Clot removal device with radiographic indicator

Abstract

A clot removal assembly is presented that includes a delivery microcatheter, a cage structure configured to transition between a delivery configuration and an expanded clamping configuration, and a shaft in communication with the cage structure and disposed substantially within the delivery microcatheter. The catheter includes a distal portion and a proximal portion, the distal portion including an elongated radiopaque indicator, and the elongated radiopaque indicator is configured to transition between a substantially straight non-indicating state and a substantially wave indicating state in response to an impact of the cage structure on the delivery microcatheter.

Description

Technical Field

[0001] The present disclosure generally relates to devices and methods for removing blockages from blood vessels during endovascular medical treatments. Background Art

[0002] In patients suffering from conditions such as acute ischemic stroke AIS, myocardial infarction MI, and pulmonary embolism PE, clot retrieval devices are often used in mechanical thrombectomy for endovascular intervention.

[0003] Tortuosity is a challenge in arteries close to the brain. For example, at the distal end of the internal carotid artery, it is not uncommon for a device to have to navigate a vessel segment with a 180° bend, a 90° bend, and a 360° bend in rapid succession over several centimeters of the vessel. This presents a challenge for the catheter, which must have sufficient column strength to transmit the forces applied by the user while also being flexible enough to navigate the tortuous distal vessel.

[0004] The clot can have any of a range of morphologies and consistencies. For example, the clot can be difficult to grip, and improper gripping can lead to fragmentation, which can cause embolism. Compression of the blood clot causes dehydration of the clot and results in a significant increase in both clot hardness and coefficient of friction, necessitating removal by clamping rather than contact aspiration.

[0005] Physicians typically rely on visual and tactile feedback to assess engagement of a clot with a clot retrieval device. In some treatments, it may be difficult to determine whether a clot is engaged by a clot retrieval device having the present technology. Summary of the Invention

[0006] In some examples, a clot removal assembly for removing a clot from a blood vessel is disclosed. The clot removal assembly may include a delivery microcatheter, a cage structure configured to transition between a delivery configuration and an expanded, clamped configuration, and a shaft in communication with the cage structure and substantially disposed within the delivery microcatheter. The delivery microcatheter may include: a distal portion including an elongated radiopaque indicator; and a proximal portion. The elongated radiopaque indicator disposed on the distal portion of the delivery microcatheter facilitates visualization of clot clamping by a user.

[0007] In some examples, the elongated radiopaque indicator can be configured to transition between a substantially straight non-indicating state and a substantially wavy indicating state in response to impact of the cage structure on the delivery microcatheter.

[0008] In some examples, the elongated radiopaque indicator can be configured to transition between a substantially straight non-indicating state and a substantially wavy indicating state in response to a proximally directed tension applied by the shaft to the cage structure.

[0009] In some examples, the elongated radiopaque indicator can be configured to transition between a substantially straight non-indicating state and a substantially wavy indicating state in response to a distally directed thrust force applied to the microcatheter.

[0010] In some examples, the elongated radiopaque indicator can include a tungsten-doped portion of the distal portion.

[0011] In some examples, the elongated radiopaque indicator includes a radiopaque coating.

[0012] In some examples, the cage structure may further include a distal segment and a proximal helical segment.The distal segment may include a first plurality of struts, and the proximal helical segment may include a second plurality of struts that is smaller than the first plurality of struts.

[0013] In some cases, the first ends of the first plurality of struts abut the second plurality of struts, and the second ends of the first plurality of struts terminate in a plurality of atraumatic joints.

[0014] In some examples, the cage structure can include a proximal helical segment and a cylindrical body segment distal to the proximal helical segment. The proximal helical segment can be configured to clamp a clot between struts of the proximal helical segment.

[0015] In some examples, the distal portion of the delivery microcatheter can include a coiled core and the proximal portion of the delivery microcatheter can include a braided core.

