The entrapment of blood clots in small blood vessels

Abstract

Presented herein is a clot removal assembly for removing a blood clot from a blood vessel, the clot removal assembly including a delivery catheter, a clot retrieval device, and a valve assembly. In some embodiments, the clot retrieval device may include a cage structure and a shaft, where the cage structure may be configured to clamp a clot. A portion of the shaft extends through the delivery catheter. In some embodiments, the valve assembly may include a distal valve, a body portion, a distal body portion, and a movable head shell. The distal valve may be configured to engage a proximal region of the delivery catheter. In some embodiments, the distal body portion may include a plurality of grooves, and the movable head may be configured to ratchet proximally across the plurality of grooves, thereby maintaining tension on the shaft.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to devices and methods for removing blockages from blood vessels during intravascular medical procedures. [Background technology]

[0002] Clot retrievers are used in mechanical clot removal for endovascular interventions, particularly when patients suffer from conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE).

[0003] Tough, fibrin-rich clots may be located in small distal vessels compared to proximal vessels. These types of clots often cannot be retrieved by aspiration alone, and currently available clot retrieval devices are either too large and damage the vessel wall, or too small and ineffective at grasping tough distal clots. Creating a clot retrieval device of an appropriate size for these tough distal clots has not been achieved to date due to the difficulty of coupling a shaft to a clot retrieval cage structure. Applicant has recognized the need for a clot retrieval cage structure of an appropriate size for removing these tough distal clots, coupled to a shaft that allows the cage structure to be used with an appropriately sized catheter for delivering the cage structure to the distal vessel.

[0004] Clots can have any of a range of morphologies and consistencies. For example, clots can be difficult to grasp, and improper grasping can result in fragmentation that can lead to embolism. Compression of the clot causes dehydration of the clot, resulting in a dramatic increase in both the clot's stiffness and coefficient of friction, which necessitates removal by clamping rather than contact suction.

[0005] Physicians typically rely on visual and tactile feedback to assess clot engagement with a clot retrieval device. In some procedures, it can be difficult to determine whether a clot has been engaged by the clot retrieval device using this technology. It can also be difficult to maintain the appropriate tension between the clot retrieval device and the proximal components, which is necessary to maintain engagement with the clot. Disclosed herein are devices, systems, and methods. Summary of the Invention [Means for solving the problem]

[0006] In some embodiments, a clot removal device for removing a blood clot from a blood vessel is disclosed. The clot removal device can include a cage structure including a first tapered portion at a proximal end of the cage structure, a shaft including a second tapered portion at a distal end of the shaft, and a proximal joint where the first tapered portion is positioned with a non-engaging overlap with the second tapered portion. The proximal joint can include a weld between the first tapered portion and the second tapered portion, and a material coating over at least a portion of the first tapered portion, at least a portion of the second tapered portion, and at least a portion of the weld.

[0007] In some embodiments, the non-engaging overlap may be laser welded at two points and the material coating may be bonded to the shaft and cage structure at two points.

[0008] In some embodiments, the distal shaft portion may be tapered so that it is narrower distally and wider proximally.

[0009] In some examples, the cage structure may further include an open distal end and a proximal helical section. The proximal helical section may extend distally from the proximal end of the cage structure and include a first plurality of struts configured to sandwich a clot between at least one of the first plurality of struts. The proximal helical section may extend across a majority of the length of the cage structure from the proximal end to the open distal end.

[0010] In some embodiments, the cage structure can further include a cylindrical body section distal to the proximal helical section. The cylindrical body section can include a second plurality of struts larger than the first plurality of struts, and the cylindrical body section has a length less than the length of the proximal helical section. In some embodiments, the cylindrical body section has an outer diameter of about 2.5 mm.

[0011] In some embodiments, a clot removal assembly for removing a blood clot from a blood vessel is disclosed. The clot removal assembly can include a delivery catheter, a clot retrieval device, and a valve assembly. In some embodiments, the delivery catheter can include a distal region and a proximal region. In some embodiments, the clot retrieval device can include a cage structure and a shaft, where the cage structure can be configured to clamp a clot. A portion of the shaft extends through the delivery catheter. In some embodiments, the valve assembly can include a distal valve, a body portion, a distal body portion, and a movable head shell. The distal valve can be configured to engage a proximal region of the delivery catheter. In some embodiments, a portion of the shaft extends through a lumen of the body portion. In some embodiments, the distal body portion can include a plurality of grooves, where the movable head can be configured to ratchet proximally across the plurality of grooves, thereby maintaining tension on the shaft.

