Transvascular Thrombectomy System

Abstract

The transvascular thrombus removal system includes an aspiration catheter and a first vacuum chamber having a blood clot filter and configured to be used within a sterile area. A vacuum line connects the first vacuum chamber to a second vacuum chamber and an aspiration pump configured to be used outside the sterile area. The first and second chambers are subjected to a low pressure by the aspiration pump. Opening of the valve allows for rapid aspiration from the patient to the first chamber. A blood clot engagement tool having a distal helical thread shape can be advanced through the catheter to engage the blood clot.

Description

Technical Field

[0001] Incorporation by Reference This application incorporates by reference in its entirety each of the following applications: U.S. Patent Application No. 17 / 857,598, filed July 5, 2022, and patented as U.S. Patent No. 11,553,935 on January 17, 2023; U.S. Patent Application No. 17 / 857,649, filed July 5, 2022, and patented as U.S. Patent No. 11,633,272 on April 25, 2023; U.S. Patent Application No. 17 / 857,919, filed July 5, 2022, and patented as U.S. Patent No. 11,638,637 on May 2, 2023; U.S. Patent Application No. 17 / 810,743, filed July 5, 2022; U.S. Provisional Patent Application No. 63 / 341,926, filed May 13, 2022; U.S. Patent Application No. 17 / 357,490, filed June 24, 2021, and patented as U.S. Patent No. 11,457,936 on October 4, 2022; U.S. Provisional Patent Application No. 63 / 044,511, filed June 26, 2020; U.S. Patent Application No. 17 / 125,723, filed December 17, 2020, and patented as U.S. Patent No. 11,065,018 on July 20, 2021; U.S. Provisional Patent Application No. 62 / 950,058, filed December 18, 2019; and U.S. Provisional Patent Application No. 63 / 064,273, filed August 11, 2020.

Background Art

[0002] The removal of blood clots (thrombectomy) from the vasculature using a transvascular approach can be accomplished anywhere in the pulmonary artery for treating various treatment sites, such as arteries in the extremities, veins in the case of deep vein thrombosis (DVT), large veins and arteries (central vasculature), such as the iliac veins and arteries, the aorta, the inferior vena cava, and pulmonary embolism (PE).

[0003] For example, venous thromboembolism (VTE) is a serious global problem. Cases of DVT and PE are diagnosed worldwide in over 10 million people annually, and in the United States in over 1 million people, and in France, Italy, Germany, Spain, Sweden, and the United Kingdom together in over 700,000 people annually. In the United States, approximately 60,000 to 100,000 people die annually from PE. DVT and PE are part of the same spectrum of diseases, and over 95% of emboli originate in the lower extremities. When PE occurs, its severity depends on the embolic load and its impact not only on the right ventricle but also on underlying cardiopulmonary comorbidities. The result of a sudden increase in pulmonary artery (PA) pressure with increased afterload and dysfunction of the right ventricle (RV) can lead to death.

[0004] Patients with high-risk PE have mainly been treated with thrombolytic therapy delivered either systemically or more locally by catheter-directed thrombolysis. These approaches result in multiple visits to catheterization laboratories and long hospital stays and often lead to hemorrhagic complications. New approaches to PE treatment include single-pass thrombectomy procedures that do not use thrombolytic agents. These thrombectomy procedures involve delivering a catheter into the PA to remove thrombus by aspiration, and the thrombus may be softened or disrupted with secondary tools prior to aspiration. Thrombectomy has fewer hemorrhagic complications and shorter hospital stays compared to thrombolytic agents, but there are many aspects that need improvement considering the challenges of the treatment itself, including the ability to capture a wide range of thrombus types and the ability to reduce the total blood loss during treatment.

[0005] The thrombus removal catheter is introduced from the puncture of the introducer of the large-diameter vein. A flexible guide wire is passed through the introducer into the vein, and the introducer is removed. The flexible guide wire provides a rail for advancing the flexible guide catheter through the right atrium, into the right ventricle, and then into the pulmonary artery. The flexible guide wire is removed and replaced with a stiff guide wire. Next, the large-diameter thrombus removal catheter with a support dilator is advanced over the stiff guide wire to the pulmonary artery, and the dilator is removed. If the large-diameter thrombus removal catheter fails to access the thrombus in the more distal portion of the blood vessel or fails to aspirate such a thrombus successfully, a smaller-diameter catheter can be inserted through the large-diameter catheter.

[0006] In addition, peripheral arterial occlusive (PAO) disease affects more than 4% of individuals over 40 years of age and its incidence increases significantly after the age of 70. Acute PAO is usually due to thrombosis in the peripheral vascular system and is associated with a significant risk of limb loss. To preserve the limbs, the treatment of acute PAO focuses on promptly restoring the patency of the artery and blood flow, such as by performing mechanical thrombus removal in a procedure similar to that described above.

[0007] Embolus aspiration using certain commercially available vacuum-assisted thrombectomy systems may sometimes need to be terminated, especially when using large aspiration catheters, due to the risk of excessive blood loss to the patient. During aspiration thrombectomy, when the tip of the catheter loses contact with the thrombus or other occlusive material, the tip is then exposed to healthy blood, followed by a complete flow of blood within the catheter. Under such conditions, the total blood loss can become excessive and, in some cases, may lead to premature termination of the procedure. For example, during the procedure, if the catheter enters healthy blood followed by a complete aspiration flow, with a 24 French size catheter, the blood loss rate can be on the order of 30 cc to 40 cc per second. If the maximum allowable blood loss is on the order of about 500 mL, the catheter cannot be operated in an unrestricted mode for more than approximately 10 to 15 seconds. Before sufficient emboli are removed, the total blood loss may reach an unacceptable level.

[0008] Thus, despite previous attempts, there remains a need for improved techniques to remove or reduce restrictive and occlusive substances due to thrombosis in either the patient's artery or vein.

Summary of the Invention

Means for Solving the Problems

[0009] In accordance with one aspect of the present invention, there is provided an embolus capture module for use in a thrombectomy system, for example in a sterile area. The embolus capture module includes a housing; an embolus capture chamber within the housing; a window within the housing that permits visual inspection of the embolus chamber; and a filter within the embolus capture chamber that is visible through the window and has an upstream surface and a downstream surface.

[0010] The inflow passage is configured to direct the inflowing blood from the aspiration catheter against the upstream surface of the filter. An aspiration control valve is provided within the inflow passage and is configured to block or permit the flow of the inflowing blood. The outflow passage is configured to direct blood from the second side of the filter to a remote vacuum cannister.

[0011] The blood clot capture module may further include a vent valve, which is operable to allow an optically transparent medium such as air or normal saline to be drawn into the blood clot chamber and to enable the discharge of blood from the blood clot chamber to a cannister remote therefrom. As a result, the upstream surface of the filter may be visible through a window, and once the vent is opened to discharge blood from the blood clot capture chamber, the blood clots accumulated on the upstream surface can be visually observed through the window. The window may comprise a transparent cylindrical portion of the housing.

[0012] The upstream surface of the filter may be substantially planar. Alternatively, the upstream surface of the filter may be convex. The filter may comprise a tubular porous membrane such as a cylinder, and the upstream surface of the filter may be on the surface facing radially outward of the membrane. The tubular filter membrane may surround a filtered blood chamber in communication with the outflow passage.

[0013] This module may further include an aspiration control unit that controls the aspiration control valve. The aspiration control unit may include a rocker switch configured to selectively crush or reopen a crushable pipe material. The aspiration control valve may normally be closed and may be configured to be biased closed by a spring.

[0014] The blood clot capture module can be provided in combination with a vacuum line that connects to a suction pump and a canister. In this case, the blood clot capture module is configured to be resident within the sterile area, and the suction pump and canister are outside the sterile area. The vacuum line can be at least about 30 inches or 50 inches or longer. In some examples, a manually operated suction device (e.g., a syringe) can be used in addition to or instead of the suction pump to allow the user to manually apply suction through the vacuum line.

[0015] In accordance with another aspect of the invention, there is provided a thrombus engagement tool configured to advance through a suction catheter and engage a thrombus. The thrombus engagement tool includes a rotatable core wire having a proximal end and a distal end; and a thrombus engagement tip at the distal end of the core wire. The tip can include a helical thread shape; and an advancing section on the distal side of the thread shape and a trailing section on the proximal side of the thread shape. The advancing section, the helical thread shape, and the trailing section can all be molded onto the core wire.

[0016] The thrombus engagement tool can further include a protrusion on the core wire within at least one of the advancing section and the trailing section to form an interference fit with the thrombus engagement tip. The protrusion can include an annular ring that can be a radiopaque marker. The thrombus engagement tool can include a first radiopaque marker within the advancing section and a second radiopaque marker within the trailing section.

[0017] The outer periphery of the helical thread shape can be substantially conforming to the inner surface of a cylinder. The thread shape can include a proximal surface that defines an undercut that slopes radially outward in the proximal direction and opens proximally.

[0018] The thrombus engagement tool may further comprise a handle on the proximal end of the core wire, configured to be rotated by hand. A limiting bearing surface may be provided on the handle to limit the distal protrusion of the thrombus engagement tip relative to the distal end of the aspiration catheter.

[0019] A method of removing occlusive material from a blood vessel by mechanical and aspiration assistance may further be provided. The method comprises providing an aspiration catheter having a central lumen and a distal end; advancing the distal end to an occlusive material within the blood vessel; applying a vacuum to the lumen to at least partially draw a blood clot into the lumen; and introducing a thrombus engagement tool into the lumen. The thrombus engagement tool may have a tip with an axial length of about 1 cm or about 5 mm or less and a helical thread shape with a major diameter at least about 0.015 inches smaller than the inner diameter of the lumen, thereby providing a suction flow path through the lumen around the outside of the tip. The method further comprises manually rotating the tip to engage the blood clot between the tip and the inner wall of the lumen.

[0020] A method of aspirating a blood vessel occlusion from a remote site comprises advancing an elongate tubular body through an access site of the blood vessel and to the blood vessel occlusion, the tubular body comprising a proximal end, a distal end, a central lumen, and a stop surface. A rotatable core is advanced distally through the lumen, the advancement stopping when a limiting surface carried by the core rotatably slidably engages the stop surface to provide a rotatable bearing that limits further distal advancement of the core within the lumen. A vacuum is applied to the lumen and the core is rotated manually to engage the thrombus. Advancing the rotatable core may be accomplished after advancing the elongate tubular body through the access site of the blood vessel and to the blood vessel occlusion. The core may be a solid core wire, or an inserted structure such as a hypo tube, or a micro catheter having a central lumen extending axially between a proximal opening and a distal opening.

[0021] The core may carry a proximal handle, and the limiting surface may be carried by the handle. The tubular body may include a proximal hub, and the stop surface may be carried by the hub. The core may carry an engaging tip having a helical thread shape, and the step of engaging a thrombus may include pinning the thrombus between a first side of the tip and the inner surface of the tubular body.