[0016] In some examples, a method of treating an embolism is disclosed. The method may include: deploying at least a portion of a cage structure of a clot retrieval assembly across a clot and distally relative to a catheter; applying tension to a shaft attached to a proximal segment of the cage structure; transitioning an elongated radiopaque indicator disposed on a distal portion of the catheter from a first substantially straight, non-indicating state to a second substantially wavy, indicating state by clamping the clot between the cage structure and the distal end of the catheter; visualizing the substantially wavy, indicating state of the elongated radiopaque indicator disposed on the distal end of the catheter; and extracting the clot, the cage structure, and the catheter.

[0017] In some cases, the method may further include moving the cage structure to pin the clot between the cage structure and an inner wall of the blood vessel.

[0018] In some cases, the clot may be composed primarily of fibrin.

[0019] In some examples, the method may include extracting a clot from a distal M2, M3, M4, A2-5, or P2-P5 vessel.

[0020] In some examples, visualizing the substantially wave state may include using fluoroscopic imaging techniques.

[0021] In some examples, a catheter is disclosed. The catheter may include a proximal region extending over a majority of the length of the catheter, a distal region extending distally from the proximal region, and a radiopaque indicator extending over at least a portion of the length of the distal region. The catheter may be configured such that a compressive force applied to the distal end of the catheter causes controlled movement of the distal region from a substantially straight, uncompressed configuration to a wavy, compressed configuration, and wherein the radiopaque indicator is configured to indicate the configuration of the distal region.

[0022] In some examples, the proximal region is configured to remain in a substantially straight configuration when a compressive force is applied at the distal end of the catheter and the distal region is moved to the wave-compressed configuration.

[0023] In some examples, the catheter can be configured such that a compressive force applied to a majority of the length of the catheter causes the proximal region to remain in a substantially straight configuration and the distal region to move to a wavy, compressed configuration.

[0024] In some examples, the distal region may include a coiled support structure and the proximal region may include a braided support structure.

[0025] In some examples, the catheter can be configured to deliver a clot retrieval device across the clot.

[0026] In some examples, the catheter can be configured to clamp a clot between a distal end of the catheter and a clot retrieval device.

[0027] Other aspects and features of the present disclosure will become apparent to those skilled in the relevant art(s) after reviewing the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other aspects of the present disclosure will be further discussed through the following description of the accompanying drawings, in which like reference numerals indicate like structural elements and features throughout the various figures. The drawings are not necessarily drawn to scale, with emphasis placed on illustrating the principles of the present disclosure. The drawings depict one or more specific implementations of the present invention by way of example only and not limitation. It is expected that those skilled in the art will be able to conceive and combine elements from the various drawings to better meet the needs of the user.

[0029] Figure 1A A side view of a clot removal assembly according to the present disclosure is shown with the microcatheter in a non-indicating state.

[0030] Figure 1B Shown according to the present disclosure Figure 1A A side view of the clot removal assembly is shown with the microcatheter in the indicated position.

[0031] Figure 2is an isometric view of a cage structure according to the present disclosure.

[0032] Figure 3A Shown is a side view of a clot removal assembly in a delivery configuration according to the present disclosure.

[0033] Figure 3B Shown according to the present disclosure Figure 3A A side view of the clot removal assembly is shown with the microcatheter in the indicated position.

[0034] Figure 4 1 is an isometric view and an enlarged cross-sectional view of a microcatheter according to the present disclosure.

[0035] Figure 5A is a cross-sectional view of a blood vessel and a clot, and a clot removal assembly disposed therein, according to the present disclosure.

[0036] Figure 5B is a cross-sectional view of a blood vessel and clot, and a clot removal assembly engaged to the clot, according to the present disclosure.

[0037] Figure 6 is a flow chart illustrating a method for treating embolism according to aspects of the present disclosure. DETAILED DESCRIPTION

[0038] 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 in many cases in the context of treating intracranial arteries, the present disclosure can also be used in other body passages as described above.

