of Neurological Disorders and Stroke showed a statistically significant improvement in 24-hour stroke scale scores in the group of patients who received intravenous t-PA within 3 hours of ischemic stroke onset. For the first time since t-PA was approved, emergency room physicians can provide effective treatment for stroke patients in addition to supportive care.

[0009] However, systemic t-PA therapy is associated with an increased risk of intracranial hemorrhage and other bleeding complications. Patients receiving t-PA are more likely to experience symptomatic intracranial hemorrhage within the first 36 hours of treatment. The frequency of symptomatic bleeding increases when t-PA is administered more than 3 hours after stroke onset. In addition to the time constraints for the use of t-PA in acute ischemic stroke, other contraindications include: whether the patient has had a stroke or severe head trauma in the past 3 months, whether the patient's systolic blood pressure is above 185 mmHg or diastolic blood pressure is above 110 mmHg, whether the patient requires aggressive treatment to lower blood pressure to specified limits, whether the patient is taking anticoagulants or has a bleeding diastolic, and / or whether the patient has recently undergone an invasive surgical procedure. Therefore, only a small percentage of selected stroke patients are eligible to receive t-PA.

[0010] Over the years, occlusive emboli have also been mechanically removed from various parts of the blood vessel (vascular) system. Mechanical therapy includes capturing and removing clots, dissolving clots, breaking and aspirating (sucking) clots and / or forming a flow channel that runs through clots. One of the earliest mechanical devices developed for the treatment of stroke is the MERCI Retriever system (Concentric Medical, Redwood City, California). Use a guide catheter with a balloon at the end to enter the internal carotid artery (ICA) from the femoral artery. Microcatheters are placed through guide catheters and used to transmit the retriever with a coil at the end through the clot, and then the microcatheters are pulled back to arrange the retriever around the clot. Then, in order to pull the clot, the microcatheter and the retriever are pulled back into the balloon guide catheter, while the balloon is inflated (filled), and a syringe is connected to the balloon guide catheter to draw the guide catheter during the clot retrieval. Compared with independent thrombolysis (thrombolysis) therapy, the device has an initially positive and favorable effect.

[0011] Other thrombectomy devices utilize expandable cages, baskets or snares to capture and retrieve clots. Temporary stents (sometimes referred to as stent retrievers / retrieval devices / thrombectomy devices or vascular remodeling devices) are used to remove or retrieve clots and restore blood vessel flow. A series of devices that use active laser or ultrasonic energy to break up clots have also been used. Other active energy devices have been used in conjunction with intra-arterial thrombolytic perfusion to accelerate the dissolution of thrombi. Many of these devices are used in conjunction with suction to help remove clots and reduce the risk of embolism. Aspiration of clots has also been used in conjunction with single-lumen catheters and syringes or suction pumps, with or without accompanying clot fragmentation. Devices that apply dynamic fluid vortexes in conjunction with suction have been used to improve the efficacy of this thrombectomy method. Finally, when clot removal or dissolution is not possible, balloons or stents have been used to form an open lumen that penetrates the clot.

[0012] Nonetheless, there remains a need for new devices and methods for treating vascular occlusions in the body, including acute ischemic stroke and occlusive cerebrovascular disease. Summary of the invention

[0013] According to one aspect of the present invention, a system for removing embolic material from an intravascular site is provided. The system includes: an elongated flexible tubular body having a proximal end, a distal end, and a sidewall, the sidewall defining at least one lumen extending axially therethrough; an axial restraint carried by the sidewall and exposed to the lumen; a rotatable core wire extending through the lumen, the core wire having a proximal end and a distal end; a restraint carried by the core wire, the restraint having a bearing surface for rotatably engaging the restraint; and an agitator tip at the distal end of the core wire, wherein the restraint and the restraint are engageable to allow the core wire to rotate but to limit distal advancement of the tip relative to the tubular body.

[0014] The axial restraint may include a proximally facing support surface, which may be supported by a radially inwardly extending protrusion or an annular flange. The limiter may include a distally facing support surface, which may be supported by a radially outwardly extending protrusion. The radially outwardly extending protrusion may include at least one spoke portion, which supports a sliding member configured to be in sliding contact with the inner surface of the tubular sidewall. Some embodiments may include three spoke portions, each spoke portion supporting a sliding member. In response to positioning the tubular body within a tortuous vascular system, the support surface prevents the agitator tip from advancing distally beyond the tubular body.

[0015] In some embodiments, the restriction comprises an annular ring. The restriction may be spaced radially outward from the core wire. At least two spokes may be provided extending between the core wire and the ring. In one embodiment, three spokes extend between the core wire and the ring. The restriction may be positioned within approximately the distal 50% or the distal 25% of the length of the catheter.

[0016] A flow path is defined between each adjacent pair of spokes, the flow path communicating with the central lumen. In one embodiment, three flow paths are provided, and the sum of the cross-sectional areas of the three flow paths is at least about 75%, 90%, or 95% of the cross-sectional area of ​​the lumen at a location within 1 cm proximal to the restriction.

[0017] The core wire tapers from a larger diameter at the proximal side to a smaller diameter at the restriction, the smaller diameter being no greater than about 30% of the larger diameter. The core wire tapers to a smaller diameter at the restriction that is no greater than about 18% of the larger diameter. The core wire tapers from a diameter of about 0.025 inches at the proximal side to a diameter of no greater than about 0.005 inches at the restriction.

[0018] The agitator tip may include helical threads. The major diameter of the helical threads may be no greater than about 90% of the inner diameter of the lumen, thereby leaving an annular flow path between the tip and the inner surface of the sidewall. The helical threads may have a blunt outer edge. The helical threads define a helical flow channel between axially adjacent threads, the sum of the cross-sectional areas of the helical flow channel and the annular flow path being at least about 10% or 20% or 25% or more of the cross-sectional area of ​​the lumen at a location where the tip is not present.

[0019] As the tubular body is positioned within tortuous vasculature, the support surface prevents the agitator tip from advancing distally beyond the tubular body.

[0020] The core wire may carry an elastic member, which may include at least one helical spring coil extending proximally from the distal end to a length in the range of about 5 cm to about 60 cm. The spring / elastic member may extend proximally from the distal end to a length in the range of about 20 cm to about 40 cm.

[0021] The core wire may be permanently positioned within the tubular body, or may be removably positioned within the tubular body.

[0022] According to another aspect of the present invention, a method for mechanically and suction-assisted removal of embolic material from a blood vessel is provided. The method comprises the steps of providing an aspiration catheter having a central lumen and a distal end; advancing the distal end to occlusive material in a blood vessel; rotating a distal end within the lumen, the distal end having an axial length of no greater than about 5 mm and a helical thread having a major diameter at least about 0.015 inches less than the inner diameter of the lumen to provide an aspiration flow path around the outside of the distal end; and applying a vacuum to the lumen and rotating the distal end to draw material into the lumen.

[0023] The rotating step may include manually rotating a core wire extending through the catheter and rotating the tip.The method may further include the step of limiting distal advancement of the core wire by rotating a restraint carried by the core wire in sliding contact with a restraint located in the central lumen.

[0024] According to another aspect of the present invention, a method of aspirating a vascular occlusion from a remote site is provided. The method includes the steps of advancing an elongated tubular body through a vascular access site and to a vascular occlusion, the tubular body including a proximal end, a distal end, a central lumen, and a stop extending from the tubular body into the lumen; advancing a rotatable core wire distally through the lumen until a limiter carried by the core wire slidably engages the stop to provide a rotatable support that limits further distal advancement of the core wire in the lumen; and applying a vacuum to the lumen and rotating the core wire to aspirate a thrombus into the lumen.

[0025] The step of applying a vacuum may include applying a pulsating vacuum. The step of advancing the elongated tubular body may be performed directly over the guidewire without any intervention of the tubular body. The step of advancing the tubular body may be advanced to at least as far as the cavernous sinus segment of the internal carotid artery or at least as far as the cerebral segment of the internal carotid artery.

[0026] The step of advancing the rotatable core wire is performed after the step of advancing the elongated tubular body through the vascular access site and to the vascular occlusion. Alternatively, the step of advancing the rotatable core wire is performed simultaneously with the step of advancing the elongated tubular body through the vascular access site and to the vascular occlusion.

[0027] According to one aspect of the present invention, a neurovascular catheter with an inclined / angled atraumatic guide tip is provided. The catheter comprises: an elongated flexible tubular body having a proximal end, a distal end, and a sidewall, the sidewall defining a central lumen. The distal region of the tubular body comprises: a tubular liner; a spiral coil surrounding the liner and having a distal end; and a tubular sheath surrounding the spiral coil and extending distally beyond the distal end of the spiral coil to terminate in the distal end face of the catheter. A tubular radiopaque marker is embedded in the tubular sheath between the distal end of the coil and the distal end face. The distal end face is located on a plane that intersects the longitudinal axis of the tubular body at an angle in the range of about 35 degrees to about 55 degrees; and the marker has a proximal end face that is substantially perpendicular to the longitudinal axis and a distal end face that is located on a plane that intersects the longitudinal axis at an angle in the range of about 35 degrees to about 55 degrees. The distal end surface defines a leading edge of the tubular body, the leading edge extending distally of a trailing edge of the tubular body, the leading edge and the trailing edge being spaced approximately 180 degrees from one another about the longitudinal axis.

[0028] The advancement section of the tubular body extends distally beyond the marker band. The advancement section may have an axial length in the range of about 1 mm to about 3 mm on the leading edge side of the tubular body. The length of the advancement section on the leading edge side of the tubular body may be greater than the length of the advancement section on the trailing edge side of the tubular body.

[0029] The axial length of the marker band on the front edge side of the tubular body may be at least about 20% longer than the axial length of the marker band on the rear edge side of the tubular body. The axial length of the marker band on the front edge side of the tubular body may be in the range of about 1 mm to about 5 mm. The marker band includes at least one axial slit.

[0030] The tubular liner can be formed by dip coating a removable mandrel. In another aspect of the present disclosure, the tubular liner can include PTFE. The tubular body can also include a tie layer between the liner and the spiral coil. The wall thickness of the tie layer can be no greater than about 0.005 inches, and the tie layer can extend along at least the farthest 20 cm of the flexible body.

[0031] The coil may include nitinol and may include an austenitic state at body temperature. The outer sheath may be formed of at least five discrete axially adjacent tubular segments. In some embodiments, the outer sheath may be formed of at least nine discrete axially adjacent tubular segments. The difference in hardness between a proximal one of the tubular segments and a distal one of the tubular segments is at least about 20D, and in some embodiments, the difference in hardness between a proximal one of the tubular segments and a distal one of the tubular segments is at least about 30D.

[0032] The tubular body may also include a tensile support for increasing the tensile resistance in the distal region. The tensile support may include an axially extending wire. The axially extending wire may be carried between the liner and the helical coil. The axially extending wire may increase the tensile strength of the tubular body to at least about 2 pounds before failure.

[0033] The present invention also relates to the following technical solutions.

[0034] Scheme 1: A catheter comprising:

[0035] An elongated flexible tubular body comprising:

[0036] a distal end surface of the catheter that lies in a first plane that intersects the longitudinal axis of the elongated flexible tubular body at a first non-orthogonal angle relative to the longitudinal axis; and

[0037] a radial support band located in a distal region of the elongated flexible tubular body and proximal to the distal end face of the catheter, the radial support band including a distal end face located on a second plane that intersects the longitudinal axis at a second non-orthogonal angle relative to the longitudinal axis, wherein the first plane is substantially parallel to the second plane, and

[0038] Wherein, the second non-orthogonal angle is between about 45 degrees and about 80 degrees.

[0039] Option 2: A catheter according to Option 1, wherein the distal region of the elongated flexible tubular body comprises: a coil; and a sheath at least partially surrounding the coil, the sheath extending distally beyond the distal end of the coil and terminating at the distal end face of the catheter.

[0040] Option 3: The catheter of Option 2, wherein the coil comprises nitinol.

[0041] Option 4: The catheter according to Option 2, wherein the shell is formed by at least five independent axially adjacent tubular segments.

[0042] Option 5: The catheter according to Option 2, wherein the radial support band is embedded in the shell between the distal end of the coil and the distal end surface of the catheter.

[0043] Option 6: The catheter of Option 2, wherein the distal region of the elongated flexible tubular body includes a liner, and the coil at least partially surrounds the liner.

[0044] Option 7: The catheter of Option 6, wherein the liner is formed by dip coating a removable mandrel.

[0045] Option 8: The catheter according to Option 6 also includes a bonding layer between the lining and the coil.

[0046] Option 9: The catheter according to Option 6 also includes a wire configured to prevent the side wall of the catheter from stretching under tension.

[0047] Option 10: The catheter of Option 9, wherein the wire comprises a length of at least about 10 cm.

[0048] Option 11: The catheter of Option 9, wherein the wire increases the tensile strength of the elongated flexible tubular body to at least about 2 pounds.

[0049] Option 12: The catheter of Option 9, wherein the wire is carried between the liner and the coil.

[0050] Option 13: The catheter of Option 1, wherein the radial support band includes a proximal end surface that is substantially perpendicular to the longitudinal axis of the elongated flexible tubular body.

[0051] Option 14: A catheter according to Option 1, wherein the distal end surface of the catheter defines a front edge of the slender flexible tubular body, the front edge extends distally of the rear edge of the slender flexible tubular body, and the front edge and the rear edge are spaced approximately 180 degrees apart from each other around the longitudinal axis.

[0052] Option 15: The catheter of Option 1, wherein the advancement segment of the elongated flexible tubular body extends distally beyond the radial support band.

[0053] Option 16: The catheter according to Option 1, wherein the axial length of the radial support band on the leading edge side of the elongated flexible tubular body is at least about 20% longer than the axial length of the radial support band on the trailing edge side of the elongated flexible tubular body.

[0054] Option 17: The catheter according to Option 1, wherein a proximal segment of the elongated flexible tubular body extending proximally of the radial support band has a lower bending stiffness than a segment of the elongated flexible tubular body on which the radial support band is disposed.

[0055] Option 18: A catheter according to Option 17, wherein the advancement segment of the slender flexible tubular body extending distally beyond the radial support band has a lower bending stiffness than the proximal segment.

[0056] Option 19: The catheter of Option 1, wherein the radial support band comprises a radiopaque material.

[0057] Option 20: The catheter of Option 1, wherein the outer diameter of the elongated flexible tubular body is between about 0.07 inches and about 0.15 inches.

[0058] Option 21: A catheter according to Option 1, wherein the outer diameter of the slender flexible tubular body is equal to or less than about 9F.

[0059] Scheme 22: A neurovascular catheter with enhanced flexibility, comprising:

[0060] proximal;

[0061] remote;

[0062] a side wall defining a central lumen, a distal region of the side wall comprising a helical coil and a distal end surface located on the distal end, the distal end surface lying in a plane intersecting a longitudinal axis of the neurovascular catheter at an angle of at least about 45 degrees and at most about 80 degrees;

[0063] An outer shell, the outer shell comprising:

[0064] a plurality of tubular segments, a proximal tubular segment of the plurality of tubular segments having a hardness of at least about 60D, a distal tubular segment of the plurality of tubular segments having a hardness of at most about 35D; and a tubular radiopaque marker, the tubular radiopaque marker being located distal to the helical coil; and

[0065] a wire located within the sidewall, the wire extending axially from the distal end toward the proximal end, the wire comprising a length of at least about 10 cm and at most about 50 cm, the wire being configured to prevent the sidewall from elongating under tension,

[0066] wherein the distal end surface of the side wall defines a leading edge of the neurovascular catheter, wherein the leading edge extends distally of a trailing edge of the neurovascular catheter,

[0067] wherein the front edge and the rear edge are spaced approximately 180 degrees from each other about the longitudinal axis,

[0068] wherein the leading edge is located on a first side of the neurovascular catheter, wherein the trailing edge is located on a second side of the neurovascular catheter, and

[0069] Wherein a first axial length of the tubular radiopaque marker on the first side is at least 20% longer than a second axial length of the tubular radiopaque marker on the second side.

[0070] Option 23: The catheter of Option 22, wherein the helical coil comprises nitinol.

[0071] Embodiment 24: The catheter according to embodiment 22, wherein the outer shell is formed by at least five independent axially adjacent tubular segments.

[0072] Option 25: The catheter according to Option 22, wherein the tubular radiopaque marker is embedded in the outer shell between the distal end of the coil and the distal end surface of the side wall.

[0073] Option 26: The catheter of Option 22, wherein the distal region of the sidewall includes a lining, and the helical coil at least partially surrounds the lining.

[0074] Option 27: The catheter of Option 26, wherein the lining is formed by dip coating a removable mandrel.

[0075] Option 28: The catheter according to Option 26 also includes a connecting layer between the lining and the spiral coil.

[0076] Option 29: The catheter according to Option 26 also includes a wire configured to prevent the side wall of the catheter from stretching under tension.

[0077] Option 30: The catheter of Option 29, wherein the wire comprises a length of at least about 10 cm.

[0078] Embodiment 31: A catheter according to embodiment 29, wherein the wire increases the tensile strength of the side wall to at least about 2 pounds.

[0079] Option 32: The catheter of Option 29, wherein the wire is carried between the liner and the helical coil.

[0080] Option 33: The catheter of Option 22, wherein the tubular radiopaque marker includes a proximal end surface that is substantially perpendicular to the longitudinal axis of the neurovascular catheter.

[0081] Embodiment 34: A catheter according to Embodiment 22, wherein the outer diameter of the sidewall is between about 0.07 inches and about 0.15 inches.

[0082] Option 35: A catheter according to Option 22, wherein the outer diameter of the side wall is equal to or less than about 9F.

[0083] Scheme 36: A catheter comprising:

[0084] An elongated flexible tubular body comprising:

[0085] a distal end surface of the catheter that lies in a first plane that intersects the longitudinal axis of the tubular body at a first non-orthogonal angle relative to the longitudinal axis; and

[0086] a radiopaque marker located in a distal region of the tubular body and proximal to the distal end face of the catheter, the marker comprising a marker distal end face that is at least partially located in a second plane that intersects the longitudinal axis at a second non-orthogonal angle relative to the longitudinal axis,

[0087] wherein the first plane is substantially parallel to the second plane, and

[0088] Wherein, the second non-orthogonal angle is between about 45 degrees and about 80 degrees.

[0089] Option 37: The catheter according to Option 36, wherein the elongated flexible tubular body further comprises an outer shell and a spiral coil.

[0090] Option 38: The catheter according to Option 37, wherein the radiopaque marker is embedded in the outer sheath between the distal end of the spiral coil and the distal end surface of the catheter.

[0091] Option 39: The catheter of Option 36, wherein the elongated flexible tubular body further comprises an inner lining and a spiral coil.

[0092] Embodiment 40: The catheter of Embodiment 39, wherein the lining is formed by dip coating a removable mandrel.

[0093] Option 41: The catheter according to Option 39 also includes a connecting layer between the lining and the spiral coil.

[0094] Option 42: The catheter according to Option 39 also includes a wire configured to prevent the side wall of the catheter from stretching under tension.

[0095] Option 43: The catheter of Option 42, wherein the wire comprises a length of at least about 10 cm.

[0096] Option 44: The catheter of Option 42, wherein the wire increases the tensile strength of the sidewall to at least about 2 pounds.

[0097] Option 45: The catheter of Option 42, wherein the wire is carried between the liner and the helical coil.

[0098] Option 46: The catheter of Option 36, wherein the radiopaque marker comprises a proximal end surface that is substantially perpendicular to the longitudinal axis of the elongated flexible tubular body.

[0099] Option 47: The catheter of Option 36, wherein the outer diameter of the elongated flexible tubular body is between about 0.07 inches and about 0.15 inches.

[0100] Option 48: A catheter according to Option 36, wherein the outer diameter of the slender flexible tubular body is equal to or less than about 9F.

[0101] Scheme 49: A catheter comprising:

[0102] An elongated flexible tubular body comprising:

[0103] rear edge of tubular body;

[0104] a tubular body front edge, the tubular body front edge being circumferentially spaced 180 degrees from the tubular body rear edge around the periphery of the tubular body, the tubular body front edge extending distally further than the tubular body rear edge;

[0105] A radiopaque marker located proximal to the distal end of the catheter, the marker comprising:

[0106] Mark the back edge;

[0107] a marking leading edge circumferentially spaced 180 degrees from the marking trailing edge around the periphery of the marking, the marking leading edge extending distally further than the marking trailing edge, the marking leading edge being located on the same side of the tubular body as the tubular body leading edge; and

[0108] a marking distal end face, the marking distal end face being at least partially at a first non-orthogonal angle relative to a longitudinal axis of the tubular flexible body; and

[0109] a catheter distal end face, the catheter distal end face being at least partially at a second non-orthogonal angle relative to the longitudinal axis of the tubular flexible body,

[0110] The distal end surface of the marker is substantially parallel to the distal end surface of the catheter.

[0111] Option 50: A catheter according to Option 49, wherein the elongated flexible tubular body further comprises: a coil; and a shell at least partially surrounding the coil, the shell extending distally beyond the distal end of the coil and terminating at the distal end face of the catheter.

[0112] Option 51: The catheter of Option 50, wherein the coil comprises nitinol.

[0113] Embodiment 52: The catheter according to embodiment 50, wherein the shell is formed by at least five independent axially adjacent tubular segments.

[0114] Option 53: The catheter according to Option 50, wherein the radiopaque marker is embedded in the shell between the distal end of the coil and the distal end surface of the catheter.

[0115] Option 54: A catheter according to Option 50, wherein the slender flexible tubular body also includes a liner, and the coil at least partially surrounds the liner.

[0116] Option 55: The catheter of Option 54, wherein the lining is formed by dip coating a removable mandrel.

[0117] Option 56: The catheter according to Option 54 also includes a bonding layer between the lining and the coil.

[0118] Option 57: The catheter according to Option 54 also includes a wire configured to prevent the side wall of the catheter from stretching under tension.

[0119] Option 58: The catheter of Option 57, wherein the wire comprises a length of at least about 10 cm.

[0120] Option 59: The catheter of Option 57, wherein the wire increases the tensile strength of the elongated flexible tubular body to at least about 2 pounds.

[0121] Option 60: The catheter of Option 57, wherein the wire is carried between the liner and the coil.

[0122] Option 61: A catheter according to Option 49, wherein the radiopaque marker includes a proximal end surface that is substantially perpendicular to the longitudinal axis of the slender flexible tubular body.

[0123] Option 62: The catheter of Option 49, wherein the advancement segment of the elongated flexible tubular body extends distally beyond the radiopaque marker.

[0124] Option 63: A catheter according to Option 49, wherein the axial length of the radiopaque marker on the leading edge side of the slender flexible tubular body is at least about 20% longer than the axial length of the radiopaque marker on the trailing edge side of the slender flexible tubular body.

[0125] Option 64: A catheter according to Option 49, wherein a proximal segment of the elongated flexible tubular body extending proximal to the radiopaque marker has a lower bending stiffness than a segment of the elongated flexible tubular body on which the radiopaque marker is mounted.

[0126] Option 65: A catheter according to Option 64, wherein the advancement segment of the slender flexible tubular body extending distally beyond the radiopaque marker has a lower bending stiffness than the proximal segment.

[0127] Option 66: The catheter of Option 49, wherein the outer diameter of the elongated flexible tubular body is between about 0.07 inches and about 0.15 inches.

[0128] Option 67: A catheter according to Option 49, wherein the outer diameter of the slender flexible tubular body is equal to or less than about 9F.

[0129] Scheme 68: A catheter comprising:

[0130] An elongated flexible tubular body comprising:

[0131] a distal end surface of the catheter that lies in a first plane that intersects the longitudinal axis of the tubular body at a first non-orthogonal angle relative to the longitudinal axis;

[0132] a radiopaque marker located in a distal region of the tubular body and proximal to the distal end face of the catheter, the radiopaque marker comprising a marker distal end face that lies at least partially on a second plane that intersects the longitudinal axis at a second non-orthogonal angle relative to the longitudinal axis; and

[0133] a tensile support comprising axially extending wires carried by the elongated flexible tubular body,

[0134] The first plane is substantially parallel to the second plane.

[0135] Option 69: A catheter according to Option 68, wherein the elongated flexible tubular body further comprises: a coil; and a shell at least partially surrounding the coil, the shell extending distally beyond the distal end of the coil and terminating at the distal end face of the catheter.

[0136] Option 70: The catheter of Option 69, wherein the coil comprises nitinol.

[0137] Embodiment 71: A catheter according to Embodiment 69, wherein the shell is formed by at least five independent axially adjacent tubular segments.

[0138] Option 72: The catheter according to Option 69, wherein the radiopaque marker is embedded in the shell between the distal end of the coil and the distal end surface of the catheter.