[0022] An insertion device for guiding the device through a hemostatic valve is also provided, which includes an elongated tubular body having a proximal end, a distal end, and a central lumen; a concave landing zone facing laterally on the proximal end having a radius of curvature increasing in the proximal direction; and an axially extending slit in the side wall extending from the distal end to the landing zone. The tubular body may further include a tapered distal tip and a proximal pull tab to facilitate removal of the insertion device from the device. The surface of the landing zone may include a color different from the outer surface of the tubular body, facilitating visualization of the landing zone and advancement of the distal end of the device into the tubular body.

[0023] A method of passing a device through a hemostatic valve may include providing an insertion device having a tubular body with a split side wall; advancing the tubular body through the hemostatic valve; advancing the device through the tubular body over the hemostatic valve; and retracting the tubular body proximally to allow the device to escape laterally through the split side wall of the tubular body, leaving the device in a fixed position across the hemostatic valve.

[0024] The step of advancing the tubular body may include advancing the tapered distal tip on the tubular body through the hemostatic valve. The step of advancing the tubular body through the hemostatic valve may be accomplished using a device pre-loaded inside the tubular body.

[0025] The distal protruding section of the tubular body may have its diameter expand in response to advancing the device through itself. The device may be a thrombus engagement tool or a secondary catheter. The secondary catheter may be a suction catheter.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0027] Referring to Figure 1, a thrombus removal system, such as for PE or DVT aspiration therapy, is illustrated. The system 10 includes a thrombus removal catheter 12 having an elongate tubular body 14 extending between a proximal end 16 and a distal end 18. A central lumen 20 (not shown in Figure 1) extends between a proximal catheter connector 22 and a distal port 24 on the distal end 18.

[0028] Although the catheter of the present invention is primarily described in the context of a suction catheter having a single central lumen, it can be readily modified to incorporate additional structures, such as two or more lumens for injection of a permanent or removable strut strength enhancing mandrel, drug, contrast agent, or perfusion agent, or to supply an inflation medium to an inflatable balloon carried by the catheter, or any combination of these features, which will be readily apparent to those skilled in the art in view of the disclosure herein. Additionally, although the present disclosure will primarily be described in the context of removing occlusive substances from the vasculature, it will be understood that it has applicability as an access catheter for delivery and removal of any of a variety of diagnostic or therapeutic devices, with or without suction.

[0029] The catheters disclosed herein can be readily adapted for systemic use whenever it is desirable to advance a low-profile, highly flexible catheter distally within various types of vasculature, such as small or large vasculature, and / or tortuous or relatively straight vasculature. For example, a catheter shaft according to any of the embodiments described herein can be dimensioned similarly suitable for use throughout the neurovascular, coronary, and peripheral vasculature, the gastrointestinal tract, the urethra, the ureters, the fallopian tubes, and other lumens, as well as any conceivable lumen. The configuration of the catheter shaft of any of the embodiments herein can also be used to provide minimally invasive percutaneous tissue access, such as diagnostic or therapeutic access to solid tissue targets (e.g., a chest or liver or brain biopsy, or tissue resection), delivery of laparoscopic tools, or access to bone, such as the spine, for delivery of screws, bone cement, or other tools, or implants.

[0030] Catheter 12 will have a length and diameter suitable for the intended access point and target location. In one example, referring to FIG. 1, catheter 12 can have an effective length generally of about 230 cm or less, about 210 cm or less, about 180 cm or less, or about 160 cm or less, and typically from about 50 cm to about 150 cm, from about 90 cm to about 130 cm, or from about 105 cm to about 115 cm, from the distal end of manifold or hub 22 to distal tip 18. The outer diameter of catheter 10 can be from about 0.035 inches to about 0.15 inches, from about 0.09 inches to about 0.13 inches, and can be smaller in the distal segment than in the proximal segment.

[0031] In an embodiment of the single central lumen, the inner diameter of catheter 12 can be about 0.1 inch or greater, about 0.088 inch or greater, or about 0.08 inch or greater, or about 0.06 or greater. In an embodiment of the single central lumen, the inner diameter of catheter 12 can be less than about 0.20 inch or 0.15 inch, or about 0.11 inch or less, about 0.1 inch or less, about 0.088 inch or less, or about 0.07 inch or less, and often less than about 0.095 inch.

[0032] In the illustrated embodiment, catheter 12 is releasably connectable to flow control module 28 via complementary connector module 30. Connector module 30 provides a releasable connection to complementary catheter connector 22 and can include a side port 32 for a releasable connection to tubing 34 that can lead to valve 36. Connector module 30 can optionally include a hemostatic valve configured to receive another device, such as a guidewire or thrombus engagement tool, as discussed below.

[0033] Valve 36 can selectively communicate tubing 34 with side port 37 or flow control module 28, which are discussed in further detail below. Side port 37 can communicate with a source of a medium, such as saline, contrast agent solution, or drug therapy, or with a manifold 38 that provides selective communication to and from each. Use of valve 36 allows injection of a desired medium without removing tubing 34 from connector module 30.

[0034] Referring to FIGS. 2 and 3, the flow control module 28 communicates with the valve 36 via the distal tube 44. The flow control module 28 communicates with the selector valve 49 via the proximal tube 46. Thereby, a flow path is established from the distal port 24, through the catheter 12, through various tubing members and the flow control module 28, to the pump assembly 42. In an alternative embodiment of the present invention, the flow control module 28 may be integrally formed within the hub of the catheter 12, or within the connector module 30, at the location where the thrombus removal catheter 12 removably or non-removably attaches. In some examples, a manually actuated suction device (e.g., a syringe) may be used in addition to, or in place of, the suction pump assembly 42 that allows the user to manually apply suction through a vacuum line. It will be understood by those skilled in the art that a manually actuated suction device may be in addition to, or in place of, the pump assembly described in any of the embodiments herein.

[0035] The flow control module 28 may include a flow regulator, such as an on-off controller, that regulates the flow through the flow path between the catheter 12 and the pump 42. The flow regulator is configured to provide a restriction to flow path reversal, such as by an expandable or contractible throttle, a ball valve, or other rotary core valve, a leaf valve, a pinch tubing, or other known in the art.

[0036] In one embodiment, the flow regulator includes a collapsible portion 29 of a tubular wall that defines a flow path, such as a section of polymeric tubing. An actuator 31 positioned adjacent to the tubing is movable in response to a control device such as a push button or toggle switch 48, which is movable between a first position where the control device compresses the tubing to completely restrict flow and a second position where the control device has moved away from the tubing such that the tubing can recover to its full inner diameter and fluid flow is enabled. The actuator 31 can be biased by a spring or have another initial-set drive device in the direction of the first (restricted) position and be movable only to the second (open) position in the presence of a positive mechanical force or release of a restriction that enables opening of the flow path. When a temporary "on" command is removed, the actuator 31 automatically returns to the first position to block flow.

[0037] The actuator 31 can be driven according to the desired functionality by a mechanical controller such as a lever or rotatable knob or by an electrically driven system such as a solenoid operable by any of a button, lever, trigger, foot pedal, or various other switches known in the art.

[0038] The flow control module 28 can house, for example, a filter chamber 33 and communicate with a vacuum cannister 58 on a pump assembly 42 via an elongate suction tubing 40. The toggle switch 48 is positioned between the filter chamber 33 and the catheter 12. In the initial-set off position of some embodiments, this enables the entire length of the suction tubing 40 and the filter chamber 33 to reach the same low pressure as the suction cannister 58 on the pump 42.

[0039] Further details of the filter assembly and related structures are illustrated in FIG. 3. The filter assembly 35 includes an outer tubular sidewall 37 having a transparent window 39. In some embodiments, the entire tubular sidewall 37 can be a transparent window. The sidewall 37 surrounds a filter 41. The filter 41 includes a filter sidewall 43 that defines an internal (downstream) chamber (not shown) for filtered blood.

[0040] When the flow path is opened by the activation switch 48, blood and thrombi are drawn in a direction from the catheter 12 through the vacuum line 44, through the first filter opening 45, and into the blood clot collection chamber 33. Any thrombi will be captured outside (upstream side) of the filter 43. The blood is drawn into the canister 58 through the filter 43 and the proximal tubing 46 along the way. In the example illustrated, the filter 43 is tubular, but alternatively can be planar or of other shapes depending on the desired configuration.

[0041] The switch 48 can then be closed, compressing the tubing 29 and separating the catheter 12 from the vacuum source. The vent 47, which is normally closed, can be temporarily opened to allow the introduction of an optically transparent medium such as saline or ambient air. This allows any residual blood in the chamber 33 to be drawn through the filter 43 and aspirated out through the proximal tubing 46, enabling visualization of any blood clots on the surface of the filter 43 through the window 39. The vent 47 can be actuated manually by the user and / or automatically by the system. In some examples, the user can manually actuate the vent 47 through actuation of a button 62 located on the flow control module 28.

[0042] For example, the vent 67 may normally be in a closed state and subsequently transition to an open configuration when the button 62 is being actuated (or vice versa). In the open configuration, the vent 67 may expose the blood clot collection chamber 33 to the ambient environment. In some examples, the exposure of the chamber 33 to the ambient environment enables the intake of air and the acceleration of blood flow towards the proximal tubing through the blood clot collection chamber 33. The increased acceleration of blood flow resulting from the actuation of the vent 47 can facilitate the visualization of blood clots by displacing the amount of blood or other fluid from the optical path between the window and the filter, and / or can reduce the amount of time required for a physician to accurately identify blood clots in the chamber 33. Also, with the valved vent, the physician can deliver pulsatile waves of negative pressure from the distal opening 24.

[0043] In the illustrated embodiment, the flow control module 28 comprises a proximal housing 31 and a distal housing 29 separated by a transparent tubular sidewall 35. The tubular sidewall 35 and the filter 43 are carried by the proximal housing 31. The housing 29 and the tubular sidewall 35 may be connected at a releasable connection 33, which in some examples includes a gasket 59 that forms a sealed connection. Complementary surface structures (e.g., inclined corresponding grooves and pins or flanges) permit rapid attachment and detachment. For example, the proximal housing 31 and the distal housing 29 may rotate relative to each other (e.g., by relative rotation across the gasket) to separate the housings from each other.

[0044] The filter 43 can be attached to either the distal housing 29 or the proximal housing 31 when the housing is separated. The tubular side wall 35 can be attached to either the distal housing 29 or the proximal housing 31 such that the tubular side wall 35 remains attached to one of the housings 29, 31 when separated. When the distal housing 29 is removed and separated from the proximal housing 31, the tubular side wall 35 can be configured to remain around the filter 43 or to be removed from above the filter 43. In either example, separating the housings 29, 31 from each other can expose the filter 43, allowing easy access to and removal of the blood clot.

[0045] The inner surface of the blood clot collection container 33 can comprise a coating that provides one or more various properties to the blood clot collection container 33. In some examples, the coating can be configured to enhance visualization through at least a portion of the blood clot collection container 33 (such as the transparent window 39). The coating can be configured to inhibit blood accumulation or to increase the property of repelling blood. In some examples, the blood clot collection container 33 can comprise a coating that inhibits foam formation during the suction procedure. The coating can be at least partially located along or over the entire inner surface of the tubular side wall 35 and / or the blood clot collection container 33. In some examples, the coating is located along the inner surface of the transparent window 39. The coating can be both hydrophobic and oleophobic. In some examples, the coating can have some hydrophilic features on a portion of the polymer that increases the oleophobic property.