[0039] The terms "distal" or "proximal" are used below to describe positions or directions relative to a treating physician. "Distal" or "distally" refers to a position away from or in a direction away from the physician. "Proximal" or "proximally" refers to a position close to or in a direction toward the physician.

[0040] 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 suitable type, including but not limited to mammals, veterinary animals, livestock animals, or pet animals. For example, the animal can be a laboratory animal specifically selected to have certain characteristics similar to humans, such as rats, dogs, pigs, monkeys, etc.

[0041] As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows the part or assembly of components to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of ±20% of the value of the recited value, for example, "about 90%" can refer to a range of values ​​from 71% to 99%.

[0042] As used herein, the terms "tubular" and "tube" are to be understood broadly and are not limited to structures that are perfectly cylindrical, have a completely circular cross-section, or have a uniform cross-section throughout their length. For example, tubular structures or systems are often illustrated as being substantially perfectly cylindrical. However, tubular systems may have tapered or curved outer surfaces without departing from the scope of the present invention.

[0043] "Comprising" or "containing" or "including" means that at least the named compound, element, particle or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if other such compounds, materials, particles, method steps have the same function as those named.

[0044] It should also be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as "about" or "approximately" one particular value and / or "about" or "approximately" another particular value. When such a range is expressed, other illustrative examples include from the one particular value and / or to the other particular value.

[0045] Accessing the cerebral, coronary, and pulmonary vasculature involves the use of a number of commercially available products and conventional procedural steps. Access products such as guidewires, guide catheters, angiographic catheters, and microcatheters are described elsewhere and are commonly used in catheterization laboratory procedures. The following description assumes that these products and methods are used in conjunction with the devices and methods of the present disclosure and do not require detailed description.

[0046] A common theme among many of the disclosed designs is an elongated radiopaque indicator 112 disposed on the delivery microcatheter 110 and configured to transition between a substantially straight, non-indicating state 114 and a substantially wavy, indicating state 115 in response to an impact of the cage structure 120 on the delivery microcatheter 110. Such an impact may be the result of a user pulling the cage structure proximally or advancing the delivery microcatheter distally while the cage structure 120 remains open (e.g., by a clot or other obstruction), thereby preventing the cage structure 120 from fully retracting into the microcatheter 110.

[0047] The cage structure 120 of the disclosed design is desirably supported by a material that is capable of automatically recovering its shape once released from a highly strained delivery configuration. Superelastic materials such as Nitinol or alloys of similar properties are particularly suitable. The material can be in a variety of forms, such as wires or strips or sheets or tubes. A particularly suitable manufacturing process is laser cutting of Nitinol tubes followed by heat setting and electropolishing of the resulting structure to form a framework of struts and connecting elements. The framework can be any of a wide range of shapes as disclosed herein and can be made visible under fluoroscopy by the addition of alloying elements such as platinum or by various other coatings or marker bands.

[0048] Figure 1A 1 is an illustration of an example clot removal assembly 100 for removing a clot 160 from a blood vessel 170. The clot removal assembly 100 can include a delivery microcatheter 110, a cage structure 120, and a shaft 130 in communication with the cage structure 120 and substantially disposed within the delivery microcatheter 110. The delivery microcatheter 110 can include a distal portion 111 and a proximal portion 113. The distal portion 111 includes an elongated radiopaque indicator 112. The proximal portion 113 can be manipulated to position the distal portion 111 within the patient.

[0049] In some examples, the elongated radiopaque indicator 112 can be configured to move in a substantially straight non-indicating state 114 (such as in FIG. 1 ) in response to impact of the cage structure 120 on the delivery microcatheter 110. Figure 1A ) and a substantially wavy indication state 115 (such as Figure 1B shown).

[0050] In some examples, the elongated radiopaque indicator 112 can be configured to transition between a substantially straight non-indicating state 114 and a substantially wavy indicating state 115 in response to a proximally directed tension applied to the cage structure 120 by the shaft 130 .

