Suction catheter with stable structural member that minimizes risk of damaging inner wall of blood vessel during suction

Abstract

An aspiration catheter includes a body having a proximal end and an opposite distal tip, with a lumen extending therethrough in a longitudinal direction from the proximal end to the distal tip. The aspiration catheter further includes a stabilizing structural member that stabilizes the body relative to the inner wall of the blood vessel to minimize movement and / or radial expansion of the distal tip of the body when subjected to aspiration that would otherwise potentially damage the inner wall of the blood vessel.

Description

[0001] Cross-references to related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 447,506, filed February 22, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure generally relates to an aspiration catheter for capturing and removing a target clot during a thrombectomy procedure. Preferably, this disclosure relates to an improved aspiration catheter subjected to aspiration (e.g., vacuum (i.e., non-circulating) or pulsation / circulation), wherein the aspiration catheter is configured to minimize displacement and / or radial overexpansion of the distal end by stabilizing the body relative to the inner wall of the vessel, thereby minimizing the potential risk of damage to the vessel inner wall. Background Technology

[0003] During endovascular treatment to capture and remove clots, aspiration (e.g., vacuum or pulsation / circulation) is typically applied to the catheter to improve efficiency. However, when subjected to aspiration (e.g., vacuum or pulsation / circulation), unintended excessive movement applied to the distal end / tip of the aspiration catheter poses a significant risk of potential damage to the vessel's inner wall. Therefore, it is desirable to develop an improved aspiration catheter that provides greater stability during aspiration, thereby reducing or mitigating the risk of potential damage to the vessel's inner wall.

[0004] Furthermore, when using aspiration (e.g., vacuum or pulsation / circulation) to capture and remove clots, aspiration catheters can be configured with radially expandable distal segments (e.g., funnel-shaped distal segments) to facilitate clot intake into the lumen of the body or axis. However, if the diameter of the taken-up clot exceeds the diameter of the expanded distal end in a radially expanded or unfolded state within the vessel, the funnel-shaped distal segment or aspiration catheter will radially overexpand, creating a significant risk of damaging the vessel's inner wall and / or becoming lodged. Therefore, it is desirable to develop an improved aspiration catheter that inhibits overexpansion of the radially expandable distal segment (e.g., funnel-shaped distal segment).

[0005] To address these issues, there is a desire to develop an improved aspiration catheter that reduces the risk of damaging the inner wall of blood vessels during aspiration. Summary of the Invention

[0006] One aspect of this disclosure relates to an improved aspiration catheter that minimizes the risk of damage to the inner wall of a blood vessel during aspiration (e.g., vacuum or pulsation / circulation).

[0007] One aspect of this disclosure relates to an improved aspiration catheter for effectively capturing a target clot therein while providing greater stability to prevent excessive movement of the distal end / tip of the aspiration catheter, thereby minimizing the risk of damage to the vascular endothelium during aspiration (e.g., vacuum or pulsation / circulation).

[0008] Another aspect of this disclosure relates to an improved aspiration catheter, which is stabilized via stabilizing structural members, thereby minimizing the risk of damage to the vascular endothelium caused by excessive distal / terminal movement during aspiration (e.g., vacuum or pulsation / circulation).

[0009] Another aspect of this disclosure relates to an improved aspiration catheter that includes stabilizing structural members to prevent excessive expansion of the expandable distal segment (e.g., funnel-shaped distal segment), thereby minimizing the risk of damage to the vessel wall and / or the risk of clots lodged therein during aspiration (e.g., vacuum or pulsation / circulation). Attached Figure Description

[0010] The foregoing and other aspects of this disclosure will be further discussed with reference to the following description and in conjunction with the accompanying drawings, in which similar numbers indicate similar structural elements and features in various figures. The drawings are not necessarily drawn to scale, but rather focus on illustrating the principles of this disclosure. The drawings depict one or more specific embodiments of the device by way of example only, and not by way of limitation.