[0139] Option 73: A catheter according to Option 69, wherein the slender flexible tubular body also includes a liner, and the coil at least partially surrounds the liner.

[0140] Option 74: The catheter of Option 73, wherein the lining is formed by dip coating a removable mandrel.

[0141] Option 75: The catheter according to Option 73 also includes a connecting layer between the lining and the coil.

[0142] Option 76: The catheter according to Option 73 also includes a wire configured to prevent the catheter from stretching under tension.

[0143] Option 77: The catheter of Option 76, wherein the wire comprises a length of at least about 10 cm.

[0144] Option 78: A catheter according to Option 76, wherein the wire increases the tensile strength of the slender flexible tubular body to at least about 2 pounds.

[0145] Option 79: The catheter of Option 76, wherein the wire is carried between the liner and the coil.

[0146] Option 80: The catheter of Option 68, wherein the radiopaque marker comprises a proximal end surface that is substantially perpendicular to the longitudinal axis of the elongated flexible tubular body.

[0147] Option 81: A catheter according to Option 68, wherein the distal end surface of the catheter defines a front edge of the slender flexible tubular body, the front edge extends distally of the rear edge of the slender flexible tubular body, and the front edge and the rear edge are spaced approximately 180 degrees apart from each other around the longitudinal axis.

[0148] Option 82: The catheter of Option 68, wherein the advancement segment of the elongated flexible tubular body extends distally beyond the radiopaque marker.

[0149] Option 83: A catheter according to Option 68, wherein the axial length of the radiopaque marker on the leading edge side of the slender flexible tubular body is at least about 20% longer than the axial length of the radiopaque marker on the trailing edge side of the slender flexible tubular body.

[0150] Option 84: The catheter of Option 68, wherein a proximal segment of the elongated flexible tubular body extending proximal to the radiopaque marker has a lower bending stiffness than a segment of the elongated flexible tubular body on which the radiopaque marker is mounted.

[0151] Option 85: A catheter according to Option 84, wherein the advancement segment of the slender flexible tubular body extending distally beyond the radiopaque marker has a lower bending stiffness than the proximal segment.

[0152] Option 86: The catheter of Option 68, wherein the outer diameter of the elongated flexible tubular body is between about 0.07 inches and about 0.15 inches.

[0153] Option 87: A catheter according to Option 68, wherein the outer diameter of the slender flexible tubular body is equal to or less than about 9F.

[0154] Scheme 88: A system for removing embolic material from an intravascular site, comprising:

[0155] an elongated flexible tubular body having a proximal end, a distal end, and a tubular sidewall defining at least one lumen extending axially therethrough;

[0156] Axial restraints;

[0157] a rotatable core wire extendable through the lumen, the core wire having a proximal end and a distal end;

[0158] a restraint carried by the core wire, the restraint having a bearing surface for engaging an axial restraint; and

[0159] at the agitator tip at the distal end of the core wire,

[0160] wherein the limiter and the axial restraint are engageable to permit rotation of the core wire but to limit distal advancement of the tip relative to the tubular body.

[0161] Option 89: A system according to Option 88, wherein the axial restraint includes a proximally facing bearing surface.

[0162] Option 90: A system according to Option 89, wherein the axial restraint includes a protrusion extending radially inward.

[0163] Option 91: A system according to Option 90, wherein the axial restraint includes an annular flange.

[0164] Option 92: A system according to Option 88, wherein the restraint includes a distally facing support surface.

[0165] Option 93: A system according to Option 92, wherein the restriction member includes a protrusion extending radially outward.

[0166] Option 94: A system according to Option 93, wherein the radially outwardly extending protrusion includes a spoke portion, and the spoke portion supports a sliding member configured to slide in contact with the inner surface of the tubular sidewall.

[0167] Option 95: A system as described in Option 94 includes three spoke portions, each spoke portion supporting a sliding member.

[0168] Option 96: A system according to Option 93, wherein the restraining member includes an annular ring.

[0169] Embodiment 97: A system according to embodiment 88, wherein the restraint comprises an annular ring spaced radially outward from the rotatable core wire.

[0170] Option 98: The system of Option 97 further comprises at least two spoke portions extending between the rotatable core wire and the ring.

[0171] Option 99: A system according to Option 98, comprising three spoke portions extending between the rotatable core wire and the ring.

[0172] Embodiment 100: The system according to embodiment 95 comprises a flow path defined between each adjacent pair of spoke portions and connected to the at least one inner cavity.

[0173] Embodiment 101: The system of embodiment 100, comprising three flow paths and the sum of the cross-sectional areas of the three flow paths is at least about 75% of the cross-sectional area of ​​the at least one lumen at a location within 1 cm proximal to the restriction.

[0174] Option 102: The system of Option 101, wherein the sum of the cross-sectional areas of the three flow paths is at least about 90% of the cross-sectional area of ​​the at least one lumen at a location within 1 cm proximal to the restriction.

[0175] Embodiment 103: The system of embodiment 88, wherein the rotatable core wire tapers from a larger diameter at a proximal point to a smaller diameter at the restraint, the smaller diameter being no greater than about 30% of the larger diameter.

[0176] Embodiment 104: A system according to embodiment 103, wherein the rotatable core wire tapers to a smaller diameter at the limit member that is no greater than about 18% of the larger diameter.

[0177] Embodiment 105: The system of embodiment 104, wherein the rotatable core wire tapers from a diameter of approximately 0.025 inches at a proximal point to a diameter of no greater than approximately 0.005 inches at the restriction.

[0178] Embodiment 106: A system according to embodiment 88, wherein the agitator tip includes a helical thread.

[0179] Embodiment 107: A system according to embodiment 106, wherein the major diameter of the helical thread is no greater than about 90% of the inner diameter of the at least one inner cavity, thereby leaving an annular flow path between the end and the inner surface of the side wall.

[0180] Option 108: According to Option 103, the system also includes an elastic member, which is carried by the rotatable core wire and extends proximally from the distal end to a length in the range of about 5 cm to about 60 cm.

[0181] Option 109: A system according to Option 108, wherein the length of the elastic member extending proximally from the distal end is in the range of about 20 cm to about 40 cm.

[0182] Embodiment 110: A system according to embodiment 106, wherein the helical thread has a blunt outer edge.

[0183] Embodiment 111: A system according to embodiment 88, wherein the restriction is positioned within approximately the distal 50% of the length of the catheter.

[0184] Embodiment 112: A system according to embodiment 111, wherein the restriction is located within approximately the distalmost 25% of the length of the catheter.

[0185] Embodiment 113: A system according to embodiment 88, wherein the rotatable core wire is removably positionable within the tubular body.

[0186] Option 114: A system according to Option 107, wherein the helical thread defines a spiral flow channel between axially adjacent threads, and the sum of the cross-sectional areas of the spiral flow channel and the annular flow path is at least about 20% of the cross-sectional area of ​​the at least one inner cavity.

[0187]

[00136] Option 115: A system according to Option 112, wherein, in response to positioning the tubular body within a tortuous vascular system, the support surface prevents the agitator tip from advancing distally beyond the tubular body.

[0188] Any feature, structure or step disclosed herein may be replaced or combined with any other feature, structure or step disclosed herein, or may be omitted. In addition, for the purpose of summarizing the present disclosure, certain aspects, advantages and features of the embodiments have been described herein. It should be understood that any or all of these advantages may not necessarily be achieved according to any particular embodiment disclosed herein. Individual aspects of the present disclosure are not necessary or indispensable. Other features and advantages of each embodiment will be apparent to those skilled in the art based on the detailed description made below in conjunction with the drawings and schemes. BRIEF DESCRIPTION OF THE DRAWINGS

[0189] Figure 1 is a schematic side view of an intracranial aspiration catheter according to the present invention, wherein the distal section is in a proximally retracted configuration.

[0190] Figure 2 yes Figure 1 A side view as in FIG. 2 , wherein the distal segment is in a distally extended configuration.

[0191] Figure 3A-3Bis a cross-sectional view of the distal end of the catheter 10 with the distal section 34 fully extended.

[0192] Figures 4A-4C Different cutting tip configurations are shown schematically.

[0193] Figure 4D-4E and 4J-4K schematically illustrate the distal dynamic funnel-shaped tip configuration.

[0194] Figure 4F-4G A dynamically flared tip with a first restraint system is shown.

[0195] Figures 4H-4I Shown is a dynamically flared tip with an alternative restraint system.

[0196] Figure 5 The cerebral arterial vasculature including the circle of Willis and the access catheter located at the occlusion in the left carotid siphon artery are depicted.

[0197] Figures 6 to 9 The sequence of steps involved in catheter positioning and aspiration of occlusive material from the middle cerebral artery is shown.

[0198] Fig.10 Removal of the catheter after aspiration of the occluding material is shown.

[0199] Figures 11A-11F The sequence of steps to access the site of a neurovascular occlusion for aspiration is depicted.

[0200] Figures 12A-12F An alternative sequence of steps involved in accessing a neurovascular occlusion site for aspiration according to one aspect of the present invention is depicted.

[0201] Fig.13 A suction system configured to apply pulsatile negative pressure through a suction catheter is shown.

[0202] Fig.14 An alternative suction system configured to apply pulsatile negative pressure through a suction catheter is shown.

[0203] Fig.15 Yet another alternative suction system configured to apply mechanical vibrations via a suction conduit is shown.

[0204] Fig.16 and 17 Yet another alternative suction system configured to apply mechanical vibrations via a suction conduit is shown.

[0205] Fig.18 Another alternative suction system is shown having an agitator configured to impart mechanical vibrations to a vibration zone on the suction conduit.

[0206] Fig.19A simplified agitator is depicted, such as a hypotube-supported wire positioned in a conduit to form a vibrating zone.

[0207] Figures 20A-20C Agitators having various distal tip configurations are depicted.

[0208] Figures 20D-20E An agitator positioned within the expandable polymer distal funnel-shaped tip is depicted.

[0209] Figures 21A-21B The distal tip of the catheter is shown moving or twisting in response to activation of the agitator.

[0210] Figures 22A-22B The injection of media from the moving or twisting distal tip of the agitator is shown.

[0211] Figures 23A-23B Injection of media from the distal tip of the agitator to aid in aspiration is shown.

[0212] Fig.23C Depicted is a proximal suction port carried by the catheter.

[0213] Fig.24A is a side view of a catheter with an internal stop ring.

[0214] Fig. 24B It passes through Fig.24A Longitudinal cross-section of the catheter and detail of the stop ring.

[0215] Fig.24C is a side view of an agitator having a Fig.24A and 24B A complementary limit piece of the stop ring.

[0216] Fig.24D yes Fig.24C Side view of the distal section of the agitator.

[0217] Fig.24E is through Fig.24D Longitudinal section of an agitator.

[0218] Fig.24F yes Fig.24C A perspective cross-sectional view of the distal section of an agitator.

[0219] Figure 24G is a cross-sectional view of the distal stop carried by the agitator.

[0220] Fig.24H is a cross-sectional view through an alternative distal stop.

[0221] Figures 25A-25CA pulsed aspiration cycle is depicted according to one embodiment.

[0222] Fig.26 A perspective view of a rotary hemostasis valve and proximal drive assembly is depicted.

[0223] Fig.27A Shown along Fig.26 A longitudinal cross-sectional view taken along line 27A-27A in FIG.

[0224] Fig.27B Show Fig.27A An enlarged longitudinal cross-sectional view of the proximal drive assembly 2602.

[0225] Fig.28 Depicted Fig.26 A cutaway perspective view of the proximal portion of the.

[0226] Fig.29 A perspective view of the agitator drive, proximal drive assembly, and rotary hemostasis valve is depicted.

[0227] Fig.30 A cross-sectional view of a conduit wall is shown according to one embodiment.

[0228] Fig.31A A cross-sectional view of a catheter wall showing one or more axially extending filaments according to another embodiment is shown.

[0229] Fig.31B Depicted Fig.31A Side view of the catheter

[0230] Fig.31C Shown along Fig.31B A cross-sectional view taken along line CC of FIG. 1 shows one or more axially extending wires.

[0231] Fig.31D is a side cross-sectional view through the angled / beveled distal catheter or extension tube tip.

[0232] Fig.32A Depicted is a side view of a catheter according to one embodiment.

[0233] Fig.32B Depicted along Fig.32A A cross-sectional view taken along line AA.

[0234] Fig.32C Shown along Fig.32A A cross-sectional view taken along line BB.

[0235] Fig.33A Depicted is a side view of a catheter according to another embodiment.

[0236] Fig.33B Describes the Fig.33A A cross-sectional view taken along line AA shows one or more axially extending wires.

[0237] Fig.33C Shown along Fig.33A A cross-sectional view taken along line BB shows one or more axially extending wires.

[0238] Fig.34A A side view of a catheter with increasing flexibility is shown according to one embodiment.

[0239] Fig.34B yes Fig.34A Proximal end view of the enhanced flexibility catheter.

[0240] Fig.35 The supportive nature of the catheter according to the invention is shown.

[0241] Fig.36 A graph depicting the modulus or stiffness of a catheter along the length of the catheter from the proximal end to the distal end.

[0242] Fig.37 Depicted is a graph of a deflection test of a catheter according to the present invention compared to a conventional catheter.

[0243] Fig.38 is a schematic side view of a transformable catheter according to the present invention.

[0244] Fig.39 is along Fig.38 A cross-sectional view taken along line 18-18 shows the heating element within the conduit side wall. DETAILED DESCRIPTION

[0245] Reference Figure 1 , a catheter 10 according to one aspect of the present invention is disclosed. Although primarily described in the context of an axially extendable / extendable distal segment aspiration catheter having a single central lumen, the catheter of the present invention can be readily modified to incorporate additional structure, such as a permanent or removable radial support force (column strength) reinforcing mandrel, two or more lumens, such as to allow drug, contrast or flushing agent infusion, or to supply inflation medium to an inflatable balloon carried by the catheter, or a combination of these features, as will be readily apparent to those skilled in the art based on the disclosure herein. In addition, the present invention will be primarily described in the context of removing occlusive material from remote vasculature in the brain, but also has applicability as an access catheter for delivering and removing any of a variety of diagnostic or therapeutic devices with or without aspiration.

[0246] The catheter disclosed herein can be easily adapted to any location throughout the body where it may be desirable to advance a low-profile distal catheter segment distally from a larger diameter proximal segment. For example, the size of an axially extendable catheter shaft according to the present invention can also be set to be used throughout the coronary and peripheral vascular systems, the gastrointestinal tract, the urethra, the ureters, the fallopian tubes, and other lumens and potential lumens. The telescopic structure of the present invention can also be used to provide minimally invasive percutaneous tissue access, such as for diagnostic or therapeutic access to solid tissue targets (e.g., breast or liver or brain biopsies or tissue resections), laparoscopic tool delivery, or access to bones such as the spine to deliver screws, bone cement, or other tools or implants.

[0247] The catheter 10 generally includes an elongated tubular body 16 extending between a proximal end 12 and a distal functional end 14. The length of the tubular body 16 depends on the desired application. For example, lengths in the region of about 120 cm to about 140 cm or longer are typically used in percutaneous transluminal (intraluminal) coronary applications for femoral artery access. Intracranial or other applications may require different catheter shaft lengths, which depend on the vascular access site, as will be understood in the art.

[0248] In the illustrated embodiment, the tubular body 16 is divided into at least a fixed proximal section 33 separated at a transition portion 32 and an axially extendable and retractable distal section 34 . Figure 2 yes Figure 1 A side view of the catheter 10 is shown with the distal section in a distally extended configuration.

[0249] Reference Figure 3A and 3B , illustrates a cross-sectional view of a distal segment 34 shown extending distally from a proximal segment 33 in accordance with the present invention. The distal segment 34 extends between a proximal end 36 and a distal end 38 and defines at least one elongated central lumen 40 extending axially therethrough. The distal end 38 may be provided with one or more movable side walls or jaws 39 that move laterally under the influence of suction toward opposing side walls or jaws 41 to enable the distal end 38 to crush or break up thrombi or other materials into smaller particles, thereby facilitating suction through the lumen 40. As discussed further below, both walls 39 and 41 may be moved toward and away from each other to break up thrombi. For some applications, the proximal segment 33 may also or alternatively be provided with one or two opposing jaws that also break up thrombi in response to vacuum or mechanical actuation.

[0250] The inner diameter of the distal section 34 can be between about 0.030 inches and about 0.112 inches, between about 0.040 inches and about 0.102 inches, between about 0.045 inches and about 0.097 inches, between about 0.050 inches and about 0.092 inches, between about 0.055 inches and about 0.087 inches, between about 0.060 inches and about 0.082 inches, between about 0.062 inches and about 0.080 inches, between about 0.064 inches and about 0.078 inches, between about 0.066 inches and 0.076 inches, between about 0.068 inches and about 0.074 inches, or between about 0.070 inches and about 0.072 inches.

[0251] The inner diameter and outer diameter of the distal section 34 may be constant or substantially constant along its longitudinal length. Alternatively, the distal section 34 may taper near its distal end. The distal section 34 may taper at a distance of less than or equal to about 5 cm, about 10 cm, about 15 cm, about 20 cm, about 23 cm, about 25 cm, about 30 cm, about 31 cm, about 35 cm, about 40 cm, about 45 cm, about 50 cm, about 60 cm, or about 70 cm from its distal end. In some embodiments, the taper may be positioned at about 25 cm to about 35 cm from the distal end of the distal section 34.

[0252] The inner diameter of the distal segment 34 may taper or decrease in the distal direction near the distal end to less than or equal to about 95%, about 90%, about 85%, about 80%, about 75%, about 70%, about 65%, about 60%, about 55%, or about 50% of the adjacent unmodified inner diameter. In some embodiments, the inner diameter of the tapered distal segment 34 may be about 50% to about 70% of the adjacent unmodified inner diameter. For example, the untapered inner diameter at the proximal end of the distal segment 34 may be about 0.071 inches and the tapered inner diameter at the distal end of the distal segment 34 may be about 0.035 inches, 0.045 inches, or 0.055 inches. The inner diameter of the distal segment 34 may taper or increase near the distal end to greater than or equal to about 102%, 104%, 106%, 108%, or more of the inner diameter just near the transition into the tapered portion. The tapered inner diameter of the distal section 34 may be (relatively reduced) less than or equal to about 0.11 inches, about 0.1 inches, about 0.090 inches, about 0.080 inches, about 0.070 inches, about 0.065 inches, about 0.060 inches, about 0.055 inches, about 0.050 inches, about 0.045 inches, about 0.040 inches, about 0.035 inches, about 0.030 inches, about 0.025 inches, about 0.020 inches, about 0.015 inches, or about 0.010 inches. In some embodiments, the length of the distal tapered portion of the distal section 34 may be about 25 cm to about 35 cm, about 25 cm to about 30 cm, about 30 cm to 35 cm, or about 30 cm.

[0253] The length of the distal segment 34 can be about 13 cm to about 53 cm, about 18 cm to about 48 cm, about 23 cm to about 43 cm, about 28 cm to about 38 cm, about 29 cm to about 39 cm, about 30 cm to about 40 cm, about 31 cm to about 41 cm, or about 32 cm to about 42 cm. The length of the distal segment 34 can be less than or equal to about 20 cm, about 25 cm, about 30 cm, about 33 cm, about 35 cm, about 40 cm, about 41 cm, about 45 cm, about 50 cm, about 55 cm, about 60 cm, about 70 cm, or about 80 cm. The length of the distal segment 34 can depend on the degree of taper of the inner diameter of the distal segment 34.

[0254] The proximal end 36 of the distal segment 34 is provided with a pull wire 42 extending proximally. The pull wire 42 extends proximally through the entire length of the tubular body 16 to the control device 24 which may be carried by the manifold 18. As already discussed, axial movement of the control device 24 produces corresponding axial movement of the distal segment 34 relative to the proximal segment 33. Alternatively, the proximal end of the pull wire 42 may exit through a port on the manifold 18 so that it may be manually grasped by a clinician and pulled or pushed to extend or retract the distal segment 34. The length of the pull wire 42 may be between about 700 mm and about 1556 mm, between about 800 mm and about 1456 mm, between about 850 mm and about 1406 mm, between about 900 mm and about 1356 mm, between about 950 mm and about 1306 mm, between about 1000 mm and about 1256 mm, between about 1020 mm and about 1236 mm, between about 1040 mm and about 1216 mm, between about 1060 mm and about 1196 mm, between about 1080 mm and about 1176 mm, between about 1100 mm and about 1156 mm, between about 1110 mm and about 1146 mm, or between about 1120 mm and about 1136 mm.

[0255] When the pull wire 42 is advanced distally to the limit of its travel, an overlap 44 is retained between the proximal end 36 of the distal segment 34 and the proximal segment 33. The overlap 44 is configured to provide a seal to achieve efficient transfer of vacuum from the proximal segment 33 to the distal segment 34. The overlap 44 may be provided with any of a variety of additional features that facilitate sealing, such as a liner, a coating, or a close tolerance sliding fit, as described elsewhere herein. Preferably, the gap between the outer diameter of the distal segment 34 and the inner diameter of the proximal segment 33 will not exceed about 0.005 inches and preferably will not exceed about 0.003 inches, at least near the transition portion 32, to provide an effective seal in a blood environment. In embodiments that include sealing feature structures as described elsewhere herein, larger gaps may be more feasible.

[0256] After the distal end of the proximal section 33 is positioned within the vascular system (e.g., the cervical carotid artery), the control device 24 is manipulated to advance the distal section 34 further distally into the vascular system. To this end, the pull wire 42 will have sufficient radial support to enable the distal tip 38 to be advanced distally, as will be discussed below.

[0257] The pull wire 42 and the distal section 34 may be as Figure 1 and 2 Alternatively, the distal segment 34 and the pull wire 42 may be configured as a separate catheter extension device, as discussed in more detail below. The catheter extension device may be introduced into the proximal end of the proximal segment 33 after the proximal segment 33 is positioned and extended as shown in FIG. Figure 3AShown is advanced distally therethrough to telescopically expand the scope of the suction system.

[0258] Reference Figure 3B , the pull wire 42 may include a tubular wall having an axially extending central lumen 45. The central lumen 45 allows for the introduction of media such as lubricants, drugs, contrast media, etc. into the distal section 34. In addition, the central lumen 45 extending through the pull wire 42 allows for the introduction of an agitator, as discussed in more detail below. Figure 3B As shown, central lumen 45 can open into lumen 40. The distal opening of central lumen 45 can be positioned at a point along the length of distal segment 34 so that central lumen 45 ends where lumen 40 begins (the distal opening of central lumen 45 can be longitudinally aligned with the proximal opening of lumen 40). The proximal opening of lumen 40 can be as shown. Figure 3B In some embodiments, the opening of lumen 40 can be flat. The distal opening of central lumen 45 can be flat, such as Figure 3B In some embodiments, the openings may be angled or slanted, similar to Figure 3B The opening of the inner cavity 40 in the.

[0259] In some embodiments, the central lumen 45 may terminate proximally of the opening of the lumen 40. In some embodiments, the central lumen 45 may terminate proximally of the distal segment 34 and / or distally of the opening of the lumen 40 (e.g., at a point within the lumen 40). For example, the central lumen 45 may terminate at the distal end of the distal segment or at a position just shorter than the distal end (e.g., no more than about 1 cm from the distal end). In some embodiments, the stiffness of the portion of the pull wire 42 extending beyond the proximal end of the distal segment 34 (e.g., into the lumen 40) with or without the central lumen 45 may decrease in the distal direction (durometer). The pull wire 42 may be relatively stiff along the portion proximal to the proximal end of the distal segment 34 to provide sufficient pushability of the extension catheter. The stiffness of the portion of the pull wire 42 distal to the proximal end of the distal segment 34 may substantially match or be less than the stiffness of the distal segment 34 along the length of the distal segment 34. The portion of the pull wire 42 distal to the proximal end of the distal segment 34 may have a uniform stiffness that is less than the stiffness of the portion proximal to the proximal end of the distal segment 34, or the pull wire may have a gradually varying or gradually decreasing stiffness in the distal direction, such that the stiffness gradually decreases from the portion proximal to the proximal end of the distal segment 34. For example, the pull wire 42 may include metal along the portion proximal to the proximal end of the distal segment 34 and may include a polymer that is softer than metal along the portion distal to the proximal end of the distal segment 34. In some embodiments, the portion distal to the distal end may be extruded to have a gradually decreasing stiffness in the distal direction.