[0051] In some examples, the elongated radiopaque indicator 112 can be configured to transition between a substantially straight non-indicating state 114 and a substantially wavy indicating state 115 in response to a distally directed thrust force applied to the microcatheter 110 .

[0052] In some examples, the elongated radiopaque indicator 112 may include a tungsten-doped portion of the distal portion 111 .

[0053] In some examples, the elongated radiopaque indicator 112 can include a radiopaque coating.

[0054] Figure 2is an isometric view of cage structure 120. In some examples, cage structure 120 can include a distal segment 124 and a proximal helical segment 125. Distal segment 124 can include a first plurality of struts 141, and proximal helical segment 125 can include a second plurality of struts 145 that are smaller than first plurality of struts 141. Because the struts in second plurality of struts 145 are shorter in length than the struts in first plurality of struts 141, second plurality of struts 145 can be smaller than first plurality of struts 141.

[0055] In some examples, first ends 142 of first plurality of struts 141 abut second plurality of struts 145 , and second ends 143 of first plurality of struts 141 terminate in a plurality of atraumatic joints 144 .

[0056] In some examples, the cage structure 120 can include a proximal helical segment 125, a cylindrical body segment 124 distal to the proximal helical segment 125, and an open distal end 150. The proximal helical segment 125 can be configured to clamp a clot 160 between the struts 145 of the proximal helical segment 125.

[0057] Figure 3A A side view of the clot removal assembly 100 is shown in a delivery configuration 122 . Figure 3B Shown Figure 3A A side view of the clot removal assembly 100 is shown with the microcatheter 110 in the indicated state. The cage structure 120 can be configured to be positioned in the delivery configuration 122 ( Figure 3A ) and expansion clamping configuration 123 ( Figure 3B ) between them.

[0058] like Figure 3A As shown, in delivery configuration 122 , cage structure 120 is disposed within delivery microcatheter 110 . In delivery configuration 122 , first plurality of struts 141 , second plurality of struts 145 , proximal helical segment 125 , and cylindrical body segment 124 can be generally aligned with the longitudinal axis of delivery microcatheter 110 .

[0059] like Figure 3BAs shown, in the expanded clamping configuration 123, the cage structure 120 can be completely or partially located outside the delivery microcatheter 110. The cage structure 120 can translate relative to the delivery microcatheter 110 along the longitudinal axis, allowing the cage structure 120 to assume various configurations between the delivery configuration 122 and the expanded clamping configuration 123. The clot 160 can partially or completely block the proximal retraction of the cage structure 120 into the delivery microcatheter 110. The distal portion 111 of the microcatheter 110 can be sufficiently flexible that this blocking impact between the delivery microcatheter 110, the clot 160, and the cage structure 120 can cause deformation of the radiopaque indicator 121 disposed at the distal portion 111 of the delivery microcatheter 112. When the distal portion 111 of the microcatheter 110 deforms, the radiopaque indicator 121 becomes wavy and thus assumes a substantially wavy indicating state 115. As the cage structure 120 is retracted through the shaft 130 and impacts the distal end of the microcatheter 110, the shaft 130 is placed under tension within the microcatheter 110 such that greater tension in the shaft 130 creates greater compressive forces on the distal portion 111 of the microcatheter 110. Due to the proximally directed pulling force applied to the shaft 130, the shaft is maintained in a non-corrugated state.

[0060] Figure 4 is an isometric view and an enlarged cross-sectional view of an example microcatheter 110. In some examples, the distal portion 111 of the delivery microcatheter 110 can include a coiled core 116, and the proximal portion 113 of the delivery microcatheter 110 can include a braided core 117. A radiopaque indicator similar to those disclosed and shown elsewhere herein, variations thereof, and alternatives thereof can be included in the distal portion of the microcatheter 110. The radiopaque indicator can be moved from a non-indicating state to an indicating state, similar to those disclosed and shown elsewhere herein, variations thereof, and alternatives thereof.