[0011] Figure 1A The distal segment of an exemplary aspiration catheter according to the present disclosure is depicted having a stabilizing structural member (e.g., a tether) for preventing excessive expansion of the radially expandable distal segment; wherein the aspiration catheter is depicted such that, when delivered through the blood vessel to the target site, the radially expandable distal segment is enclosed within an outer guide. Figure 1B The image depicts the radially enlarged distal segment of the aspiration catheter being pulled out from the external guide, wherein the tether inhibits the excessive expansion of the radially enlargeable distal segment caused by the ingestion of excessively large clots therein. Figure 2A The distal segment of another example of an aspiration catheter according to the present disclosure is depicted, having an axially compressible bellows segment as a stabilizing structural member, wherein the axially compressible bellows segment is shown in an unstable (i.e., axially non-compressible) state. Figure 2B Depicting Figure 2A The distal segment of an exemplary aspiration catheter, wherein an axially compressible bellows segment is shown in a stable state (i.e., axially compressed state). Figure 3AA distal segment of another exemplary aspiration catheter according to the present disclosure is depicted, having an externally inflatable balloon cannula as a stabilizing structural member, wherein the externally inflatable balloon cannula is shown in an unstable (i.e., non-inflated) state. Figure 3B Depicting Figure 3A The distal segment of an exemplary aspiration catheter, wherein an externally inflatable balloon cannula is shown in a stable (i.e., inflated) state; Figure 4A The distal segment of another example of an aspiration catheter is depicted, the aspiration catheter including a traction member extending axially through the lumen and secured to the distal segment, wherein the traction member is shown in a non-deployed or non-actuated state while the aspiration catheter is in an unstable state. Figure 4B Depicting Figure 4A The distal segment of an exemplary aspiration catheter, wherein the traction member is shown in an deployed or actuated state, thereby altering the axial profile of the aspiration catheter (e.g., buckling, meandering, or spiraling) to a stable state. Figure 5A The distal segment of another example of an aspiration catheter according to the present disclosure is depicted, the aspiration catheter having an externally pre-filled gel sheath as a stabilizing structural member and actuated (i.e., axially compressed) via a traction member extending axially through the lumen and fixed to the distal segment of the aspiration catheter, wherein the externally pre-filled gel sheath is shown in an unstable (i.e., axially uncompressed) state before being pulled on the traction member; Figure 5B Depicting Figure 3A The distal segment of an exemplary aspiration catheter, wherein an externally pre-filled gel sheath is shown in a stable (i.e., axially compressed) state in response to traction on a traction member; Figure 6A The distal segment of another example of aspiration catheter is depicted, which includes a nitinol wire serving as a stabilizing structural member, the nitinol wire being thermally activated by a circuit; wherein the nitinol wire is shown in an unstable state (i.e., martensitic phase – temperature above the austenitic transformation completion temperature), such that the distal segment of the aspiration catheter remains compliant and traceable. Figure 6B Depicting the effect on the target site during suction. Figure 6B The distal segment of an exemplary aspiration catheter, wherein the nickel-titanium line is shown as being in a stable state (i.e., austenitic phase – temperature below the austenitic transformation temperature), thereby hardening the distal segment of the aspiration catheter to stabilize the distal end / terminus. Figure 7 This is an exemplary aspiration cannula at the target site during aspiration. Figure 6AWith modifications, the nickel-titanium filament assembly in this paper is curved, spiral, or undulating in a stable state (i.e., austenitic phase – temperature below the austenitic transformation temperature), thereby stiffening the distal segment of the aspiration catheter to stabilize the body relative to the inner wall of the vessel, thereby minimizing the movement of the distal tip / end during aspiration. Figure 8A This is a distal segment of another exemplary aspiration catheter according to the present disclosure, which is secured within the lumen of an outer sheath via a movable hinge; wherein the aspiration catheter is depicted during delivery to the target site prior to the application of aspiration. Figure 8B yes Figure 8A The distal segment of an exemplary aspiration catheter undergoing aspiration is depicted, in which the aspiration catheter is isolated from the outer sheath by a movable hinge, so that axial movement (e.g., back and forth) of the aspiration catheter during aspiration is not transmitted to the outer sheath. Figure 9A Another exemplary aspiration catheter according to the present disclosure is depicted, wherein along its distal segment is an inflatable balloon with an embossed outer surface as a stabilizing member according to the present disclosure; wherein the inflatable balloon is shown in an unstable (i.e., uninflated) state while being delivered through the blood vessel to the target site prior to aspiration. Figure 9B Depicting Figure 9B An exemplary aspiration conduit, wherein an externally inflatable bladder having an embossed outer surface is shown in a stable (i.e., inflated) state, positioned at the target site during aspiration; Figure 9C It passes through along line IX(C)-IX(C). Figure 9B A radial cross-sectional view of an externally inflatable balloon with an embossed surface, wherein the externally inflatable balloon is shown in a stable (i.e., inflated) state; Figure 9D yes Figure 9A A modification to the example in which the distal segment of the outer surface of the aspiration catheter itself, rather than the external inflatable balloon, has an embossed surface; Figure 10A A distal segment of another example of an aspiration catheter according to the present disclosure is depicted, which is nested within an outer guide held together by an elastomeric polymer forming an air gap therebetween, the elastomeric polymer serving as a stabilizing structural member, thereby allowing but restricting movement of the distal end / tip during aspiration. Figure 10B yes Figure 10A A radial sectional view of the suction catheter along line X(B)-X(B); and Figure 11An exemplary suction conduit system includes a vacuum pump connected in fluid communication to the suction conduit, which is delivered to the target site before capturing / taking up clots in the target site, wherein the suction conduit may include any of the stabilizing structural members shown above. Detailed Implementation