[0012] In some embodiments, the movable head shell can include teeth configured to engage the grooves, a threaded portion, and a screw head configured to engage the threaded portion and collapse the seal, the seal locking the shaft in place relative to the screw head when collapsed, and the teeth configured to disengage from the grooves in the body when flexed away from the central axis of the valve.

[0013] In some embodiments, the cage structure can include a proximal helical section and a cylindrical body section distal to the proximal helical section. The cylindrical body section can include a second plurality of struts that are larger than the first plurality of struts of the proximal helical section. In some embodiments, the cylindrical body section can have a length that is less than the length of the proximal helical section.

[0014] In some embodiments, the clot removal assembly can further include a proximal joint connecting the shaft to the proximal helical section. The proximal joint can be formed by laser welding together a non-engaging overlap between a tapered portion of the shaft and a tapered portion of the cage structure and providing a material coating on the proximal joint. In some embodiments, the non-engaging overlap is laser welded at two points and the material coating is coupled to the shaft and the cage structure at two points.

[0015] In some embodiments, the movable headshell may further include an external grip disposed at a proximal end of the movable headshell.

[0016] In some embodiments, the distal end of the movable headshell may include a thin plastic cylindrical wall configured to deform in response to pinching, which causes bending away from the central axis of the valve.

[0017] In some embodiments, the catheter may further include an inner diameter of about 0.013 inches.

[0018] In some embodiments, a method of removing a clot from a blood vessel is disclosed that may include deploying at least a portion of a cage structure of a clot retrieval device out of a catheter and across the clot, engaging a proximal portion of the catheter with a distal valve of a valve assembly, engaging a proximal portion of a shaft of the clot retrieval device with a movable head shell of the valve assembly, pulling the movable head shell of the valve proximally to clamp the clot, securing the movable head shell relative to the distal valve, thereby maintaining tension on the shaft, and withdrawing the cage structure and clot from the blood vessel.

[0019] In some embodiments, securing the movable headshell relative to the distal valve and thereby maintaining tension on the shaft may include engaging teeth disposed on the movable headshell with first grooves disposed on the distal body portion of the valve assembly, and gripping the shaft by compressing a seal between the screw head and threaded portion of the movable headshell.

[0020] In some embodiments, securing the movable headshell relative to the distal valve and thereby maintaining tension on the shaft may include sliding the movable headshell proximally and engaging the teeth with a second groove that is further proximally than the first groove.

[0021] In some examples, the method can include applying suction to the catheter through a side port disposed in the valve.

[0022] In some embodiments, the method may include clamping the movable headshell and releasing the tension by disengaging the teeth.

[0023] In some embodiments, the method may further include moving the cage structure to compress the clot between the cage structure and the interior wall of the blood vessel.

[0024] In some examples, the clot may be composed mostly of fibrin.

[0025] In some embodiments, the method can include withdrawing the clot from a distal M2, M3, M4, A2-5, or P2-P5 vessel.

[0026] Other aspects and features of the present disclosure will become apparent to those skilled in the art from the following detailed description considered in conjunction with the accompanying figures. [Brief explanation of the drawings]

[0027] The above and further aspects of the present disclosure will be further considered in conjunction with the following description of the accompanying drawings, in which like numerals indicate like structural elements and features in the various drawings. The drawings are not necessarily to scale, emphasis instead being placed on illustrating the principles of the present disclosure. The figures depict one or more implementations of the apparatus of the present invention by way of example only, and not by way of limitation. It is expected that one skilled in the art may conceive and combine elements from multiple drawings to better suit the needs of a user. [Figure 1] 1 shows a perspective view of a clot removal assembly having a delivery catheter, a clot retrieval device, and a valve assembly in accordance with the present disclosure. [Figure 2] FIG. 2 is an isometric view of the clot retrieval device shown in FIG. 1. [Figure 3] 1 illustrates an isometric view of a coupling according to the present disclosure. [Figure 4] 1A-1D are isometric and enlarged cross-sectional views of a microcatheter according to the present disclosure. [Figure 5A] 1 is a cross-sectional view of a blood vessel, a clot, and a clot removal assembly disposed therein, in accordance with the present disclosure. [Figure 5B] 1 is a cross-sectional view of a blood vessel, a clot, and a clot removal assembly engaged with the clot, in accordance with the present disclosure. [Figure 6] 1 shows a valve assembly according to the present disclosure. [Figure 7] 1 illustrates a portion of a valve assembly including a movable headshell having an external grip according to the present disclosure. [Figure 8] 1 is a flow chart illustrating a method for removing a blood clot from a patient's blood vessel, according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or its application and uses. Although the present disclosure is described mostly in the context of treating intracranial arteries, the present disclosure may also be used in other body passageways as mentioned above.