[0260] Reference Figures 4A to 4CThe distal tip 38 may be provided with any of a variety of structures that produce active motion, such as a snapping action, in response to the application of an actuation force, such as a vacuum in the lumen 40. Alternatively, an axially movable control wire may be connected to the sidewall of the distal tip 38 to achieve a cutting action under a positive mechanical force. Figure 4A The distal tip 38 is shown in an open configuration, while Figure 4B Such a distal tip 38 is shown in which the opposing side walls 39 and 41 are drawn together by drawing negative pressure into the lumen 40. This can be achieved by providing a tapered thickness in the side walls 39 and 41 or providing a groove or living hinge that facilitates lateral movement of at least one of the side walls 39 and 41.

[0261] Or, refer to Figure 4C A pivot point or hinge 43 may be provided to enable the side wall 39 to move laterally to operate as a clamping jaw. The two opposing side walls may move in a bilaterally symmetrical manner medially and laterally like a duckbill valve. Three or more clamping jaws may be provided, for example three triangular clamping jaws separated by about 120° intervals, which close under the suction pulse to form a pyramidal closed end.

[0262] In some embodiments of the present invention, the distal tip 14 preferably has the ability to expand beyond the nominal diameter of the distal section 34. This provides a conical funnel-shaped tip with an enlarged distal opening to facilitate the introduction of thrombogenic material into the lumen 40. Figure 4D-4K The diameter of the distal opening of the fully opened funnel exceeds the diameter of the cylindrical extension of the adjacent tubular body by at least about 10%, preferably at least about 25% or 45% or more. This can be achieved by providing the distal end 14 with an expandable material or by providing a plurality of laterally movable jaws or petals, such as at least about three or five or six or more petals that can be advanced radially inwardly into a capturing orientation and moved radially outwardly to provide an increased open inner diameter of the suction lumen 40 in the distal direction.

[0263] The flexible flaps can be maintained in a radially inwardly tilted configuration during transluminal (intraluminal) introduction of the distal segment 34, for example, by applying negative pressure via the lumen 40. After the negative pressure is removed, the flaps can tilt radially outward in response to a preset bias. The application of a pulsating vacuum can then cause the flaps to close radially inwardly to perform the above-described bite function.

[0264] The distal funnel opening may be actuated in various other ways apparent to those skilled in the art, such as by providing a pull wire or an axially slidable outer or inner sleeve to open and close the funnel in response to mechanical movement of the pull wire or sleeve. Alternatively, the funnel opening may be controlled by rotating a control wire or tubular sleeve relative to the distal section 34 to activate a diaphragm or a spiral mechanism (e.g., a spiral ribbon or wire carried by the distal tip).

[0265] The normal state of the distal funnel can be a cylindrical configuration, and a mechanical, thermal or electrical actuator can be used to expand the distal funnel opening. Alternatively, the normal state of the funnel can be conical, and a mechanical, thermal or electrical actuator can be used to reduce the diameter, for example, for transluminal guidance. The wing flaps or other walls of the funnel or elements configured in the walls of the funnel may include shape memory materials such as shape memory polymers or metal alloys (such as nitinol), which can be cut from a tubing laser or woven into a fine mesh. The geometry of the funnel can be transformed by applying heat (such as body heat, or heat from a heat source carried by a catheter (such as a resistance wire in the wall or near the end of the catheter). Alternatively, heat can be applied from a heat source (such as a heated fluid) or a removable heater (such as an elongated flexible body with a resistance coil) introduced via the central lumen 40. Alternatively, transition of the funnel from one configuration to another may alternatively be accomplished by reducing the temperature of the funnel to below body temperature (e.g., by introducing a cooled fluid in thermal communication with the funnel end or providing a Joule-Thomson expansion chamber near the distal end of the catheter or a removable cooling catheter).

[0266] In an alternative configuration, the sidewall of the funnel is provided with an inflatable balloon in the form of a ring or hoop that communicates with an inflation lumen extending over the entire length of the catheter. Introduction of an inflation medium inflates the annular balloon, thereby converting the configuration of the funnel tip from a reduced diameter to an expanded diameter.

[0267] In an alternative configuration, the distal tip is biased into a funnel configuration and constrained into a cylindrical configuration, for example, for transluminal guidance. The constraint can be removed when it is desired to expand the funnel tip. The constraint can include an outer tubular covering septum or loop configured to be removed by pulling a pull wire in a proximal direction. Alternatively, the constraint can be a bioabsorbable material that dissolves after a preset amount of time exceeding the expected time from vascular entry to the final intravascular position.

[0268] Reference Figures 4J-4K The distal flared tip may include an embedded resilient element (e.g., a coil, strut, or cage) such as spring steel, nitinol, or other elements known in the art that biases the tip into the flared configuration. Alternatively, a resilient element, such as in the form of a nitinol cage, may be present on the inner diameter of the catheter. The polymer tip constrains the resilient element to provide, for example, Figure 4JThe cylindrical outer configuration shown is for transluminal guidance. For example, the polymer (e.g., a hydrophilic mixture) is softened by body heat or moisture so that the elastic element can transform the end into a Figure 4K The funnel configuration shown. Alternatively, a conical NiTi cage at the end is coated with a double hydrophilic non-cross-linked glue. As the catheter is advanced, the glue dissolves and gradually opens the end into a funnel. The polymer end can be formed without an embedded elastic member, but instead includes a co-extrusion having multiple layers, wherein the thickness of the multiple layers is different, and hydrophilic components are mixed in different ratios to control the opening. Multiple axially extending pull wires can be embedded through the extrusion lumen extending axially on the entire catheter wall. Push or pull the wire to open / close the distal end of the catheter to open or collapse. The funnel-shaped, incompletely expanded NiTi stent can be arranged at the end region that spans between high and low hardness zones but has a greater length in the high hardness zone. Once ready to engage with the clot, the stent can be pushed further distally into the low hardness end. After the clot is fully retrieved, the stent is pulled back into the high hardness zone, thereby collapsing the funnel. This is an example of actively making the end funnel-shaped on demand.

[0269] Reference Figure 4F , illustrates a cross-sectional view of the distal end of a tubular catheter body, such as distal section 34. The tubular body is provided with a distal tip 38 in the form of a self-expandable (e.g., nitinol) mesh 50, which is constrained by an outer tubular restraint 52. The restraint 52 may include a proximally retractable tubular body of a control device extending proximally to a proximal manifold, a peel-away sheath carried by an elongated proximally retractable pull wire, or other mechanisms disclosed elsewhere herein. Figure 4G As shown, proximal retraction of the tubular restraint 52 relative to the tubular body 34 or distal advancement of the tubular body 34 relative to the restraint 52 exposes and releases the mesh 50 to self-expand into a funnel shape, thereby facilitating the capture and removal of intravascular debris.

[0270] Reference Figure 4H and 4I , the self-expanding conical mesh 50 is constrained by interweaving internal restraining wires 54. The restraining wires 54 can be surgical guide wires, or specialized restraining wires. The proximal retraction of the restraining wires 54 releases the mesh 50 to self-expand into the final funnel configuration. The release of the mesh 50 can be achieved in various alternative ways, such as bioabsorbable materials, and electrolytic separation.

[0271] The proximal end 12 of the catheter 10 is also provided with a manifold 18 having one or more access ports as known in the art. Generally speaking, the manifold 18 is provided with a proximal port (e.g., a guidewire port 20 in an over-the-wire construction (OTW construction)), and at least one side port (e.g., a suction port 22). Alternatively, the suction port 22 may be omitted if the surgical procedure includes proximally removing the guidewire from the guidewire port 20 after placement of the suction catheter and performing suction through the guidewire port. Additional access ports and lumens may be provided as desired, depending on the functional capabilities of the catheter. The manifold 18 may be injection molded from any of a variety of medical grade plastics, or formed according to other techniques known in the art.

[0272] The manifold 18 may additionally be provided with a control device 24 for controlling the axial position of the distal section 34 of the catheter. The control device 24 may take any of a variety of forms, depending on the mechanical structure of the distal section 34 and the desired axial range. In the illustrated embodiment, the control device 24 comprises a slider switch that is mechanically coupled to the distal section 34 for axial movement, such that proximal retraction of the slider switch 24 produces proximal movement of the distal section 34. This allows the distal section 34 to be moved as shown in FIG. Figure 1 As shown, the distal section 33 is retracted. The distal axial advancement of the slider switch 24 produces the distal axial advancement of the distal section 34, as shown. Figure 2 and 3.

[0273] Any of a variety of control devices may be employed, including switches, buttons, joysticks, knobs, pull / push wires, and other control devices apparent to those skilled in the art in light of the disclosure herein. The control device will typically be coupled to the distal section via a control wire 42 .

[0274] Alternatively, the proximal section 33 and the distal section 34 may be provided as separate devices, in which configuration the proximal control device may be omitted. The distal end of the proximal section 33 may be provided with one or more jaws as previously discussed for chopping or otherwise breaking up a thrombus or other occlusion into small pieces or otherwise facilitating aspiration. The proximal section 33 may additionally be mechanically coupled to or adapted to be coupled to a source of vibration or rotational motion, such as to provide an intermittent or pulsatile motion as described elsewhere herein, to facilitate introduction into the vascular system.

[0275] Using axial reciprocation and / or rotation and / or snapping action of the distal jaws, the clinician may be able to reach the occlusion using the proximal section 33. See, e.g. Figure 5 , wherein the proximal section 33 is able to reach the occlusion in the left carotid siphon. However, if the proximal section 33 cannot be sufficiently advanced close to the occlusion, a separate telescopic distal section 34 can be introduced into the proximal section 33 and Figure 2 and6 -10 is shown as advancing through it and beyond until reaching the occlusion.

[0276] Cerebral circulation is regulated in such a way that a generally constant total cerebral blood flow (CBF) is maintained under different conditions. For example, a decrease in flow to one part of the brain (such as in an acute ischemic stroke) can be compensated by an increase in flow to another part, so that the CBF of any one area of ​​the brain remains constant. More importantly, when a part of the brain is ischemic due to a vascular occlusion, the brain compensates by increasing blood flow to the ischemic area via its collateral circulation.

[0277] Figure 5 The cerebral arterial vascular system including the circle of Willis is depicted. The aorta 100 gives rise to the right brachiocephalic artery 82, the left common carotid artery (CCA) 80, and the left subclavian artery 84. The brachiocephalic artery 82 further branches into the right common carotid artery 85 and the right subclavian artery 83. The left CCA gives rise to the left internal carotid artery (ICA) 90 which becomes the left middle cerebral artery (MCA) 97 and the left anterior cerebral artery (ACA) 99. In front, the circle of Willis is formed by the internal carotid artery, the anterior cerebral artery, and the anterior communicating artery 91 connecting the two ACAs. The right and left ICAs also connect the right posterior communicating artery 72 and the left posterior communicating artery 95 to the right posterior cerebral artery (PCA) 74 and the left PCA 94, respectively. The two posterior communicating arteries and the PCA and the source of the posterior cerebral artery from the basilar artery 92 form a circle in the back.

[0278] When an acute occlusion occurs, for example, in the left carotid siphon 70, Figure 5 As shown, blood flow increases in the right cerebral artery, left external carotid artery 78, right vertebral artery 76, and left vertebral artery 77, resulting in a change in the direction of flow through the circle of Willis to compensate for the sudden decrease in blood flow in the left carotid siphon. Specifically, blood flow reverses in the right posterior communicating artery 72, right PCA 74, and left posterior communicating artery 95. The anterior communicating artery 91 opens, thereby reversing flow in the left ACA 99, and flow increases in the left external carotid artery, thereby reversing flow along the left ophthalmic artery 75, all of which contribute to flow in the left ICA 90 distal to the occlusion to provide perfusion to the ischemic area distal to the occlusion.

[0279] like Figure 5 As shown, the proximal section of the catheter 10 is guided transluminally along or over a guidewire to the proximal side of the occlusion. The transluminal guidance can be accomplished with the distal section 34 of the catheter in a first, proximal, retracted configuration. This enables distal advancement of the proximal section 33 until further advancement is inhibited by small and / or tortuous vasculature. Alternatively, the distal section 34 is a separate device and is not inserted into the proximal section 33 until it is determined that the proximal section 33 cannot safely reach the occlusion. Figure 5 In the example shown, the proximal section 33 can safely reach the occlusion without the need to insert or distally extend the distal section 34.

[0280] The distal end of the proximal section 33 of the suction catheter 10 is usually inserted over a guidewire through an incision in a peripheral artery and advanced to a more distal carotid or intracranial artery (such as the carotid artery, terminal ICA, carotid siphon, MCA or ACA) as long as it is considered safe. The occluded site can be located using cerebral angiography or IVUS. In an emergency, after locating the occlusion with the aid of IVUS or standard carotid Doppler and TCD, the catheter can be inserted directly into the symptomatic carotid artery.

[0281] If sufficient distal guidance of the proximal section 33 to reach the occlusion does not appear to be safely achieved, the distal section 34 is inserted into the proximal port 20 and / or extended distally beyond the proximal section 33 until the distal tip 38 is positioned adjacent the proximal edge of the occlusion.

[0282] Reference Figure 6 , the occlusion 70 is lodged in the middle cerebral artery 97. The proximal segment 33 is located in the ICA and cannot be guided beyond a certain point, such as at the branch 96, to the MCA artery 97. The proximal segment 33 may be provided with the distal segment 34 carried therein. Alternatively, once it has been determined that the proximal segment 33 alone cannot directly reach the occlusion 70, a separate distal segment 34 may be introduced into the proximal end of the proximal segment 33. Figure 7 and 8 As can be seen in FIG. 7 , the distal section 34 can thereafter be transluminally guided through the distal tortuous vasculature between the proximal section 33 and the occlusion 70 .

[0283] Reference Fig. 9 , the occluder 70 can thereafter be drawn into the distal segment 34 while applying a constant or pulsating negative pressure with or without the use of jaws or other actuation on the distal end of the distal segment 34 as described elsewhere herein. Once the occluder 70 has been drawn into the distal segment 34, or sufficiently drawn into the distal segment 34 that it can be withdrawn proximally from the body, the proximal segment 33 and the distal segment 34 are thereafter withdrawn proximally.

[0284] Suction may be applied in a constant mode or a pulsatile mode through lumen 40. Preferably, the pulsatile application of vacuum will cause distal tip 38 to open and close like a jaw, which facilitates reshaping of the thrombus or breaking or nibbling the thrombus material into strands or pieces to facilitate retrieval under negative pressure through lumen 40. The application of suction may be accompanied by distal advancement of distal tip 38 into the thrombus material.

[0285] The pulsating application of vacuum may oscillate between a positive vacuum and zero vacuum or between a first lower negative pressure and a second higher negative pressure. Alternatively, a slight positive pressure may be alternated with a negative pressure, wherein the negative pressure is primarily applied to provide a net suction through the lumen 40. The pulse cycle is discussed in more detail in conjunction with FIG. 25.

[0286] The proximal manifold and / or a proximal control unit (not shown) connected to the manifold may enable the clinician to adjust any of a variety of pulse parameters, including pulse rate, pulse duration, timing between pulses, and intensity of the pulsating vacuum.

[0287] Thereafter, the distal section can be proximally retracted into the proximal section 33 and the catheter proximally retracted from the patient. Alternatively, proximal retraction of the catheter 10 can be accomplished with the distal section 34 in a distally extended position. A vasodilator, such as nifedipine or sodium nitroprusside, can be injected through the second lumen to inhibit vasospasm caused by use of the device.

[0288] The pressure may be monitored by a pressure gauge carried by the catheter or by a wire located in the lumen of the catheter.A pressure control and display device may be included in the proximal control unit or proximal end of the catheter, allowing the intravascular suction to be regulated.

[0289] Local hypothermia, which has been shown to be neuroprotective, can be administered by perfusion of hypothermic oxygenated blood or fluid. During fluid perfusion, mild hypothermia of about 32°C to 34°C can be introduced. Perfusion through a port on the manifold 18 can be accomplished by withdrawing venous blood from a peripheral vein and processing it through a heart-lung machine or by withdrawing oxygenated blood from a peripheral artery (e.g., the femoral artery) and pumping it back into the carotid artery.

[0290] If continuous and / or intermittent aspiration fails to dislodge the occlusion, a thrombolytic agent, such as t-PA, may be infused through the central lumen 40 or a secondary lumen to dissolve any thrombotic material with greater local efficacy and fewer systemic complications. However, administration of thrombolytic agents may not be recommended for devices inserted directly into the carotid artery due to the increased risk of bleeding.

[0291] The intensity of the intermittent or pulsating vacuum applied to the lumen 40 can be adjusted so that the distal end 38 of the catheter 10 experiences an axial reciprocating motion or water hammer effect, which can further promote both transluminal guidance and the removal or fragmentation of occlusions. Water hammer, or more generally fluid hammer, is a pressure shock or pressure wave caused when a fluid in motion is forced to suddenly stop or change direction, resulting in a change in momentum. Water hammer is usually generated when a valve at the end of a piping system is suddenly closed, and the pressure wave propagates in the pipe. When a solenoid or valve is suddenly closed and stops the flow of fluid or other pulse generators are activated, a pressure shock or pressure wave is generated in the lumen 40 of the suction catheter 10. As the pressure wave propagates in the catheter 10, it causes the catheter 10 to vibrate axially. Because the vibration can reduce the surface friction between the outer diameter of the catheter 10 and the inner diameter of the vessel wall, it enables the catheter to track through tortuous anatomical structures and assist in capturing thrombi.

[0292] Reference Figures 11A-11F , the cerebral circulation 1100 is simplified for ease of illustrating the procedural steps. A thrombotic occlusion 1102 is in the right middle cerebral artery (RMCA) 1104. The RMCA 1104 branches off from the right internal carotid artery (RICA) 1106. The RICA 1106 branches off from the right common carotid artery (RCCA) (not shown). The RICA 1106 includes a cerebral segment 1108 (farthest from the aorta 100), a cavernous sinus segment 1110, and a petrous segment 1112 (closest to the aorta 100). The RCCA branches off from the brachiocephalic artery. The brachiocephalic artery branches off from the arch 1114 of the aorta 100.

[0293] The following describes the procedural steps for aspirating thrombotic occlusions. Fig.11A , introducer sheath 1120 is introduced at femoral artery 1118. The outer diameter of introducer sheath 1120 may be equal to or less than about 12F, 11F, 10F, 9F, 8F, 7F, or 6F. Then, guide sheath 1122 is inserted through introducer sheath 1120. The outer diameter of guide sheath 1122 may be equal to or less than about 9F, 8F, 7F, 6F, 5F, 4F, or 3F, and the inner diameter of introducer sheath 1120 may be greater than the outer diameter of guide sheath 1122.

[0294] Reference Fig. 11B , insert the insertion catheter 1124 through the guide sheath 1122. The outer diameter of the insertion catheter 1124 may be equal to or less than about 9F, 8F, 7F, 6F, 5F, 4F, or 3F, and the inner diameter of the guide sheath 1122 may be larger than the outer diameter of the insertion catheter 1124. In some cases, a first guide wire 1126 ( Fig. 11BThen, the guide sheath 1122, the insertion catheter 1124, and optionally the first guide wire 1126 are tracked forward to the aortic arch 1114. The insertion catheter 1124 is used to engage the starting point of the blood vessel. Fig. 11B In the embodiment, the insertion catheter 1124 is engaged with the starting point 1116 of the brachiocephalic artery 82. Angiography is performed by injecting a contrast medium through the insertion catheter 1124. In the case where the first guide wire 1126 is used before angiography, the first guide wire 1126 is removed before the contrast medium is injected.

[0295] Reference Fig. 11C , insert the first guide wire 1126 through the lumen of the insertion catheter 1124. Then, the first guide wire 1126, the insertion catheter 1124 and the guide sheath 1122 are advanced together to the ICA 1106. Fig.11D Due to the stiffness of a typical guide sheath 1122 currently available on the market (e.g., the Neuron MAX system produced by Penumbra), the most distal vessel to which the guide sheath 1122 can be guided is the rocky segment 1112 of the ICA 1106. Once the first guide wire 1126, insertion catheter 1124, and guide sheath 1122 are advanced to the ICA 1106, both the first guide wire 1126 and the insertion catheter 1124 are removed.

[0296] Reference Fig.11E , a second guidewire 1132 loaded into the central lumen of a reperfusion catheter 1130 (e.g., 3Max) is introduced through the guide sheath 1122, and the reperfusion catheter 1130 is loaded into the central lumen of an aspiration catheter 1128 (e.g., ACE 68). The diameter of the second guidewire 1132 may be equal to or less than about 0.03", about 0.025", about 0.02", about 0.016", about 0.014", about 0.01", or about 0.005". The inner diameter of the reperfusion catheter 1130 may be greater than the outer diameter of the second guidewire 1132. The inner diameter of the aspiration catheter 1128 may be greater than the outer diameter of the reperfusion catheter 1130. The inner diameter of the guide sheath 1122 may be greater than the outer diameter of the aspiration catheter 1128. Then, the second guidewire 1132 is advanced distally and positioned proximal to the clot 1102 in the MCA 1104.

[0297] Reference Fig.11F , the aspiration catheter 1128 is tracked along the reperfusion catheter 1130 and the second guidewire 1132 to the proximal end of the clot 1102 in the MCA 1104. Both the second guidewire 1132 and the reperfusion catheter 1130 are removed. Vacuum pressure is then applied at the proximal end of the aspiration catheter 1128 to aspirate the clot 1102 through the central lumen of the aspiration catheter 1128.

[0298] Combination Figures 12A-12FA preferred simplified method for aspirating a thrombotic occlusion according to the present invention is described. An alternative procedure for aspirating a thrombotic occlusion utilizes a transition guidewire (intermediate guidewire) and a transition guide sheath (exchange guide sheath). The transition guidewire has a soft and trackable (easy to follow the route) distal section with a smaller diameter so that the transition guidewire can be advanced further than in the Fig. 11C In addition, the transition guide sheath has a soft and trackable distal section so that the transition guide sheath can be advanced deeper than in Fig.11D The guide sheath 1122 depicted in FIG. 1 is deep. The use of a transition guide wire and a transition guide sheath that can be advanced to the area near the clot avoids the need to use a second guide wire or a reperfusion catheter to reach the clot.

[0299] Reference Fig. 12A , introducer sheath 1220 is introduced at femoral artery 1218. The outer diameter of introducer sheath 1220 can be equal to or less than about 12F, 11F, 10F, 9F, 8F, 7F, or 6F. Then, a transition guide sheath 1222 (such as a combined access and aspiration catheter discussed in more detail below) is inserted through introducer sheath 1120 at femoral artery 1218. The outer diameter of guide sheath 1222 can be equal to or less than about 9F, 8F, 7F, 6F, 5F, 4F, or 3F. Fig. 12B , insert the insertion catheter 1224 through the transition guide sheath 1222. The outer diameter of the insertion catheter 1224 may be less than about 9F, 8F, 7F, 6F, 5F, 4F, or 3F, and the inner diameter of the transition guide sheath 1222 may be larger than the outer diameter of the insertion catheter 1224. In some cases, a first guide wire ( Fig. 12B 0.079", about 0.066", about 0.053", about 0.038", about 0.035", about 0.030", or about 0.013".

[0300] The transition guide sheath 1222, the insertion catheter 1224, and optionally the first guidewire are tracked all the way to the aortic arch 1214. Fig. 12B Insertion of catheter 1224 can be used to select the starting point of the blood vessel. Fig. 12B In the embodiment, the insertion catheter 1224 is engaged with the starting point 1216 of the brachiocephalic artery 82. Angiography can be performed by injecting a contrast agent through the insertion catheter 1224. In the case where a first guide wire is used before angiography, the first guide wire is preferably removed before injecting the contrast agent.

[0301] Reference Fig. 12C, the transition guidewire 1226 is inserted through the lumen of the insertion catheter 1224 or the guide sheath 1222. The diameter of at least a portion of the transition guidewire 1226 (e.g., the proximal diameter) is substantially similar to the diameter of the first guidewire 1126. The diameter of at least a portion of the transition guidewire 1226 (e.g., the distal diameter) may be smaller than the diameter of the first guidewire 1126 and may have a diameter along the proximal section of at least about 0.030" and in one embodiment about 0.038". The transition portion begins in a range of about 15cm-30cm from the distal end and typically no more than about 20cm or 25cm from the distal end, and on the distal side of the transition portion, the diameter tapers to no more than about 0.018" and in one embodiment about 0.016". Reference Fig.12D , the insertion catheter 1224 (if used) may be removed because it is too rigid to be advanced into the MCA 1204. In certain embodiments of the present invention, the transition guidewire 1226 provides sufficient support so that the combined access and aspiration catheter 1224 can be advanced directly over the transition guidewire without the use of any intermediate intervening devices. The transition guidewire 1226 is then advanced into the MCA 1204. The transition guidewire 1226 has a diameter greater than Fig. 11C 12. The distal section of the transition guidewire 1226 includes a soft and atraumatic tip and can be tracked to a remote neurovascular system, such as the MCA 1204 distal to the petrous segment 1212 of the ICA 1206.