[0012] As used herein, the term “about” or “approximately” for any numerical value or range indicates appropriate dimensional tolerances that allow a collection of parts or components to achieve the intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of ±20% of the enumerated values; for example, “about 90%” may refer to a range of values ​​from 71% to 99%.

[0013] As used herein, the terms “tubular” and “tube” should be interpreted broadly and are not limited to structures that are perfectly cylindrical or have a perfectly circular cross-section or a uniform cross-section over their entire length. For example, tubular structures or systems are typically shown as structures that are substantially cylindrical. However, without departing from the scope of this disclosure, tubular systems may have tapered or curved outer surfaces.

[0014] Documents incorporated herein by reference shall be considered an integral part of this application, and unless any term defined in such incorporated documents conflicts with the definition expressly or implicitly given in this specification, the definition in this specification shall be taken into account only.

[0015] Figure 11 A suction catheter 1105 is shown, having a proximal hub 1107 in fluid communication with a suction (e.g., vacuum or pulsation / circulation) pump 1100, and is delivered across the vessel to the target site of the clot before suction (e.g., vacuum or pulsation / circulation) is applied. Applying suction (e.g., vacuum or pulsation / circulation) causes excessive movement of the distal tip / end of the suction catheter 1105 during clot capture and removal, resulting in a significant risk of damage to the vessel wall. This disclosure relates to an improved suction catheter configured to minimize the potential risk of damage to the vessel wall when subjected to suction (e.g., vacuum (i.e., non-circulation) or pulsation / circulation). According to this disclosure, one way to minimize the potential risk of damage to the vessel wall is to stabilize the suction catheter relative to the vessel wall in order to minimize excessive axial movement of the distal tip / end during suction. It is also recognized that when clots exceeding the diameter of the funnel-shaped distal segment are ingested and may even become lodged in the vessel, there is a risk of potential damage to the vessel wall due to overexpansion of the radially expandable distal segment of the aspiration catheter (e.g., the funnel-shaped distal segment). According to this disclosure, this potential risk of damage to the vessel wall is addressed by limiting or restraining overexpansion (i.e., radial widening) of the radially expandable distal segment of the aspiration catheter.

[0016] Several non-limiting examples of stabilizing structural members are shown and described below for stabilizing the aspiration catheter relative to the inner wall of the blood vessel to minimize movement of the distal end / tip of the aspiration catheter during aspiration (e.g., vacuum or pulsation / circulation).

[0017] Figure 2A and Figure 2B An exemplary aspiration catheter according to the present disclosure is depicted, which includes a stabilizing structural member as part of the distal end / proximal side of the distal segment of the aspiration catheter, which expands radially when actuated or deployed via a traction member (e.g., a traction line). Figure 2A The aspiration catheter 205 is depicted as being delivered through a blood vessel to a target site proximal to the target clot before aspiration (e.g., vacuum or pulsation / circulation) is applied. A traction member 245 (e.g., a filament) extends axially through the lumen of the aspiration catheter 205 while being secured (e.g., a collar or anchor) at its distal end within the distal segment of the aspiration catheter 205. Figure 2A and Figure 2B In the example, the stabilizing member is an axially compressible segment 255a (e.g., a bellows segment).