[0029] The terms "distal" or "proximal" are used in the following description with reference to a position or direction relative to the treating physician. "Distal" or "distally" is a position away from the physician or a direction away from the physician. "Proximal" or "proximally" or "near" is a position closer to the physician or a direction toward the physician.

[0030] As discussed herein, a "patient" or "subject" can be a human or any animal. It should be understood that the animal can be of any of a variety of applicable types, including, but not limited to, mammals, veterinary animals, livestock animals, or companion animals. By way of example, the animal can be a laboratory animal specifically selected to have certain characteristics similar to humans, such as rats, dogs, pigs, monkeys, etc.

[0031] As used herein, the term "about" or "approximately" in connection with any numerical value or numerical range indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function for its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value; for example, "about 90%" may refer to a range of values ​​of 71% to 99%.

[0032] As used herein, the terms "tubular" and "pipe / tube" are intended to be broadly construed and are not limited to structures having a right cylindrical or strictly circular cross section, or to structures having a uniform cross section along their entire length. For example, a tubular structure or tubular system is generally illustrated as a substantially right cylindrical structure. However, a tubular system may have a tapered or curved outer surface without departing from the scope of the present invention.

[0033] "Comprising" or "containing" or "including" means that at least the specified compounds, elements, particles, or method steps are present in a composition or article or method, but does not exclude the presence of other such compounds, elements, particles, or method steps, even if they have the same function as the specified ones.

[0034] It should also be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges can be expressed herein as from "about" or "approximately" one particular value and / or to "about" or "approximately" another particular value. When such a range is expressed, other exemplary embodiments also include from the one particular value and / or to the other particular value.

[0035] Accessing the cerebral, coronary, and pulmonary veins involves the use of numerous commercially available products and conventional procedural steps. Access products such as guidewires, guide catheters, angiography catheters, and microcatheters are described elsewhere and are routinely used in catheterization procedures. In the following description, these products and methods are assumed to be used in conjunction with the devices and methods of the present disclosure and need not necessarily be described in detail.

[0036] A common theme throughout many of the disclosed designs is a clot removal assembly 200 for removing a blood clot 700 from a blood vessel. The clot removal assembly 200 may include a delivery catheter 300, a clot retrieval device, and a valve assembly.

[0037] 1 is a diagram of an exemplary clot removal assembly for removing a blood clot 700 from a blood vessel. The clot removal assembly may include a delivery catheter 300, a clot retrieval device 110, and a valve assembly 400. In some embodiments, the clot retrieval device 100 may include a cage structure 110 and a shaft 120, where the cage structure 110 may be configured to clamp the clot 700. A portion of the shaft 120 extends through the delivery catheter 300. In some embodiments, the valve assembly 400 may include a distal valve 427, a body portion 410, a distal body portion 412, and a movable head shell 420. The distal valve 427 may be configured to engage a proximal region 320 of the delivery catheter 300. In some embodiments, a portion of the shaft 120 extends through a lumen of the body portion. In some embodiments, distal body portion 412 can include a plurality of grooves 411, and movable head 420 can be configured to ratchet proximally over the plurality of grooves 411, thereby maintaining tension on shaft 120. In some embodiments, shaft 120 can be a tapered wire shaft and can be made from stainless steel, MP35N, Nitinol, or other material with a suitably high modulus and tensile strength.

[0038] Figure 2 is an isometric view of the clot retrieval device shown in Figure 1. In some embodiments, clot removal device 100 can include a cage structure 110 including a first tapered portion at a proximal end 119 of cage structure 110, a shaft 120 including a second tapered portion at a distal end of shaft 120, and a proximal coupling portion 123 where the first tapered portion is positioned at a non-engaging overlap 130 with the second tapered portion (see Figure 3).