[0061] In some examples, the coiled core 116 can provide a level of flexibility to the delivery microcatheter 110, which allows the user to better navigate tortuous distal vessels. In some examples, the braided core 117 of the proximal portion 113 can provide a level of column strength to the delivery microcatheter 110, which helps the user navigate the tip of the microcatheter to the target anatomical structure. In some examples, the flexibility of the distal portion 111 including the coiled core coupled with the column strength of the proximal portion including the braided core can facilitate transition of the elongated radiopaque indicator 112 between a substantially straight non-indicating state 114 and a substantially wavy indicating state 115.

[0062] In some examples, the catheter 110 can include a proximal region 113 extending over a majority of the length of the catheter, a distal region 111 extending distally from the proximal region 113, and a radiopaque indicator 112 extending over at least a portion of the length of the distal region 111. The catheter 110 can be configured such that a compressive force applied at a distal end 118 of the catheter causes controlled movement of the distal region from a substantially straight, uncompressed configuration 114 to a wavy, compressed configuration 115, and wherein the radiopaque indicator 112 is configured to indicate the configuration of the distal region 111.

[0063] In some examples, the proximal region 113 is configured to remain in a substantially straight configuration 119 when a compressive force is applied at the distal end 118 of the catheter and the distal region moves to the wavy compressed configuration 115 .

[0064] In some examples, the catheter 110 may be configured such that a compressive force applied to a majority of the length of the catheter causes the proximal region to remain in a substantially straight configuration 114 and the distal region to move to a wavy, compressed configuration 115 .

[0065] Figure 5A is a cross-sectional view of a blood vessel 171 , a clot 160 , and a clot removal assembly 100 disposed therein. In some examples, the catheter 110 can be configured to deliver the clot retrieval device 120 across the clot 160 .

[0066] Figure 5B yes Figure 5A A cross-sectional view of a blood vessel 171, a clot 160, and a clot removal assembly 100 is shown, with the clot removal assembly 100 engaged to the clot 160. In some examples, the proximal helical segment 125 of the cage structure 120 can be sized to coil against the wall of the blood vessel 171 within the blood vessel 171. The helical segment 125 can push the clot 160 into the blood vessel wall, thereby pinning the clot 160 so that the clot is prevented from moving distally through the blood vessel 171. The microcatheter 110 can be advanced distally, causing the struts of the helical segment 125 to move toward each other like tweezers.

[0067] The clot 160 may have a solid portion that can be clamped between the distal end of the catheter 110 and the struts of the helical segment 125 of the cage structure 120. This clamping can be achieved by advancing the microcatheter 110 or intermediate catheter over the cage structure 120 until a portion of the clot 160 is compressed between the distal end of the catheter 110 and the crown or struts on the proximal portion of the cage structure 120. This clamping facilitates removal of the clot 160 because it increases the grip of the cage structure 120 on the clot, particularly a fibrin-rich clot. Proximal retraction of the clamped clot can elongate the clot 160 by pulling it away from the vessel wall during the displacement process, thereby reducing displacement forces.

[0068] In some examples, the distal segment 124 of the cage structure 120 can have a barrel shape that is sized to expand to occlude the blood vessel 171 such that the clot 160 is prevented from moving distally when the clot 160 and the assembly 100 are moved proximally to extract the clot 120. In some examples, the distal segment 124 can also be configured to expand through a soft portion of the clot 160 to further engage the clot 160.

[0069] The pinching of the clot between the catheter 110 and the cage structure 120 may cause the radiopaque indicator 112 to be in a substantially straight non-indicating state 114 (such as Figure 1A The state shown) is different from the substantially wave-indicating state 115 (such as Figure 1B states shown).

[0070] Figure 6 A method 300 of treating embolism as disclosed herein is shown. As will be appreciated, Figure 6 The method steps in may be implemented by any of the example apparatus described herein or by similar apparatus.