[0302] Reference Fig.12E , advancing the transition guide sheath 1222 to or beyond the cavernous sinus segment 1210 or the cerebral segment 1208 of the ICA 1206. Fig.11D Unlike the guide sheath 1122 depicted in FIG. 1 , the transition guide sheath 1222 can be advanced beyond the petrous segment 1212 to the cavernous sinus segment 1210 or the cerebral segment 1208 because the transition guide sheath 1222 has the following features, for example, combined with Fig.30 The soft but trackable distal section described in more detail.The larger proximal diameter and stiffer body of the transition guidewire 1226 can provide better support for the transition guide sheath 1222 to track through the vascular system.

[0303] Reference Fig.12F After the transition guide sheath 1222 is advanced to the cerebral segment 1208 of the ICA 1206, the transition guide wire 1226 is removed. Then, vacuum pressure is applied at the proximal end of the transition guide sheath 1222 to aspirate the clot 1202 through the central lumen of the transition guide sheath 1222. The inner diameter of the transition guide sheath 1222 may be equal to or greater than about 0.100", about 0.088", about 0.080", about 0.070", or about 0.060". The inner diameter of the transition guide sheath 1222 is greater than the inner diameter of the transition guide sheath 1222. Fig.11EThis translates into more efficient aspiration, as depicted in the aspiration catheter 1128. The cross-sectional area of ​​the central lumen of the transition guide sheath 1222 can be nearly twice as large as the cross-sectional area of ​​the largest aspiration catheter 1128 currently available.

[0304] If the guide sheath 1222 cannot track deeply enough into the distal vasculature to reach a clot or other desired target site, a telescoping extension segment as discussed elsewhere herein may be introduced into the proximal end of the sheath 1222 and advanced distally to extend beyond the distal end of the sheath 1222 and thereby expand the reach of the aspiration system. In one embodiment of the invention, the extension segment has an inner diameter of approximately 0.070".

[0305] If thrombotic material cannot be drawn into the sheath 1222 or extension section under a constant vacuum, a pulsating vacuum may be applied as discussed below. If the pulsating vacuum does not capture the clot satisfactorily, an agitator may be advanced through the sheath 1222 and extension section to facilitate drawing the clot into the central lumen. Additional details of the agitator and its use are disclosed below.

[0306] A pulsating vacuum pressure aspirator may be used to increase the efficacy of aspiration for vascular thrombectomy and to improve catheter tracking capabilities through tortuous vasculature. Fig.13 One embodiment of a pulsating vacuum pressure aspirator 300 for applying intermittent or pulsating vacuum to the lumen 40 is shown. In the illustrated embodiment, the pulsating vacuum pressure aspirator 300 is fluidly connected to the proximal end 12 of the catheter 10 and includes a vacuum generator 302, a vacuum chamber 310, a collection tank 312, a solenoid valve (solenoid-operated valve) 314, a frequency modulator 316, a valve controller 318, and a remote controller 320.

[0307] The vacuum generator 302 includes a vacuum pump 304, a vacuum gauge 306, and a pressure regulating control 308. The vacuum pump 304 generates a vacuum. The vacuum gauge 306 is fluidly connected to the vacuum pump 304 and indicates the vacuum pressure generated by the pump 304. The pressure regulating control 308 allows the user to set a specific vacuum pressure. Any of a variety of control devices may be used, including switches, buttons, joysticks, knobs, and other control devices that are apparent to those skilled in the art based on the disclosure herein.

[0308] The vacuum chamber 310 is fluidly connected to the vacuum generator 302 and serves as a pressure accumulator and / or buffer. The collection tank 312 is fluidly connected to the vacuum chamber 310 and collects debris. The collection tank 312 can be a removable vial that collects debris or tissue that can be used for pathological diagnosis. The vacuum chamber 310 and the collection tank 312 can be separate components that are fluidly connected to each other, or a combined component. In the illustrated embodiment, the vacuum chamber 310 and the collection tank 312 are a combined component and are fluidly connected to the vacuum generator 302.

[0309] Solenoid valve 314 is located in the fluid connection path between a Luer or other connector configured to releasably connect to the access port of catheter 10 and vacuum chamber 310 / collection canister 312. Solenoid valve 314 controls fluid flow from catheter 10 to vacuum chamber 310 / collection canister 312.

[0310] The pulsating vacuum pressure aspirator 300 may include a frequency modulator 316 for controlling the solenoid valve 314. The frequency modulator 316 generates different electric wave frequencies and waveforms, which are converted into the movement of the solenoid valve 314 by the valve controller 318. The waveforms generated from the frequency modulator 316 include sine waves, square waves, and sawtooth waves. The waveforms generated from the frequency modulator 316 typically have a frequency of less than about 500 Hz, less than about 20 Hz, or less than about 5 Hz in some operating modes. The waveform has a duty cycle in the range of 0% (wherein the solenoid valve 314 is completely closed) to 100% (wherein the solenoid valve 314 is fully opened).

[0311] The valve controller 318 regulates the opening and closing of the solenoid valve 314. The valve controller 318 may be electrically or mechanically connected to the solenoid valve 314. Any of a variety of control devices may be used, including electrical controllers, switches, buttons, joysticks, knobs, and other control devices that are apparent to those skilled in the art based on the disclosure herein. The valve controller 318 may be mechanically controlled by a user or may be electrically controlled by the frequency regulator 316. The frequency regulator 316 and the valve controller 318 may be separate components that are electrically or mechanically connected, or may be a combined component.

[0312] The remote controller 320 enables the physician to control the frequency modulator 316 and / or the valve controller 318 for various purposes, such as opening / closing the valve, selecting different wave frequencies, and selecting different waveforms, while manipulating the catheter 10 at the patient side. The remote controller 320 may communicate with the aspirator 300 either wired or wirelessly.

[0313] By adjusting the frequency, duty cycle and waveform, one skilled in the art can match or approximate the resonant frequency to the natural frequency of the catheter. This can further improve the efficacy of the suction. The natural frequency of the catheter is typically less than about 260 Hz.

[0314] exist Fig.14 In another embodiment shown, a solenoid valve 414 is positioned in and fluidly connects an air / fluid reservoir 422 at atmospheric pressure and a suction line 424 connecting the catheter 10 to the vacuum chamber 410 / collection tank 412. Fig.13In the first embodiment of the present invention, the system regulates the pressure in the catheter 10 by allowing the pressure to change from vacuum to atmospheric pressure. When the solenoid valve 414 opens to the air / fluid reservoir 422 at atmospheric pressure, the vacuum pressure in the suction line 424 is reduced to atmospheric pressure. When the solenoid valve 414 is closed, it increases the vacuum pressure in the suction line 424.

[0315] exist Fig.15 In yet another embodiment shown, an electromagnetically actuated diaphragm 522 is attached to an aspiration line 524 that connects the conduit 10 to the vacuum chamber 510 / collection tank 512. The electromagnetically actuated diaphragm 522, similar to a speaker driver, generates acoustic pressure waves in the conduit 10. The diaphragm 522 typically has a structure similar to a speaker driver and includes a frame 526, a cone 528, a dust cap 530, a surround 532, a bracket or vibration damper 534, a voice coil 536, and a magnet 538. The intensity of the acoustic pressure waves can be regulated by the strength of the magnet 538. The frequency modulator 516 connected to the remote control 520 is electrically connected to the diaphragm 522 and generates different radio wave frequencies and waveforms, which are converted by the diaphragm 522 into acoustic pressure waves in the aspiration line 524 and the conduit 10.

[0316] A tortuous vasculature is a common reason for the inability to treat vascular occlusions in the body due to the inability to track the catheter to the diseased site. It is a challenge to guide a catheter through tortuous anatomical structures such as the neurovascular system. The catheter must be very flexible so as not to damage the vessel wall. At the same time, it must be able to pass through multiple sharp bends without kinking. In addition, it must have sufficient radial support to transmit forces axially in order to advance through the vascular system. All of these performance characteristics are conflicting design requirements. It is difficult to optimize one performance characteristic without sacrificing other performance characteristics.

[0317] Reducing the friction between the inner diameter of the blood vessel and the outer diameter of the catheter can minimize the axial force required to propel the catheter through the tortuous vascular system. Therefore, the radial support force of the catheter can be traded for the optimization of other performance requirements of the catheter. An example of a method of reducing the friction between the inner diameter of the blood vessel and the outer diameter of the catheter is to apply a thin coating, usually hydrophilic, to the outer diameter of the catheter to reduce its surface friction coefficient when it is in the body.

[0318] As an addition or alternative to the water hammer structure discussed above, axial mechanical vibrations or shock waves can be propagated to the distal end of the catheter or generated at the distal end of the catheter using various vibration generators (e.g., a spark gap generator, a piezoelectric pulse generator, an electric solenoid, a rotating shaft (wire) having one or more bends or with an eccentric hammer, or any of various other pulse generating sources known in lithotripsy technology, for example). The mechanical shock wave or pulse generator can be built into the proximal manifold 18, and / or mechanically connected to the manifold or proximal catheter shaft as required. Preferably, a control device is provided on the manifold or on a proximal control device connected to the manifold to enable the clinician to change the intensity and time parameters of the mechanical pulse. The shock wave can propagate along the proximal section 33 to assist in transluminal advancement, and / or propagate along the distal section 34 via the pull wire 42, depending on the desired clinical performance.

[0319] exist Fig.16 and 17 In the embodiment shown in , the distal end 608 of the vibration device 600 is arranged to be fluidly connected to the proximal end 12 (not shown) of the catheter 10 and to generate lateral and / or longitudinal vibrations in the catheter 10. By inducing lateral vibrations in the catheter 10, the effective contact surface area between the blood vessel and the catheter 10 is reduced, which in turn reduces the surface friction between the inner diameter of the blood vessel and the outer diameter of the catheter. In addition, by inducing longitudinal vibrations in the catheter 10, the vibration device 600 destroys the static friction between the inner diameter of the blood vessel and the outer diameter of the catheter 10, which reduces the total surface friction. By reducing the friction between the inner diameter of the blood vessel and the outer diameter of the catheter 10, the vibration device 600 improves the catheter tracking through the tortuous vascular system.

[0320] In the illustrated embodiment, the proximal end 602 of the vibrating device 600 can be connected to a vacuum pressure source, such as a vacuum generator. A proximal connector 604 is attached to the housing 606. In at least one embodiment, the proximal connector 604 can be a Luer connector. A distal end 608 of the vibrating device 600 is connected to the catheter 10. A distal connector 610 is held in place by a flexible seal 612 attached to the housing 606. In at least one embodiment, the distal connector 610 can be a Luer connector. The flexible seal 612 allows the distal connector 610 to move longitudinally and laterally. A flexible tubing connects the proximal connector 604 and the distal connector 610 to form a suction channel 614 for fluid to pass through.

[0321] The vibration device has a controller 616 that turns the vibration action on / off and changes its frequency. In this embodiment, the controller 616 is depicted as a slide switch. Any of a variety of control devices may be used, including electrical controllers, switches, buttons, joysticks, knobs, and other control devices that are obvious to those skilled in the art based on the disclosure herein.

[0322] A vibration generator such as motor 618 has an eccentrically mounted inertia hammer on its axis that generates vibration. Any variety of motors can be used, including electric motors, electromagnetic actuators, and piezoelectric transducers. The vibration frequency is related to the RPM of motor 618. Drive circuit 620 is connected to motor 618 and controller 616 and drives motor 618 at different RPMs based on the manipulation of controller 616. In the illustrated embodiment, circuit 620 drives motor 618 at different RPMs based on the position of the slide switch. Battery 622 is connected to drive circuit 620 and motor 618 and supplies them with power.

[0323] The motor 618 can be mounted perpendicular to the length of the suction channel 614 to form longitudinal vibrations. In addition, a mechanical cam can be attached to the motor 618 to form a larger longitudinal reciprocating motion. The frequency range generated by the motor is typically less than about 85 Hz. In order to achieve sound frequencies in the range of about 85 Hz to about 260 Hz, an electromagnetic actuator can be used to replace the motor. In order to achieve ultrasonic frequencies in the range of about 20 Hz to about 1.6 MHz, a piezoelectric transducer can be used.

[0324] exist Fig.18 In yet another embodiment shown, an agitator such as a stylet 702 is permanently or removably inserted into the lumen 40 of the catheter 10 and rotated to generate vibrations in the catheter 10, thereby improving the catheter tracking through tortuous vascular systems. The stylet 702, which has an outer diameter ranging from about 0.005 inches (about 0.127 mm) to about 0.035 inches (about 0.889 mm), may have at least one bend or at least one weight. When located in the catheter, the peak-to-peak lateral distance between the bends will be less than the inner diameter of the catheter 10. The bends or weights of the stylet 702 may be located at different locations along the entire length of the catheter 10 or included in the vibration region within the most distal 50%, 30%, or 10% of the catheter length, depending on the desired performance, with the goal of generating the most ideal vibration when tracking the catheter 10 through the distal vascular system.

[0325] Alternatively, the stylet 702 may have an asymmetrical weight, such as a flange / bead at a distal vibration zone or at its distal end. The stylet 702 may comprise a monofilament or a braided or woven wire or thread.

[0326] In another alternative, stylet 702 may have a heater (eg, an electrical coil) at its distal end that facilitates lysis of thrombus or alters the size of thrombus drawn into the catheter.

[0327] The proximal end of the stylet is attached to a motor driver 704 capable of generating rotational and / or axial reciprocating motions of various frequencies to form a motor driver-stylet assembly 700. Assembly 700 has a controller 706 for turning on / off the rotational action and changing its frequency. In the present embodiment, controller 706 is depicted as an on / off button. Any of a variety of control devices may be used, including electrical controllers, switches, buttons, joysticks, knobs, and other control devices that are obvious to those skilled in the art based on the disclosure herein. A proximal Luer connector 708 or other connector of catheter 10 reversibly attaches catheter 10 to the motor driver 704.

[0328] Once the catheter 10 has reached its desired position, the entire motor driver-stylet assembly 700 may be disassembled and removed from the catheter 10, thereby leaving the central suction lumen.

[0329] In patients with vertebral artery occlusion, treatment with angioplasty can cause complications due to embolism of occlusive lesions downstream of the basilar artery. Emboli small enough to enter the larger basilar artery through the vertebral artery are usually blocked at the top of the basilar artery, where the basilar artery bifurcates into the posterior cerebral artery. The resulting reduction in blood flow to the ascending reticular formation of the midbrain and thalamus produces immediate loss of consciousness. The device described herein can be used to remove thromboembolic material from the vertebral artery or more distally (such as in the M1, M2 or M3 arteries).

[0330] Combination Figure 19-2 4 further describes an agitator for providing guided vibration assistance and / or aiding in the capture and suction of debris. Fig.19 , the agitator 1900 may include an elongated flexible body, such as a wire or hypotube, having a proximal control end and a distal active region or active end. The hypotube agitator has a longitudinally extending internal lumen that allows for medium infusion. Fig.19 , the agitator 1900 includes a wire or hypotube 1904 introduced into the proximal end of the catheter 1902 and advanced to the distal end 1907 of the catheter 1902. The distal end 1905 of the agitator 1900 can be placed at the distal end of the catheter 1902, beyond the distal end or inside the distal end. The agitator 1900 can be pre-loaded into the catheter 1902 and inserted into the patient together with the catheter 1902 or added after the catheter 1902 has been placed. When loaded inside the catheter 1902, the agitator 1900 can extend roughly longitudinally along the length of the catheter 1902. The agitator 1900 can also include a controller at the proximal end to axially adjust the distal end position. The controller of the agitator 1900 can be used to axially adjust the position of the distal end 1905 when the agitator 1900 is introduced into a variable length catheter such as discussed in conjunction with Figure 3.

[0331] In one embodiment of the present invention, the agitator and the drive system are constructed as separate devices. Figure 3B ) has been positioned within a few (e.g., no more than about 3 or 2) centimeters of the occlusion, the distal end of the agitator 1900 may be introduced into the proximal end of the central lumen 45 of the pull wire 42. Thereafter, the agitator 1900 may be advanced distally such that the distal segment of the agitator 1900 extends beyond the distal end of the pull wire 42 and into the distal segment 34. The portion of the agitator 1900 housed within the lumen 45 of the pull wire 42 is constrained from any substantial lateral movement. However, the distal portion of the agitator 1900 extending beyond the distal end of the pull wire 42 is relatively unconstrained laterally and is able to agitate the thrombus to facilitate drawing the thrombus into and through the distal segment 34. Once the thrombus has been drawn proximally to the enlarged inner diameter at the proximal end of the distal segment 34 under vacuum and by actuation of the agitator as desired, the risk of occlusion is greatly reduced.

[0332] The agitator 1900 can be rotated manually or via a motor 1906 driven from the proximal end of the catheter 1902 to rotate or translate the distal end of the agitator 1900. The driver 1906 can be permanently or removably connected to the proximal end of the agitator 1900. The driver 1906 can be a manually controlled manual driver, such as a guide wire twister. The driver 1906 can be a motorized driver. The motorized driver can be manually controlled in terms of one or more factors (such as rotation direction (CCW / CW), speed, duration, etc.). The motorized driver can be automatically controlled in terms of one or more factors (such as direction (CCW / CW), speed, duration, etc.). In one mode, the rotation direction of the agitator is periodically reversed.

[0333] The automatically controlled drive may include an actuator, and actuating the actuator may perform a pre-programmed series of steps. The actuator may be a button, a dial, a knob, a switch, a joystick, a valve, a slider, a keyboard, or any combination thereof. The drive 1906 may also be under synchronous control, wherein the drive 1906 drives the agitator 1900 synchronously with the aspiration and the injection of the medium. The agitator 1900 may be configured to promote movement at the distal end to help engage and move the clot.

[0334] A medium may be perfused into / around the clot area to help dislodge the clot from the vasculature.

[0335] The agitator 1900 includes a distal end 1912, a proximal end 1914, and a distal tip 1905. The proximal end 1914 of the agitator 1900 has a cross-section and / or wall thickness large enough to transmit the torque required to rotate the distal end 1912 of the agitator 1900 when disposed in the catheter 1902 in a tortuous vascular system. The outer diameter of the agitator 1900 can be about 0.25 mm to about 0.65 mm, about 0.3 mm to about 0.6 mm, about 0.35 mm to about 0.55 mm, about 0.4 mm to about 0.5 mm, about 0.42 mm to about 0.48 mm, or about 0.44 mm to about 0.46 mm. In the case of sea wave tube 1904, the wall thickness of sea wave tube 1904 can be about 0.01 mm to about 0.29 mm, about 0.05 mm to about 0.25 mm, about 0.1 mm to about 0.2 mm, about 0.12 mm to about 0.18 mm, about 0.13 mm to about 0.17 mm, or about 0.14 mm to about 0.16 mm.

[0336] The agitator 1900 may additionally be provided with a guide tube 1910, such as a hypotube, to allow the agitator to rotate, or reciprocate axially or rotationally, while constraining the proximal drive section of the agitator 1900 to prevent lateral movement. The distal end 1911 of the guide tube 1910 may be positioned within about 25 cm of the distal end of the agitator 1900, or within about 20 cm or 15 cm or less, depending on the desired performance. The distal section of the agitator 1900 extending beyond the distal end 1911 of the guide tube 1910 is laterally unconstrained within the inner diameter of the distal section 34 and can be used to agitate and facilitate the suction of material into and through the central lumen.

[0337] The diameter of the agitator 1900 can be constant along its longitudinal length. The diameter of the agitator 1900 can increase or decrease along its longitudinal length to match the features of the catheter 1902. In one embodiment, the diameter of the agitator 1900 decreases in the distal direction along its longitudinal length through at least one step or tapered region to provide enhanced flexibility.

[0338] The distal end 1912 of the agitator 1900 can be straight. Alternatively, the distal end 1912 of the agitator 1900 can be curved or formed into a different shape to interact with the clot. Fig.19 The bend 1917 is shown spaced apart from the distal tip 1905 by a motion section 1909 having a length of about 1 mm to about 15 mm. Figures 20A-20C A more complex exemplary shape for the moving section 1909 of the agitator 1900 is depicted. Figures 20D-20E An agitator positioned within the inflatable polymer distal funnel-shaped tip is depicted.

[0339] The agitator 1900 may include a single uniform material or multiple materials. The material of the agitator 1900 may be processed (e.g., heat treated / annealed) to impart different characteristics for local performance requirements. The agitator 1900 may be configured to provide flexibility while exerting high torque transmission. The agitator 1900 may be made of nitinol, 304 stainless steel, 316LVM stainless steel, PTFE, polyparaxylene, or any combination thereof. At least a portion of the surface of the agitator 1900 may be coated. The entire length of the agitator 1900 may be coated. The coating on the agitator 1900 may provide lubrication between the inner diameter wall of the catheter 1902 and the agitator 1900. In the case where there is an intermediate hypotube disposed between the wall of the catheter 1902 and the agitator 1900 (e.g., a restraining tube 1910 or a tubular pull wire 42), the coating on the agitator 1900 may provide lubrication between the intermediate hypotube and the proximal drive portion of the agitator 1900. The coating material of the wire or hypotube 1904 includes PTFE, polyparaxylene, Teflon or any combination thereof.

[0340] Any inner diameter and outer diameter of any catheter shaft or other catheter components disclosed herein may be provided with a lubricating coating or may be made of a lubricating material. For example, a hydrophilic polymer (such as a copolymer of polyacrylamide, PEO, thermoplastic starch, PVP, a hydrophilic polymer) may be extruded together with a hydrophobic polymer (such as a PEO soft segmented polyurethane mixed with Tecoflex). The lubricating coating or lubricating material may include a surface modification additive (SMA) during melt processing. The lubricating coating or lubricating material at least contributes to the ease of guidance, lower inner diameter surface friction, or better clot removal. In some embodiments, it may also be desirable to post-process with an electron beam, gamma ray, UV, etc. to be exposed to moisture, temperature, etc. The catheter may be made of a polyurethane impregnated with PEO (such as Hydrothane, Tecophilic polyurethane) to achieve outer diameter and inner diameter lubrication and inherent thrombotic resistance, thereby not requiring a secondary coating process.

[0341] Reference Fig. 20A , the distal end 2012 of the agitator 1900 may include a coil 2020 to catch a stuck clot and twist the distal end 2010 of the catheter 2002 and the clot during rotation 2006. The coil 2020 may be a tight offset coil and may include at least one and optionally two or three or more complete turns.

[0342] Reference Fig. 20B , the distal end 2012 of the agitator 1900 may include a hook 2022 for grasping and emulsifying the clot. The hook 2022 may be concave on the proximal side, or may extend transversely to the axis of the agitator body, thereby extending in a circumferential orientation. Fig. 20C, the distal end 2012 of the agitator 1900 may include a loose coil or spring 2024. The loose coil or spring 2024 may expand (lengthen) and contract (shorten) as the direction of rotation changes.

[0343] Reference Figures 20D-20E , the distal end 2012 of the agitator 2000 may include a coil 2026 to grab a stuck clot and twist the distal end 2010 of the catheter 2002 and the clot during rotation. In addition, the distal end 2010 of the catheter 2002 may include a polymer sidewall that reshapes upon hydration. The coil 2026 maintains the guidewire lumen during placement of the catheter. The polymer enables the distal end 2010 of the catheter 2002 to expand into a funnel shape after absorbing serum from the blood. See Fig.20E .

[0344] Reference Figures 21A-21B , the distal tip 2110 of the catheter 2102 can move or twist by interacting with the agitator 1900. When the distal end of the agitator 1900 is rotated (e.g., via the driver 2106), the motion segment 1909 and distal tip 1905 of the agitator interact with the side wall of the catheter 2102, causing the side wall to twist as shown by the dashed line 2112. The length of the motion segment, the stiffness of the agitator 1900, and the rotation speed determine the interaction with the wall of the catheter 2102 and the amount of twist imparted to the catheter 2102 as the agitator 1900 rotates.

[0345] Alternatively, the distal tip 2110 of the catheter 2102 can be moved or twisted by a pulsed medium jet present at one or more holes near the distal end of the hypotube 2124. The hypotube 2124 has an internal lumen extending along the longitudinal length of the hypotube 2124. One or more side holes 2128 can be arranged near the distal end of the hypotube 2124 and allow fluid communication between the lumen of the hypotube 2124 and the exterior of the hypotube 2124 (i.e., the lumen of the catheter 2102). The medium (e.g., saline) can be introduced into the proximal end of the hypotube 2124 under pressure, pass through the lumen of the hypotube 2124, and then pass through the one or more holes of the hypotube 2124. When the medium is injected into the hypotube 2124 in a pulsed manner, the pulsed medium jet is ejected from the hole of the hypotube 2124 and transmits force to the wall of the catheter 2102, thereby causing a twisting motion of the catheter 2102. The hypotube 2124 can also be rotated (eg, via the driver 2106 ) to facilitate twisting motion of the catheter 2102 .