[0039] In some examples, cage structure 110 may further include an open distal end 113 and a proximal helical section 111. Proximal helical section 111 may extend distally from proximal end 119 of cage structure 110 and include a first plurality of struts 112 configured to sandwich a clot 700 between at least one of first plurality of struts 112. Proximal helical section 111 may extend across a majority of length 127 of cage structure 110 from proximal end 119 to open distal end 113.

[0040] In some embodiments, cage structure 110 can further include a cylindrical body section 114 distal to proximal helical section 111. Cylindrical body section 114 can include a second plurality of struts 115 that are larger than first plurality of struts 112, and cylindrical body section 114 has a length 116 that is shorter than a length 117 of proximal helical section 111. In some embodiments, cylindrical body section 114 has an outer diameter 118 of about 2.5 mm.

[0041] The cage structure 110 of the disclosed design is desirably made from a material that can automatically recover its shape when released from a severely deformed delivery configuration. Superelastic materials such as nitinol or alloys with similar properties are particularly suitable. The material can be in many forms, such as wire, strip, sheet, or tube. A particularly suitable manufacturing process is to laser cut a nitinol tube, then heat treat and electropolish the resulting structure to create a framework of struts and connecting elements. This framework can be made into any of a wide variety of shapes as disclosed herein and may be visualized under fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0042] In some embodiments, the cage structure 110 may further include cells, struts, and various shapes and designs configured to sandwich a fibrin-rich clot, including those described in U.S. Patent Nos. 10,292,723, 10,363,054, 10,617,435, 11,253,278, and 11,147,572, each of which is incorporated by reference in its entirety as if set forth verbatim herein. As described in International Publication No. WO 2012 / 120490(A), the entire contents of which are incorporated by reference herein, compression of the clot 700 by the cage structure 110, for example, by the cylindrical body section 114, may alter the properties of the clot 700, making it harder and "stickier," thereby making it more difficult to retrieve.

[0043] In some embodiments, distal advancement of catheter 300 relative to cage structure 110 may compress clot 300 between the distal end of catheter 300 and cage structure 110, improving clamping of clot 700 and securing the captured clot segment. The user may feel this clamping as resistance and stop advancing catheter 300, allowing the user to advance delivery catheter 300 a fixed distance up shaft 120, e.g., 30%-50% of the shaft length.

[0044] 3 shows a cross-sectional view of a joint according to the present disclosure. In some embodiments, proximal joint 123 can include a weld between the first tapered portion and the second tapered portion and a material coating 124 covering at least a portion of the first tapered portion, at least a portion of the second tapered portion, and at least a portion of the weld. In some embodiments, non-engaging overlap portion 130 can be laser welded at two points 133, and material coating 124 can be bonded to shaft 120 and cage structure 110 at two points 134.

[0045] In some embodiments, the clot removal assembly may further include a proximal joint 123 connecting the shaft 120 to the proximal helical section 111. The proximal joint 123 may be formed by laser welding together a non-engaging overlap 130 between the tapered portion of the shaft 120 and the tapered portion of the cage structure 110 and providing a material coating 124 on and / or over the proximal joint 123. In some embodiments, the non-engaging overlap 130 is laser welded at two points 133, and the material coating 124 is bonded to the shaft 120 and the cage structure 110 between the two points 134. Thus, in one embodiment, once the non-engaging overlap 130 is welded 133, the material coating 124 may function as a “sleeve” that further covers and reinforces the joint (i.e., the non-engaging overlap 130), providing support when needed (i.e., between points 134). Note that the material coating 124 may be a physical polymer sleeve in some embodiments.

[0046] One objective of the present invention is to reduce the size of the proximal junction 123, which acts as the junction between the cage structure 110 and the shaft 120. Prior art junctions may be 0.018 inches at their widest point. The present proximal junction 123 allows for a reduced size to pass through a 0.013 inch delivery catheter. Even at its largest size, this represents an approximately 38% reduction in size compared to the prior art. Note that certain prior art stent retrievers are sized to treat large vessel occlusions (LVOs), which occur when a major artery in the brain is blocked. LVO stroke occlusions occur in one of the following major cerebral blood vessels in the brain (T lesion, T occlusion). More distal clots form in smaller arteries, including the distal M2, M3, M4, A2-A5, and P2-P5 vessels. The smaller the proximal junction 123, the smaller the delivery catheter; therefore, the cage device 110 can be delivered farther into the cerebral blood vessels than most prior art devices.