[0071] At block 302, method 300 may include deploying at least a portion of a cage structure of a clot retrieval assembly across the clot and distally relative to the catheter. The cage structure may be configured similarly to the example cage structure 120 disclosed herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art. The clot retrieval assembly may be configured similarly to the example clot retrieval assembly 100 disclosed herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art. The cage structure may be deployed similarly to the example cage structure 120 disclosed herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art. Figure 1B 、 Figure 3B 、 Figure 5B As shown, as disclosed elsewhere herein, variations thereon and alternatives thereto will be appreciated by those skilled in the relevant art.

[0072] At block 304, method 300 may include applying tension to a shaft attached to the proximal segment of the cage structure. The shaft may be configured similarly to the example shaft 130 disclosed herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art. The proximal segment of the cage structure may be configured similarly to the example proximal segment 125 of the cage structure 120 disclosed herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art.

[0073] At box 306, method 300 may include converting an elongated radiopaque indicator disposed on the distal portion of the catheter from a first substantially straight non-indicating state to a second substantially wavy indicating state by clamping the clot between the cage structure and the distal end of the catheter. The elongated radiopaque indicator may be configured similarly to the example radiopaque indicator 112 disclosed herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art. The distal portion of the catheter may be configured similarly to the example distal portion 111 of the catheter 110 disclosed herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art. The straight non-indicating state may be similar to the non-indicating state 114 (similar to Figure 1A 、 Figure 3A or Figure 5A As shown, as disclosed elsewhere herein), variations thereof, and alternatives thereof, as understood by those skilled in the relevant art. The second substantially wave indicating state may be similar to indicating state 115 (similar to Figure 1B 、 Figure 3B or Figure 5B As shown, as disclosed elsewhere herein), variations thereof, and alternatives thereto, as will be understood by those skilled in the relevant art. The clot may be clamped to the distal end of the catheter (similar to Figure 5B As shown, as disclosed elsewhere herein), variations thereon and alternatives thereto, as understood by those skilled in the relevant art.

[0074] In block 307, the method 300 may include moving the cage structure to pin the clot between the cage structure and the inner wall of the blood vessel. The clot may be pinned by the cage structure as disclosed herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art.

[0075] At block 308, the method may include visualizing a substantially wavy indicative state of an elongated radiopaque indicator disposed on the distal end of the catheter. In some examples, visualizing the substantially wavy state may include using fluoroscopic imaging techniques.

[0076] At block 310 , the method may include extracting the clot, the cage structure, and the catheter.

[0077] In some cases, the clot may be composed primarily of fibrin.

[0078] In some examples, the method 300 may include extracting a clot from a distal M2, M3, M4, A2-5, or P2-P5 vessel. The dimensions of any of these vessels are known in the art, and one skilled in the relevant art will understand that the components of the clot retrieval assembly may be appropriately sized to achieve the goal of removing a clot from these vessels.

[0079] In some examples, the cage structure 120 may also include cells, struts, and various shapes and designs configured to clamp 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 herein by reference in its entirety as if recited verbatim. Compression of the clot by the cage structure 120 (including by the cylindrical body segment 124) may alter clot properties and render the clot less easily retrievable by making it firmer and "stickier," similar to as described in WO 2012 / 120490 A, the entire contents of which are incorporated herein by reference.

[0080] In some examples, distal advancement of the microcatheter 110 relative to the cage structure 120 may compress the clot 160 between the distal end 118 of the microcatheter 110 and the cage structure 120, thereby increasing the grip of the clot 160 and the security of the captured clot segments. The user may feel this grip as resistance and stop advancing the microcatheter 110, the user may advance the delivery microcatheter 110 a fixed distance over the shaft 130, such as 30% to 50% of the shaft length, or the user may visualize the substantially wavy indication 115 of the radiopaque indicator 112 to confirm the grip of the clot 160 before retracting the clot removal assembly 100.

[0081] Maintaining relative tension between the cage structure 120 and the delivery microcatheter 110 is necessary to ensure that the grip between the clot removal assembly 100 and the clot 160 does not degrade. By retracting the clot 160 and the clot removal assembly 100 together, the occluding clot 160 can be detached and retracted into a proximally positioned access guide catheter (not shown) or introducer sheath (not shown) and removed from the patient.