[0346] Reference Figures 22A-22B, the hypotube 2204 may have one or more holes 2210 and bend near its distal portion to provide a motion section 1909. A medium (e.g., saline, a drug, a lubricant such as polyethylene glycol) is injected from the proximal end 2200, passes through the internal lumen, and exits the hole 2210 of the hypotube 2204 (the direction of medium ejection is shown as 2208). A vacuum is applied to the central lumen at the proximal end 2200 of the catheter 2202, so that the medium ejected from the hole 2210 of the hypotube 2204 is sucked proximally along the central lumen of the catheter 2202 toward its proximal end 2200.

[0347] As the hypotube 2204 rotates, the hypotube 2204 ejects the medium and simultaneously twists the distal tip of the catheter 2202. When the distal tip of the catheter 2202 is twisted by the rotation of the hypotube 2204, the twisting of the catheter 2202 can push the clot 2214 from side to side, and the hypotube 2204 simultaneously ejects the medium at the interface between the clot 2214 and the catheter 2202, thereby providing a lubricated channel for the clot 2214 to loosen and flow into the catheter 2202.

[0348] Regardless of whether the medium is injected, the rotation of the motion section 1909 helps to break up or reshape the thrombus and facilitate its entry into the aspiration lumen. In some cases, the clot can be completely aspirated into the central lumen. In other cases, the clot can only be partially aspirated into the central lumen, such as in Fig. 22B In this case, the application of vacuum can be maintained while the rotation of the agitator is stopped to hold the clot on the distal end of the catheter. The catheter can then be withdrawn proximally, pulling the clot with it into the access sheath and out of the proximal vascular access point.

[0349] Reference Figures 23A-23B The hypotube 2304 may have one or more holes along its surface closer to the distal end to facilitate movement or flow of the clot 2314 within the catheter 2302 toward its proximal end 2300. A vacuum 2316 is applied at the proximal end 2300 of the catheter 2302 to move the removed clot 2314 from the distal end of the catheter 2302 to the proximal end 2300. Fig.23A As shown, the holes can provide a thin film 2312 around the inside of the wall of the catheter 2302 to facilitate the flow of the medium and / or clot 2313 and minimize any obstruction by the clot 2314. Fig. 23B As shown, the hypotube 2304 may have one or more holes to provide a jet of medium radially ejected from the hypotube 2304 to grasp, pull and / or emulsify the clot 2314 as it passes through the one or more holes on the surface of the hypotube 2304.

[0350] Reference Fig.23C, a vacuum port 2416 may be provided near the proximal end 2400 of the catheter 2304, for example on a manifold, to releasably connect to a vacuum source to aspirate clots from the vascular system. This allows the vacuum port 2416 to be distinct from the proximal port 2417 for receiving the agitator 1900. This can minimize the risk that movement or control of the wire or hypotube 2404 at its proximal end may be adversely affected by the vacuum, aspirated clots, and / or media. The vacuum port may be connected to the catheter 2400 via a rotary hemostasis valve discussed below.

[0351] Reference Figures 24A-24H , shows an embolization system 2401 according to the present invention having a distal tip with enhanced axial position control.

[0352] Reference Fig.24A and 24B Any suction catheter or tubular extension section disclosed herein may be provided with a distal axial restraint to cooperate with a complementary stop on the agitator to allow the agitator to rotate but limit the agitator's distal axial travel range. This allows the agitator distal tip to be precisely positioned relative to the distal end of the catheter, unaffected by the bending of the catheter shaft, and prevents the distal tip from extending beyond a preset position, such as the distal end of the catheter.

[0353] In the illustrated embodiment, the distal restraint or restraining element comprises at least one projection extending radially inward from the inner surface of the tubular body, which is configured to limit the inner diameter of the suction lumen and provide an interference surface to engage the distal side with the agitator. The restraint may comprise one or two or three or four or more projections, such as lugs, or as shown in the figure, may comprise an annular ring providing a continuous, annular, proximal-facing limiting surface. The proximal bearing surface of the axial restraint may be located within a position within about 50cm or 30cm or 15cm of the distal end of the tubular body. In order to optimize the alignment of the distal rotatable end 450 with the distal port of the catheter, and to make this axial alignment not affected by the bending of the relative axial position of the catheter outlet port and the end otherwise, the proximal bearing surface of the axial restraint is usually within a range of about 3mm to about 50mm from the distal port on the catheter, about 5mm to about 20mm in some embodiments, and at a position within a range of about 6mm to about 14mm in one embodiment.

[0354] The distal restraint can be a metal (e.g., nitinol, stainless steel, aluminum, etc.) circular band or ring or protrusion 2402 mounted on or built into a sidewall 2403 of the catheter near the distal tip, with the distal restraint element 2402 extending into the inner diameter of the catheter. In addition, the distal restraint element 2402 can be radiopaque to be visible under fluoroscopy. The distal restraint element 2402 has a proximally facing surface 2405, such as an annular circumferential bearing surface, that extends into the inner diameter of the catheter to engage / interact with a distal stop 2414 on the rotation assembly. For example, the distal stop 2414 can be a circular feature on the rotation assembly that interacts with the distal restraint element 2402 of the catheter to stop distal advancement and prevent the distal tip from shifting beyond the distal tip of the catheter.

[0355] In one embodiment, the ring 2402 is in a relaxed form before being fixed in the catheter lumen, and the ring 2402 is C-shaped or cylindrical with an axially extending slit to form an open ring. The ring 2402 is compressed using a clamp that shrinks the ring into a closed circular shape so that the ring can slide in a (e.g., 0.071 inch) catheter. When the ring is released from the clamp, the ring radially expands to the maximum diameter allowed by the catheter inner diameter. The radial force of the ring engages the inner surface of the catheter and resists axial displacement under the applied force of the intended use. In another embodiment, the ring is a completely closed, continuous annular structure (such as a typical marking band) and its distal end is slightly opened in a radially outward direction to form a locking edge. The ring is inserted into the catheter from the distal end. When an axial force is applied from the proximal side, the open section with the locking edge fixes the ring in place / retains it in place.

[0356] Reference Fig.24C and 24D , the distal section 2407 of the rotatable core wire includes a torque coil 2412 around the core wire 2410. The torque coil 2412 includes an outer coil 2413 concentrically surrounding an inner coil 2415, and the inner coil and the outer coil have opposite winding directions. Although the coil 2412 is shown as having a constant diameter, this leaves an internal embedded space between the coil and the core wire due to the tapered / tapered core wire. When the area of ​​the suction lumen between the coil and the inner wall of the corresponding catheter is optimally maximized, the diameter of the coil 2412 can gradually decrease in the distal direction to follow / follow the taper / tapering of the core wire. This can be achieved by winding the coil onto a core wire used as a tapered mandrel, or using other techniques known in the art. In this execution, the outer diameter (OD) of the core wire gradually decreases in the distal direction, while the area of ​​the suction lumen gradually increases in the distal direction.

[0357] like Fig.24E and 24FAs further shown in FIG. 4 , the torque coil 2412 extends between the proximal end 430 and the distal end 432. The proximal end 430 is fixed to the tapered portion of the core wire 2410. Fig.24E As shown, the core wire 2410 tapers from a larger diameter in a proximal region to a smaller diameter in a distal region 434, the core wire having a distal transition portion 436 between the tapered section and the distal region 434, the distal region may have a substantially constant diameter as a whole. The inner diameter of the inner coil 2415 is complementary to (approximately the same as) the outer diameter at the proximal end 430 of the core wire 2410. The tapered section of the core wire 2410 extends in a proximal direction from the distal transition portion 436 to a proximal transition portion (not shown), the core wire 2410 having a constant diameter proximal to the proximal transition portion.

[0358] The torque coil 2412 may also be provided with a proximal radiopaque marker and / or connector such as a solder joint 438. In the illustrated embodiment, the proximal connector 438 is in the form of an annular silver solder band that surrounds the inner coil 415 and abuts the proximal end of the outer coil 2413.

[0359] The axial length of the torque coil 2412 is in the range of about 10 mm to about 50 mm, and in some embodiments, in the range of about 20 mm to about 40 mm. The distal transition portion 436 and the distal stop 2414 can be positioned in the range of about 5 mm to about 20 mm from the proximal end of the distal cap 2420, and in some embodiments, in the range of about 8 mm to about 12 mm.

[0360] Reference Fig.24E , the distal stop 2414 may be provided with one or two or three or more spokes 440 extending radially outward from the outer coil 413 and optionally supported by an annular hub 442 carried by the torque coil 2412. The spokes 440 support a slider 441 having an outer peripheral surface 442, which is configured to slide inside the inner diameter of the delivery catheter lumen. Preferably, at least three or at least four or at least five or more spokes 440 are provided, which are equally spaced to provide rotational balance. In the illustrated embodiment, three spokes 440 are provided, which are spaced at intervals of approximately 120° around the circumference of the torque coil 2412.

[0361] The distal stop 2414 carries a plurality of distal surfaces 446, such as on the slider 441. The distal surfaces 446 are configured to slidably engage with a proximal surface of a stop on the inner diameter of the delivery catheter, such as a proximally facing surface 2405 on a radially inwardly extending annular flange or ring 2402. See previously discussed Fig. 24BThis creates an interference fit with the bearing surface such that when the distal surface 446 slidably engages the proximal surface 2405 on the retaining ring 2402, the distal stop 2414 can rotate within the delivery catheter and cannot travel further in the axial distal direction.

[0362] Reference Fig.24E , the distal end 432 of the torque coil 2412 is provided with a distal cap 2420. The distal cap 2420 may include an annular band, such as a radiopaque marker band, bonded to the outer surface of the inner coil 2415 and axially distally adjacent to or overlapping the distal end of the outer coil 2413. A proximally extending attachment, such as an annular flange 2417, may be provided on the agitator tip 2416 for bonding to the distal cap 2420 and, in the illustrated embodiment, to the outer coil 2413. The distal cap 2420 may also be bonded directly or indirectly to the distal end of the core wire 2410.

[0363] The agitator tip 2416 is provided with a distal end 450 and a proximally extending helical flange 452 that increases in diameter in the proximal direction. The flange may extend at least about one full turn, and typically less than about five, four, or three turns, around the longitudinal axis of the core wire 2410. The helical flange is provided with a rounded blunt edge 454 that is configured to slidably rotate within a tubular delivery catheter.

[0364] The maximum outer diameter of the tip 2416 is typically at least about 0.005 inches smaller than the inner diameter of the catheter aspiration lumen through which the embolotherapy system 2401 is intended to be advanced, and preferably at least about 0.01 inches or 0.015 inches or more, as measured at the axial operative position of the tip 2416 when the stop 2414 is engaged with the stop ring. For example, a tip having a maximum outer diameter in the range of about 0.050 inches to 0.056 inches will be positioned in a catheter having a distal inner diameter in the range of about 0.068 inches to about 0.073 inches, and in one embodiment about 0.071 inches. With the tip centered in the lumen of the delivery (absorption) catheter, the tip is spaced from the inner wall of the catheter in all directions by a distance of at least about 0.005 inches, and in some embodiments at least about 0.007 inches or 0.010 inches or more.

[0365] Thus, an unobstructed flow path is formed in the annular space between the maximum outer diameter of the tip and the inner diameter of the catheter lumen. This annular flow path cooperates with the vacuum and spiral tip to grasp the occlusive material under rotation and vacuum and pull it into the catheter. The annular flow path is significantly larger than any flow path created by manufacturing tolerances of a tip that is configured to shear embolic material between the tip and the catheter wall.

[0366] Because a helical channel is defined between every two adjacent threads of the tip, additional aspiration volume is obtained. The cross-sectional area of ​​the helical flow path of a tip having a maximum outer diameter in the range of about 0.050 inches to about 0.056 inches will typically be at least about 0.0003 square inches, and in some embodiments at least about 0.00035 or at least about 0.000375 inches. Thus, the total aspiration flow path along the helical tip is the sum of the helical flow path through the tip and the annular flow path defined between the outer diameter of the tip and the inner diameter of the catheter lumen.

[0367] The combination of the rounded edges 454 on the threads 452, the slow manual rotation of the tip less than about 20 or 10 or 5 or less turns, and the space between the threads 452 and the inner wall of the catheter allows suction both through the spiral channel formed between adjacent spiral threads and around the outside of the tip 2416, so that the assembly is configured to engage and capture embolic material without shearing it between the sharp edges and the inner wall of the catheter. Once engaged, additional rotation draws the suction catheter distally onto the clot to ensconce the proximal portion of the clot to facilitate proximal retraction and removal. Depending on the desired performance, the axial length of the tip 2416 including the attachment sleeve 2417 is typically less than about 6 mm, and preferably less than about 4 mm or 3 mm or 2.5 mm or less.

[0368] Depending on the desired performance, the pitch angle / thread angle of the threads 452 may generally vary in the range of about 35 degrees to about 80 degrees. A thread pitch angle in the range of about 40-50 degrees may be most suitable for hard clots, while a thread pitch angle in the range of about 50 to 70 degrees may be most suitable for soft clots. For certain embodiments, the pitch angle will be in the range of about 40-65 degrees or about 40-50 degrees.

[0369] The end 2416 may also be provided with a feature structure for attracting and / or enhancing the adhesion of clots to the end. For example, a texture such as a micropore, microparticle, nanopore or nanoparticle surface may be provided on the end by treating the material of the end or by applying a coating. A coating of a clot-attracting portion such as a polymer or a drug may be applied to the surface of the end. For example, a roughened polyurethane (Tecothane, Tecoflex) coating may be applied to at least the surface of the threads and optionally to the entire end. Desirably, the polyurethane may be roughened, for example, by solvent treatment after coating, and the adhesion of the coating to the end may be enhanced by roughening the surface of the end before coating.

[0370] Alternatively, the core wire 2410 may be provided with an insulating coating to allow the propagation of negative charge to be delivered to the end to attract thrombus. The two conductors may extend over the entire length of the body, such as in a coaxial configuration. Energy parameters and considerations are described in U.S. Patent No. 10,028,782 to Orion and U.S. Patent Publication No. 2018 / 0116717 to Taff et al., each of which is expressly incorporated herein in its entirety by reference. As another alternative, the end 2416 may be cooled to a low temperature to produce a small frozen adhesion between the end and the thrombus. Considerations for forming a small low-temperature end for an intravascular catheter are disclosed in U.S. Patent Publication No. 2015 / 0112195 to Berger et al. and in U.S. Patent Publication No. 2018 / 0116704 to Ryba et al., each of which is expressly incorporated herein in its entirety by reference.

[0371] Reference Figure 24G , shows a cross section through the distal stop 2414, wherein the slider 441 is a continuous circumferential wall having a continuous peripheral bearing surface 442. The three struts 440 are spaced apart to define three flow channels 443 extending axially therethrough. The sum of the surface areas of the leading edges of the struts 440 as a percentage of the sum of the surface areas of the open flow channels 443 is preferably minimized. This allows for maximizing the suction area while still providing a distal surface 446 (see Fig.24F ) provide sufficient axial support to engage a complementary stop surface on the inner wall of the catheter and prevent the tip 2416 from advancing distally beyond a preset relationship with the catheter. The sum of the front (distal facing) surface areas of the struts is typically less than about 45% of the total area of ​​the flow channel 443, and is typically less than about 30%, 25%, or 20% of the total area of ​​the flow channel 443.

[0372] In an embodiment having a torque coil 2412, the outer diameter of the coil is about 0.028 inches and the outer diameter of the stop 2414 is about 0.068 inches. The wall thickness of the strut is typically less than about 0.015 inches, and typically less than about 0.010 inches, and in some embodiments, less than about 0.008 inches or less than about 0.005 inches or less. The length of the strut 440 in the axial direction of the catheter is sufficient to support the assembly to prevent distal travel beyond the catheter stop ring, and can be at least about 50% of the outer diameter of the stop 2414. In a stop 2414 having an outer diameter of about 0.68 inches, the strut 2440 has an axial length of at least about 0.75 mm or 0.95 mm.

[0373] Reference Fig.24H , shows a stopper 2414 having three different slides 441, each of which is supported by a single support 440. The sum of the circumferences of the three peripheral surfaces preferably does not exceed Figure 24GThe hub 443 is preferably about 75% of the entire circumference of the continuous circumferential peripheral surface 442 shown in the figure and in some embodiments does not exceed about 50% or 40% of the entire circumference of the continuous circumferential peripheral surface 442. This further increases the cross-sectional area of ​​the flow path 443. In a catheter with an inner diameter of no more than about 0.07 inches, the outer diameter of the hub 443 is at least about 0.026 or 0.028 or 0.030 or more, and the sum of the flow paths 443 is at least about 0.0015 inches, preferably at least about 0.020 or 0.022 inches or more. The area of ​​the leading edge of the strut 440 and the slider 441 is preferably less than about 0.003 inches, and preferably less than about 0.001 inches or 0.0008 inches or less. In the axial direction of the catheter, the length of the strut 440 is at least about 0.50mm or 0.75mm, and in one embodiment, the length of the strut 440 and the slider 441 is about 1mm.

[0374] One method of using the above system is described below. A 0.088 LDP guide catheter is introduced and advanced, if possible, until the catheter tip is slightly proximal to the site of obstruction. Fig.24A The 0.071 suction catheter of A and B is introduced through the 088LDP and advanced until the catheter tip reaches the surface of the clot. All intermediate catheters or guidewires (if applicable) are removed. A rotatable core wire is introduced so that its distal end is flush with the distal end of the 0.071 suction catheter. The proximal RHV is sealed and a vacuum is applied to the 0.071 suction catheter using a suction pump. The core wire is manually rotated approximately 2 to 10 times, usually no more than 20 times, to engage the clot without cutting, and the catheter partially positioned over the clot is pulled distally, interrupting the rotation of the core wire.

[0375] The suction catheter is anchored to the clot at this point. The 0.088LDP catheter is then advanced over the suction catheter, which functions similarly to a guidewire, until the 0.088 catheter reaches the surface of the clot. A vacuum source, such as a VacLok syringe, is used to apply vacuum to the 088LDP guide catheter. The suction catheter, with the clot anchored at its tip, is retracted proximally through the 088LDP guide catheter while maintaining the 088LDP in position at the site of the occlusion.

[0376] If flow has not been restored with the 0.088LDP, the core wire can be removed from the aspiration catheter. If necessary, the spiral tip of the core wire can be wiped to remove residual clot, and the core wire and aspiration catheter can then be returned to the occlusion site and the clot retrieval procedure repeated until flow is restored. After flow is restored, the 0.088LDP catheter can be removed.

[0377] Reference Figures 25A-25CExperiments have shown that intermittent vacuum can help extract a stuck clot at the distal end 2512 of the catheter 2510 by loosening the clot and reshaping it to fit in the catheter 2510 after each vacuum and release cycle. Simply stopping the vacuum is not sufficient to loosen the clot. It has been found that completely releasing (venting to atmospheric pressure) the vacuum and allowing the clot to loosen before applying the vacuum again can most effectively extract the stuck clot. The period of each vacuum and release cycle can be equal to or greater than about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 seconds.

[0378] Figures 25A-25C A logical sequence of vacuum applied to catheter 2510 and a release cycle is shown. Release line 2518 and vacuum line 2520 are connected to or near the proximal end of catheter 2510. Release line 2518 is connected to atmospheric pressure on its proximal end and has a release valve 2514 configured to open or close fluid communication between catheter 2510 and the vacuum. Vacuum line 2520 is connected to the vacuum on its proximal end and has a vacuum valve 2516 configured to open or close fluid communication between catheter 2510 and the vacuum.

[0379] In such Fig.25A In the first step shown, the relief valve 2514 is closed and the vacuum valve 2516 is opened so that a vacuum is applied to the catheter 2510 to draw out the clot. Fig.25B As shown, the relief valve 2514 is opened while the vacuum valve 2516 remains open. Since the relief line 2518 and the vacuum line 2520 are in fluid communication, either directly or via at least a portion of the conduit 2510, the vacuum is primarily applied through the relief line 2518, thereby reducing the vacuum applied to the conduit. Fig.25C As shown, vacuum valve 2516 is closed, thereby allowing the vacuum to be completely released and allowing the clot to loosen. Then, the release valve 2514 is closed and the vacuum valve 2516 is opened to start from FIG. 25A to FIG. 25C Another cycle of .

[0380] Reference Fig.26 , showing a proximal drive assembly and / or a rotary hemostasis valve providing an interface for driving the agitator 1900, thereby providing a port for injection of media and a suction port. Fig.26 , 27A, 27B and 28, the proximal drive assembly 2602 and the rotary hemostatic valve 2620 may be releasably or permanently coupled to the proximal end of the agitator 1900. The proximal portion of the agitator 1900 proximally passes through the lumen of the rotary hemostatic valve 2620 and then through the lumen of the proximal drive assembly 2602. The proximal end of the agitator 1900 may terminate inside the lumen of the proximal drive assembly 2602. The distal portion of the proximal drive assembly 2602 is inserted into the proximal end of the rotary hemostatic valve 2620. In another embodiment, the proximal drive assembly 2602 may be integrated into the rotary hemostatic valve 2620.

[0381] The rotary hemostatic valve (RHV) 2620 includes a distal connector 2630 at its distal end, which is configured to connect the rotary hemostatic valve to the proximal end of a catheter (not shown). The distal connector 2630 can be a Luer connector. The rotary hemostatic valve 2620 includes a central lumen along its longitudinal length, through which the proximal section of the agitator 1900 passes. The rotary hemostatic valve 2620 also includes a suction port 2622, which branches out from the central lumen of the rotary hemostatic valve 2620 and provides a suction flow path. The rotary hemostatic valve 2620 includes a RHV seal 2626 and a proximal rotating collar 2628 at its proximal end. The proximal rotating collar 2628 controls the opening and closing of the RHV seal 2626. A user (e.g., a doctor) can open or close the RHV seal 2626 by rotating the proximal rotating collar 2628. The RHV seal 2626 does not allow fluid communication between the internal lumen distal to the RHV seal 2626 and the internal lumen proximal to the RHV seal 2626 when closed. At the same time, the RHV seal 2626 does not hinder the longitudinal movement of the distal portion of the proximal drive assembly 2602 within the rotary hemostasis valve 2629.

[0382] Experiments show that as the wire or hypotube 1900 rotates back and forth (i.e., oscillates), the distal end of the agitator 1900 changes its position relative to the catheter. The distal end of the agitator 1900 is shown as shortening / lengthening as the wire or hypotube 2624 winds / unwinds in the catheter due to the rotation of the agitator 1900 or the increase / decrease in the medium injection pressure. The proximal rotating collar 2628 and the RHV seal 2626 allow the user (e.g., a doctor) to cause this length change and advance / withdraw the agitator 1900 relative to the catheter and fix it in place by simply moving the proximal drive assembly 2602 into / out of the rotary hemostatic valve 2629. If the agitator 1900 is pre-loaded into the catheter, the distance can be initially set at a nominal position. In another embodiment, the proximal rotating collar 2628 of the rotary hemostatic valve 2620 can be a part of the proximal drive assembly 2602.

[0383] The proximal drive assembly 2602 includes a proximal drive connector 2604 connected to the driver and a medium injection port 2610 for injecting medium therein. The proximal drive assembly also includes a bearing 2606 that allows the proximal drive connector 2604 to rotate freely relative to the proximal drive assembly 2602. The proximal drive connector 2604 can be coupled to the proximal end of the agitator 1900 so that the rotation of the proximal drive connector 2604 is converted into the rotation of the wire or hypotube 1900. The proximal drive assembly also includes a drive tube seal 2608 that prevents fluid communication between the internal lumen (of the proximal drive assembly 2602) distal to the drive tube seal 2608 and the internal lumen proximal to the drive tube seal 2608.

[0384] Reference Fig.29 , the driver 2950 is removably connected to the proximal end of the proximal drive assembly 2902 via the proximal drive connector 2604. The driver 2950 is configured to drive the agitator 1900. The driver 2950 is a motorized driver that is automatically controlled in terms of one or more factors such as direction (CCW / CW), speed, duration, etc. The driver 2950 includes a control device 2954 such as a button, which executes a series of preprogrammed steps when pressed. The driver 2950 can accept synchronization control, wherein when the rear portion of the driver 2950 is inserted into the synchronization port 2952, the driver 2950 drives the agitator 1900 synchronously with aspiration and medium injection.

