Thrombectomy device having a radiopaque indicator - Patent Application 20070122997

Abstract

Presented herein is a clot removal assembly including a delivery microcatheter, a cage structure configured to change 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 including an elongated radiopaque indicator and a proximal portion, the elongated radiopaque indicator configured to change between a substantially linear non-display state and a substantially wavy visible state in response to impaction of the cage structure on the delivery microcatheter.

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] Tortuosity is a problem in arteries approaching the brain. For example, it is not uncommon at the distal end of the internal carotid artery for a device to have to navigate several centimeters of vessel section with 180° bends, 90° bends, and 360° bends. This presents a challenge for catheters, which must have sufficient column strength to transmit the forces applied by the user while also being flexible enough to navigate the tortuous distal vessels.

[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 the clot retrieval device. In some procedures, it can be difficult to determine whether the clot has been engaged by the clot retrieval device using this technology. Summary of the Invention [Means for solving the problem]

[0006] 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 microcatheter, a cage structure configured to change 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 delivery microcatheter can include a distal portion including an elongated radiopaque indicator and a proximal portion. The elongated radiopaque indicator disposed in the distal portion of the delivery microcatheter assists a user in visualizing the clamping of the clot.

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

[0008] In some examples, the elongated radiopaque indicator can be configured to change between a substantially straight non-display state and a substantially wavy visible state in response to a proximal pulling force applied to the cage structure by the shaft.

[0009] In some examples, the elongated radiopaque indicator can be configured to change between a substantially linear non-display state and a substantially wavy visible state in response to a distal pushing 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 embodiments, the elongated radiopaque indicator comprises a radiopaque coating.

[0012] In some embodiments, the cage structure can further include a distal section and a proximal helical section, wherein the distal section can include a first plurality of struts and the proximal helical section can include a second plurality of struts that are smaller than the first plurality of struts.

[0013] In some embodiments, first ends of the first plurality of struts abut the second plurality of struts and 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 section and a cylindrical body section distal to the proximal helical section, wherein the proximal helical section can be configured to sandwich a clot between struts of the proximal helical section.

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

[0016] In some embodiments, a method of treating an embolism is disclosed that may include deploying at least a portion of a cage structure of a clot retrieval assembly distally relative to a catheter across a clot, applying tension to a shaft attached to a proximal section of the cage structure, changing an elongated radiopaque indicator disposed in a distal portion of the catheter from a first substantially straight non-display state to a second substantially wavy-display state by sandwiching the clot between the cage structure and the distal end of the catheter, visualizing the substantially wavy-display state of the elongated radiopaque indicator disposed in the distal end of the catheter, and withdrawing the clot, the cage structure, and the catheter.

[0017] 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.

[0018] In some examples, the clot may be composed mostly of fibrin.

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

[0020] In some examples, the substantially corrugated condition may include using fluoroscopic imaging techniques.

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

[0022] In some embodiments, the proximal region is configured to remain in a substantially straight configuration when a compressive force is applied to the distal end of the catheter and the distal region moves to a wavy, compressed configuration.

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

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

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

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

[0027] 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]

[0028] 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 1A] 1 illustrates a side view of a clot removal assembly with a microcatheter not shown in accordance with the present disclosure. [Figure 1B] 1B illustrates a side view of the clot removal assembly shown in FIG. 1A with the microcatheter in a visible state, according to the present disclosure. [Figure 2] FIG. 1 is an isometric view of a cage structure according to the present disclosure. [Figure 3A] 1 shows a side view of a clot removal assembly in a delivery configuration in accordance with the present disclosure. [Figure 3B] 3B illustrates a side view of the clot removal assembly shown in FIG. 3A with the microcatheter in a visible state, in accordance with 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] FIG. 1 is a flow diagram illustrating a method of treating an embolism, according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0029] 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.

[0030] 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.

[0031] 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.

[0032] As used herein, the terms "about" or "approximately" in connection with any numerical value or range of values ​​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%.

[0033] 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.

[0034] "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.

[0035] 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.

[0036] 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.

[0037] A common theme throughout many of the disclosed designs is an elongated radiopaque indicator 112 disposed on the delivery microcatheter 110 and configured to change between a substantially linear non-display state 114 and a substantially wavy visible state 115 in response to impaction of the cage structure 120 on the delivery microcatheter 110. This impaction can result in the user pulling the cage structure proximally or advancing the delivery microcatheter distally while the cage structure 120 is held open (e.g., by a clot or other obstruction), preventing the cage structure 120 from fully retracting into the microcatheter 110.