[0082] The shaft 130 may be a tapered spool and may be made of stainless steel, MP35N, Nitinol, or other material with suitably high modulus and tensile strength.

[0083] The elongated radiopaque indicator 112 may be made radiopaque by adding a filler material such as tungsten sulfate or barium sulfate. However, other radiopaque materials are contemplated including but not limited to bismuth subcarbonate, barium oxychloride, gold, platinum, iridium, tantalum, or alloys of any of these materials.

[0084] As described in this document, a range of designs are contemplated for each of these elements, and any of these elements may be used in combination with any other element, but to avoid repetition, they are not shown in every possible combination.

[0085] In some examples, clot 160 may be composed primarily of fibrin.

[0086] In some examples, method 300 may include extracting clot 160 from a distal M2, M3, M4, A2-5, or P2-P5 vessel.

[0087] In some examples, visualizing substantially wavy state 115 may include using fluoroscopic imaging techniques.

[0088] In some examples, a catheter 110 is disclosed. The catheter 110 can include a proximal region 113 extending over a majority of the length of the catheter 110, a distal region 111 extending distally from the proximal region 113, and a radiopaque indicator 112 extending over at least a portion of the length of the distal region 111. The catheter 110 can be configured such that a compressive force applied to a distal end 118 of the catheter 110 causes controlled movement of the distal region 111 from a substantially straight, uncompressed configuration 114 to a wavy, compressed configuration 115, and wherein the radiopaque indicator 112 is configured to indicate the configuration of the distal region 111.

[0089] In some examples, the proximal region 113 is configured to remain in the substantially straight configuration 119 when a compressive force is applied at the distal end 118 of the catheter 110 and the distal region 111 moves to the wavy compressed configuration 115 .

[0090] In some examples, the catheter 110 may be configured such that a compressive force applied to a majority of the length of the catheter 110 causes the proximal region 113 to remain in the substantially straight configuration 119 and the distal region to move to the wavy compressed configuration 115 .

[0091] In some examples, distal region 111 may include a coiled support structure 116 and proximal region 113 may include a braided support structure 117 .

[0092] In some examples, catheter 110 may be configured to deliver clot retrieval device 120 across clot 160 .

[0093] In some examples, the catheter 110 may be configured to clamp the clot 160 between the distal end 118 of the catheter 110 and the clot retrieval device 120 .

[0094] Other aspects and features of the present disclosure will become apparent to those skilled in the relevant art(s) upon review of the following detailed description in conjunction with the accompanying drawings.

[0095] In describing the examples, terminology has been employed for the sake of clarity. It is intended that each term assume its broadest meaning as understood by persons skilled in the relevant art, and encompass all technical equivalents that operate in a similar manner to achieve similar purposes. It should also be understood that reference to one or more steps of a method does not preclude the presence of additional method steps or intermediate method steps between those explicitly identified steps. The steps of the method may be performed in an order different from that described herein without departing from the scope of the disclosed technology. Similarly, it should also be understood that reference to one or more components in a device or system does not preclude the presence of additional components or intermediate components between those explicitly identified components.

[0096] 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. Although specific examples of the present disclosure have been described, various modifications may be made to the apparatus and methods without departing from the scope and spirit of the present disclosure. For example, although the examples described herein relate to specific components, the present disclosure includes other examples of implementing the functions using various combinations of components, implementing the functions using alternative materials, combining components of various examples, combining components of various examples with known components, and the like. The present disclosure contemplates replacing the components shown herein with other well-known and commercially available products. Such modifications will generally be apparent to those skilled in the relevant art and are intended to fall within the scope of the appended claims.

Claims

1. A clot removal assembly comprising: A delivery microcatheter comprising: a distal portion comprising an elongated radiopaque indicator, and a proximal portion; a cage structure configured to transition between a delivery configuration and an expanded, clamped configuration; and a shaft in communication with the cage structure and disposed substantially within the delivery microcatheter, Wherein the elongated radiopaque indicator is configured to transition between a substantially straight non-indicating state and a substantially wavy indicating state in response to impact of the cage structure on the delivery microcatheter.