[0046] The suction pump assembly 42 can be releasably communicated with the flow control module 28, such as by a luer connection between the selector valve 45 and the tubing 40. The suction pump assembly 42 can comprise a vacuum pump 50, and can also include a vacuum gauge 51 and an optional pressure regulating controller 54. The vacuum gauge 51 is in fluid communication with the vacuum pump and displays the vacuum pressure generated by the pump. The pressure regulating controller 54 enables the user to set a specific vacuum pressure. The power button 56 activates the pump 50.

[0047] The vacuum canister 58 can be provided with a vent 53 to the atmosphere that is opened and closed by a valve. In one embodiment, the valve is normally closed to allow the vacuum within the canister to reach a desired low pressure. The valve can be temporarily opened as desired to allow the introduction of air and the reduction of the vacuum, for example, to reduce foaming within the vacuum canister 58.

[0048] The vent can function to reduce foaming and increase visibility within the canister. In some examples, the vent 53 comprises a permanently open vent, such as one in the lid or sidewall of the vacuum canister. The vent can comprise an opening formed through a lid or sidewall having a diameter of about 0.5 mm or 0.25 mm or less, and can be a laser cut hole through a metal sheet and in the form of a disk carried by the lid.

[0049] In addition to or instead of the vent, the inner surface of the canister 58 can be provided with a coating of one or more materials that suppress foaming of blood under vacuum. The coating can be located at least partially or completely along the inner surface of the vacuum canister 58. The coating can be both hydrophobic and oleophobic. In some examples, the coating can have some hydrophilic features on a polymer portion that increases oleophobic properties.

[0050] Any of a variety of controllers, including switches, buttons, levers, rotatable knobs, and others that would be apparent to one of ordinary skill in the art in view of the disclosure herein, can be utilized to operate various pump functions. Alternatively, the suction pump 50 can be a manually actuated pump such as a syringe.

[0051] In some applications, it may be desirable to provide a non-blocking constraint on the flow between the vacuum cannister 58 and the flow control module 28. A flow restrictor can be coupled in series to the vacuum line 40, such as by a luer connector. In one embodiment, the flow restrictor enables switching between a low flow configuration and a high flow configuration. The flow restrictor can comprise a variable restrictor that can be adjusted by the user. This can be accomplished by selectively diverting the flow between relatively small and large diameter openings, variable diameter openings, or other flow regulators, examples of which include those disclosed in U.S. Patent Publication No. 2021 / 0315597 to Buck, et al., entitled "Aspiration System with Accelerated Response", the disclosure of which is hereby incorporated by reference in its entirety.

[0052] In a particular embodiment, a rotatable drum comprises a first transverse flow path having a first diameter. The drum is rotatable within a housing having an inlet port and an outlet port. The drum can rotate to fluidly connect the inlet port to the outlet port through the first flow path. Also, a second flow path having a second different diameter extends transversely through the drum, offset in the rotational direction from the first flow path. The drum can rotate to communicate the inlet port to the outlet port through the second flow path, thereby providing a flow rate through the drum that is different from the flow rate provided by the first flow path.

[0053] The filter chamber 33 on the flow control module 28 or on the connector module 30 is spaced apart from the remote vacuum pump 42 and the vacuum cannister 58 that enhances suction performance. Conventional suction pumps and filters are intended to be located outside the sterile area and may be sufficiently remote from the patient such that the length of the suction tubing 40 between the pump assembly 42 and the catheter 12 needs to be at least about 50 inches or about 100 inches or greater. For example, the tubing 40 can be about 102 inches.

[0054] The pump typically includes a suction cannister 58 for blood collection. When suction is desired in a prior art system, the low-pressure cannister 58 is communicated with the catheter 12 via the suction tubing 40 by opening a valve to suction substances from the patient. However, the length of the suction tubing extending from the inside to the outside of the sterile area operates as a flow restrictor, creating a delay between the time to activate the vacuum button on the pump assembly 42 and the actual application of suction to the blood clot at the distal end of the catheter.

[0055] In the illustrated embodiment, the only flow restriction between the vacuum source (filter chamber 33) and the patient is the relatively short suction path between the on / off valve in the handpiece actuated by the toggle switch 48 and the distal end 18 of the catheter. When the suction controller 48 is activated to open the flow path, the flow restriction and the enclosed volume on the patient side of the filter chamber 33 are relatively small compared to the flow restriction and the enclosed volume through the suction tubing 40 on the pump side of the filter chamber 33.

[0056] This dual chamber configuration creates a rapid initial rise in the negative pressure felt at the distal end 18 of the catheter 12 upon activation of the suction control device 48 and a rapid filling of chamber 33. The response time between activation of the suction control device 48 and the realization of suction actually felt at the thrombus is significantly faster than the response time achieved in a conventional system having only the vacuum chamber 58 located at the pump assembly 42 outside the sterile area, allowing for a significantly higher initial flow.

[0057] The rapid initial rise in the negative pressure felt at the distal end of the catheter will dissipate as pressure equilibrium is achieved between the filter chamber 33 and the canister 58. When the suction controller 48 is deactivated, the vacuum pump 50 will gradually reduce and return the pressure in the filter chamber 33 to the level in the vacuum canister 58 at the pump.

[0058] An illustration of a simplified fluid flow is shown in FIG. 4, and a qualitative flow rate diagram is illustrated in FIG. 5. The flow restriction between the chamber 33 and the distal end 18 of the catheter 12 is relatively small compared to the flow restriction between the vacuum cannister 58 and the vacuum chamber 33. This allows the negative pressure peak felt at the distal end 18 to occur almost instantaneously from the activation of the vacuum switch 48. The flow rate of material into the catheter 12 reaches a peak rapidly and converges as the vacuum chamber 33 is filled with aspirated material. The vacuum in the chamber 33 decreases to a minimum and, when the toggle switch 48 is moved to the closed position, slowly recovers by means of the large vacuum chamber 58 and the associated pump through the tubing 40. In some examples of use, the clinician may choose to close the vacuum switch 48 at or shortly after the time of maximum flow rate, providing only a short burst or series of bursts of pulsatile vacuum to facilitate the aspiration of thrombus into the catheter 12. During use, a similar effect can be established by utilizing the vent 47. The vacuum in the chamber 33 can be decreased to a minimum when the button 62 is actuated such that the vent is opened. Thereafter, the vacuum chamber 33 can be slowly refilled by means of the large vacuum chamber 58 and the associated pump through the tubing 40 when the button 62 and the vent 47 are moved to the closed position. In some examples of use, the clinician may choose to open the vent 47 at or shortly after the time of maximum flow rate, providing only a short burst or series of bursts of pulsatile vacuum to facilitate the aspiration of thrombus into the catheter 12.

[0059] If a blood clot cannot be aspirated into the catheter by application of a vacuum, a long, flexible thrombus engagement tool can be advanced through the aspiration catheter to facilitate retrieval of the blood clot. The thrombus engagement tool can comprise an elongate flexible shaft having a proximal handpiece such as a knob configured to be rotated by hand. The distal end carries a blood clot engagement tip which can include one or more engagement structures extending radially outwardly such as a helical thread configuration.

[0060] Referring to FIGS. 6A-6C, the thrombus engagement tool 80 can comprise an elongate flexible shaft 82 having a proximal end 84 and a distal end 86. A proximal handpiece, such as a handle 88 that applies a rotational force, can be configured to be rotated by hand. The distal end 86 carries a thrombus engagement tip 90, which can include one or more radially outwardly extending structures such as a helical thread shape 92. The handle 88 can have an indication of the direction of rotation, such as a printed or molded arrow 94, that indicates the direction to rotate the handle 88 to engage the helical thread shape 92 with the thrombus.

[0061] Referring to FIG. 6B, the distal tip 90 includes a helical thread shape 92 that extends between a distal threaded shape end 96 and a proximal threaded shape end 94 and is supported by a flexible shaft 98. The axial length of the distal tip 90, measured along the flexible shaft 98, is at least about 5 mm or 10 mm or 15 mm or 20 mm, and in some embodiments is about 30 mm or less than 20 mm. Preferably, the axial length ranges from about 20 mm to about 25 mm.

[0062] The helical thread shape 92 winds around the axis in at least about 1 or 2 or 4 or more full rotations, but in some embodiments in about 10 or less or about 6 or less rotations. Preferably, the thread shape 92 winds around the axis within a range of about 2.5 to about 4.5 rotations. In some embodiments, the axial length along the threaded portion of the tip ranges from about 5 to about 15 mm, preferably from about 8 mm to about 12 mm.

[0063] The helical thread shape 92 in this embodiment can have a constant pitch throughout its length. The pitch can range from about 5 to about 10 thread shapes per inch, depending on the desired performance. For example, the spacing between thread shapes in the axial thread shape can range from about 2 mm to about 6 mm, preferably from about 3 mm to about 4 mm.

[0064] Alternatively, the thread shape may have a plurality of pitches (e.g., stepped or progressive) designed to engage, transport, or grip a thrombus within the catheter lumen. The distal pitch may be less than the proximal pitch. The pitch may vary continuously along the length of the thread shape or may be stepped from a first, constant pitch in the proximal zone to a second, different pitch in the distal zone of the thread shape. The thread shape 92 may comprise a continuous single helical ridge or may have a plurality of discontinuities to form a plurality of tooth-like or serrated portions arranged helically around the core wire.

[0065] The maximum OD of the thread shape 92 is preferably smaller than the diameter of the intended sliding fit within the catheter lumen and can generally be at least about 0.015 inches or at least about 0.010 inches smaller than the catheter lumen ID. In some embodiments, the maximum OD of the tip is significantly smaller than the inner diameter of the catheter lumen so as to provide more space for the thrombus along the side of the tip, yet still create a significant gripping force through lateral engagement with the thrombus and the helical thread shape.

[0066] In one embodiment, the maximum diameter of the helical thread shape is about 0.110 inches and the catheter lumen ID is about 0.275 inches (24F) (a 0.165 - inch gap between the helical thread shape and the catheter wall). In another embodiment, the maximum OD of the tip ranges from about 0.03 to about 0.06 inches within a catheter having a distal end ID in the range of about 0.068 inches to about 0.073 inches. This leaves a substantial tip recirculation path.

[0067] For certain applications, the maximum OD of the distal end is about 35% or less or about 40% or less or about 60% or less of the ID of the corresponding catheter, and can range from about 35% to about 55% of the catheter ID. In some examples, the maximum OD of the distal end can be slightly less than the ID of the corresponding catheter to provide a sliding fit within the intended catheter lumen. For example, the maximum OD of the distal end can be about 90% or more or about 95% or more or about 97% or more of the ID of the corresponding catheter.