[0038] The cage structure 120 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 (e.g., platinum, etc.) or through various other coatings or marker bands.

[0039] 1A is a diagram of an exemplary clot removal assembly 100 for removing a blood clot 160 from a blood vessel 170. The clot removal assembly 100 may include a delivery microcatheter 110, a cage structure 120, and a shaft 130 in communication with the cage structure 120 and disposed substantially within the delivery microcatheter 110. The delivery microcatheter 110 may include a distal portion 111 and a proximal portion 113. The distal portion 111 includes an elongated radiopaque indicator 112. The proximal portion 113 may be manipulated to position the distal portion 111 within a patient.

[0040] In some embodiments, the elongated radiopaque indicator 112 can be configured to change between a substantially linear non-display state 114 as shown in FIG. 1A and a substantially wavy visible state 115 as shown in FIG. 1B in response to impact of the cage structure 120 on the delivery microcatheter 110.

[0041] In some embodiments, the elongated radiopaque indicator 112 can be configured to change between a substantially straight non-display state 114 and a substantially wavy display state 115 in response to a proximal pulling force applied to the cage structure 120 by the shaft 130.

[0042] In some embodiments, the elongated radiopaque indicator 112 can be configured to change between a substantially linear non-display state 114 and a substantially wavy visible state 115 in response to a distal pushing force applied to the microcatheter 110.

[0043] In some embodiments, elongated radiopaque indicator 112 may include a tungsten-doped portion of distal portion 111 .

[0044] In some embodiments, the elongated radiopaque indicator 112 may include a radiopaque coating.

[0045] 2 is an isometric view of cage structure 120. In some embodiments, cage structure may further include distal section 124 and proximal helical section 125. Distal section 124 may include a first plurality of struts 141, and proximal helical section 125 may include a second plurality of struts 145 that are smaller than first plurality of struts 141. Second plurality of struts 145 may be smaller than first plurality of struts 141 by virtue of the struts of second plurality of struts 145 having a shorter length than the struts of first plurality of struts 141.

[0046] In some embodiments, first ends 142 of the first plurality of struts 141 abut against second plurality of struts 145, and second ends 143 of the first plurality of struts 141 terminate at multiple atraumatic joints 144.

[0047] In some embodiments, the cage structure 120 can include a proximal helical section 125, a cylindrical body section 124 distal to the proximal helical section 125, and an open distal end 150. The proximal helical section 125 can be configured to sandwich a clot 160 between the struts 145 of the proximal helical section 125.

[0048] Figure 3A shows a side view of clot removal assembly 100 in delivery configuration 122. Figure 3B shows a side view of clot removal assembly 100 shown in Figure 3A with microcatheter 110 in an indicated state. Cage structure 120 can be configured to change between delivery configuration 122 (Figure 3A) and expanded clamping configuration 123 (Figure 3B).

[0049] 3A , in the delivery configuration 122, the cage structure 120 is disposed within the delivery microcatheter 110. In the delivery configuration 122, the first plurality of struts 141, the second plurality of struts 145, the proximal helical section 125, and the cylindrical body section 124 may be generally aligned with the longitudinal axis of the delivery microcatheter 110.

[0050] 3B , in the expanded, clamping configuration 123, the cage structure 120 can be completely or partially outside the delivery microcatheter 110. The cage structure 120 can be translated along its longitudinal axis relative to the delivery microcatheter 110 such that the cage structure 120 can assume various configurations between the delivery configuration 122 and the expanded, clamping configuration 123. The clot 160 can partially or completely block the cage structure 120 from retracting proximally into the delivery microcatheter 110. The distal portion 111 of the microcatheter 112 can be sufficiently flexible so that this blocking collision between the delivery microcatheter 110, the clot 160, and the cage structure 120 can deform the radiopaque indicator 121 disposed at the distal portion 111 of the delivery microcatheter 110. As the distal portion 111 of the microcatheter 110 deforms, the radiopaque indicator 121 becomes wavy, thus assuming a substantially wavy display state 115. When the cage structure 120 is retracted by the shaft 130 and impacts the distal end of the microcatheter 110, the shaft 130 is under tension within the microcatheter 110, and as a result, greater tension in the shaft 130 results in greater compression in the distal portion 111 of the microcatheter 110. The shaft 130 remains in a non-corrugated state due to the proximal pulling force applied to it.