2. The clot removal assembly of claim 1, wherein: The elongated radiopaque indicator is configured to transition between the substantially straight non-indicating state and the substantially wavy indicating state in response to a proximally directed tension applied by the shaft to the cage structure.

3. The clot removal assembly of claim 1 , wherein: The elongated radiopaque indicator is configured to transition between the substantially straight non-indicating state and the substantially wavy indicating state in response to a distally directed thrust force applied to the delivery microcatheter.

4. The clot removal assembly of claim 1, wherein: The elongated radiopaque indicator includes a tungsten-doped portion of the distal portion.

5. The clot removal assembly of claim 1, wherein: The elongated radiopaque indicator includes a radiopaque coating.

6. The clot removal assembly of claim 1, wherein: The cage structure also includes a distal segment including a first plurality of struts and a proximal helical segment including a second plurality of struts that is smaller than the first plurality of struts.

7. The clot removal assembly of claim 6, wherein: The first ends of the first plurality of struts abut the second plurality of struts, and the second ends of the first plurality of struts terminate in a plurality of atraumatic joints.

8. The clot removal assembly of claim 1, wherein: The cage structure includes a proximal helical segment, a cylindrical body segment distal to the proximal helical segment, and an open distal end, wherein the proximal helical segment is configured to clamp a clot between struts of the proximal helical segment.

9. The clot removal assembly of claim 1, wherein: The distal portion of the delivery microcatheter includes a coiled core, and the proximal portion of the delivery microcatheter includes a braided core.

10. A method for treating embolism, comprising: deploying at least a portion of a cage structure of the clot retrieval assembly across the clot and distally relative to the catheter; applying tension to a shaft attached to the proximal segment of the cage structure; transitioning an elongated radiopaque indicator disposed on the distal portion of the catheter from a first substantially straight non-indicating state to a second substantially wavy indicating state by clamping the clot between the cage structure and the distal end of the catheter; visualizing the second substantially wavy indicating state of the elongated radiopaque indicator disposed on the distal end of the catheter; and The clot, the cage structure, and the catheter are extracted.

11. The method according to claim 10, further comprising: The cage structure is moved to pin the clot between the cage structure and the inner wall of the blood vessel.

12. The method according to claim 10, wherein: The clot consists mostly of fibrin.

13. The method according to claim 12, further comprising: The clot was extracted from the distal M2, M3, M4, A2-5 or P2-P5 vessels.

14. The method according to claim 10, wherein: Visualizing the second substantially wavy state includes using fluoroscopic imaging techniques.

15. A catheter comprising: a proximal region extending over a majority of the length of the catheter; a distal region extending distally from the proximal region; as well as a radiopaque indicator extending over at least a portion of the length of the distal region, wherein the catheter is configured such that a compressive force applied at the distal end of the catheter causes controlled movement of the distal region from a substantially straight uncompressed configuration to a wavy compressed configuration, and Wherein the radiopaque indicator is configured to indicate a configuration of the distal region.

16. The catheter according to claim 15, wherein The proximal region is configured to remain in a substantially straight configuration when the compressive force is applied at the distal end of the catheter and the distal region moves to the wavy compressed configuration.

17. The catheter according to claim 15, wherein The catheter is configured such that the compressive force applied to a majority of the length of the catheter causes the proximal region to remain in a substantially straight configuration and the distal region to move to the wavy compressed configuration.

18. The catheter according to claim 15, wherein the distal region comprises a coiled support structure, and Wherein the proximal region comprises a braided support structure.

19. The catheter of claim 15, wherein The catheter is configured to deliver a clot retrieval device across the clot.

20. The catheter of claim 19, wherein The catheter is configured to clamp the clot between a distal end of the catheter and the clot retrieval device.

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