[0385] The system for retrieving clots includes: an aspiration catheter; an agitator 1900 that can extend longitudinally within the lumen of the aspiration catheter; and a driver with or without a synchronization port that can be connected to the proximal end of the agitator 1900 (e.g., via a rotary hemostasis valve or a proximal drive assembly). The system can allow pulsed aspiration and / or pulsed injection of a medium. The medium can include water, saline solution, or a medium containing an effective amount of a drug (e.g., a drug therapy such as heparin, clopidogrel, tPA). The various components can be manipulated separately or in a synchronized manner using predetermined operating parameters (e.g., for synchronized aspiration, injection, and rotation).

[0386] A method of retrieving a clot may include providing an aspiration catheter, an agitator extending longitudinally within or positionable within a lumen of the aspiration catheter, and a driver coupled to a proximal end of the agitator; positioning the catheter in proximity to the clot; attempting to aspirate the clot; if unsuccessful, advancing the agitator distally through the catheter; activating the driver to rotate the agitator and loosen the clot; optionally injecting a medium through the agitator to lubricate the clot and / or forming a jet of the medium from a distal end of the agitator configured to assist in aspiration of the clot; transporting the clot proximally within the lumen of the catheter by applying a vacuum at the proximal end of the catheter; and optionally pulsing the vacuum. As the pieces of the clot separate, transport may be aided by the rotating agitator and / or the injected medium.

[0387] In order to disengage more stubborn clots, the timing of suction, media injection and / or rotation of the wire or hypotube can be appropriately set. Excessive media accumulation around the clot will form a plug. When suction is activated and / or pulsed, the vacuum can attract the "plug" proximally inside the lumen of the wire or hypotube like a syringe plunger. As more media is added, a higher local vacuum can be maintained around the clot and more momentum can be added to the "plug". Appropriately setting the timing of the rotation of the wire or hypotube relative to suction and media injection can help to twist the clot or fatigue the clot and cause it to detach from the vascular system.

[0388] Any catheter shaft or individual segments or telescopic extensions of a catheter shaft according to the present invention may include a multilayer structure having a high degree of flexibility and sufficient pushability to penetrate deep into the cerebral vascular system, for example at least deep into the petrous segment, cavernous sinus segment or cerebral segment of the internal carotid artery (ICA).

[0389] In one example, referring to Fig.30 , the catheter 3000 may have an effective length from the manifold to the distal end of about 70 cm to about 150 cm, about 80 cm to about 140 cm, about 90 cm to about 130 cm, about 100 cm to about 120 cm, or about 105 cm to about 115 cm. The outer diameter of the catheter 3000 may be about 0.07 inches to about 0.15 inches, about 0.08 inches to about 0.14 inches, about 0.09 inches to about 0.13 inches, about 0.1 inches to about 0.12 inches, or about 0.105 inches to about 0.115 inches, and may be smaller in the distal section than in the proximal section. The inner diameter 3108 of the catheter 3000 in the single central lumen embodiment may be greater than or equal to about 0.11 inches, greater than or equal to about 0.1 inches, greater than or equal to about 0.09 inches, greater than or equal to about 0.088 inches, greater than or equal to about 0.08 inches, greater than or equal to about 0.07 inches, greater than or equal to about 0.06 inches, or greater than or equal to about 0.05 inches. The inner diameter 3108 of the catheter 3000 in the single central lumen embodiment may be less than or equal to about 0.11 inches, less than or equal to about 0.1 inches, less than or equal to about 0.09 inches, less than or equal to about 0.088 inches, less than or equal to about 0.08 inches, less than or equal to about 0.07 inches, less than or equal to about 0.06 inches, or less than or equal to about 0.05 inches. Reference Fig.30, a liner 3014 can be formed by dip coating a mandrel (not shown) to provide a thin-walled tubular inner layer of the catheter body 3000. The dip coating can be generated by coating a wire such as a silver-coated copper wire in PTFE. Thereafter, the mandrel can be stretched axially to reduce the diameter, and the mandrel is removed to leave a tubular liner. Then a soft bonding layer 3012, such as polyurethane (e.g., TecoflexTM) can be coated on the outer surface of the tubular liner 3014 to generate a layer having a thickness of no more than about 0.005 inches and about 0.001 inches in some embodiments. The bonding layer 3012 usually extends at least about 10 cm or 20 cm along the farthest side of the catheter shaft 3000, usually less than about 50 cm, and in one embodiment can extend the far side of the catheter shaft 3000, 3100 by about 30 cm.

[0390] Thereafter, a braid (e.g., 75 ppi stainless steel braid 3010) may be wrapped around the liner 3014 through the proximal region all the way to the distal transition 3011. A coil 3024 comprising a shape memory material such as a Nitinol alloy may then be wrapped around the liner 3014 from the distal transition 3011 to the distal end of the catheter 3000. In one embodiment, the Nitinol coil has a transition temperature below body temperature so that the Nitinol remains in an austenitic (elastic) state at body temperature. Adjacent loops or filaments of the coil 3024 may be tightly wound in the proximal region, while the distal section has looser spacing between adjacent loops. In embodiments having a coil segment 3024 with an axial length at least between about 20% and 30% of the total catheter length (e.g., a coil length of 28 cm in a 110 cm catheter shaft 3000), at least the distal 1 or 2 or 3 or 4 cm of the coil will have a spacing of at least about 130% and in some embodiments at least about 150% or more of the spacing in the proximal coil segment. In a 110 cm catheter shaft 3000 with a nitinol coil, the spacing in the proximal coil may be about 0.004 inches and at least about 0.006 inches or 0.007 inches or more in the distal segment. In embodiments including an extension catheter, the distal extendable portion of the catheter may be constructed in the manner described above. The length of the coil 3024 may be proportional to the length of the extendable catheter segment or the total (e.g., extended) length of the catheter 3000. The coil 3024 may extend at least about 50%, 60%, 70%, 80%, or 90% of the length of the extendable section from the distal end of the extendable section. In some embodiments, the catheter 3000 or the extendable section may not include a braid, and the coil 3024 may extend to the proximal end of the extendable section (100% of the length).

[0391] The distal end of the coil 3024 can be spaced proximally from the distal end of the liner 3014 to provide space for an annular radiopaque marker 3400, for example. In some embodiments, the coil 3024 can be retracted proximally from the distal end by no more than about 1 cm, 2 cm, or 3 cm. In one embodiment, the distal end of the catheter 3000 is provided with an inclined distal surface 3006 that is located in a plane that is at an angle of at least about 10° or 20°, and in one embodiment, about 30°, to the longitudinal axis of the catheter 3000. The radiopaque marker 3040 can be in a plane transverse to the longitudinal axis. Alternatively, at least the distal-facing edge of the annular radiopaque marker 3040 can be an ellipse that is located in a plane that is inclined relative to the longitudinal axis to be complementary to the oblique angle of the distal surface 3006. Fig.31D Additional details are described in association.

[0392] After the proximal braid 3010, distal coil 3024, and RO marker 3040 are applied, an outer sheath 3020, such as a shrink wrap tube, may be applied to enclose the catheter body 3000. The outer shrink wrap sleeve 3020 may include any of a variety of materials, such as polyethylene, polyurethane, polyether block amide (e.g., PEBAX™), nylon, or other materials known in the art. Sufficient heat is applied to cause the polymer to flow into and embed into the proximal braid and distal coil.

[0393] In one embodiment, the outer shrink wrap sheath 3020 is formed by sequentially advancing a plurality of short tubular segments 3022, 3026, 3028, 3030, 3032, 3034, 3036, 3038 concentrically over the catheter shaft subassembly and applying heat to shrink the segments onto the catheter 3000 and provide a smooth, continuous outer tubular body. The above structure can extend along at least the distal-most 10 cm of the catheter body 3000, and preferably at least about the distal-most 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, or more than 40 cm. The entire length of the outer shrink wrap shell 3020 can be formed by multiple tubular segments, and the length of the distal tubular segments (e.g., 3022, 3026, 3028, 3030, 3032, 3034, 3036, 3038) can be shorter than the one or more tubular segments forming the proximal portion of the outer shrink wrap shell 3020 so as to provide a sharper transition in flexibility to the distal end of the catheter 3000.

[0394] The hardness of each outer wall segment can be reduced in the distal direction. For example, the proximal segments such as 3022 and 3026 can have a hardness of at least about 60 or 70D, while the hardness of the successive segments in the distal direction gradually decreases to a hardness of no more than about 35D or 25D or less. The 25cm segment can have at least about 3 or 5 or 7 or more segments and the catheter 3000 can have at least about 6 or 8 or 10 or more different flexible zones as a whole. The outer diameter of the distal 1 or 2 or 4 or more segments 3036, 3038 after contraction can be smaller than the more proximal segments 3022-3034, and a stepped reduction in the outer diameter is produced in the final catheter body 3000. The length of the smaller outer diameter segment 3004 can be in the range of about 3cm to about 15cm, in some embodiments in the range of about 5cm to about 10cm, for example about 7 or 8cm, and can be achieved by providing a smaller wall thickness for the distal segments 3036, 3038.

[0395] Reference Figures 31A-31C , the catheter may also include a tensile support for increasing the tensile resistance in the distal region. The tensile support may include a wire, more specifically, may include one or more axially extending wires 3042. The one or more axially extending wires 3042 may be axially disposed in the catheter wall near the distal end of the catheter. The one or more axially extending wires 3042 act as a tensile support and prevent the catheter wall from stretching under tension (e.g., when the catheter is retracted proximally through a tortuous vascular system).

[0396] At least one of the one or more axially extending wires 3042 may extend proximally along the length of the catheter wall from a distance within about 1.0 cm from the distal end of the catheter to less than about 5 cm from the distal end of the catheter, less than about 10 cm from the distal end of the catheter, less than about 15 cm from the distal end of the catheter, less than about 20 cm from the distal end of the catheter, less than about 25 cm from the distal end of the catheter, less than about 30 cm from the distal end of the catheter, less than about 35 cm from the distal end of the catheter, less than about 40 cm from the distal end of the catheter, or less than about 50 cm from the distal end of the catheter.

[0397] The one or more axially extending wires 3042 may have a length greater than or equal to about 50 cm, greater than or equal to about 40 cm, greater than or equal to about 35 cm, greater than or equal to about 30 cm, greater than or equal to about 25 cm, greater than or equal to about 20 cm, greater than or equal to about 15 cm, greater than or equal to about 10 cm, or greater than or equal to about 5 cm.

[0398] At least one of the one or more axially extending wires 3042 can have a length of less than or equal to about 50 cm, less than or equal to about 40 cm, less than or equal to about 35 cm, less than or equal to about 30 cm, less than or equal to about 25 cm, less than or equal to about 20 cm, less than or equal to about 15 cm, less than or equal to about 10 cm, or less than or equal to about 5 cm. At least one of the one or more axially extending wires 3042 can extend at least approximately the most distal 50 cm of the catheter length, at least approximately the most distal 40 cm of the catheter length, at least approximately the most distal 35 cm of the catheter length, at least approximately the most distal 30 cm of the catheter length, at least approximately the most distal 25 cm of the catheter length, at least approximately the most distal 20 cm of the catheter length, at least approximately the most distal 15 cm of the catheter length, at least approximately the most distal 10 cm of the catheter length, or at least approximately the most distal 5 cm of the catheter length.

[0399] In some embodiments, the wire extends proximally from the distal end of the catheter along the length of the coil 24 and terminates proximally within about 5 cm or 2 cm or less on either side of the transition 3011 between the coil 3024 and the braid 3010. The wire can terminate at the transition 3011 without overlapping the braid 3010.

[0400] In another embodiment, the distal-most portion of the catheter 3000 may include a hardness of less than about 35D (e.g., 25D) to form a highly flexible distal portion of the catheter and the distal-most portion of the catheter 3000 may have a length of about 25 cm to about 35 cm. The distal portion may include one or more tubular segments (e.g., segment 3038) of the same hardness. A series of proximally adjacent tubular segments may form a transition region between the proximal harder portion of the catheter 3000 and the distal highly flexible portion of the catheter. The series of tubular segments forming the transition region may have the same or substantially similar lengths, such as about 1 cm.

[0401] The relatively short length of the series of tubular segments can provide a sharp drop in hardness over the transition region. For example, the transition region can have a proximal tubular segment 3036 (proximally adjacent to the distal portion) with a hardness of about 35D. The adjacent proximal segment 3034 can have a hardness of about 55D. The adjacent proximal segment 3032 can have a hardness of about 63D. The adjacent proximal segment 3030 can have a hardness of about 72D.

[0402] The more proximal segment may include a durometer greater than about 72D and may extend to the proximal end of the extension catheter segment or catheter. For example, the extension catheter segment may include a proximal portion greater than about 72D between about 1 cm and about 3 cm. In some embodiments, the proximal portion may be about 2 cm long. In some embodiments, the most distal segment (e.g., 3038-3030) may include PEBAXTM , while the more proximal segments may include a generally harder material such as

[0403] The inner diameter of the catheter 3000 or catheter extension section can be about 0.06 to 0.08 inches, about 0.065 to 0.075 inches, or about 0.068 to 0.073 inches. In some embodiments, the inner diameter is about 0.071 inches.

[0404] In some embodiments, the distal-most portion can be tapered to a reduced inner diameter, as described elsewhere herein. The tapering can occur approximately between the distal highly flexible portion and the transition zone (e.g., on the most proximal portion of the distal highly flexible portion). The tapering can be relatively gradual (e.g., occurring at approximately more than 10 cm), or can be relatively sharp (e.g., occurring at less than about 5 cm). The inner diameter can be tapered to an inner diameter between approximately 0.03 and 0.06 inches. For example, the inner diameter at the distal end of the catheter 3000 can be approximately 0.035 inches, approximately 0.045 inches, or approximately 0.055 inches. In some embodiments, the inner diameter can remain constant at least on the catheter extension segment.

[0405] In some embodiments, the coil 3024 may extend proximally from the distal end of the catheter 3000 along a highly flexible distal portion that terminates at the distal end of the transition region. In other embodiments, the coil 3024 may extend from the distal end of the catheter to the proximal end of the transition region, extending to a point along the transition region or extending proximally beyond the transition region. In other embodiments, the coil 3024 may extend over the entire length of the catheter extension section or the catheter 3000, as described elsewhere herein. When present, the braid 3010 may extend from the proximal end of the coil 3024 to the proximal end of the catheter extension section or the catheter 3000.

[0406] The one or more axially extending wires 3042 may be disposed adjacent to or radially outside the bonding layer 3012 or the liner 3014. The one or more axially extending wires 3042 may be disposed adjacent to or radially inside the braid 3010 and / or the coil 3024. The one or more axially extending wires 3042 may be carried between the liner 3014 and the helical coil 3024.

[0407] When more than one axially extending wire 3042 is disposed in the catheter wall, the axially extending wire 3042 can be disposed in a radially symmetrical manner. For example, the angle between two axially extending wires 3042 relative to the radial center of the catheter can be about 180 degrees. Alternatively, depending on the desired clinical performance (e.g., flexibility, tracking), the axially extending wire 3042 can be disposed in a radially asymmetric manner. The angle between any two axially extending wires 3042 relative to the radial center of the catheter can be less than about 180 degrees, less than or equal to about 165 degrees, less than or equal to about 150 degrees, less than or equal to about 135 degrees, less than or equal to about 120 degrees, less than or equal to about 105 degrees, less than or equal to about 90 degrees, less than or equal to about 75 degrees, less than or equal to about 60 degrees, less than or equal to about 45 degrees, less than or equal to about 30 degrees, less than or equal to about 15 degrees, less than or equal to about 10 degrees, or less than or equal to about 5 degrees.

[0408] The one or more axially extending wires 3042 may be made of materials such as Kevlar, polyester, meta-para-aramid, or any combination thereof. At least one of the one or more axially extending wires 3042 may include a single fiber or a multi-fiber bundle, and the fiber or bundle may have a circular or rectangular cross-section. The term fiber or wire does not describe the composition, and they may include any of a variety of high tensile strength polymers, metals, or alloys, depending on design considerations such as the desired tensile fracture limit and wall thickness. The cross-sectional dimensions of the one or more axially extending wires 3042 measured in the radial direction may not exceed about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 20%, 25%, or 30% of the cross-sectional dimensions of the catheter 3000. The cross-sectional dimension of the one or more axially extending wires 3042 measured in the radial direction may not exceed about 0.001 inches, about 0.002 inches, about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, about 0.009 inches, about 0.010 inches, about 0.015 inches, about 0.020 inches, about 0.025 inches or about 0.030 inches.

[0409] The one or more axially extending wires 3042 can increase the tensile strength of the distal region of the catheter to at least about 1 pound, at least about 2 pounds, at least about 3 pounds, at least about 4 pounds, at least about 5 pounds, at least about 6 pounds, at least about 7 pounds, at least about 8 pounds, or at least about 10 pounds or more.

[0410] Any of the suction catheters or tubular extension segments disclosed herein, whether or not including an axial wire, can be provided with an angled distal tip. Fig.31D, the distal tip 3110 of the catheter includes a tubular body 3112, which includes a pusher section 3114, a marker band 3116, and a proximal section 3118. A tubular liner 3120 may extend the entire length of the distal catheter tip 3110 and may include dip-coated PTFE.

[0411] A reinforcing element 3122 , such as a braid or spring coil, is embedded in an outer sheath 3124 , which may extend the entire length of the distal catheter tip 3110 .

[0412] The advancement segment 3114 terminates distally at a bevel 3126 to provide a front sidewall portion 3128 having a length measured between the distal end 3130 and the distal tip 3132 of the marker band 3116. In the illustrated embodiment, the axial length of the rear sidewall portion 3134 of the advancement segment 3114 is approximately equal to the axial length of the front sidewall portion 3128, measured at a position about 180 degrees around the catheter from the front sidewall portion 3128. The axial length of the front sidewall portion 3128 can be in the range of about 0.1 mm to about 5 mm, and is typically in the range of about 1 mm to 3 mm. Depending on the desired performance, the axial length of the rear sidewall portion 3134 can be shorter than the axial length of the front sidewall portion 3128 by at least about 0.1 mm or 0.5 mm or 1 mm or 2 mm or more.

[0413] The bevel 3126 is inclined at an angle A relative to the longitudinal axis of the catheter, and the angle A is in the range of about 45 degrees to about 80 degrees. For some embodiments, relative to the longitudinal axis of the catheter, the angle is in the range of about 55 degrees to about 65 degrees or in the range of about 55 degrees to about 65 degrees. In one embodiment, angle A is about 60 degrees. The result of angle A less than 90 degrees is the elongation of the main axis of the area of ​​the distal port, which increases the surface area of ​​the port and can enhance the absorption or retention of clots. Compared with the surface area of ​​a circular port (angle A is 90 degrees), the area of ​​the inclined port is generally at least about 105%, and no more than about 130%, in some embodiments, in the range of about 110% to about 125%, and in one example is about 115%.

[0414] In the illustrated embodiment, the axial length of the advancement section is substantially constant along the circumference of the catheter, such that the chamfer 3126 is substantially parallel to the distal surface 3136 of the marker band 3116. The marker band 3116 has a proximal surface that is substantially transverse to the longitudinal axis of the catheter, thereby forming a marker band 3116 having a right-angled trapezoidal configuration in a side view. The short sidewall 3138 is rotationally aligned with the rear sidewall portion 3134 and has an axial length in the range of about 0.2 mm to about 4 mm, and typically in the range of about 0.5 mm to about 2 mm. The opposite long sidewall 3140 is rotationally aligned with the front sidewall portion 3128. Depending on the desired performance, the long sidewall 3140 of the marker band 3116 is typically at least about 10% or 20% longer than the short sidewall 3138, and can be at least about 50% or 70% or 90% longer than the short sidewall 3138 or more. Typically, the long sidewalls 3140 will have a length of at least about 0.5 mm or 1 mm and less than about 5 mm or 4 mm.

[0415] The marker band may have at least one, and optionally two or three or more, axially extending slits throughout its length to allow for radial expansion. The slits may be located on the short sidewall 3138 or the long sidewall 3140, or between the two, depending on the desired bending characteristics. The marker band may include any of a variety of radiopaque materials, such as a platinum / iridium alloy, with a wall thickness preferably not exceeding about 0.003 inches, and in one embodiment about 0.001 inches.

[0416] The marker band region of the assembled catheter will have a relatively high bending stiffness and high compressive strength, for example at least about 50% less or at least about 100% less than the proximal segment 18, but typically not about 200% greater than the proximal segment 3118. The high compressive strength can provide radial support for the adjacent advancement segment 3114, particularly the anterior sidewall portion 3128, to facilitate the function of the distal tip 3132 as an atraumatic buffer during transluminal advancement and resist collapse under vacuum. The proximal segment 3118 preferably has a lower bending stiffness than the marker band region, and the advancement portion 3114 preferably has an even lower bending stiffness and compressive strength than the proximal segment 3118.

[0417] The advancement segment 3114 may include a distal extension of an outer sheath 3124 and an optional liner 3120, with no other internal support structure distal to the marker band 3116. The outer sheath may include extruded Tecothane. The advancement segment 3114 may have a bending stiffness and a radial crush stiffness that are no greater than about 50% of the corresponding values ​​for the proximal segment 3118, and in some embodiments, no greater than about 25%, 15%, or 5%, or less of the corresponding values.

[0418] As has been described elsewhere herein, the support fibers 3142 extend through at least a distal portion of the length of the proximal section 3118. As shown, the support fibers 3142 may terminate distally at the proximal surface of the marker band 3116 and extend axially radially outward of the tubular liner 3120 and radially inward of the support coil 3122. The fibers 3142 may extend substantially parallel to the longitudinal axis, or may be inclined into a slight helical structure having no more than 10 or 7 or 3 or 1 or less complete turns around the catheter along the length of the helical structure. The fibers may comprise a high tensile strength material such as a multifilament yarn spun from a liquid crystal polymer such as a Vectran multifilament LCP fiber.

[0419] Reference Figures 32A-32C Depending on whether the catheter 3000 can be sufficiently distally guided to reach the target site, the intraluminal catheter 3200 (e.g., a telescopic extension section having a proximally extending control wire (e.g., Figure 3A and 3B The distal section 34) in the catheter 3000 can be inserted through the catheter 3000 from the proximal end of the catheter 3000. The intraluminal catheter 3200 is inserted so that the distal end of the intraluminal catheter 3200 further extends distally beyond the distal end of the catheter 3000. The outer diameter of the intraluminal catheter 3200 is smaller than the inner diameter of the catheter 3000. In this way, the intraluminal catheter 3200 can slide within the inner lumen of the catheter 3000.

[0420] The intraluminal catheter 3200 has the features of the sidewall structure described herein for the catheter 3000. The axial length of the tubular extension section may be less than about 50% and typically less than about 25% of the length of the catheter 3000. The axial length of the tubular extension section will typically be at least about 10 cm or 15 cm or 20 cm or 25 cm or more, but typically will not exceed about 70 cm or 50 cm or 30 cm.

[0421] Reference Figures 33A-33C , the intraluminal catheter 3200 may have one or more axially extending wires 3242. The one or more axially extending wires 3242 have the characteristics of the one or more axially extending wires 3042 of the catheter 3000, but the cross-sectional dimensions of the one or more axially extending wires 3242 of the intraluminal catheter 3200 measured in the radial direction may be smaller than the corresponding dimensions of the wires 3042 in the catheter 3000.

[0422] Reference Figures 34A-34B , showing the combination of Fig.30An example of an outer shell segment stacking pattern of a progressive flexible catheter of the type discussed. The distal segment 3038 may have a length in the range of about 1-3 cm and a hardness of less than about 35D or 30D. The adjacent proximal segment 3036 may have a length in the range of about 4-6 cm and a hardness of less than about 35D or 30D. The adjacent proximal segment 3034 may have a length in the range of about 4-6 cm and a hardness of about 35D or less. The adjacent proximal segment 3032 may have a length in the range of about 1-3 cm and a hardness in the range of about 35D to about 45D (e.g., 40D). The adjacent proximal segment 3030 may have a length in the range of about 1-3 cm and a hardness in the range of about 50D to about 60D (e.g., about 55D). Adjacent proximal section 3028 may have a length in the range of about 1-3cm and a hardness in the range of about 35D to about 50D to about 60D (e.g., about 55D). Adjacent proximal section 3026 may have a length in the range of about 1-3cm and a hardness of at least about 60D and typically less than about 75D. More proximal sections may have a hardness of at least about 65D or 70D. The two or three most distal sections may include materials such as Tecothane, and more proximal sections may include PEBAX or other catheter sheath materials known in the art. At least three or five or seven or nine or more discrete sections may be used, thereby having a hardness change of at least about 10D, preferably at least about 20D and at least about 30D or 40D or more between the highest hardness and the lowest hardness along the catheter shaft length in some embodiments.