[0068] This embodiment of the thrombus engagement tool does not have any centering structure for the distal end 90 or the shaft 82, so the distal end 90 is normally pushed to one side of the suction lumen. When a blood clot is clogged between the distal end 90 and the opposing inner surface of the catheter sidewall, manual operations such as rotation of the distal end 90 can be used to engage the blood clot like a worm gear, and the blood clot can be grasped and retracted (for example, by pinning it against the opposing catheter sidewall) or the release of the occlusion can be facilitated to assist in the uptake of the blood clot into the catheter. The manual operation can also include axial proximal and distal reciprocating motions along with rotation during suction, thereby facilitating the uptake of the blood clot into the catheter.

[0069] Thus, an unobstructed flow path is created within the annular (when the distal end is centered) space between the maximum OD of the distal end and the ID of the catheter lumen. This annular flow path cooperates with the vacuum and the helical distal end to grasp and draw in occlusive substances under rotation and vacuum into the catheter. The annular flow path is significantly larger than any flow path created by manufacturing tolerances at the distal end configured to shear the plugging substance between the catheter wall.

[0070] As a result, a helical channel is defined between each two adjacent thread forms at the distal end, obtaining an additional suction volume. The cross-sectional area of the helical flow path at the distal end having a maximum OD in the range of from about 0.0400 to about 0.0406 inches is generally at least about 0.0003 square inches, and in some embodiments at least about 0.00035 or at least about 0.000375 inches. The total suction flow path across the helical distal end is thus the sum of the helical flow path through the distal end and the annular flow path defined between the OD of the distal end and the ID of the catheter lumen.

[0071] Suction occurs not only through the helical channels formed between adjacent helical thread forms but also around the outside of the distal end, and the assembly is configured to engage and capture the occluding material, but not shear it between the sharp edge of the thread form and the inner wall of the catheter.

[0072] The distal advancement section 100 advantageously allows the thrombus engagement device 80 to move at least partially through the thrombus without "pushing" the thrombus distally as the distal end 90 advances. Thereby, it can be suppressed that thrombus (or any of its fine particles) passes downstream within the blood vessel during the engagement between the thrombus and the device 80.

[0073] In some examples, the distal advancement section 100 can be made to include a continuous helical thread form 92. For example, the distal advancement section 100 can include a threaded section continuous from the helical thread form 92. The threaded distal advancement section 100 can maintain an outer diameter that matches the remaining portion of the helical thread form 92 in some examples. The threaded distal advancement section 100 can include a threaded form tapered distally towards an outer diameter that is relatively smaller still with respect to the remaining portion of the helical thread form 92 in some examples. For example, the helical thread form 92 can include a proximal cylindrical section and a distal tapered section extending along the distal advancement section 100.

[0074] The profile of the tip 90 at the end face along the axis of rotation can be circular and / or, in some examples, can vary to produce a non-circular pattern around the axis of rotation. For example, the profile can comprise a helical pattern, such as a non-ovoid cross-section that rotates along the axis of rotation to produce a helical profile. Thus, the tip seen in the end elevation can show a major diameter and a minor diameter. The minor diameter can be about 95% or 90% or 80% or 70% or less of the major diameter, depending on the desired performance. In the illustrated example, the outer edge 93 of the thread form 92 is present along the surface of the cylinder.

[0075] Thus, in the illustrated embodiment, the outer edge 93 of the thread form 92 has an axially straight surface that substantially conforms in shape to the surface of the cylinder. The distal side 95 of the thread form 92 slopes radially outward in the proximal direction. The proximal side 97 of the thread form 92 also slopes radially outward in the proximal direction, thereby defining an undercut facing proximally along the length of the thread form.

[0076] Referring to FIGS. 6B and 6C, the illustrated tip 90 includes a non-traumatic and tapered distal advancement section 100 that extends between the atraumatic distal tip 102 and the transition to the distal end 96 of the thread form 92. The helical thread form 92 extends proximally from the transition to the proximal end 94 of the helical thread form 92. In some examples, the trailing section 104 can extend between the proximal end 94 of the thread form and the proximal end 106 of the tip.

[0077] The axial length of the distal advancement section 100 can be at least about 5 mm or at least about 8 mm or 9 mm and generally less than about 15 mm, and in some embodiments is in the range of about 8 mm to about 12 mm.

[0078] The outer diameter of the flexible shaft 82 is generally less than about 0.02 inches, or less than about 0.015 inches, and in one embodiment is about 0.008 inches. In some examples, the flexible shaft 82 can comprise a distally tapered section. The distally tapered section can advantageously increase the flexibility of the tip and / or maximize suction. The outer diameter at the distal end of the distally tapered section of the flexible shaft 82 is generally less than about 0.01 inches, or less than about 0.008 inches, and in one embodiment is about 0.006 inches or less.

[0079] The outer diameter of the advancing section 100 at the distal tip 102 is generally less than about 0.024 inches, or less than about 0.020 inches, and in one embodiment is about 0.018 inches. The maximum outer diameter of the advancing section 100 and the helical thread shape 92 can be in the range of about 0.020 to about 0.045 inches, and in one embodiment is less than about 0.040 inches, for example about 0.035 inches. The advancing section, helical thread shape, and trailing section of the tip 90 can be molded as a single component onto the flexible shaft 82 using any of a variety of polymers known in catheter technology.

[0080] Referring to FIG. 6C, a first radiopaque marker 110 can be carried on the flexible shaft 82 inside the advancing section 100. A second radiopaque marker 112 can be carried on the flexible shaft 82 within the trailing section 104. Each radiopaque marker can comprise a radiopaque wire, such as a platinum iridium alloy wire, in a radiopaque tube or coil, the wire having a diameter of about 0.002 inches and positioned around or wound around the flexible shaft 82 and soldered to the flexible shaft 82 to create an RO sleeve or coil having an outer diameter of less than about 0.020 inches, for example about 0.012 inches. The radiopaque marker also provides an axial interference fit between the flexible shaft 82 and the advancing section 100 and the trailing section 104 to resist axial withdrawal of the core wire from the tip 90 (tip detachment).

[0081] In certain embodiments, the maximum OD of the thread profile 92 is at least about 15% or 25% or 30% or more of the OD of the advancement section 100, and by exceeding the maximum OD of the advancement section 100, it facilitates the intersection of the advancement section 100 and the thrombus and the engagement of the thread profile 92 with the thrombus.

[0082] Depending on the clinical application, if the distal tip 102 is present, it may be desirable to control the extent to which it extends beyond the distal end of the distal catheter 12. In certain embodiments, the distal tip 102 may be permitted to extend at least about 2 cm or 3 cm beyond the catheter, and preferably from 4 to 8 cm (such as for enabling manual removal of the engaged thrombus), but generally will be restricted to extend below a pre-set distance such as 12 cm or 8 cm or 5 cm (e.g., in the range of about 5 cm to about 10 cm) beyond the catheter, depending on the desired performance.

[0083] The distal advancement of the tip 102 can be restricted by providing mechanical interference at the desired distal limit of travel. In one embodiment, a distal stop surface 114 (see FIG. 6A), which may be on the handle 88, provides an interference engagement with a complementary proximal surface (such as the proximal surface 33 on the connector module 30 or the catheter hub) carried by the aspiration catheter that has advanced the thrombus engagement tool 80 therein. Alternatively, the distal engagement surface can be carried anywhere along the length of the thrombus engagement tool 80 for a sliding rotational engagement with a complementary proximally facing stop surface carried by the catheter. Further details of the distal limiting configuration can be found in U.S. Patent Application Serial No. 17 / 036,258, filed September 29, 2020, entitled "Embolic Retrieval Catheter", the entire disclosure of which is hereby expressly incorporated by reference herein.

[0084] Due to the restrictions imposed on the distal advancement of the helical tip, a first configuration can be achieved, in which the distal tip can be advanced through the catheter and positioned at a first position approximately aligned with the distal end of catheter 12. The physician can then advance the tip to a second position extending beyond the distal end of the catheter, for purposes such as inspection and cleaning.

[0085] The position indicator 85 can be carried by the flexible shaft 82 and spaced from the distal surface 114 by a distance corresponding to the maximum length of the thrombus engagement tool intended to extend beyond the distal end of the catheter. When the position indicator 85 is located at a corresponding reference point relative to the catheter hub, the distal tip 102 can be located approximately at the distal end of the catheter. In this way, the physician will know that any further distal advancement of the thrombus engagement tool will extend beyond the distal end of the catheter. When the distal surface 114 contacts the catheter hub, the extension will reach its maximum.

[0086] The position indicator 85 can include any of a variety of visual or tactile features, such as a color change or a colored band surrounding the flexible shaft 82. In an embodiment of a visual mark (color change or circumferential line), the distal tip 102 can be located approximately at the distal end of the catheter when the indicator is visible just outside the hub. In another embodiment, the position indicator 85 includes a transition between the distal end of the hypo tube 87 and the flexible shaft 82 thereunder. This provides tactile feedback as the indicator (step in outer diameter) encounters and passes through the valve of the RHV. The hypo tube 87 can additionally function as a stress relief or anti-kinking feature and can have an axial length in the range of about 3 cm to about 15 cm, and in some embodiments in the range of about 5 cm to about 9 cm.

[0087] Referring to FIG. 7A, an example of a stacking pattern of an outer jacket section for a progressive flexibility catheter of the type discussed in relation to FIG. 1 is illustrated. The distal section 120 can have a length in the range of about 1 - 3 cm and a durometer of less than about 35D or 30D. The adjacent proximal section 122 can have a length in the range of about 4 - 6 cm and a durometer of less than about 35D or 30D. The adjacent proximal section 124 can have a length in the range of about 4 - 6 cm and a durometer of 35D or less. The adjacent proximal section 126 can have a length in the range of about 1 - 3 cm and a durometer in the range of about 35D to about 45D (e.g., 40D). The adjacent proximal section 128 can have a length in the range of about 1 - 3 cm and a durometer in the range of about 50D to about 60D (e.g., about 55D). The adjacent proximal section 130 can have a length in the range of about 1 - 3 cm and a durometer in the range of about 35D to, in the range of about 50D to about 60D (e.g., about 55D). The adjacent proximal section 132 can have a length in the range of about 1 - 3 cm and a durometer of at least about 60D and typically less than about 75D. Further proximal sections can have a durometer of at least about 65D or 70D.

[0088] The two or three most distal sections can comprise materials such as Tecothane and / or PEBAX, and further proximal sections can comprise PEBAX or other catheter jacket materials known in the art. At least three or five or seven or nine or more individual sections can be utilized, and those sections can have a change in durometer between the highest and lowest along the length of the catheter shaft of at least about 10D, preferably at least about 20D and in some embodiments at least about 30D or 40D or greater.

[0089] Figures 7A - 7E illustrate various embodiments of a catheter, at least some of which incorporate a plurality of outer catheter jacket segments that vary flexibility along the length of the catheter body by varying length and / or stiffness. It will be understood that any of the features shown or described in connection with any of the catheters of Figures 7A - 7E can be used with any of the embodiments described and / or contemplated herein. It will also be understood that any of the features described and / or contemplated in connection with any of the embodiments disclosed herein can be utilized with any of the catheters described in connection with Figures 7A - 7E. As with any of the embodiments herein, any of the features, structures, materials, methods, or steps described and / or illustrated in the embodiments of Figures 7A - 7E can also be used with or instead of any of the features, structures, materials, methods, or steps described and / or illustrated in any other embodiment herein.