[0047] In some embodiments, distal shaft portion 121 may be tapered so that it is narrower distally and wider proximally.

[0048] 4 is an isometric and enlarged cross-sectional view of an exemplary catheter 300. In some embodiments, the delivery catheter 300 can include a distal region 310 and a proximal region 320. In some embodiments, the distal portion 310 of the delivery catheter 300 can include a coiled core, and the proximal portion 320 of the delivery catheter 300 can include a braided core.

[0049] In some embodiments, the coiled core may provide the catheter 300 with a level of flexibility that allows the user to better navigate tortuous distal vessels. In some embodiments, the braided core of the proximal portion 320 may provide the delivery catheter 300 with a level of column strength that aids the user in navigating the tip of the microcatheter to the target anatomy.

[0050] In some embodiments, the catheter 300 can be configured such that a compressive force applied across most of the length of the catheter 300 causes the proximal region 320 to remain substantially straight and the distal region to become corrugated.

[0051] In some embodiments, catheter 300 can be configured to deliver clot retrieval device 100 across clot 700 .

[0052] In some embodiments, catheter 300 can be configured to clamp clot 700 between the distal end of the catheter and clot retrieval device 100 .

[0053] In some embodiments, the catheter 300 may further include an inner diameter of about 0.013 inches.

[0054] 5A is a cross-sectional view of a blood vessel 800, a clot 700, and a clot removal assembly 200 disposed therein. In some embodiments, a catheter 300 can be configured to deliver a clot retrieval device 100 across the clot 700.

[0055] 5B is a cross-sectional view of blood vessel 800, clot 300, and clot removal assembly 200 shown in FIG. 1 with clot removal assembly 200 engaging clot 700. In some embodiments, proximal helical section 111 of cage structure 110 can be sized to wrap within blood vessel 800 against the wall of blood vessel 800. Helical section 111 can compress clot 700 to force it against the vessel wall and prevent clot 700 from migrating distally through blood vessel 800. Catheter 300 can be advanced distally, moving helical sections 111 toward each other like tweezers.

[0056] The clot 700 may have a stiff portion that may be sandwiched between the tip of the catheter 300 and the helical section 111 of the cage structure 110. The sandwiching may be achieved by advancing the catheter 300 or an intermediate catheter over the cage structure 110 until a portion of the clot 700 is compressed between the tip of the catheter 300 and a crown or strut of the proximal portion of the cage structure 110. This sandwiching increases the grip of the cage structure 110 on the clot 700, particularly fibrin-rich clots, thereby facilitating clot removal. Proximal contraction of the sandwiched clot may reduce the expulsion force by elongating the clot 700 and pulling it away from the vessel wall during the expulsion process.

[0057] 6 is a cross-sectional view of a valve assembly 400 according to the present disclosure. In some embodiments, the valve assembly 400 can include a distal valve 427, a body portion 410, a distal body portion 412, and a movable head shell 420. The distal valve 427 can be configured to engage the proximal region 310 of the delivery catheter 300. In some embodiments, a portion of the shaft 120 extends through the lumen 413 of the body portion 410. In some embodiments, the distal body portion 412 can include a plurality of grooves 411, and the movable head shell 420 can be configured to ratchet proximally over the plurality of grooves 411, thereby maintaining tension on the shaft 120.

[0058] Shaft tension can be important during certain procedures. As discussed above, the present cage structure 110 is designed to clamp small, tough clots. Once a clot is clamped, any release of tension on the shaft can release the clamp and the clot. Providing controls on the valve assembly 400 to allow the user to maintain tension on the shaft helps make it easier to maintain that tension.

[0059] In some embodiments, the movable head shell 420 may include teeth 421 configured to engage with the grooves 411, a threaded portion 422, and a screw head 424 configured to engage with the threaded portion 422 and crush the seal 425, which when crushed locks the shaft 120 in place relative to the screw head 424, and the teeth 421 are configured to disengage from the grooves 411 of the body 410 when bent away from the central axis 430 of the valve 400.

[0060] 7 shows a portion of a valve assembly 400 including a movable headshell 420 having an external grip 426 in accordance with the present disclosure. In some embodiments, the movable headshell 420 may further include the external grip 426 disposed on a proximal end 423 of the movable headshell 420. In some embodiments, the distal end 427 of the movable headshell 420 may include a thin plastic cylindrical wall configured to deform in response to pinching, which causes bending away from the central axis of the valve.