[0423] Catheter performance metrics include back-up support, tracking, pushability, and kink resistance. Back-up support refers to the ability of the catheter to remain in place within the anatomy and provide a stable platform for intraluminal device advancement. Fig.35, when the device is pushed through the catheter 3202, if there is not enough support in the catheter 3202, the distal portion 3204 of the catheter 3202 may be dislodged, pulled out, or withdrawn from the blood vessel 3206, where the blood vessel 3206 branches out from the main blood vessel (e.g., the brachiocephalic artery 82, the common carotid artery 80, or the subclavian artery 84). The support of the catheter 3202 can be improved by setting a high hardness or modulus for the proximal region and a low hardness or modulus for the distal region. The hardness or modulus of the proximal region of the catheter 3202 can be increased by braid reinforcement. The region of the catheter with enhanced hardness or modulus can be placed near the branch point where the aortic arch 1114, 1214 branches into the brachiocephalic artery 82, the common carotid artery 80, or the subclavian artery 84 or near other anatomical structures (i.e., branch points) where the main blood vessel branches into one or more smaller blood vessels, thereby providing an opportunity for the catheter with poor support to dislodge. For example, the region of enhanced stiffness or modulus of the catheter may be positioned within about 0.5 cm, about 1 cm, about 2 cm, about 3 cm, about 4 cm, about 5 cm, or about 6 cm of a branch point where a main vessel branches into one or more smaller vessels.

[0424] Trackability refers to the ability of a catheter to track forward to a more distal side (e.g., track forward to M1) than other catheters. For example, a catheter that can reach the cerebral segment of the internal carotid artery (ICA) has better trackability than a catheter that can reach the cavernous sinus segment or the petrous segment of the ICA. The trackability of the catheter can be improved by using a catheter wall with a low hardness or modulus or by adding a coating (e.g., a hydrophilic coating) on ​​at least a portion of the catheter wall. In one embodiment, the hydrophilic coating can be arranged along the most distal region of the catheter. The hydrophilic coating on the catheter can extend to about 1 cm, about 5 cm, about 10 cm, about 15 cm, or about 20 cm from the distal end of the catheter. The region with a lower hardness or modulus can be located at the most distal region of the catheter. The region with a lower hardness or modulus can extend to about 1 cm, about 5 cm, about 10 cm, about 15 cm, or about 20 cm from the distal end of the catheter.

[0425] Pushability refers to the rigidity of the catheter being sufficient to push through the anatomical structure without "buckling". The pushability of the catheter can be improved by increasing the hardness or modulus of the catheter. The pushability of the catheter can also be improved by setting a high hardness or modulus for the proximal region and a low hardness or modulus for the distal region. The transition region of the catheter where the hardness or modulus changes along its longitudinal length (e.g., the hardness or modulus decreases from the proximal end to the distal end) can start at about 50%, 60%, 70%, 75%, 80% or more of the catheter length from its proximal end.

[0426] Kink resistance refers to the ability of a catheter to resist kinking. Furthermore, if the catheter does kink, the kink resistance of the catheter helps it return to its original shape. Kink resistance is important in the distal section of the catheter which is more susceptible to kinking than the proximal section. The kink resistance of the catheter can be improved by adding one or more NiTi coils (or coils that are at least partially Nitinol) to the catheter wall.

[0427] Fig.36 A graph of the hardness or modulus of a catheter according to the present invention along the length of the catheter from the proximal end (x=0) to the distal end (x=1) is depicted. A catheter according to one embodiment may have a hardness or modulus (E) that decreases as it approaches its distal end. The proximal end of the catheter has a higher hardness or modulus than the distal end of the catheter. The high hardness or modulus near the proximal end provides excellent support for the catheter. The hardness or modulus of the catheter is approximately constant along its length near the proximal end 3302 of the catheter. Then, the hardness or modulus of the catheter decreases near the distal end 3304 of the catheter. The hardness or modulus of the catheter may begin to decrease (i.e., a transition region) at about 50%, 70%, 75%, 80%, or 90% of the catheter length from its proximal end. The catheter may have a decreasing hardness or modulus near its distal end by using a material with a lower hardness or modulus near the distal end or having a thinner catheter wall. The reduced hardness or modulus near the distal end provides excellent tracking of the catheter.

[0428] Fig.37 A flexibility test graph of a catheter according to the present invention compared to a conventional catheter is depicted. The flexibility of the catheter was measured by a three-point flexure test with a span of one inch and a displacement of 2 mm. In other words, Fig.37 The force (i.e., flexure load) required to vertically displace a one-inch long catheter segment by 2 mm is depicted with respect to the distance from the strain relief point (i.e., the proximal end of the catheter) to the force application point. Fig.37 All catheters tested in Fig.36 The modulus or flexibility curve is similar to that shown in FIG. 1 . The modulus of the catheter remains approximately constant along its length near the proximal end and then tapers off near the distal end.

[0429] Conduit according to the present invention has a flexure load that is roughly constant along the longitudinal length near the near end and a flexure load that is rapidly reduced near the far end. In the conduit with a length of about 125cm, conduit can have a flexure load greater than or equal to about 1.0lbF, about 1.5lbF, about 2.0lbF, about 2.5lbF, about 3.0lbF or about 3.5lbF at about 85cm from the near end. Conduit can have a flexure load less than or equal to about 2.5lbF, about 2.0lbF, about 1.5lbF, about 1.0lbF or about 0.5lbF at about 95cm from the near end. Conduit can have a flexure load less than or equal to about 1.5lbF, about 1.0lbF, about 0.75lbF, about 0.5lbF, about 0.25lbF or about 0.1lbF at about 105cm from the near end. The catheter can have a flexure load of less than or equal to about 1.0 lbF, about 0.75 lbF, about 0.5 lbF, about 0.4 lbF, about 0.3 lbF, about 0.2 lbF, or about 0.1 lb F at about 115 cm from the proximal end. For catheters of different lengths, the above dimensions can be marked as a percentage of the catheter length from the distal end of the catheter.

[0430] In accordance with Fig.30 In certain embodiments of the configuration, the flexure load is less than about 3.0 or 3.25 lbF at 65 cm from the proximal end and is greater than about 2.25 or 2.5 lbF on average at 65 cm to 85 cm from the proximal end. The flexure load drops to no more than about 1.0 lbF and preferably no more than about 0.5 lbF at about 95 cm from the proximal end. This provides enhanced support while maintaining enhanced tracking into the distal vasculature.

[0431] In other embodiments, the catheter may have a flexure load greater than or equal to about 1.0 lbF, about 1.5 lbF, about 2.0 lbF, about 2.5 lbF, about 3.0 lbF, or about 3.5 lbF at about 60 cm from the proximal end. The catheter may have a flexure load less than or equal to about 2.0 lbF, about 1.5 lbF, about 1.0 lbF, or about 0.5 lbF at about 70 cm from the proximal end. The catheter may have a flexure load less than or equal to about 1.0 lbF, about 0.75 lbF, about 0.5 lbF, about 0.4 lbF, about 0.3 lbF, about 0.2 lbF, or about 0.1 lbF at about 80 cm from the proximal end. The catheter may have a flexure load of less than or equal to about 1.0 lbF, about 0.75 lbF, about 0.5 lbF, about 0.4 lbF, about 0.3 lbF, about 0.2 lbF, or about 0.1 lbF at about 90 cm from the proximal end.

[0432] The catheter may have a transition region wherein its flexure load change is greater than or equal to about 1.0 lb F, about 1.5 lb F, about 2.0 lb F, about 2.5 lb F, about 3.0 lb F, or about 3.5 lb F. The longitudinal length of the transition region may be less than or equal to about 20 cm, about 15 cm, about 10 cm, about 5 cm, about 3 cm, or about 1 cm.

[0433] Compared to Neuron Max (Penumbra) 3402, catheters according to the present invention (e.g., 3404, 3406, 3408, 3410) have comparable moduli near their proximal ends. Thus, catheters according to the present invention provide comparable support to Neuron Max. In addition, the catheters have a modulus that decreases more rapidly near the transition region (between the proximal and distal ends) than Neuron Max.

[0434] The catheters according to the present invention have a greater modulus near their proximal ends and a comparable modulus near their distal ends than the Ace 68 catheter (Penumbra) 3412, the Ace 64 catheter (Penumbra) 3414, the Benchmark 71 catheter (Penumbra) 3416, and the Sofia Plus (MicroVention) 3418. Thus, the catheters according to the present invention provide comparable tracking and better support than conventional catheters. The catheters according to the present invention can achieve this modulus profile even when their inner diameter (and thus lumen volume) is greater than or equal to the inner diameter of the Ace 68, Ace 64, Benchmark 71, and Sofia Plus (in the range of 0.064 inches to 0.071 inches).

[0435] Reference Fig.38 , a transformable access sheath 200 is shown. The access sheath 200 includes an elongated flexible tubular body 202 extending between a proximal end 204 and a distal end 206. A proximal access port 208 communicates with a distal port 210 on the distal end 206 via a central lumen 212. Fig.39 .

[0436] At least one transition zone 214 is disposed on the tubular body 202. The transition zone 214 can be controllably transformed between a relatively rigid configuration and a relatively flexible configuration. The access sheath 200 can be advanced distally through a tortuous anatomical structure as needed with at least one transition zone 214 in a relatively rigid configuration to provide radial support or facilitate guiding an instrument therethrough. The transition zone 214 can be controllably transformed into a relatively flexible configuration as needed to guide through a sharp bend in a vascular system.

[0437] In the illustrated embodiment, three transition zones 214 are shown. However, one or two or three or four or more transition zones may be utilized, depending on the desired clinical presentation. The length of the transition zone 214 may be about 1 cm to about 20 or 30 cm or more. In certain embodiments, the length of the transition zone will be in the range of about 2 cm to about 10 cm. The length and location of the transition zone may depend on the target anatomy for the access catheter and may be positioned accordingly.

[0438] Reference Fig.39 , showing the Fig.38 18-18 of FIG. 2 and sectional view through transition zone 214. The tubular body 202 includes a sidewall 216 having at least one heating element 218, which is carried by or embedded in the sidewall 216. In the illustrated embodiment, the heater 218 can be a conductive wire, such as a wire on a conductive spiral coil or braid. The conductive wire can be disposed or laminated within the inner and outer layers of the sidewall 216. In at least one embodiment, the inner layer of the sidewall 216 can include polytetrafluoroethylene (PTFE) for lubrication. In at least one embodiment, the outer layer of the sidewall 216 can include a biocompatible material preferably having a glass transition temperature of about 40° C. to about 80° C.

[0439] Alternatively, a conductive polymer may be utilized to form the sidewall 216. The conductive coating may alternatively be printed, laminated, embedded, or otherwise applied to the outside, inside, or laminated within the inner and outer layers of the sidewall 216. In at least one embodiment, the resistance of the heater 218 may be calibrated to a specific heating temperature, such as 40-80° C., for a predetermined voltage level of the power supply. This may eliminate the need for a thermocouple and prevent potential overheating.

[0440] One or more electrical conductors may extend between the transition zone 214 and a proximal activation port 215 adapted to couple with a source of electrical power from an external controller. In a monopolar configuration, a single conductor for each transition zone 214 may extend proximally to the activation port 215. A second conductor may lead to or include a conductive surface on the tubular body 202 to conduct power through the patient's body to an external electrode, as is understood in the art. Alternatively, in a bipolar embodiment, each transition zone 214 may be provided with at least two electrical conductors extending proximally to the activation port 215.

[0441] At least the transition zone includes a biocompatible material that is relatively strong at body temperature (e.g., 37° C.) but transforms to a relatively soft, flexible material when heat is applied. Typical suitable materials have a relatively low melting point so that they can soften at temperatures that are not high enough to damage living blood vessels. In any case, the material has a softening point or glass transition temperature above body temperature, while the melting point is significantly above body temperature and above the temperature reached by activating the heating element 218. In one embodiment, the biocompatible material preferably has a glass transition temperature of about 40° C. to about 80° C. Suitable materials may include polymers having a polymer chain orientation that causes the polymer to break when heated.

[0442] Examples of suitable biostable materials are polymers, typically thermoplastic polymers such as polyolefins and polyurethanes and most other biocompatible polymers. Typical suitable bioabsorbable materials include polyglycolide (PGA), poly(L-lactide) (PLLA), poly(ε-caprolactone) (PCL) and mixtures or combinations thereof. Polyglycolide, for example, has a glass transition temperature between 35-40° C., which has a significantly higher melting point.

[0443] In this regard, a typical operating (softening) temperature is approximately between about 40°C and 80°C, typically between about 40°C and 60°C, to induce a softening transition of the transition zone 214 and allow for a transition back to a firm state when power is removed and the transition zone 214 returns to body temperature. Temperatures above about 80°C may be acceptable for short periods of time, depending on the total energy delivered. Any temperature to which the heater 218 is raised is limited by the temperature that the patient's body can tolerate without causing damage to the vessel wall or causing thrombosis. Therefore, if the qualified polymer exhibits appropriate flexibility at the softening point temperature and exhibits appropriate firmness at lower body temperatures, it is desirable to remain within the lower end of the above temperature range.

[0444] After being heated, the energy activated biocompatible transition zone 214 softens so that it can be guided through, for example, a sharp bend. The material should be sufficiently softened by the application of energy so that its flexibility is enhanced, but the structural integrity required for guidance is maintained and its shape is retained so that it will harden back to its original configuration after the heat source is interrupted. In order to maintain the integrity of the tubular body, the side wall 216 can be provided with a flexibility enhancement structure, such as a spirally wound wire, ribbon or polymer wire bundle such as polyimide, or other braids or textiles known in the field of neurovascular catheters. Resistive coils or other resistance wires can also provide mechanical enhancement when the transition zone is in a softened state.

[0445] Heating may alternatively be provided by positioning a heat source, such as a resistive heating element, carried by the heater catheter within the central lumen 212. Once the catheter has reached its final position in the vascular system, the heater catheter may be withdrawn proximally from the central lumen 212, which may now be used to aspirate or receive therethrough the distal segment 34. In either heater configuration, the power source may be disposed within or electrically coupled to the aspiration catheter or the proximal manifold on the heater catheter.

[0446] The catheter of the present invention can be accessed through an incision in a peripheral artery (e.g., right femoral artery, left femoral artery, right radial artery, left radial artery, right brachial artery, left brachial artery, right axillary artery, left axillary artery, right subclavian artery, or left subclavian artery) using conventional techniques. In an emergency, an incision can also be made in the right carotid artery or the left carotid artery.

[0447] Avoiding a tight (close) fit between the guidewire 40 and the inner diameter of the guidewire lumen 28 improves the slidability of the catheter on the guidewire. In ultra-small diameter catheter designs, it may be desirable to apply a lubricating coating to the outer surface of the guidewire 40 and / or the inner surface of the wall defining the lumen 38 to minimize the friction of the catheter 10 relative to the guidewire 40 during axial movement. Various coatings can be used, such as Paralene, Teflon, silicone, polyimide-polytetrafluoroethylene composites, or other materials known in the art and appropriate according to the material of the guidewire or inner tubular wall 38.

[0448] The suction catheter of the present invention suitable for intracranial application generally has a total length in the range of 60 cm to 250 cm, typically about 135 cm to about 175 cm. The length of the proximal section 33 is typically 20 cm to 220 cm, more typically 100 cm to about 120 cm. The length of the distal section 34 is typically in the range of 10 cm to about 60 cm, typically about 25 cm to about 40 cm.

[0449] The catheter of the present invention can be composed of any of a variety of biocompatible polymeric resins having suitable properties when formed into a tubular catheter body segment. Exemplary materials include polyvinyl chloride, polyether, polyamide, polyethylene, polyurethane, copolymers thereof, and the like. In one embodiment, both the proximal body segment 33 and the distal body segment 34 include polyvinyl chloride (PVC), wherein the proximal body segment is formed of relatively rigid PVC and the distal body segment is formed of relatively flexible soft PVC. Optionally, the proximal body segment can be reinforced using a metal or polymer braid or other conventional reinforcement layer.

[0450] The proximal body segment will have sufficient radial support to allow axial positioning of the catheter through the guide catheter, wherein at least a portion of the proximal body segment 33 extends beyond the guide catheter and into the patient's vascular system. The proximal body segment may have a Shore hardness in the range of 50D to 100D, typically about 70D to 80D. Typically, the proximal shaft will have a flexural modulus of 20,000psi to 1,000,000psi, preferably 100,000psi to 600,000psi. The distal body segment 34 will be sufficiently flexible and soft so that it can be guided to the patient's more narrow distal vascular system. In a very flexible embodiment, the Shore hardness of the distal body segment 34 may be in the range of about 20A to about 100A, and the flexural modulus of the distal segment 34 may be about 50psi to about 15,000psi.

[0451] The catheter body may also include other components, such as radiopaque fillers; colorants; reinforcement materials; reinforcement layers, such as braids or helical reinforcement elements; etc. In particular, the proximal body section may be reinforced to increase its radial support and torsional resistance (torque transmission), while preferably limiting its wall thickness and outer diameter.

[0452] Typically, radiopaque markers will be provided at least at the distal end 14 and at the transition region 32 located at the distal end of the proximal section 33. One type of radiopaque marker includes a metal band recessed within or carried outside the distal end of the proximal body section 33. Suitable marker bands can be made of a variety of materials, including platinum, gold, and tungsten / rhenium alloys. Preferably, the radiopaque marker band will be recessed in the annular channel to produce a smooth outer surface.

[0453] The proximal section 33 of the tubular body 16 may be made according to any of a variety of known techniques for making an interventional catheter body (e.g., by extrusion of an appropriate biocompatible polymeric material). Alternatively, at least the proximal portion or the entire length of the tubular body 16 may include a polymer or metal spring coil, a solid wall hypodermic needle tube, or a braided reinforced wall, as known in the microcatheter technology.

[0454] In catheters for neurovascular applications, the proximal section 33 of the body 16 will typically have an outer diameter in the range of about 0.117 inches to about 0.078 inches. In one embodiment, the proximal section 33 has an outer diameter of about 0.104 inches and an inner diameter of about 0.088 inches. The distal section 34 has an outer diameter of about 0.085 inches and an inner diameter of about 0.070 inches.

[0455] Diameters outside of the preferred range may also be used provided that the functional structure of the diameter is acceptable for the intended use of the catheter. For example, the lower limit on the diameter of any portion of the tubular body 16 in a given application will be a function of the number of fluid or other functional lumens contained in the catheter and the minimum acceptable suction flow and collapse resistance.

[0456] The tubular body 16 must have sufficient structural integrity (e.g., radial support or "pushability") to allow the catheter to be advanced to a distal position without buckling or undesired bending of the tubular body. The ability of the body 16 to transmit torque may also be desirable, for example to avoid kinking during rotation to assist steering. The tubular body 16 and in particular the distal section 34 may be provided with any of a variety of torque and / or radial support enhancement structures. For example, axially extending stiffening wires, helically wound support layers, braided or woven reinforcement wires may be constructed in or stacked on the tubular body 16. See, for example, U.S. Pat. No. 5,891,114 to Chien et al., the entirety of the disclosure of which is incorporated herein by reference.

[0457] In many applications, the proximal section 33 does not have to traverse an artery with a particularly small profile or tortuous shape. For example, most or all of the proximal section 33 is in a relatively large diameter guide catheter. The transition portion 32 can be located on the catheter shaft 16 to roughly correspond to or exceed the distal end of the guide catheter.

[0458] For certain applications such as intracranial catheterization, the distal segment 34 is preferably at least about 5 cm or 10 cm long and small enough in diameter to pass through blood vessels as small as 3 mm or 2 mm or less. The distal segment may have a length of at least about 20 cm or 30 cm or 40 cm or more, depending on the intended target vessel or treatment site.

[0459] Whether carried as an integrated device within the proximal section or inserted as a separate device into the proximal section during surgery, the distal section is much shorter than the proximal section. When the distal ends of the distal section and the distal ends of the proximal section are axially aligned, the proximal end of the distal section is distally spaced from the proximal end of the proximal section. A control element, such as a control wire or tube, spans the distance between the proximal end of the distal section and the proximal manifold or proximal control device.

[0460] In the above configurations, the proximal end of the distal segment is typically distally spaced apart from the proximal end of the proximal segment by at least about 25% of the length of the proximal segment, and in some embodiments at least about 50% or 70% or more.

[0461] According to one aspect, a telescopic catheter is provided, comprising: an elongated flexible tubular body including a proximal segment having at least one inner lumen and a distal segment axially movably disposed in the inner lumen; and a control device for advancing the distal segment from a first proximal retracted position within the proximal segment to a second extended position extending distally beyond the proximal segment; and a movable tip located at the distal end of the distal segment, comprising a distal opening movable between a smaller configuration and a larger configuration.

[0462] In one aspect of the disclosure, the control device includes a pull wire extending through the proximal section. In another aspect of the disclosure, the distal section can be advanced distally to extend beyond the proximal section by at least about 10 cm. In yet another aspect of the disclosure, the distal section can be advanced distally to extend beyond the proximal section by at least about 25 cm.

[0463] In one aspect of the disclosure, the distal opening is movable in response to movement of a control line. In another aspect of the disclosure, the distal opening is movable between a smaller configuration and a larger configuration in response to application of a vacuum to the lumen. In yet another aspect of the disclosure, the size of the distal opening is changed by lateral movement of a sidewall on the distal segment. In yet another aspect of the disclosure, the distal opening includes at least one movable jaw. In another aspect of the disclosure, the distal end of the distal segment includes a duckbill valve configuration.

[0464] In one aspect of the present disclosure, the telescopic catheter may further include a controller for applying intermittent vacuum to the lumen. The controller may be configured to apply vacuum pulses to the lumen separated by gaps of intermediate pressure. The controller may be configured to alternate between applying pulses of higher negative pressure and lower negative pressure. The distal tip of the catheter may reciprocate axially in response to applying vacuum pulses to the lumen.

[0465] According to one aspect, a system for aspirating vascular occlusive material from a remote site is provided, comprising: an elongated flexible tubular body including at least one central lumen extending along its longitudinal length; an agitator extendable through the central lumen of the tubular body so that its distal end is positioned near the distal end of the tubular body; a drive connectable to a proximal end of the agitator and configured to actuate the agitator; and a vacuum port located near the proximal end of the tubular body and in fluid communication with the central lumen of the tubular body.

[0466] In one aspect of the present disclosure, the agitator comprises an elongated tube. The agitator may include a wire extending through the elongated tube and having at least one bend near its distal end. In another aspect of the present disclosure, the agitator comprises a proximal end, a distal end, and a ring at the distal end. In yet another aspect of the present disclosure, the drive is configured to cause the agitator to cyclically rotate in alternating directions.

[0467] In one aspect of the present disclosure, the agitator includes: at least one lumen along its longitudinal length; an inlet near its proximal end, which is configured to allow fluid communication between the lumen of the agitator and a source of medium; and at least one outlet, which is configured to allow fluid communication between the lumen of the agitator and a central lumen of the tubular body. The system for aspirating vascular occlusive material may also include a control device for releasing the medium from the outlet of the agitator into the central lumen of the tubular body. The distal portion of the tubular body may be configured to vibrate in a lateral direction in response to the injection of the medium.

[0468] In one aspect of the present disclosure, the system for aspirating vascular occlusions further includes a controller for applying a pulsating vacuum cycle to the central lumen. In another aspect of the present disclosure, the system for aspirating vascular occlusions further includes a rotary hemostatic valve coupled to the proximal end of the tubular body, the rotary hemostatic valve including: at least one main lumen along its longitudinal length, the proximal portion of the agitator configured to pass through the main lumen, and a suction lumen branched from the main lumen and provided with a vacuum port. In yet another aspect of the present disclosure, the system further includes a proximal drive assembly coupled to the proximal end of the tubular body, the proximal drive assembly including: at least one main lumen along its longitudinal length for receiving the agitator; a medium injection port for injecting medium therein, which is in fluid communication with the central lumen of the tubular body; and a proximal drive connection at the proximal end, which is operably connected between the agitator and the driver.

[0469] According to another aspect, a method for aspirating a vascular occlusion from a remote site is provided, the method comprising: providing a system for aspirating a vascular occlusion; placing a tubular body proximate to the occlusion; activating a driver to actuate an agitator and loosen the occlusion; and aspirating occlusive material into a central lumen by applying a vacuum to the central lumen. In one aspect of the present disclosure, a method for aspirating a vascular occlusion from a remote site is provided, comprising: providing a system for aspirating a vascular occlusion; placing a tubular body proximate to the occlusion; activating a driver to rotate a distal tip of an agitator; injecting a medium via an inflow port; and aspirating occlusive material into a central lumen by applying a vacuum to the central lumen. Actuation of the driver, aspiration, and injection of the medium may be synchronized to facilitate removal and / or aspiration of the occlusion.