[0051] 4 is an isometric and enlarged cross-sectional view of an exemplary microcatheter 110. In some embodiments, 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 illustrated elsewhere herein, variations thereof, and alternatives thereof can be included in the distal portion of the microcatheter 110. The radiopaque indicator, similar to those disclosed and illustrated elsewhere herein, variations thereof, and alternatives thereof, can be moved from an invisible state to a visible state.

[0052] In some embodiments, the coiled core 116 may provide the delivery microcatheter 110 with a level of flexibility that allows a user to better navigate tortuous distal vessels. In some embodiments, the braided core 117 of the proximal portion 113 may provide the delivery microcatheter 110 with a level of column strength that assists a user in navigating the tip of the microcatheter to the target anatomy. In some embodiments, the flexibility of the distal portion 111 including the coiled core combined with the column strength of the proximal portion including the braided core may assist the elongated radiopaque indicator 112 in changing between a substantially straight non-display state 114 and a substantially wavy displayed state 115.

[0053] In some examples, catheter 110 may include a proximal region 113 extending across a majority of the length of the catheter, a distal region 111 extending distally from proximal region 113, and a radiopaque indicator 112 extending across at least a portion of the length of distal region 111. Catheter 110 may be configured such that a compressive force applied to a distal end 118 of the catheter results in controlled movement of the distal region from a substantially straight, uncompressed configuration 114 to a corrugated, compressed configuration 115, with radiopaque indicator 112 configured to indicate the configuration of distal region 111.

[0054] In some embodiments, the proximal region 113 is configured to remain in a substantially straight configuration 119 when a compressive force is applied to the distal end 118 of the catheter and the distal region moves to a wavy compressed configuration 115.

[0055] In some embodiments, the catheter 110 can be configured such that a compressive force applied over most 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.

[0056] 5A is a cross-sectional view of a blood vessel 171, a clot 160, and a clot removal assembly 100 disposed therein. In some embodiments, a catheter 110 can be configured to deliver a clot retrieval device 120 across the clot 160.

[0057] 5B is a cross-sectional view of blood vessel 171, clot 160, and clot removal assembly 100 shown in FIG. 5A with clot removal assembly 100 engaging clot 160. In some embodiments, helical section 125 of cage structure 120 can be sized to wrap within blood vessel 171 against the wall of blood vessel 171. Helical section 125 can compress clot 160 to force it against the vessel wall and prevent the clot from migrating distally through blood vessel 171. Microcatheter 110 can be advanced distally, moving struts of helical section 125 toward each other like tweezers.

[0058] The clot 160 may have a stiff portion that may be pinched between the tip of the catheter 110 and the struts of the helical section 125 of the cage structure 120. Pinching may 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 tip of the catheter 110 and the crown or struts of the proximal portion of the cage structure 120. This pinching increases the grip of the cage structure 120 on the clot 160, particularly fibrin-rich clots, thereby facilitating clot removal. Proximal contraction of the pinched clot may reduce expulsion forces by elongating the clot 160 and pulling it away from the vessel wall during the expulsion process.

[0059] In some embodiments, distal section 124 of cage structure 120 may have a barrel shape sized to expand to occlude blood vessel 171, thereby preventing clot 160 from moving distally as clot 120 and assembly 100 move proximally to extract clot 160. In some embodiments, distal section 124 may be further configured to expand through a soft portion of clot 160 to further engage clot 160.

[0060] The clamping of the clot between the catheter 110 and the cage structure 120 can cause the radiopaque indicator 112 to change between a substantially linear non-display state 114 as shown in FIG. 1A and a substantially wavy display state 115 as shown in FIG. 1B in response to impact of the cage structure 120 on the delivery microcatheter 110.

[0061] Figure 6 illustrates a method 300 for treating an embolism as disclosed herein. The method steps of Figure 6 can be implemented by any of the exemplary means described herein, or by similar means, as will be appreciated.