[0090] Figures 7B - 7E illustrate embodiments of various catheters 400, 500, 600. The catheters 400, 500, 600 can include different characteristics (e.g., length, diameter, etc.) such that one or more of the catheters 400, 500, 600 can interact with any of the other catheters 400, 500, 600 in any of a variety of ways. In one example, as illustrated by Figure 7E, each of the catheters 400, 500, 600 can include different sizes such that the catheters 400, 500, 600 are allowed to at least partially extend through one or more of the other catheters 400, 500, 600. The length of each of the catheters 400, 500, 600 can vary such that the smaller catheter is allowed to pass nested within and distally beyond the larger catheter.

[0091] As an example, the catheter 500 can be configured to pass through and extend beyond the catheter 400. As a further example, the catheter 600 can be configured to telescopically pass through and extend beyond at least one of the catheter 500 or the catheter 400. Although FIG. 7E illustrates an example of a telescoping catheter stack including each of the catheters 400, 500, 600, it will be understood by those skilled in the art that any combination of the catheters 400, 500, 600 can be utilized. For example, the system can incorporate the use of the catheter 400 and the catheter 500, the use of the catheter 400 and the catheter 600, or the use of the catheter 500 and the catheter 600.

[0092] The catheter 400 can comprise an 8F catheter. In some examples, the catheter 400 can comprise a diameter larger than the diameter of any of the remaining catheters in the system. Additionally or alternatively, the catheter 400 can comprise an overall length shorter than the length of any of the remaining catheters in the system. In this way, the catheter 400 can comprise the outermost catheter in the telescoping system and can allow any of the remaining catheters 500, 600 to extend distally beyond the distal end of the catheter 400. The catheter 400 can comprise a length between about 35 cm and about 105 cm, or a length between about 45 cm and about 95 cm. The catheter 400 can comprise a length from about 50 cm to about 90 cm. The catheter 400 can comprise an overall length at least shorter than any catheter having a diameter smaller than the catheter 400 (e.g., catheter 500, 600, etc.).

[0093] The catheter 500 may comprise a 6F catheter. In some examples, the catheter 500 may comprise a diameter between the diameters of the remaining catheters in the system. Additionally or alternatively, the catheter 500 may comprise a length between the lengths of the remaining catheters in the system. In this way, the catheter 500 may comprise a central catheter within the telescoping system and may be configured to extend through and beyond one or more of the catheters while at the same time allowing another catheter to extend distally beyond the distal end of the catheter 500. The catheter 500 may comprise a length between about 120 cm and about 155 cm or between about 130 cm and about 145 cm. The catheter 500 may comprise a length from about 135 cm to about 137 cm. The catheter 500 may comprise a length that is at least as long as any catheter having a diameter larger than the catheter 500 (such as the catheter 400, etc.). The catheter 500 may comprise a length that is at least as short as any catheter having a diameter smaller than the catheter 500 (such as the catheter 600, etc.).

[0094] The catheter 600 may comprise a 5F catheter. In some examples, the catheter 600 may comprise a diameter smaller than the diameters of the remaining catheters in the system. Additionally or alternatively, the catheter 600 may comprise a length longer than any of the lengths of the remaining catheters in the system. In this way, the catheter 600 may comprise the innermost catheter within the telescoping system and may be configured to extend through and beyond one or more of the other catheters. The catheter 600 may comprise a length between about 145 cm and about 175 cm or between about 155 cm and about 165 cm. The catheter 600 may comprise a length of about 160 cm. The catheter 600 may comprise a length that is at least as long as any catheter having a diameter larger than the catheter 600 (such as the catheter 400, 500, etc.).

[0095] One or more catheters 400, 500, 600 may include coils and / or braids within a sidewall that extends through at least a portion of the sidewall of catheters 400, 500, 600, as discussed herein. The braid may have characteristics that vary along the length of each catheter 400, 500, 600 to produce various desired characteristics of catheters 400, 500, 600. For example, the wire density of the braid may vary gradually or stepwise along the length of catheters 400, 500, 600, and / or may vary between individual sections of catheters 400, 500, 600.

[0096] Catheter 600 may comprise one or more individual sections having braid characteristics that vary between one or more sections. In some examples, catheter 600 may comprise a first section, a second (e.g., intermediate) section, and a third distal section. However, it will be understood by those skilled in the art that catheter 600 may comprise a lesser number of sections (e.g., one or two sections) or a greater number of sections (e.g., four or more sections). The characteristics of the sidewall, such as length and / or wire density braid along each respective section, may vary between sections. In some examples, the picks per inch (ppi) count of the braid related to the wire density of the braid may gradually transition between one or more catheter sections. For example, the ppi count of the braid may, in some examples, generally remain unchanged through the length of the first section and the length of the third section, but may gradually transition along the length of the second, intermediate section.

[0097] The first section of catheter 600 may have a length of at least about 20 cm. For example, the length of the first section may be from about 25 cm to about 35 cm or, in one example, about 30 cm. The braid through the first section may have a wire density of at least about 100 ppi. For example, the braid through the first section may have a wire density of at least about 120 ppi or, more specifically, about 130 ppi.

[0098] The third section of the catheter 600 can have a length of at least about 100 cm. For example, the length of the third section can be from about 120 cm to about 140 cm, or more specifically, about 130 cm. The braiding through the third section can have a wire density of about 85 ppi or less. For example, the braiding through the third section can have a wire density from about 70 ppi to about 80 ppi.

[0099] The second section of the catheter 600 can be an intermediate section between the first and third sections. The second section can have a length of at least about 3 cm. In some examples, the second section can have a length of about 20 cm or less, or more specifically, about 10 cm or less. For example, the length of the second section can be about 5 cm. The braiding through the second section can have a wire density that is less than or equal to the wire density of the first section and greater than or equal to the wire density of the third section.

[0100] The catheter 500 can comprise one or more individual sections having braiding characteristics that vary between one or more of the sections. In some examples, the catheter 500 can comprise a first section, a second (e.g., intermediate) section, and a third section. However, it will be understood by those skilled in the art that the catheter can comprise a lesser number of sections (e.g., one or two sections) or a greater number of sections (e.g., four sections or more). The characteristics of the sidewall, such as length and / or wire density braiding along each section, can vary between the sections. In some examples, the ppi count of the braiding related to the wire density of the braiding can gradually transition between one or more catheter sections. For example, the ppi count of the braiding can, in some examples, generally remain unchanged through the length of the first and third sections, but can gradually transition along the length of the second, intermediate section.

[0101] The first section of the catheter 500 can have a length of at least about 20 cm. For example, the length of the first section can be from about 25 cm to about 35 cm or, in one example, about 30 cm. The braid passing through the first section can have a wire density of at least about 100 ppi. For example, the braid passing through the first section can have a wire density of at least about 120 ppi or, in one example, about 130 ppi.

[0102] The third section of the catheter 500 can have a length of at least about 80 cm. For example, the length of the third section can be from about 100 cm to about 120 cm or, in one example, about 105 cm. The braid passing through the third section can have a wire density of 100 ppi or less. For example, the braid passing through the third section can have a wire density from about 80 ppi to about 90 ppi.

[0103] The second section of the catheter 600 can be an intermediate section between the first and third sections. The second section can have a length of at least about 3 cm. In some examples, the second section can have a length of about 20 cm or less or, more specifically, about 10 cm or less. For example, the length of the second section can be about 5 cm. The braid through the second section can have a wire density that is less than or equal to the wire density of the first section and greater than or equal to the wire density of the third section.

[0104] Catheter 400 can comprise one or more individual sections having braiding characteristics that vary between one or more sections. In some examples, catheter 400 can comprise one section. However, it will be understood by those skilled in the art that catheter 400 can comprise a greater number of sections (e.g., two sections, three sections, four sections, or more). For example, catheter 400 can comprise any one or the three sections described in relation to catheter 500 or catheter 600. The characteristics of the sidewall, such as length and / or wire density braiding, can vary along catheter 400. In some examples, the ppi count of the braiding related to the wire density of the braiding can gradually shift along catheter 400 to increase flexibility in the distal direction. The sections of catheter 400 can have a length of at least about 40 cm. For example, the length of the section can be from about 50 cm to about 60 cm or, in one example, about 55 cm. The braiding through the section can have a wire density of at least about 80 ppi. For example, the braiding through the section can have a wire density of at least about 90 ppi.

[0105] In some examples, the braiding can extend along the entire length of the catheter sidewall. In some examples, there is no junction between the braiding and the coil within the catheter and / or no coil is incorporated into the catheter sidewall. It will be understood that this braiding configuration can be applied to any of the catheters disclosed herein, including but not limited to catheters 400, 500, 600.

[0106] One or more of the catheters 400, 500, 600 can be a stacked pattern of outer jacket segments for a catheter of progressive flexibility. Each of the outer jacket segments has properties that vary along the length of each catheter 400, 500, 600 to produce various desired properties of the catheters 400, 500, 600. For example, each segment of the outer jacket can have a corresponding Shore D hardness that varies the flexibility along the length of the catheters 400, 500, 600. The outer jacket segments can be made of a thermoplastic elastomer made from a flexible polyether and a rigid polyamide (e.g., Pebax (registered trademark)). In some examples, each segment of the outer jacket can comprise a thermoplastic elastomer of different deformation forms that modifies flexibility.

[0107] Catheter 600 can comprise a plurality of individual segments of an outer jacket having a flexibility that varies between one or more of the segments. In some examples, catheter 600 can comprise a plurality of segments. The properties of the sidewall, such as Shore D hardness and / or flexibility, can vary between the segments. In some examples, the Shore D hardness of the outer jacket segments can vary gradually such that it is high at the proximal end segment of the outer jacket and low at the distal end segment of the outer jacket.

[0108] The proximal end segment of the outer jacket of catheter 600 can have a Shore D hardness of at least about 60. For example, the Shore D hardness of the proximal end segment can be from about 70 to about 80 or, more specifically, at least about 75.

[0109] The distal end segment of the outer jacket of catheter 600 can have a Shore D hardness of at most about 40. For example, the Shore D hardness of the distal end segment can be from about 30 to about 20 or, more specifically, about 27 or less.

[0110] The plurality of intermediate sections between the distal section and the proximal section can each comprise various Shore D hardnesses. In some examples, each section can have a Shore D hardness that decreases in the distal direction and is less than the Shore D hardness of the adjacent proximal section. For example, the Shore D hardness of the first section can be from about 30 to about 50 or, more specifically, about 40. The first section can be located at a distance of from about 120 cm to about 160 cm or, more specifically, about 140 cm from the distal end face of the catheter 600 in some examples. As another example, the Shore D hardness of the second section can be from about 50 to about 70 or, more specifically, about 65. The second section can be located at a distance of from about 220 cm to about 260 cm or, more specifically, about 240 cm from the distal end face of the catheter 600 in some examples.