[0470] According to one aspect, a method of aspirating a vascular occlusion from a remote site is provided, comprising: advancing a guidewire to a site at least as far as the cavernous sinus segment of an internal carotid artery; advancing a tubular body directly over the guidewire to a site at least as far as the cavernous sinus segment; removing the guidewire from the tubular body; and aspirating a thrombus into the tubular body by applying a vacuum to the tubular body. In one aspect of the disclosure, the method of aspirating a vascular occlusion comprises advancing the tubular body to at least as far as the cerebral segment of the internal carotid artery. In another aspect of the disclosure, the method of aspirating a vascular occlusion comprises advancing the guidewire to at least as far as the middle cerebral artery.

[0471] In another aspect of the present disclosure, the method for aspirating a vascular occlusion further includes providing sufficient stop support to the tubular body to resist the tubular body from coming out and entering the aorta. In one aspect, the stop support can be provided by advancing the tubular body on a guidewire having a distal end at least as far as the cavernous sinus segment of the internal carotid artery, and the diameter at the point where the guidewire enters the brachiocephalic artery is at least about 0.030 inches. In another aspect, the stop support can be provided by advancing the tubular body on a guidewire having a distal end at least as far as the cavernous sinus segment of the internal carotid artery, and the diameter at the point where the guidewire enters the brachiocephalic artery is at least about 0.038 inches. By having a distal segment with a diameter not greater than about 0.020 inches, the guidewire can be guided to at least the cerebral segment of the internal carotid artery. By having a distal segment with a diameter of about 0.016 inches, the guidewire can be guided to at least the cerebral segment of the internal carotid artery. The length of the distal segment may not exceed about 25 cm. The length of the distal segment may not exceed about 20 cm.

[0472] According to another aspect, a method for tracking an aspiration catheter from a femoral access site to a site at least as far as the cavernous sinus segment of the internal carotid artery is provided, the method comprising the steps of: advancing a guidewire from the femoral access site to at least as far as the cerebral segment of the internal carotid artery, the guidewire having a proximal segment and a distal segment, the proximal segment having a diameter of at least about 0.030 inches, the distal segment having a length of no more than about 25 cm and a diameter of no more than about 0.020 inches; tracking the aspiration catheter directly over the guidewire and tracking to a site at least as far as the cavernous sinus segment, the aspiration catheter having a distal end and a central lumen at the distal end, the distal end having a diameter of at least about 0.080 inches and having an inclined distal tip. In one aspect of the present disclosure, the diameter of the proximal segment of the guidewire is about 0.038 inches, and the diameter of the distal segment is about 0.016 inches.

[0473] In another aspect of the present disclosure, a distal segment of a catheter includes a sidewall defining a central lumen, the sidewall including: a tubular liner; a soft bonding layer separated from the lumen by the liner; a helical coil surrounding the bonding layer, adjacent turns of the coil being gradually more and more spaced apart in a distal direction; and an outer sheath surrounding the helical coil, the outer sheath being formed by a plurality of tubular segments coaxially disposed around the coil; wherein one of the tubular segments on the proximal side has a hardness of at least about 60D, and one of the tubular segments on the distal side has a hardness of no more than about 35D. The tubular liner is formed by dip coating a removable mandrel and may include PTFE. The bonding layer may include polyurethane. The wall thickness of the bonding layer may not exceed about 0.005 inches and may extend along at least the distal most 20 cm of the flexible body. The coil may include a shape memory material.

[0474] According to one aspect, a neurovascular catheter with enhanced flexibility is provided, comprising: an elongated flexible body having a proximal end, a distal end, and a side wall defining a central lumen, the distal region of the side wall comprising: a tubular liner; a soft connecting layer separated from the lumen by the liner; a helical coil surrounding the connecting layer, the adjacent turns of the coil being gradually more and more spaced apart in the distal direction; and an outer sheath surrounding the helical coil, the outer sheath being formed by a plurality of tubular segments coaxially disposed around the coil; wherein one of the tubular segments on the proximal side has a hardness of at least about 60D, and one of the tubular segments on the distal side has a hardness of no more than about 35D. In one aspect of the present disclosure, the tubular liner is formed by dip coating a removable mandrel. In another aspect of the present disclosure, the tubular liner comprises PTFE.

[0475] In yet another aspect of the present disclosure, the tie layer comprises polyurethane. The tie layer may have a wall thickness of no more than about 0.005 inches and may extend along at least the distal-most 20 cm of the flexible body. In one aspect of the present disclosure, the coil comprises a shape memory material. The coil may comprise nitinol, and the nitinol may comprise an austenitic state at body temperature.

[0476] In one aspect of the present disclosure, the outer shell is formed of at least five discrete tubular segments. The outer shell may be formed of at least nine discrete tubular segments. The difference in hardness between the proximal one of the tubular segments and the distal one of the tubular segments may be at least about 20D. The difference in hardness between the proximal one of the tubular segments and the distal one of the tubular segments may be at least about 30D.

[0477] In another aspect of the present disclosure, the flexible enhanced neurovascular catheter also includes a tensile support for improving the tensile resistance in the distal region. The tensile support may include a wire and may include an axially extending wire. The axially extending wire may be carried between the liner and the spiral coil. The axially extending wire may increase the tensile strength to at least about 1 pound, at least about 2 pounds, at least about 3 pounds, at least about 4 pounds, at least about 5 pounds, at least about 6 pounds, at least about 7 pounds, at least about 8 pounds, or at least about 10 pounds or more.

[0478] According to one aspect, a neurovascular catheter with enhanced flexibility is provided, comprising: an elongated flexible body having a proximal end, a distal end, and a sidewall defining a central lumen, a distal region of the sidewall comprising: an outer sheath surrounding a helical coil, the outer sheath being formed by a plurality of tubular segments coaxially disposed about the coil; wherein a proximal one of the tubular segments has a hardness of at least about 60D, and a distal one of the tubular segments has a hardness of no more than about 35D; and an axially extending wire located within the sidewall extending at least about the distal most 10 cm of the length of the catheter. The wire may extend at least about the distal most 15 cm of the length of the catheter. The wire may extend at least about the distal most 20 cm of the length of the catheter. The wire may comprise a plurality of fibers and may extend axially between the coil and the liner.

[0479] In one aspect of the present disclosure, the sidewall further comprises: a tubular liner; a soft bonding layer separated from the lumen by the liner; wherein the helical coil surrounds the bonding layer and adjacent turns of the coil are gradually spaced apart in the distal direction. The tubular liner may be formed by dip coating a removable mandrel and may include PTFE. The bonding layer may include polyurethane and may have a wall thickness of no more than about 0.005 inches. The bonding layer may extend along at least the distal-most 20 cm of the flexible body. The coil may include a shape memory material and may include nitinol. The nitinol may include an austenitic state at body temperature.

[0480] In one aspect of the present disclosure, the outer shell can be formed of at least five discrete tubular segments. In another aspect of the present disclosure, the outer shell can be formed of at least nine discrete tubular segments. The difference in hardness between a proximal tubular segment and a distal tubular segment can be at least about 20D. The difference in hardness between a proximal tubular segment and a distal tubular segment can be at least about 30D. In another aspect of the present disclosure, the catheter can withstand at least about 3.5 pounds of tension before failure. In yet another aspect, the catheter can withstand at least about 5 pounds of tension before failure.

[0481] According to one aspect, a method for forming a highly flexible distal zone on a neurovascular catheter is provided, comprising the following steps: dip-coating a removable mandrel to form a tubular inner layer on the mandrel; coating the tubular inner layer with a soft bonding layer; applying a spiral coil on the outside of the bonding layer; placing a plurality of tubular segments on the spiral coil, the plurality of segments having a hardness that decreases in the distal direction; heating the tubular segments to form a highly flexible distal zone on the neurovascular catheter; and removing the mandrel. In one aspect of the present disclosure, the step of removing the mandrel includes axially stretching the mandrel. In another aspect of the present disclosure, the method for forming a highly flexible distal zone on a neurovascular catheter includes placing at least seven segments on the spiral coil. In another aspect of the present disclosure, the method for forming a highly flexible distal zone on a neurovascular catheter includes placing at least nine segments on the spiral coil.

[0482] In one aspect of the present disclosure, the difference in hardness between a proximal tubular segment and a distal tubular segment is at least about 20D. The difference in hardness between a proximal tubular segment and a distal tubular segment can be at least about 30D. The tubular inner layer can include PTFE. In another aspect of the present disclosure, the tie layer includes polyurethane. The tie layer can have a wall thickness of no more than about 0.005 inches. The tie layer can extend along at least the distal-most 20 cm of the flexible body.

[0483] In one aspect of the present disclosure, the coil comprises a shape memory material. The coil may comprise nitinol. The nitinol may comprise an austenitic state at body temperature. In another aspect of the present disclosure, the method of forming a highly flexible distal zone on a neurovascular catheter further comprises the step of placing at least one tensile strength reinforcing wire between the coil and the connecting layer before heat shrinking the tubular segment. The wire may extend along at least approximately the distal 15 cm of the length of the catheter. The wire may extend along at least approximately the distal 20 cm of the length of the catheter. The wire may comprise a plurality of fibers. In yet another aspect of the present disclosure, the method of forming a highly flexible distal zone on a neurovascular catheter further comprises the step of placing at least one tensile strength reinforcing wire on the connecting layer before the step of applying the spiral coil.

[0484] According to another aspect, a method for aspirating a vascular occlusion from a remote site is provided, comprising: advancing an elongated tubular body through a vascular access site and into a body vessel, the tubular body comprising a proximal end, a distal end, and a central lumen; positioning the distal end at least as distal as the cavernous sinus segment of a middle cerebral artery; applying a vacuum to the lumen to aspirate a thrombus into the lumen; and mechanically fragmenting the thrombus to facilitate entry into the lumen.

[0485] In one aspect of the present disclosure, the mechanically disrupting step introduces vibration at the distal end of the tubular body. The vibration may be introduced by rotating an agitator within the tubular body. The method of aspirating a vascular occlusion may include rotating a wire within the tubular body. The method of aspirating a vascular occlusion may include rotating a tube within the tubular body and may further include the step of introducing a medium through the tube. The method of aspirating a vascular occlusion may include the step of introducing a lubricant through the tube to assist the thrombus in traveling through the lumen and may include the step of introducing polyethylene glycol through the tube.

[0486] In another aspect of the present disclosure, the step of applying a vacuum comprises applying a pulsating vacuum. In yet another aspect of the present disclosure, the step of advancing the elongated tubular body is performed directly over the guide wire without introducing any intervening tubular body. The method of aspirating a vascular occlusion may comprise advancing the tubular body to at least as far as the cavernous sinus segment of the internal carotid artery. The method of aspirating a vascular occlusion may comprise advancing the guide wire to at least as far as the cerebral segment of the internal carotid artery. The method of aspirating a vascular occlusion may comprise advancing the guide wire to at least as far as the middle cerebral artery.

[0487] In one aspect of the present disclosure, the method of aspirating a vascular occlusion further includes providing sufficient stop support to the tubular body to resist dislodging of the tubular body and entering the aorta. Stop support can be provided to the tubular body by advancing the tubular body over a guidewire having a distal end positioned at least as far as the cavernous sinus segment of the internal carotid artery, and the diameter at the point where the guidewire enters the brachiocephalic artery is at least about 0.030 inches. Stop support can be provided to the tubular body by advancing the tubular body over a guidewire having a distal end positioned at least as far as the cavernous sinus segment of the internal carotid artery, and the diameter at the point where the guidewire enters the brachiocephalic artery is at least about 0.038 inches.

[0488] In one aspect of the present disclosure, the guidewire can be guided to at least the cerebral segment of the internal carotid artery by having a distal segment with a diameter of no more than about 0.020 inches. The guidewire can be guided to at least the cerebral segment of the internal carotid artery by having a distal segment with a diameter of about 0.016 inches. In another aspect of the present disclosure, the method of aspirating a vascular occlusion further includes the step of introducing an agitator into the tubular body after the placement step. The proximal section of the agitator can extend through the constraining tube, and the distal section of the agitator can extend beyond the distal end of the constraining tube.

[0489] According to one aspect, a method of aspirating a vascular occlusion from a remote site is provided, comprising: advancing a guidewire through a vascular access site and transvascularly to at least as far as the cavernous segment of the internal carotid artery; accessing a site at least as far as the cavernous segment by advancing a combined access and aspiration catheter directly over the guidewire; removing the guidewire; and aspirating a thrombus via the combined access and aspiration catheter. In one aspect of the disclosure, the method of aspirating a vascular occlusion comprises advancing a combined access and aspiration catheter to at least as far as the cerebral segment of the internal carotid artery. In another aspect of the disclosure, the method of aspirating a vascular occlusion comprises advancing a guidewire to at least as far as the middle cerebral artery.

[0490] In yet another aspect of the present disclosure, the method of aspirating a vascular occlusion further includes providing sufficient stop support to the combined entry and aspiration catheter to resist dislodgment of the catheter and entry into the aorta. Stop support may be provided for the combined entry and aspiration catheter by advancing the combined entry and aspiration catheter over a guidewire having a distal end positioned at least as far as the cavernous sinus segment of the internal carotid artery, and having a diameter of at least about 0.030 inches at the point where the guidewire enters the brachiocephalic artery. Stop support may be provided for the combined entry and aspiration catheter by advancing the combined entry and aspiration catheter over a guidewire having a distal end positioned at least as far as the cavernous sinus segment of the internal carotid artery, and having a diameter of at least about 0.038 inches at the point where the guidewire enters the brachiocephalic artery.

[0491] In one aspect of the present disclosure, the guidewire can be guided to at least the cerebral segment of the internal carotid artery by having a distal segment with a diameter no greater than about 0.020 inches. The guidewire can be guided to at least the cerebral segment of the internal carotid artery by having a distal segment with a diameter of about 0.016 inches. The diameter of the proximal segment of the guidewire can be about 0.038 inches, and the diameter of the distal segment can be about 0.016 inches.

[0492] In another aspect of the present disclosure, a distal segment of a combined access and aspiration catheter includes a side wall defining a central lumen, the side wall including: a tubular liner; a soft bonding layer separated from the lumen by the liner; a helical coil surrounding the bonding layer, adjacent turns of the coil being gradually more and more spaced apart in the distal direction; and an outer sheath surrounding the helical coil, the outer sheath being formed by a plurality of tubular segments coaxially disposed around the coil; wherein one of the tubular segments on the proximal side has a hardness of at least about 60D, and one of the tubular segments on the distal side has a hardness of no more than about 35D. The tubular liner is formed by dip coating a removable mandrel. The tubular liner may include PTFE. The bonding layer may include polyurethane. The wall thickness of the bonding layer may not exceed about 0.005 inches and may extend along at least the distal most 20 cm of the flexible body.

[0493] In one aspect of the present disclosure, the coil comprises a shape memory material. In another aspect of the present disclosure, the method of aspirating a vascular occlusive further comprises introducing an agitator into the combined access and aspiration catheter. The method of aspirating a vascular occlusive may further comprise vibrating a distal portion of the agitator during the aspirating step. The method of aspirating a vascular occlusive may further comprise introducing a fluid medium via the agitator during the aspirating step. The method of aspirating a vascular occlusive may further comprise introducing polyethylene glycol via the agitator during the aspirating step.

[0494] According to one aspect, a neurovascular catheter is provided, comprising: an elongated flexible tubular body having a proximal end, a distal end, and a sidewall defining a central lumen, the distal region of the tubular body comprising: a tubular liner; a tie layer separated from the lumen by the liner; a helical coil surrounding the tie layer, the adjacent turns of the coil being gradually more and more spaced apart in the distal direction; an outer sheath surrounding the helical coil; and an opening at the distal end, the opening being expandable from a first inner diameter for transluminal guidance to a second larger inner diameter that is conducive to drawing thrombi into the lumen. In one aspect of the present disclosure, the distal opening may expand in response to contact with blood. In another aspect of the present disclosure, the distal opening may expand in response to being affected by body temperature. In yet another aspect of the present disclosure, the distal opening may expand in response to the removal of a constraint. The constraint may include a polymer having reduced structural integrity in an intravascular environment.

[0495] In one aspect of the present disclosure, the catheter body adjacent to the distal opening includes an embedded support member offset radially outward. The catheter body adjacent to the distal opening may include an embedded nitinol frame. The support member may include a wire mesh. The support member may include a stent. In another aspect of the present disclosure, the catheter body adjacent to the distal opening includes a hydrophilic mixture. In another aspect of the present disclosure, the tubular liner is formed by dip coating a removable mandrel. The tubular liner may include PTFE.

[0496] In yet another aspect of the present disclosure, the tie layer comprises polyurethane. The tie layer may have a wall thickness of no more than about 0.005 inches. The tie layer may extend along at least the distal-most 20 cm of the flexible body. In another aspect of the present disclosure, the coil comprises a shape memory material. The coil may comprise nitinol. The nitinol may comprise an austenitic state at body temperature. In one aspect of the present disclosure, the outer shell is formed by at least five discrete tubular segments. The outer shell may be formed by at least nine discrete tubular segments. The hardness difference between one of the proximal tubular segments and one of the distal tubular segments may be at least about 20D. The hardness difference between one of the proximal tubular segments and one of the distal tubular segments may be at least about 30D.

[0497] According to one aspect, a neurovascular catheter extension segment is provided, comprising: an elongated flexible control wire having a proximal end and a distal end; a tubular extension segment having a side wall supported by the distal end of the control wire and defining a central lumen, the side wall comprising: a tubular liner; a bonding layer separated from the lumen by the liner; a helical coil surrounding the bonding layer; and an outer sheath surrounding the helical coil. In one aspect of the present disclosure, the outer sheath is formed by a plurality of tubular segments coaxially disposed around the coil. A proximal tubular segment may have a hardness of at least about 60D, while a distal tubular segment may have a hardness of no more than about 35D.

[0498] In another aspect of the present disclosure, the tubular liner is formed by dip coating a removable mandrel. The tubular liner may include PTFE. In yet another aspect of the present disclosure, the tie layer includes polyurethane. The tie layer may have a wall thickness of no more than about 0.005 inches. The tie layer may extend along at least the farthest 20 cm of the tubular extension section. In one aspect of the present disclosure, the coil includes a shape memory material. The coil may include nitinol. The nitinol may include an austenitic state at body temperature.

[0499] In one aspect of the present disclosure, the outer shell is formed by at least five discrete tubular segments. The outer shell may be formed by at least nine discrete tubular segments. The hardness difference between a proximal tubular segment and a distal tubular segment may be at least about 20D. The hardness difference between a proximal tubular segment and a distal tubular segment may be at least about 30D. In another aspect of the present disclosure, the control line includes a central lumen. The central lumen of the control line may be connected to the central lumen of the tubular extension segment. In another aspect of the present disclosure, the inner diameter of the neurovascular catheter extension segment is at least 2 times the inner diameter of the central lumen of the control line. The inner diameter of the neurovascular catheter extension segment may be at least 3 times the inner diameter of the central lumen of the control line.

[0500] According to another aspect, a neurovascular catheter extension section system is provided, comprising an agitator and the above-described neurovascular catheter extension section, the agitator being configured to extend through a central lumen of a control wire and into a central lumen of a tubular extension section.

[0501] Although the present invention has been described with respect to certain preferred embodiments, those skilled in the art can incorporate it into other embodiments according to the disclosure herein. Therefore, the scope of the present invention is not intended to be limited by the specific embodiments disclosed herein, but is defined by the full scope of the attached scheme.

Claims

1. A catheter, comprising: An elongated flexible tubular body comprising: a distal end surface of the catheter that lies in a first plane that intersects the longitudinal axis of the elongated flexible tubular body at a first non-orthogonal angle relative to the longitudinal axis; and a radial support band located in a distal region of the elongated flexible tubular body and proximal to the distal end face of the catheter, the radial support band including a distal end face located on a second plane that intersects the longitudinal axis at a second non-orthogonal angle relative to the longitudinal axis, wherein the first plane is substantially parallel to the second plane, and Wherein, the second non-orthogonal angle is between about 45 degrees and about 80 degrees.

2. The catheter according to claim 1, wherein: The distal region of the elongated flexible tubular body comprises: Coil; and A sheath at least partially surrounds the coil, the sheath extending distally beyond the distal end of the coil and terminating at the distal end surface of the catheter.

3. A catheter according to claim 2, wherein: The coil includes Nitinol.

4. The catheter according to claim 2, wherein: The shell is formed from at least five separate axially adjacent tubular sections.

5. The catheter according to claim 2, wherein: The radial support band is embedded in the sheath between the distal end of the coil and the distal end surface of the catheter.

6. A neurovascular catheter with enhanced flexibility, comprising: proximal; remote; a side wall defining a central lumen, a distal region of the side wall comprising a helical coil and a distal end surface located on the distal end, the distal end surface lying in a plane intersecting a longitudinal axis of the neurovascular catheter at an angle of at least about 45 degrees and at most about 80 degrees; An outer shell, the outer shell comprising: a plurality of tubular segments, a proximal tubular segment of the plurality of tubular segments having a hardness of at least about 60D, a distal tubular segment of the plurality of tubular segments having a hardness of at most about 35D; and a tubular radiopaque marker, the tubular radiopaque marker being located distal to the helical coil; and a wire located within the sidewall, the wire extending axially from the distal end toward the proximal end, the wire comprising a length of at least about 10 cm and at most about 50 cm, the wire being configured to prevent the sidewall from elongating under tension, wherein the distal end surface of the side wall defines a leading edge of the neurovascular catheter, wherein the leading edge extends distally of a trailing edge of the neurovascular catheter, wherein the front edge and the rear edge are spaced approximately 180 degrees from each other about the longitudinal axis, wherein the leading edge is located on a first side of the neurovascular catheter, wherein the trailing edge is located on a second side of the neurovascular catheter, and Wherein a first axial length of the tubular radiopaque marker on the first side is at least 20% longer than a second axial length of the tubular radiopaque marker on the second side.

7. A catheter, comprising: An elongated flexible tubular body comprising: a distal end surface of the catheter that lies in a first plane that intersects the longitudinal axis of the tubular body at a first non-orthogonal angle relative to the longitudinal axis; and a radiopaque marker located in a distal region of the tubular body and proximal to the distal end face of the catheter, the marker comprising a marker distal end face that is at least partially located in a second plane that intersects the longitudinal axis at a second non-orthogonal angle relative to the longitudinal axis, wherein the first plane is substantially parallel to the second plane, and Wherein, the second non-orthogonal angle is between about 45 degrees and about 80 degrees.

8. A catheter, comprising: An elongated flexible tubular body comprising: rear edge of tubular body; a tubular body front edge, the tubular body front edge being circumferentially spaced 180 degrees from the tubular body rear edge around the periphery of the tubular body, the tubular body front edge extending distally further than the tubular body rear edge; A radiopaque marker located proximal to the distal end of the catheter, the marker comprising: Mark the back edge; a marking leading edge circumferentially spaced 180 degrees from the marking trailing edge around the periphery of the marking, the marking leading edge extending distally further than the marking trailing edge, the marking leading edge being located on the same side of the tubular body as the tubular body leading edge; and a marking distal end face, the marking distal end face being at least partially at a first non-orthogonal angle relative to a longitudinal axis of the tubular flexible body; and a catheter distal end face, the catheter distal end face being at least partially at a second non-orthogonal angle relative to the longitudinal axis of the tubular flexible body, The distal end surface of the marker is substantially parallel to the distal end surface of the catheter.

9. A catheter, comprising: An elongated flexible tubular body comprising: a distal end surface of the catheter that lies in a first plane that intersects the longitudinal axis of the tubular body at a first non-orthogonal angle relative to the longitudinal axis; a radiopaque marker located in a distal region of the tubular body and proximal to the distal end face of the catheter, the radiopaque marker comprising a marker distal end face that lies at least partially on a second plane that intersects the longitudinal axis at a second non-orthogonal angle relative to the longitudinal axis; and a tensile support comprising axially extending wires carried by the elongated flexible tubular body, The first plane is substantially parallel to the second plane.

10. A system for removing embolic material from an intravascular site, comprising: an elongated flexible tubular body having a proximal end, a distal end, and a tubular sidewall defining at least one lumen extending axially therethrough; Axial restraints; a rotatable core wire extendable through the lumen, the core wire having a proximal end and a distal end; a restraint carried by the core wire, the restraint having a bearing surface for engaging an axial restraint; and at the agitator tip at the distal end of the core wire, wherein the limiter and the axial restraint are engageable to permit rotation of the core wire but to limit distal advancement of the tip relative to the tubular body.

Images