[0062] At block 302, the method 300 may include deploying at least a portion of a cage structure of a clot retrieval assembly distal to the catheter across the clot. The cage structure may be configured similar to the exemplary cage structure 120 disclosed herein, variations thereof, and alternatives thereof, as will be understood by one of ordinary skill in the art. The clot retrieval assembly may be configured similar to the exemplary clot retrieval assembly 100 disclosed herein, variations thereof, and alternatives thereof, as will be understood by one of ordinary skill in the art. The cage structure may be deployed similar to variations thereof and alternatives thereof, as shown in FIGS. 1B, 3B, and 5B, and as otherwise disclosed herein, as will be understood by one of ordinary skill in the art.

[0063] At block 304, the method 300 may include applying tension to a shaft attached to the proximal section of the cage structure. The shaft may be configured similarly to the exemplary shaft 130, variations thereof, and alternatives thereof disclosed herein, as will be understood by one of ordinary skill in the art. The proximal section of the cage structure may be configured similarly to the proximal section 125 of the cage structure 120, variations thereof, and alternatives thereof disclosed herein, as will be understood by one of ordinary skill in the art.

[0064] At block 306, the method 300 may include changing an elongated radiopaque indicator disposed in a distal portion of the catheter from a first, substantially linear, non-display state to a second, substantially wavy, non-display state by sandwiching the clot between the cage structure and the distal end of the catheter. The elongated radiopaque marker may be configured similarly to the exemplary radiopaque indicator 112, variations thereof, and alternatives thereof disclosed herein, as will be understood by one of ordinary skill in the art. The distal portion of the catheter may be configured similarly to the exemplary distal portion 111 of the catheter 110, variations thereof, and alternatives thereof disclosed herein, as will be understood by one of ordinary skill in the art. The linear non-display state may be similar to that shown in FIG. 1A, FIG. 3A, or FIG. 5A, and as otherwise disclosed herein, as will be understood by one of ordinary skill in the art. The second substantially wave-shaped display state can be similar to display state 115, variations and alternatives thereof, as shown in Figures 1B, 3B, or 5B, as otherwise disclosed herein, and as understood by one of ordinary skill in the art. The clot can be clamped at the distal end of the catheter, as shown in Figure 5B, as otherwise disclosed herein, and as understood by one of ordinary skill in the art.

[0065] At block 307, the method 300 may further include moving the cage structure to compress the clot between the cage structure and the interior wall of the blood vessel. The clot may be trapped by the cage structure, its variations, and alternatives disclosed herein, as will be understood by one of ordinary skill in the art.

[0066] At block 308, the method may include visualizing a substantially wavy display of an elongated radiopaque indicator disposed at the distal end of the catheter. In some examples, visualizing the substantially wavy display may include using fluoroscopic imaging techniques.

[0067] At block 310, the method may include withdrawing the clot, cage structure, and catheter.

[0068] In some examples, the clot may be composed mostly of fibrin.

[0069] In some embodiments, the method 300 can include extracting a clot from a distal M2, M3, M4, A2-5, or P2-P5 vessel. Sizes of any of these vessels are known in the art, and one skilled in the art will understand that the components of the clot retrieval assembly can be appropriately sized to achieve the goal of removing a clot from these vessels.

[0070] In some embodiments, the cage structure 120 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 by the cage structure 120, for example, by the cylindrical body section 124, may alter the properties of the clot, making it harder and "stickier," thereby making it more difficult to retrieve.

[0071] In some embodiments, 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, improving the clamping of the clot 160 and the security of the captured clot segment. The user may feel this clamping as resistance and stop the advancement of the microcatheter 110, the user may advance the delivery microcatheter 110 a fixed distance up the shaft 130, for example, 30% to 50% of the shaft length, or the user may visualize the substantially wavy display state 115 of the radiopaque indicator 112 to confirm clamping of the clot 160 before retracting the clot removal assembly 100.

[0072] The relative tension between the cage structure 120 and the delivery microcatheter 110 must be maintained so that the clamping force between the clot removal assembly 100 and the clot 160 does not weaken. By retracting both the clot 160 and the clot removal assembly 100, the occlusive clot 160 can be displaced and retracted into the access guide catheter or introducer sheath and removed from the patient.

[0073] Shaft 130 may be a tapered wire shaft and may be made from stainless steel, MP35N, Nitinol, or other material with a suitably high modulus and tensile strength.

[0074] The elongated radiopaque indicator 112 may be made radiopaque by adding a filler material such as tungsten 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.

[0075] 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.