[0111] Catheter 500 can comprise a plurality of individual sections of an outer jacket having a flexibility that varies between one or more sections. In some examples, the catheter can comprise a plurality of sections. The properties of the sidewall, such as Shore D hardness and / or flexibility, can vary between the sections. In some examples, the Shore D hardness of the outer jacket sections can vary gradually such that it is high at the proximal end section of the outer jacket and low at the distal end section of the outer jacket.

[0112] The proximal end section of the outer jacket of catheter 500 can have a Shore D hardness of at least about 60. For example, the Shore D hardness of the proximal end section can be from about 70 to about 80 or, more specifically, at least about 75.

[0113] The distal end section of the outer jacket of catheter 500 can have a Shore D hardness of at most about 40. For example, the Shore D hardness of the distal end section can be from about 30 to about 20 or, more specifically, about 27 or less.

[0114] The plurality of intermediate sections between the distal section and the proximal section can each comprise various Shore D hardnesses. In some examples, each section can have a decreasing Shore D hardness in the distal direction and have a Shore D hardness smaller than the section adjacent proximally thereto. For example, the Shore D hardness of the first section can be from about 30 to about 50 or, more specifically, about 40. The first section can be located at a distance of from about 70 cm to about 110 cm or, more specifically, about 90 cm from the distal end face of the catheter 500 in some examples. As another example, the Shore D hardness of the second section can be from about 50 to about 70 or, more specifically, about 65. The second section can be located at a distance of from about 160 cm to about 200 cm or, more specifically, about 180 cm from the distal end face of the catheter 500 in some examples.

[0115] Catheter 400 can comprise a plurality of individual sections of an outer jacket having a flexibility that varies between one or more of the sections. In some examples, catheter 400 can comprise a plurality of sections. The properties of the sidewall, such as Shore D hardness and / or flexibility, can vary between the sections. In some examples, the Shore D hardness of the outer jacket section can gradually transition from the proximal end section of the outer jacket to the distal end section of the outer jacket.

[0116] The proximal end section of the outer jacket of catheter 400 can have a Shore D hardness of at least about 60. For example, the Shore D hardness of the proximal end section can be from about 70 to about 80 or, more specifically, about 75.

[0117] The distal end section of the outer jacket of catheter 400 can have a Shore D hardness of at most about 40. For example, the Shore D hardness of the distal end section can be from about 30 to about 20 or, more specifically, about 27 or less.

[0118] The plurality of intermediate sections between the distal section and the proximal section can each comprise various Shore D hardnesses. In some examples, each section can have a Shore D hardness that decreases in the distal direction and is less than that of the proximally adjacent section. For example, the Shore D hardness of the first section can be from about 30 to about 50 or, more specifically, about 40. The first section can be located at a distance of from about 65 cm to about 105 cm or, more specifically, about 85 cm from the distal end face of the catheter 400 in some examples. As another example, the Shore D hardness of the second section can be from about 40 to about 65 or, more specifically, about 55. The second section can be located at a distance of from about 105 cm to about 145 cm or, more specifically, about 125 cm from the distal end face of the catheter 400 in some examples. As a further example, the Shore D hardness of the third section can be from about 60 to about 80 or, more specifically, about 70. The third section can be located at a distance of from about 140 cm to about 180 cm or, more specifically, about 160 cm from the distal end face of the catheter 400 in some examples.

[0119] The catheter 400 can comprise a tubular length of about 90 + / - 5 cm. In some examples, the catheter 400 can comprise a tubular length of about 50 + / - 5 cm. The plurality of individual sections of the outer jacket of the catheter 400 can vary with respect to the tubular length of the catheter 400. The length of each of the plurality of individual sections of the outer jacket of the catheter 400 can vary with respect to the tubular length of the catheter 400.

[0120] In some examples, the coating can be located along the outer diameter of the distal portion of the catheter sidewall. The coating can be configured to reduce the frictional resistance of the distal portion of the catheter sidewall with any adjacent structure (e.g., the blood vessel wall). In some examples, the coating increases the lubricity of the outer sidewall of the distal portion of the catheter. Advantageously, the coating can reduce the friction on the distal end of the catheter advancing through the tortuous vascular system. Thereby, particularly in situations where the catheter contains increased flexibility along the distal end portion of the catheter, the advancement and rotation of the distal end of the catheter are facilitated. The coating can extend proximally from or adjacent to the distal end face of the catheter. The coating can extend proximally for at least about 20 cm. In some examples, the coating extends from the distal end face of the catheter to up to about 50 cm. For example, the coating can extend from the distal end face of the catheter for a length of about 25 cm to about 35 cm or, more specifically, about 30 cm. It will be understood that this coating can be applied to any catheter disclosed herein, including but not limited to catheters 400, 500, 600.

[0121] FIG. 8 illustrates a cross-section through the sidewall of the distal portion of a single lumen catheter. The internal support layer can comprise either a coil or a braid. In the coil embodiment, adjacent loops or filars of coil 140 can have a constant pitch throughout the length of the coil, or can be wound more tightly in the proximal zone such that in the distal section, the spacing between adjacent loops can be looser. In embodiments having a coil section 140 having an axial length between at least about 20% and about 30% of the total catheter length (e.g., a 28 cm coil length in a 110 cm catheter shaft 16), at least the distal about 1 cm or about 2 cm or about 3 cm or about 4 cm of the coil can have a spacing that is at least about 130% greater than the spacing in the proximal coil section, and in some embodiments at least about 150% greater. In a 110 cm catheter shaft 3000 having Nitinol coils, the spacing in the proximal coil can be about 0.004 inches, and in the distal section can be at least about 0.006 inches or about 0.007 inches or greater.

[0122] The distal end of the coil or braid 140 can be spaced proximally from the distal end of the internal liner 142, for example, providing room for an annular radiopaque marker 144. The coil or braid 140 can, in some embodiments, be positioned proximally recessed from the distal end by approximately about 1 cm, about 2 cm, or about 3 cm or less. In one embodiment, the distal end of catheter 12 has an angled (tilted) distal surface 146 that lies in a plane having an angle of at least about 10 degrees or about 20 degrees, and in one embodiment about 30 degrees, relative to the longitudinal axis of catheter 10. At least the edge of the annular radiopaque marker 144 facing distally can be elliptical and lie in a plane tilted with respect to the longitudinal axis complementary to the angle of the distal surface 146. Further details are described in connection with FIG. 9 below.

[0123] After applying braiding or a combination of braiding and coiling on the termination layer 152 and / or on the liner, the distal braiding or coiling and the RO marker 144 are provided with an outer jacket 156, such as a polymer tube, formed from a plurality of axially adjacent cylindrical segments surrounding the catheter body 16. The outer sleeve 156 can comprise any of a variety of materials, such as polyethylene, polyurethane, polyether block amide (e.g., Pebax (PEBAX®)), nylon, or other known ones. By applying sufficient heat, the polymer flows into and embeds within the proximal braiding and distal coiling.

[0124] In one embodiment, the outer jacket 156 is formed by sequentially advancing a plurality of short tubular segments 133, 132, 130, 128, 126, 124, 122, 120 concentrically over the catheter shaft subassembly, applying heat to shrink the segments onto the catheter 12 to provide a smooth and continuous outer tubular body. The previously segmented structure can extend along at least the most distal approximately 10 cm of the catheter body 10, and preferably at least approximately the most distal approximately 20 cm, about 25 cm, about 30 cm, about 35 cm, about 40 cm, or greater than about 40 cm. The overall length of the outer jacket 156 can be formed from the tubular segments, and the length of the distal tubular segment can be shorter than one or more of the tubular segments that form the proximal portion of the outer jacket 156 proximal to the junction between the braiding 150 and the coil 140 to provide a sharp transition in flexibility towards the proximal backup support and the distal end of the catheter 12.

[0125] The durometer of the outer wall segments can decrease in the distal direction. For example, proximal segments such as 133 and 132 can have a durometer of at least about 60D or about 70D, and the durometers of successive segments in the distal direction gradually decrease to a durometer of about 35D or about 25D or lower. The 25 cm section can have at least about 3 or about 5 or about 7 or more segments, and the entire catheter 12 can have at least about 6 or about 8 or about 10 or more distinct flexibility zones. The distal 1 or 2 or 4 or more segments 122, 120 can have a smaller OD after shrinkage than the more proximal segments 133 - 124, resulting in a decrease in OD with respect to the completed catheter body 16. The length of the smaller OD section 160 can range from about 3 cm to about 15 cm, and in some embodiments, ranges from about 5 cm to about 10 cm such as about 7 cm or about 8 cm, and can be accomplished by providing distal segments 122, 120 with a smaller wall thickness.

[0126] In another embodiment, the most distal portion of the catheter 12 can comprise a durometer of less than approximately 35D (e.g., 25D) so as to form a highly flexible distal portion of the catheter, and can have a length between approximately 25 cm and approximately 35 cm. The distal portion can comprise one or more tubular segments (e.g., segment 120) of the same durometer. A series of proximally adjacent tubular segments can form a transition region between the proximal rigid portion of the catheter 12 and the distal highly flexible portion of the catheter. The series of tubular segments forming the transition region can have the same or substantially the same length, e.g., approximately 1 cm.

[0127] A series of tubular segments each of relatively short length provides a sharp drop in durometer over the transition region. For example, the transition region may have a proximal tubular segment 122 (adjacent proximally to the distal portion) with an approximate durometer of 35D. The adjacent proximal segment 124 may have an approximate durometer of 55D. The adjacent proximal segment 126 may have an approximate durometer of 63D. The adjacent proximal segment 128 may have an approximate durometer of 72D.

[0128] Even more proximal segments may comprise a durometer greater than approximately 72D and may extend to the proximal end of the catheter. By way of example, the catheter segment may comprise a proximal portion greater than approximately 72D between about 1 cm and about 3 cm. In some embodiments, the proximal portion may be about 2 cm in length. In some embodiments, the most distal segments (e.g., 120, 122) may comprise Pebax (PEBAX (trademark)), and even more proximal segments may generally comprise a stiffer material, such as Vestamid (registered trademark).

[0129] The inner diameter of the catheter 10 may be between approximately 0.06 and 0.08 inches, between approximately 0.065 and 0.075 inches, or between approximately 0.068 and 0.073 inches. In some embodiments, the inner diameter is approximately 0.071 inches.

[0130] In some embodiments, the distal portion may be stepped or tapered with a reduced inner diameter, such as within sections 122 and 120. The taper may occur approximately between the distal highly flexible portion and the transition region (e.g., on the proximal portion of the distal highly flexible portion). The taper may be relatively gradual (e.g., occurring over approximately 10 cm or more) or relatively steep (e.g., occurring over approximately less than 5 cm). The inner diameter may be tapered down to an inner diameter between about 0.03 and about 0.06 inches. For example, the inner diameter may be about 0.035 inches, about 0.045 inches, or about 0.055 inches at the distal end of catheter 12. In some embodiments, the inner diameter may remain constant over at least the extension section of the catheter.