[0061] Figure 8 illustrates a method 500 for removing a blood clot from a blood vessel as disclosed herein. It will be appreciated that the steps of the method of Figure 8 may be performed by any of the exemplary means described herein, or by similar means.

[0062] At block 510, method 500 may include deploying at least a portion of a cage structure of the clot retrieval device out of the catheter and across the clot. The cage structure of the clot removal device may be configured similarly to the exemplary cage structure 110 of clot removal device 100 disclosed herein, variations thereof, and alternatives thereof, as would be understood by one of ordinary skill in the art. The cage structure may be deployed similarly to the exemplary cage structure 110 of clot removal device 100 disclosed herein, variations thereof, and alternatives thereof, as would be understood by one of ordinary skill in the art. The clot removal device may be configured similarly to the exemplary clot removal device 100 disclosed herein, variations thereof, and alternatives thereof, as would be understood by one of ordinary skill in the art.

[0063] At block 520, the method 500 may include engaging a proximal portion of the catheter with a distal valve of the valve assembly. The catheter may be configured similarly to the exemplary catheter 300 disclosed herein, variations thereof, and alternatives thereof, as will be understood by one of ordinary skill in the art. The valve assembly may be configured similarly to the exemplary valve assembly 400 (and its subcomponents), variations thereof, and alternatives thereof, as will be understood by one of ordinary skill in the art.

[0064] At block 525, the method 500 may include engaging a proximal portion of the shaft of the clot retrieval device with the movable headshell of the valve assembly. The shaft may be configured similarly to the exemplary shaft 120, variations thereof, and alternatives thereof disclosed herein, as will be understood by those skilled in the art.

[0065] At block 530, the method 500 may include pulling the movable head shell of the valve proximally to clamp the clot.

[0066] At block 540, the method 500 may include securing the movable headshell relative to the distal valve, thereby maintaining tension on the shaft.

[0067] At block 550, the method 500 may include extracting the cage structure and clot from the blood vessel. In some embodiments, the method 500 may include extracting the clot 700 from a distal M2, M3, M4, A2-5, or P2-P5 vessel. The sizes of any of these vessels are known in the art, and one of ordinary skill in the art would understand that the components of the clot removal assembly may be appropriately sized to achieve the goal of removing clots from these vessels. Despite this knowledge of vessel size being known to those skilled in the art, it has heretofore been very difficult to create a clot removal device such as that disclosed herein due to the difficulty of coupling the clamping cage structure to the shaft. This problem is solved by the couplings described herein.

[0068] In some embodiments, the method 500 may include using fluoroscopic imaging techniques.

[0069] In some embodiments, clot 700 may be composed mostly of fibrin.

[0070] As described throughout this document, a range of designs is contemplated for each of these elements, and it is intended that any of these elements may be used with any other element, although to avoid repetition, these elements are not shown in all possible combinations.

[0071] Other aspects and features of the present disclosure will become apparent to those skilled in the art from the following detailed description considered in conjunction with the accompanying figures.

[0072] In describing the embodiments, technical terms are used for clarity. Each term is intended to have its broadest meaning as understood by one of ordinary skill in the art and is intended to include all technical equivalents that operate in a similar manner to accomplish a similar purpose. It should also be understood that a reference to one or more steps of a method does not preclude the presence of additional or intervening method steps between those explicitly identified steps. Method steps may be performed in a different order than described herein without departing from the scope of the disclosed technology. Similarly, it should also be understood that a reference to one or more components of a device, system, or assembly does not preclude the presence of additional or intervening components between those explicitly identified components.

[0073] The descriptions contained herein are examples of the present disclosure and are not intended to limit the scope of the present disclosure in any way. While specific embodiments of the present disclosure have been described, various modifications to the apparatus and methods can be made without departing from the scope and spirit of the present disclosure. For example, while the embodiments described herein refer to specific components, the present disclosure includes other embodiments that utilize combinations of various components to achieve the described functionality, utilize alternative materials to achieve the described functionality, combine components from various embodiments, combine components from various embodiments with known components, and the like. The present disclosure contemplates the substitution of other well-known, commercially available products for the component parts illustrated herein. These modifications will often be apparent to those skilled in the art to which the present disclosure pertains, and are intended to be within the scope of the following claims.