[0076] In some embodiments, clot 160 may be composed mostly of fibrin.

[0077] In some embodiments, the method 300 can include extracting the clot 160 from a distal M2, M3, M4, A2-5, or P2-P5 vessel.

[0078] In some embodiments, visualizing the substantially corrugated state 115 may include using fluoroscopic imaging techniques.

[0079] In some embodiments, a catheter 110 is disclosed. The catheter 110 may include a proximal region 113 extending across 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 across at least a portion of the length of the distal region 111. The catheter 110 may be configured such that a compressive force applied to a distal end 118 of the catheter 110 results in controlled movement of the distal region 111 from a substantially straight, uncompressed configuration 114 to a corrugated, compressed configuration 115, with the radiopaque indicator 112 configured to indicate the configuration of the distal region 111.

[0080] In some embodiments, the proximal region 113 is configured to remain in a substantially straight configuration 119 as a compressive force is applied to the distal end 118 of the catheter 110 and the distal region 111 moves to a wavy compressed configuration 115.

[0081] In some embodiments, the catheter 110 can be configured such that a compressive force applied over most of the length of the catheter 110 causes the proximal region 113 to remain in a substantially straight configuration 119 and the distal region to move to a wavy compressed configuration 115.

[0082] In some examples, distal region 111 may include a coiled support structure 116 and proximal region 113 includes a braided support structure 117 .

[0083] In some embodiments, catheter 110 can be configured to deliver clot retrieval device 120 across clot 160 .

[0084] In some embodiments, catheter 110 can be configured to clamp clot 160 between distal end 118 of catheter 110 and clot retrieval device 120 .

[0085] 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.

[0086] 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 in a device or system does not preclude the presence of additional or intervening components between those explicitly identified components.

[0087] 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 and are intended to be within the scope of the following claims.

[0088] [Embodiment] (1) A clot removal assembly comprising: 1. A delivery microcatheter comprising: a distal portion including an elongated radiopaque indicator; a delivery microcatheter comprising a proximal portion; a cage structure configured to change between a delivery configuration and an expanded clamping configuration; a shaft in communication with the cage structure and disposed substantially within the delivery microcatheter; a clot removal assembly, wherein the elongated radiopaque indicator is configured to change between a substantially linear non-display state and a substantially wavy visible state in response to impact of the cage structure against the delivery microcatheter. (2) A clot removal assembly as described in embodiment 1, wherein the elongated radiopaque indicator is configured to change between the substantially straight non-display state and the substantially wavy display state in response to a proximal pulling force applied to the cage structure by the shaft. (3) The clot removal assembly of embodiment 1, wherein the elongated radiopaque indicator is configured to change between the substantially linear non-display state and the substantially wavy display state in response to a distal pushing force applied to the delivery microcatheter. (4) A clot removal assembly as described in embodiment 1, wherein the elongated radiopaque indicator comprises a tungsten-doped portion of the distal portion. (5) A clot removal assembly as described in embodiment 1, wherein the elongated radiopaque indicator comprises a radiopaque coating.

[0089] (6) A clot removal assembly as described in embodiment 1, wherein the cage structure further comprises a distal section and a proximal spiral section, the distal section comprising a first plurality of struts, and the proximal spiral section comprising a second plurality of struts smaller than the first plurality of struts. (7) A clot removal assembly as described in embodiment 6, wherein first ends of the first plurality of struts abut the second plurality of struts and second ends of the first plurality of struts terminate in a plurality of atraumatic joints. (8) A clot removal assembly as described in embodiment 1, wherein the cage structure comprises a proximal spiral section, a cylindrical body section distal to the proximal spiral section, and an open distal end, and the proximal spiral section is configured to clamp a clot between struts of the proximal spiral section. (9) The clot removal assembly of embodiment 1, wherein the distal portion of the delivery microcatheter comprises a coiled core and the proximal portion of the delivery microcatheter comprises a braided core. (10) A method for treating embolism, said method comprising: deploying at least a portion of a cage structure of the clot retrieval assembly distal to the catheter across the clot; applying tension to a shaft attached to a proximal section of the cage structure; changing an elongated radiopaque indicator disposed in a distal portion of the catheter from a first substantially linear non-display state to a second substantially wavy displayed state by sandwiching the clot between the cage structure and the distal end of the catheter; visualizing the second substantially wavy display state of the elongated radiopaque indicator disposed at the distal end of the catheter; and withdrawing the clot, the cage structure, and the catheter.