[0131] In some hybrid coil / braid embodiments, coil 140 may extend proximally from the distal end of catheter 12 along a highly flexible distal portion that terminates or overlaps at the distal end of braid 150. In other embodiments, coil 140 may extend the entire length of catheter 12. Braid 150, if present, may extend from approximately the proximal end of transition section 163 of coil 140 to the proximal end of catheter 12.

[0132] Any of the catheters disclosed herein may comprise an angled distal tip. Referring to FIG. 9, the distal catheter tip 18 comprises a tubular body 14 including an advancement section 200 and a marker band 144. An internal tubular liner 142 may extend throughout the length of the distal catheter tip and may comprise dip-coated PTFE.

[0133] Reinforcing components 140, such as braids and / or spring coils, are embedded within an outer jacket that may extend the entire length of the catheter proximal to the radiopaque marker.

[0134] The advancing section 200 terminates distally within the angled surface 146 and provides a leading sidewall portion 202 having a length measured between the distal end 204 of the marker band 144 and the distal tip 206. The trailing sidewall portion 208 of the advancing section 200 has an axial length in the illustrated embodiment that is approximately equal to the axial length of the leading sidewall portion 202 measured approximately 180 degrees around the catheter from the leading sidewall portion 202. The leading sidewall portion 202 can have an axial length in the range of from about 0.1 mm to about 5 mm and generally in the range of about 1 to 3 mm. The trailing sidewall portion 208 can be at least about 0.1 or 0.5 or 1 mm or 2 mm less than or shorter than the axial length of the leading sidewall portion 202, depending on the desired performance.

[0135] The angled surface 146 is inclined at an angle A in the range of from about 45 degrees to about 80 degrees from the longitudinal axis of the catheter. In certain embodiments, this angle is in the range of from about 50 degrees to about 70 degrees or from about 55 degrees to about 65 degrees from the longitudinal axis of the catheter. In one embodiment, the angle A is about 60 degrees. One consequence of angle A being less than 90 degrees is that the major axis of the region of the distal port extends, increasing the surface area of the port and enhancing thrombus aspiration or thrombus retention. Compared to the surface area of a circular, transverse port (angle A of 90 degrees), the area of the angled port is generally at least about 105% and up to about 130%, in some embodiments in the range of about 110% to about 125%, and in one example about 115%.

[0136] In the illustrated embodiment, the axial length of the proximal section is substantially constant around the circumference of the catheter such that the angled surface 146 is approximately parallel to the distal surface 210 of the marker band 144. The marker band 144 has a proximal surface that is approximately transverse to the longitudinal axis of the catheter and forms a marker band 144 having a right trapezoidal structure in a side elevation view. The short side wall 212 is rotationally aligned with the trailing side wall portion 208 and has an axial length in the range of from about 0.2 mm to about 4 mm and typically in the range of from about 0.5 mm to about 2 mm. The opposing long side wall 214 is rotationally aligned with the leading side wall portion 202. The long side wall 214 of the marker band 144 is generally at least about 10% or 20% longer than the short side wall 212 and, depending on the desired performance, can be at least about 50% or 70% or 90% longer than the short side wall 212 or longer. Generally, the long side wall 214 will have a length of at least about 0.5 mm or 1 mm and less than about 5 mm or about 4 mm.

[0137] Any of the marker bands described herein can be a continuous annular structure or optionally can have one or optionally two or three or more slits that extend axially throughout its length. The slits can be located on the short side wall 212 or the long side wall 214 or between them, depending on the desired bending properties. Any of the marker bands described herein can preferably comprise any of a variety of radiopaque materials having a wall thickness of about 0.003 inches or less, such as a platinum / iridium alloy, and in one embodiment is about 0.001 inches.

[0138] The advancement section 200 can comprise an outer polymer jacket and optionally a distal extension of an inner liner, and is distal from the marker band 144 without any other internal support structure. The outer jacket can comprise extruded (Tecothane) and / or Pebax (PEBAX). The advancement section 200 can have a bending stiffness and a radial crush stiffness that are about 50% or less relative to the corresponding values of the adjacent proximal catheter body, and in some embodiments about 25% or 15% or 5% or less or less than that.

[0139] The proximal end of the catheter 12 preferably comprises a hemostatic valve, which facilitates the introduction of a thrombus engagement tool or a secondary catheter therethrough. The hemostatic valve can be carried by the connector module 30 or directly by the proximal catheter connector 22. Any of various hemostatic valve configurations can be used.

[0140] Referring to FIGS. 10A - 10C, a valve insertion device according to another embodiment is illustrated. The insertion device enables opening a valve (e.g., a hemostatic valve having an elastomeric membrane valve with a passive slit and / or an introducer sheath valve), supporting it in the opened configuration, and at the same time providing lumen access through the valve such that a delicate secondary device, such as a thrombus engagement tool or a catheter, can advance therethrough without encountering any resistance or damage from the valve.

[0141] The insertion device 300 comprises an elongated tubular body 302 having a proximal end 304, a distal end 306, and a central lumen 308 extending therethrough. The tubular body 302 has an inner diameter sufficient to accommodate secondary devices and an OD that can pass through a compatible hemostatic valve. Generally, the tubular body will have an outer diameter in the range of about 0.04’’ to about 0.1 and a length in the range of about 1’’ to about 4’’. The tubular body 302 can be formed as an extrudate from any of a variety of common catheter polymers such as nylon, PEEK, polyethylene, polyimide, or others known in the art having sufficient crush resistance and column strength to maintain integrity and ingress under the closing pressure of the hemostatic valve.

[0142] The proximal end 304 of the tubular body 302 can be provided with a funnel-shaped landing zone 322 that connects to the central lumen, facilitating the introduction of the distal tip of the secondary device into the insertion device. In the illustrated embodiment, the proximal end of the tubular body comprises an inclined surface 314. The distal leading edge 316 of the inclined surface 314 is axially distal from the trailing proximal edge 318 of the surface 314 by a distance D. The distance D [between 316 and 318] is at least about 0.1’’ and is typically about 0.5’’ or less.

[0143] The inclined surface cooperates with the curved sidewall of the tube to create a side opening for feeding the distal tip of the secondary device into the proximal end of the lumen. For this purpose, the sidewall at the trailing edge 318 can have a curvature with a radius greater than the radius of curvature at the leading edge 316, with a gradually varying radius therebetween creating a funnel shape in the landing zone 322.

[0144] The tubular body 302 comprises an axially extending slit 310 that extends between the distal end 306 and the leading edge 316 of the inclined surface 314, thereby enabling the insertion device to be peeled laterally away from the secondary device extending through the insertion device once passage of the secondary device through the hemostatic valve has been enabled by the insertion device.

[0145] The pull tab 312 can be provided on the proximal end 302 of the tubular body, enabling the insertion device 300 to be gripped and pulled in from a secondary device extending through the insertion device. The pull tab 312 can be integrally formed with the tubular body 302 (e.g., as a portion of the side wall of the tubular material as illustrated), or can be attached thereto, such as by adhesive bonding or by mechanical compression or interference engagement. In the illustrated embodiment, the pull tab 312 is inclined so as to be laterally away from the longitudinal axis of the tubular body, enabling coaxial access and introduction of the catheter into the insertion device 300.

[0146] In one embodiment of the insertion device, the tubular body has a substantially constant diameter throughout most of its length (e.g., at least about 80% or 90%). However, the outer diameter at least in the distal tip section 324 can taper to a smaller outer diameter at the distal end. This enables the insertion device to fit more readily into the hemostatic valve under distal compression. In one example, the tubular body has an 8 French ID along most of its length, but tapers to 6 French in the distal tip section 324. This insertion device facilitates the introduction of either a 6 French or 8 French catheter through the hemostatic valve, as the 8 French catheter can simply be forced to expand the tapered distal end due to the axial slit 310.

[0147] In one embodiment, the concave inlet funnel-shaped surface of the landing zone 322 can be provided with a visible mark, such as a different color from the outer surface of the tubular body 302, to facilitate visualization of the funnel opening and assist in loading a secondary catheter into the funnel. This can be accomplished by providing a colored coating on either the inner or outer surface of the tubular material, or by forming at least a portion of the tubular material as a coextrusion of dissimilar-colored materials.

[0148] [Exemplary Embodiment] The following: Housing; Blood clot capture chamber within the housing; Window within the housing that permits visual inspection of the blood clot capture chamber; A filter within the blood clot capture chamber, visible through the window and having an upstream surface and a downstream surface; Inlet flow path configured to direct the inflowing blood from the aspiration catheter against the upstream surface of the filter; Normally closed aspiration control valve within the inlet flow path, configured to block the flow of the aspirated blood flowing in until it operates to permit the inflow of the aspirated blood; and Outlet flow path configured to direct blood from the downstream side of the filter to a remote vacuum cannister A blood clot capture module for use in a thrombus extraction system, comprising one or more of the above.

[0149] The blood clot capture module according to any embodiment herein, further comprising a normally closed vent operable to permit air to be drawn into the blood clot capture chamber.

[0150] The blood clot capture module according to any embodiment herein, wherein the upstream surface of the filter is visible through the window.

[0151] The blood clot capture module according to any embodiment herein, wherein the upstream surface of the filter is substantially planar.

[0152] The blood clot capture module according to any embodiment herein, wherein the upstream surface of the filter is convex.

[0153] The blood clot capture module according to any embodiment herein, wherein the filter comprises a blood-permeable membrane, and the upstream surface of the filter is on the radially outward-facing surface of the blood-permeable membrane.

[0154] The blood clot capture module according to any embodiment described herein, wherein the hemodialysis membrane at least partially surrounds a filtered blood chamber in fluid communication with an outflow channel.

[0155] The blood clot capture module according to any embodiment described herein, wherein the window comprises a transparent tubular portion of the housing.

[0156] The blood clot capture module according to any embodiment described herein, further comprising a suction actuator configured to control a suction control valve.

[0157] The blood clot capture module according to any embodiment described herein, wherein the suction actuator comprises a rocker switch.

[0158] A blood clot capture module according to any embodiment described herein, combined with a vacuum line connecting a suction pump and a cannister, wherein the blood clot capture module is configured to be resident within a sterile area, while the suction pump and the cannister are resident outside the sterile area.

[0159] The blood clot capture module according to any embodiment described herein, wherein the vacuum line is at least about 30 inches in length.

[0160] The blood clot capture module according to any embodiment described herein, wherein the suction control valve comprises crushable tubing.

[0161] The blood clot capture module according to any embodiment described herein, further comprising a selector valve within the vacuum line.

[0162] The blood clot capture module according to any embodiment described herein, wherein the suction pump comprises a syringe.

[0163] The blood clot capture module according to any embodiment described herein, comprising a proximal housing and a distal housing separated by a transparent tubular sidewall.

[0164] The blood clot capture module according to any embodiment herein, wherein at least one of the proximal housing and the distal housing is releasably connected to a transparent tubular sidewall.

[0165] The blood clot capture module according to any embodiment herein, further comprising a coating for suppressing blood accumulation on the inner surface of the window.