[0074] [Embodiment] (1) A clot removal device, comprising: a cage structure comprising a first tapered portion at a proximal end of the cage structure; a shaft comprising a second tapered portion at a distal end of the shaft; a proximal joint where the first tapered portion is positioned at a non-engaging overlap with the second tapered portion, the proximal joint comprising a weld between the first tapered portion and the second tapered portion, and a material coating over at least a portion of the first tapered portion, at least a portion of the second tapered portion, and at least a portion of the weld. (2) the non-engaging overlapping portion is laser welded at two points; 2. The clot removal device of claim 1, wherein the material coating is attached to the shaft and the cage structure at two points. (3) A clot removal device as described in embodiment 1, wherein the second tapered portion is tapered and is narrower distally and wider proximally. (4) The cage structure is an open distal end; and A clot removal device as described in embodiment 1, further comprising a proximal spiral section comprising a first plurality of struts extending distally from the proximal end of the cage structure and configured to sandwich a blood clot between at least one of the first plurality of struts, the proximal spiral section extending along the majority of the length of the cage structure from the proximal end to the open distal end. (5) the cage structure further comprises a cylindrical body section distal to the proximal helical section; the cylindrical body section includes a second plurality of struts that are larger than the first plurality of struts; 5. The clot removal device of claim 4, wherein the cylindrical body section has a length that is shorter than the length of the proximal spiral section.

[0075] (6) A clot removal device as described in embodiment 5, wherein the cylindrical body section has an outer diameter of about 2.5 mm. (7) A clot removal assembly comprising: a delivery catheter comprising a distal region and a proximal region; a clot retrieval device comprising a cage structure and a shaft, the cage structure configured to clamp a clot, a portion of the shaft extending through the delivery catheter; a valve assembly comprising a distal valve, a body portion, a distal body portion, and a movable head shell, the distal valve configured to engage the proximal region of the delivery catheter, a portion of the shaft extending through a lumen of the body portion, the distal body portion comprising a plurality of grooves, and the movable head shell configured to ratchet proximally across the plurality of grooves, thereby maintaining tension on the shaft; (8) The movable head shell is a tooth configured to engage the groove; The screw part and a screw head configured to engage the threaded portion to crush the seal; the seal, when crushed, locks the shaft in place relative to the screw head; 8. The clot removal assembly of claim 7, wherein the teeth are configured to disengage from the grooves of the body portion when bent away from the central axis of the valve assembly. (9) A clot removal assembly as described in embodiment 7, wherein the cage structure comprises a proximal spiral section and a cylindrical body section distal to the proximal spiral section, the cylindrical body section comprising a second plurality of struts larger than the first plurality of struts of the proximal spiral section. (10) A clot removal assembly as described in embodiment 9, wherein the cylindrical body section has a length less than the length of the proximal spiral section.

[0076] (11) The clot removal assembly of embodiment 9, further comprising a proximal joint connecting the shaft to the proximal spiral section, the proximal joint being formed by laser welding together non-engaging overlap portions between the tapered portion of the shaft and the tapered portion of the cage structure and providing a material coating on the proximal joint. (12) The non-engaging overlapping portion is laser welded at two points; 12. The clot removal assembly of claim 11, wherein the material coating is bonded to the shaft and the cage structure at two points. (13) The clot removal assembly of claim 7, wherein the movable head shell further comprises an external grip disposed at a proximal end of the movable head shell. (14) A clot removal assembly as described in embodiment 7, wherein the distal end of the movable head shell comprises a thin plastic cylindrical wall configured to deform in response to clamping, the clamping causing the bending. (15) The clot removal assembly of embodiment 14, wherein the delivery catheter further has an inner diameter of about 0.33 mm (about 0.013 inches).