[0090] (11) The method of claim 10, further comprising moving the cage structure to compress the clot between the cage structure and an inner wall of the blood vessel. (12) The method of embodiment 10, wherein the clot comprises a majority of fibrin. (13) The method of embodiment 12, further comprising withdrawing the clot from a distal M2, M3, M4, A2-5, or P2-P5 vessel. (14) The method of embodiment 10, wherein visualizing the second substantially corrugated state includes using fluoroscopic imaging techniques. (15) A catheter, a proximal region extending over a majority of the length of the catheter; a distal region extending distally from the proximal region; a radiopaque indicator extending over at least a portion of the length of the distal region; the catheter is configured such that a compressive force applied to a distal end of the catheter results in controlled movement of the distal region from a substantially linear uncompressed configuration to a wavy compressed configuration; A catheter, wherein the radiopaque indicator is configured to indicate a configuration of the distal region.

[0091] (16) The catheter of claim 15, wherein the proximal region is configured to remain in a substantially straight configuration when the compressive force is applied to the distal end of the catheter and the distal region moves to the wavy, compressed configuration. (17) The catheter of 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 distal region comprises a coiled support structure; 16. The catheter of claim 15, wherein the proximal region comprises a braided support structure. (19) The catheter of embodiment 15, wherein the catheter is configured to deliver a clot retrieval device across the clot. (20) The catheter of embodiment 19, wherein the catheter is configured to clamp the clot between the distal end of the catheter and the clot retrieval device.

Claims

1. 1. A clot removal assembly comprising:

1. A delivery microcatheter comprising: a distal portion including an elongated radiopaque indicator; a delivery microcatheter comprising a proximal portion; a cage structure configured to change between a delivery configuration and an expanded clamping configuration; a shaft in communication with the cage structure and disposed substantially within the delivery microcatheter; a clot removal assembly, wherein the elongated radiopaque indicator is configured to change between a substantially linear non-display state and a substantially wavy visible state in response to impact of the cage structure against the delivery microcatheter.

2. 2. The clot removal assembly of claim 1, wherein the elongated radiopaque indicator is configured to change between the substantially straight non-display state and the substantially wavy visible state in response to a proximal pulling force applied to the cage structure by the shaft.

3. 2. The clot removal assembly of claim 1, wherein the elongated radiopaque indicator is configured to change between the substantially linear non-display state and the substantially wavy visible state in response to a distal pushing force applied to the delivery microcatheter.

4. The clot removal assembly of claim 1 , wherein the elongated radiopaque indicator comprises 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. 2. The clot removal assembly of claim 1, wherein the cage structure further comprises a distal section and a proximal helical section, the distal section comprising a first plurality of struts, and the proximal helical section comprising a second plurality of struts smaller than the first plurality of struts.

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

8. 2. The clot removal assembly of claim 1, wherein the cage structure comprises a proximal helical section, a cylindrical body section distal to the proximal helical section, and an open distal end, the proximal helical section configured to sandwich a clot between struts of the proximal helical section.

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

10. A catheter, a proximal region extending over a majority of the length of the catheter; a distal region extending distally from the proximal region; a radiopaque indicator extending over at least a portion of the length of the distal region; the catheter is configured such that a compressive force applied to a distal end of the catheter results in controlled movement of the distal region from a substantially linear uncompressed configuration to a wavy compressed configuration; A catheter, wherein the radiopaque indicator is configured to indicate a configuration of the distal region.

11. 11. The catheter of claim 10, wherein the proximal region is configured to remain in a substantially straight configuration when the compressive force is applied to the distal end of the catheter and the distal region moves to the wavy, compressed configuration.

12. 11. The catheter of claim 10, wherein the catheter is configured such that the compressive force applied across the majority of the length of the catheter leaves the proximal region in a substantially straight configuration and moves the distal region to the wavy, compressed configuration.

13. the distal region comprises a coiled support structure; The catheter of claim 10 , wherein the proximal region comprises a braided support structure.

14. The catheter of claim 10 , wherein the catheter is configured to deliver a clot retrieval device across a clot.

15. The catheter of claim 14 , wherein the catheter is configured to clamp the clot between the distal end of the catheter and the clot retrieval device.

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