[0166] A thrombus engagement tool configured to be advanced through a catheter and to engage a thrombus, comprising: A rotatable core having a proximal end and a distal end; and A helical thread shape; An advancing section on the distal side of the helical thread shape; A trailing section on the proximal side of the helical thread shape A thrombus engagement tip on the distal end of the rotatable core, comprising: One or more of the above.

[0167] The thrombus engagement tool according to any embodiment herein, further comprising a protrusion carried by the rotatable core, the protrusion being inside at least one of the advancing section and the trailing section and forming an interference fit with the thrombus engagement tip.

[0168] The thrombus engagement tool according to any embodiment herein, wherein the protrusion comprises an annular ring.

[0169] The thrombus engagement tool according to any embodiment herein, wherein the protrusion comprises a radiopaque marker.

[0170] The thrombus engagement tool according to any embodiment herein, comprising a first radiopaque marker inside the advancing section and a second radiopaque marker inside the trailing section.

[0171] The thrombotic engagement tool according to any embodiment of the present specification, wherein the outer periphery of the helical thread shape substantially matches the surface of the cylinder.

[0172] The thrombotic engagement tool according to any embodiment of the present specification, comprising a proximal surface that inclines radially outward in the proximal direction and defines an undercut open proximally, and the helical thread shape.

[0173] The thrombotic engagement tool according to any embodiment of the present specification, further comprising a handle on the proximal end of the rotatable core.

[0174] The thrombotic engagement tool according to any embodiment of the present specification, comprising a limiting bearing surface on the handle configured to limit the distal protrusion of the thrombotic engagement tip relative to the distal end of the aspiration catheter.

[0175] The thrombotic engagement tool according to any embodiment of the present specification, wherein the advancement section, the helical thread shape, and the trailing section are all injection molded on the rotatable core.

[0176] The thrombotic engagement tool according to any embodiment of the present specification, in which a rotatable core is inserted into a catheter.

[0177] The thrombotic engagement tool according to any embodiment of the present specification, wherein the rotatable core is a solid wire.

[0178] The thrombotic engagement tool according to any embodiment of the present specification, wherein the advancement section includes a non-traumatic tip.

[0179] The thrombotic engagement tool according to any embodiment of the present specification, wherein the non-traumatic tip includes a soft polymer.

[0180] The thrombotic engagement tool according to any embodiment of the present specification, wherein the handle further includes a mark in the rotation direction.

[0181] The thrombus engagement tip has an axial length in the range of about 15 mm to about 30 mm, and the thrombus engagement tool according to any embodiment of the present specification.

[0182] A thrombus engagement tool according to any embodiment of the present specification, combined with a catheter having an inner diameter, wherein the helical thread-shaped outer diameter is about 60% or less of the inner diameter of the catheter.

[0183] The thrombus engagement tool according to any embodiment of the present specification, wherein the helical thread-shaped outer diameter is about 40% or less of the inner diameter of the catheter.

[0184] The thrombus engagement tool according to any embodiment of the present specification, further comprising a position indicator carried by a rotatable core.

[0185] The thrombus engagement tool according to any embodiment of the present specification, wherein the position indicator comprises the distal end of a tube surrounding the rotatable core.

[0186] A method for removing embolic material from a blood vessel using mechanical and aspiration assistance, comprising the following: Providing an aspiration catheter having a central lumen and a distal end; Advancing the distal end to an occlusive substance within the blood vessel; Applying a vacuum to the central lumen to draw a blood clot into the central lumen; Introducing a thrombus engagement tool into the central lumen, the thrombus engagement tool having a tip comprising a helical thread shape with a major diameter at least about 0.015 inches smaller than the inner diameter of the central lumen, and the helical thread shape being configured to provide an aspiration flow path around the tip; and Manually operating the tip to engage a blood clot between the tip and the inner wall of the central lumen, A method comprising one or more of the above.

[0187] A method for removing an occlusive substance according to any embodiment of the present specification, wherein the tip is carried by a rotatable core having a proximal handle.

[0188] A method for removing an occlusive substance according to any embodiment of the present specification, wherein a rotatable core is inserted into a catheter.

[0189] A method for removing an occlusive substance according to any embodiment of the present specification, wherein the rotatable core is a microcatheter.

[0190] A method for removing an occlusive substance according to any embodiment of the present specification, wherein the rotatable core is a wire.

[0191] A method for removing an occlusive substance according to any embodiment of the present specification, wherein the axial length of the threaded portion at the tip is in the range of about 5 mm to about 15 mm.

[0192] A method for removing an occlusive substance according to any embodiment of the present specification, further comprising introducing a catheter through the femoral artery prior to the advancing step.

[0193] A method for removing an occlusive substance according to any embodiment of the present specification, comprising advancing a catheter to a pulmonary thrombus site.

[0194] A method for removing an occlusive substance according to any embodiment of the present specification, comprising advancing a catheter to a deep vein thrombosis site.

[0195] A method for removing an occlusive substance according to any embodiment of the present specification, comprising introducing a thrombus engagement tool having a tip with a large diameter that is about 60% or less of the inner diameter of the central lumen.

[0196] A method for removing an occlusive substance according to any embodiment of the present specification, comprising introducing a thrombus engagement tool having a tip with a large diameter that is about 40% or less of the inner diameter of the central lumen.

[0197] A method for removing an occlusive substance according to any embodiment herein, wherein the distal end is displaced laterally within the central lumen in response to the uptake of the blood clot.

[0198] A method for removing an occlusive substance according to any embodiment herein, wherein the outer profile of the threaded tip at the end face is substantially circular.

[0199] A method for removing an occlusive substance according to any embodiment herein, wherein the thread shape has a proximal surface and a distal surface, and the proximal surface is inclined radially outward in the proximal direction.

[0200] A method for removing an occlusive substance according to any embodiment herein, further comprising axially reciprocating a thrombus engagement tool within the catheter.

[0201] A method for removing an occlusive substance according to any embodiment herein, further comprising axially extending the distal end of the catheter beyond the distal end of the catheter.

[0202] A method for removing an occlusive substance according to any embodiment herein, comprising extending the distal tip at least about 2 cm beyond the distal end of the catheter.

[0203] A method for removing an occlusive substance according to any embodiment herein, comprising axially aligning the distal end of the catheter and the distal tip using a position indicator on a rotatable core.

[0204] A method for removing an occlusive substance according to any embodiment herein, further comprising advancing the thrombus engagement tool through a rotary hemostatic valve before introducing the thrombus engagement tool into the central lumen.

[0205] A method for removing an occlusive substance according to any embodiment herein, wherein the position indicator provides tactile feedback as the position indicator passes through the hemostatic valve.

[0206] An insertion device for guiding a device through a valve, comprising the following: An elongated tubular body having a proximal end, a distal end, and a side wall that at least partially defines a central lumen; A concave landing zone that faces laterally on the proximal end and has a radius of curvature that increases in the proximal direction; and An axially extending slit within the side wall that extends from the distal end to the concave landing zone, An insertion device comprising one or more of the above.

[0207] The insertion device according to any embodiment herein, further comprising a tapered distal tip.

[0208] The insertion device according to any embodiment herein, further comprising a pull tab.

[0209] The insertion device according to any embodiment herein, wherein the surface of the concave landing zone comprises a color different from the outer surface of the elongated tubular body.

[0210] A method of passing a device through a valve, comprising the following: Providing an insertion device having a tubular body with a split side wall; Advancing the tubular body through the valve; Advancing the device through the tubular body and beyond the valve; and Retracting the tubular body proximally to cause the device to escape laterally from the tubular body through the split side wall and leave the device in a fixed position across the valve, A method comprising one or more of the above.

[0211] The method of passing a device through a valve according to any embodiment herein, wherein advancing the tubular body through the valve comprises advancing a tapered distal tip on the tubular body through the valve.

[0212] Advancing the tubular body through the valve is accomplished using a device pre-loaded inside the tubular body, a method of passing a device through a valve as described in any embodiment of this specification.

[0213] A method of passing a device through a valve as described in any embodiment of this specification, wherein the distal tip section of the tubular body expands in diameter in response to advancing the device through the valve.

[0214] A method of passing a device through a valve as described in any embodiment of this specification, wherein the device is a thrombus engagement tool.

[0215] A method of passing a device through a valve as described in any embodiment of this specification, wherein the device is a secondary catheter.

[0216] A method of passing a device through a valve as described in any embodiment of this specification, wherein the device is a suction catheter.

Claims

1. Housing equipped with a distal tube; Blood clot capture chamber within the aforementioned housing; A window within the housing that allows visual inspection of the blood clot capture chamber; A filter in the blood clot capture chamber, which is visible through the window and has an upstream surface and a downstream surface; An inflow channel configured to guide the blood flowing in from the suction catheter towards the upstream surface of the filter; A suction control valve located on the housing within the inflow channel, configured to block the flow of incoming aspirated blood until it is activated to allow the inflow of aspirated blood; and Outlet channel configured to guide blood from the downstream side of the filter to a remote vacuum canister A blood clot capture module used in a thrombectomy system, comprising: A blood clot capture module in which the housing is configured to communicate fluidly with the suction catheter via the distal tube.

2. The blood clot capture module according to claim 1, further comprising a normally closed vent that can be opened to allow air to be drawn into the blood clot capture chamber.

3. The blood clot capture module according to claim 1, wherein the upstream surface of the filter is visible through a window.

4. The blood clot capture module according to claim 1, wherein the upstream surface of the filter is substantially planar.

5. The blood clot capture module according to claim 1, wherein the upstream surface of the filter is convex.

6. The blood clot capture module according to claim 5, wherein the filter includes a blood permeable membrane, and the upstream surface of the filter is on the radially outward-facing surface of the blood permeable membrane.

7. The blood clot capture module according to claim 6, wherein the blood permeable membrane at least partially surrounds a filtered blood chamber that is in fluid communication with the outflow channel.

8. The blood clot capture module according to claim 1, wherein the window includes a transparent tubular portion of the housing.

9. The blood clot capture module according to claim 1, further comprising a suction actuator configured to control the suction control valve.

10. The blood clot capture module according to claim 9, wherein the suction actuator includes a rocker switch configured to selectively crush or reopen a crushable tubular material.

11. A blood clot capture module according to claim 1, combined with a vacuum line connected to a suction pump and a canister, wherein the blood clot capture module is configured to be located within a sterile area, while the suction pump and canister are located outside the sterile area.

12. The blood clot capture module according to claim 11, wherein the vacuum line is at least about 30 inches long.

13. The blood clot capture module according to claim 11, further comprising a selector valve in the vacuum line.

14. The blood clot capture module according to claim 11, wherein the suction pump includes a syringe.

15. The blood clot capture module according to claim 1, wherein the suction control valve includes a crushable tubular material.

16. The blood clot capture module according to claim 15, wherein at least a portion of the crushable tubular material is located inside the housing.

17. The blood clot capture module according to claim 1, comprising a proximal housing and a distal housing separated by transparent tubular side walls.

18. The blood clot capture module according to claim 17, wherein at least one of the proximal housing and the distal housing is releasably connected to the transparent tubular side wall.

19. The blood clot capture module according to claim 1, further comprising a coating that suppresses blood accumulation on the inner surface of the window.

Images