[0077] (16) A method for removing a blood clot from a blood vessel, comprising: deploying at least a portion of a cage structure of the clot retrieval device out of the catheter and across the clot; engaging a proximal portion of the catheter with a distal valve of a valve assembly; engaging a proximal portion of the shaft of the clot retrieval device with a movable head shell of the valve assembly; pulling the movable head shell of the valve proximally to clamp the clot; fixing the movable headshell relative to the distal valve, thereby maintaining tension on the shaft; and withdrawing the cage structure and the clot from the blood vessel. (17) Fixing the movable head shell relative to the distal valve, thereby maintaining tension on the shaft, engaging teeth disposed on the movable headshell with first grooves disposed on a distal body portion of the valve assembly; 17. The method of claim 16, comprising gripping the shaft by compressing a seal between the screw head and threaded portion of the movable head shell. (18) The method of embodiment 17, wherein fixing the movable headshell relative to the distal valve and thereby maintaining tension on the shaft includes sliding the movable headshell proximally and engaging the teeth with a second groove that is further proximally than the first groove. (19) The method of embodiment 18, further comprising applying suction to the catheter through a side port disposed in the valve. (20) The method of claim 18, further comprising clamping the movable head shell to release the tension by disengaging the teeth.

Claims

1. 1. A clot removal device comprising: a cage structure comprising a first tapered portion at a proximal end of the cage structure; a shaft comprising a second tapered portion at a distal end of the shaft; a proximal joint where the first tapered portion is positioned at a non-engaging overlap with the second tapered portion, the proximal joint comprising a weld between the first tapered portion and the second tapered portion, and a material coating over at least a portion of the first tapered portion, at least a portion of the second tapered portion, and at least a portion of the weld.

2. the non-engaging overlap portion is laser welded at two points; The clot removal device of claim 1 , wherein the material coating is bonded to the shaft and the cage structure at two points.

3. The clot removal device of claim 1 , wherein the second tapered section is tapered and is narrower distally and wider proximally.

4. The cage structure includes: an open distal end; and 2. The clot removal device of claim 1, further comprising a proximal spiral section comprising a first plurality of struts extending distally from the proximal end of the cage structure and configured to sandwich a blood clot between at least one of the first plurality of struts, the proximal spiral section extending across a majority of the length of the cage structure from the proximal end to the open distal end.

5. the cage structure further comprises a cylindrical body section distal to the proximal helical section; the cylindrical body section includes a second plurality of struts that are larger than the first plurality of struts; The clot removal device of claim 4 , wherein the cylindrical body section has a length that is less than a length of the proximal helical section.

6. The clot removal device of claim 5 , wherein the cylindrical body section has an outer diameter of about 2.5 mm.

7. 1. A clot removal assembly comprising: a delivery catheter comprising a distal region and a proximal region; a clot retrieval device comprising a cage structure and a shaft, the cage structure configured to clamp a clot, a portion of the shaft extending through the delivery catheter; a valve assembly comprising a distal valve, a body portion, a distal body portion, and a movable head shell, the distal valve configured to engage the proximal region of the delivery catheter, a portion of the shaft extending through a lumen of the body portion, the distal body portion comprising a plurality of grooves, and the movable head shell configured to ratchet proximally across the plurality of grooves, thereby maintaining tension on the shaft;

8. The movable head shell is a tooth configured to engage the groove; The screw part and a screw head configured to engage the threaded portion to crush the seal; the seal, when crushed, locks the shaft in place relative to the screw head; The clot removal assembly of claim 7 , wherein the teeth are configured to disengage from the grooves in the body portion when flexed away from a central axis of the valve assembly.

9. 8. The clot removal assembly of claim 7, wherein the cage structure comprises a proximal helical section and a cylindrical body section distal to the proximal helical section, the cylindrical body section comprising a second plurality of struts larger than the first plurality of struts of the proximal helical section.

10. The clot removal assembly of claim 9 , wherein the cylindrical body section has a length that is less than a length of the proximal helical section.

11. 10. The clot removal assembly of claim 9, further comprising a proximal joint connecting the shaft to the proximal helical section, the proximal joint being formed by laser welding together non-engaging overlaps between the tapered portion of the shaft and the tapered portion of the cage structure and providing a material coating on the proximal joint.

12. the non-engaging overlap portion is laser welded at two points; The clot removal assembly of claim 11 , wherein the material coating is bonded to the shaft and the cage structure at two points.

13. The clot removal assembly of claim 7 , wherein the movable headshell further comprises an external grip disposed at a proximal end of the movable headshell.

14. The clot removal assembly of claim 7 , wherein the distal end of the movable headshell comprises a thin plastic cylindrical wall configured to deform in response to clamping, the clamping causing the bending.

15. 15. The clot removal assembly of claim 14, wherein the delivery catheter further has an inner diameter of about 0.013 inches.

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