[0018] During operation, when delivered through the blood vessel to the target site proximal to the clot, the traction member 245 (e.g., the filament) is not actuated (i.e., not pulled in the proximal direction), such that the axially compressible segment 255a (e.g., the bellows segment) remains in a default unstable (i.e., radially constricted) state. Therefore, the aspiration catheter 205, including the axially compressible segment 255a, has a traceable, generally uniform outer diameter for navigation through the blood vessel to the target site. Figure 2A Once the aspiration catheter is delivered to the target site in the blood vessel, aspiration (e.g., vacuum or pulsation / circulation) is applied to capture the clot. The traction member 245 (e.g., a filament) is actuated by traction in the proximal direction. Subsequently, the axially compressible segment 255a (e.g., a bellows segment) transitions to a stable state, wherein a portion of its radially expanded portion (similar to an accordion section) physically contacts the inner wall of the blood vessel, thereby stabilizing the distal end / tip of the aspiration catheter during aspiration. Figure 2B ).

[0019] Figure 3A and Figure 3B Another example of an aspiration catheter according to this disclosure is provided, wherein the stabilizing member is an external radially expandable cannula (e.g., an externally expandable balloon cannula 255b) disposed externally along the distal segment of the aspiration catheter 205 at the proximal side of the distal end / terminus. Figure 3AThe externally inflatable balloon cannula 255b is depicted in an unstable (i.e., contracted) state before receiving the expansion medium via the expansion lumen 245'. When in... Figure 3A In this unstable (i.e., constricted) state, the aspiration catheter 205 can be delivered through the blood vessel to a target site proximal to the clot. Once correctly positioned proximal to the clot in the blood vessel, aspiration (e.g., vacuum or pulsation / circulation) is applied to capture the clot. Before, simultaneously with, or after aspiration begins, an expansion medium is delivered via the expansion lumen 245', thereby transitioning the external inflatable balloon cannula 255b to a stable (i.e., inflated) state with direct physical contact with the vessel wall, thus stabilizing the aspiration catheter relative to the vessel wall and minimizing movement of the distal end / tip of the aspiration catheter during aspiration. Figure 3B ).

[0020] In yet another example of the aspiration catheter according to this disclosure, the stabilizing member is provided by intentionally altering its overall longitudinal / axial shape in response to an actuation (i.e., traction in the axial direction) of the traction member. When referred to in this disclosure, the term "altering the overall longitudinal / axial shape" is defined as the aspiration catheter having a central longitudinal axis that is no longer equidistant from the inner wall of the lumen. Figure 4B In the example shown, the described altered overall longitudinal / axial shape is meandering, spiral, or tortuous on the alternating sides of the aspiration catheter. See also Figure 4A The suction catheter 205 has a traction member 245 (e.g., a wire) that is fixed at its distal end to a distal segment of the suction catheter and extends through the lumen in a proximal direction. Figure 4A The aspiration catheter 205 is depicted in an unstable state (i.e., unchanged overall axial / longitudinal shape, wherein the central longitudinal axis extending therethrough is substantially equidistant from the inner wall of the lumen). In response to actuation of a pulling member (e.g., a filament) (i.e., traction in the proximal direction), the aspiration catheter 205 transitions to a stable state (i.e., changed overall axial / longitudinal shape, wherein the central longitudinal axis extending therethrough is no longer equidistant from the inner wall of the lumen).

[0021] During operation, when delivered through the blood vessel to the target site proximal to the clot, the traction member 245 (e.g., a filament) is not actuated (i.e., not pulled in the proximal direction), allowing the aspiration catheter 205 to remain in a default unstable state (i.e., unchanged overall axial / longitudinal shape, where the central longitudinal axis extending through it is substantially equidistant from the inner wall of the lumen). Once the aspiration catheter 205 is delivered to the target site in the blood vessel, aspiration (e.g., vacuum or pulsation / circulation) is applied to capture the clot. In response to actuation of the traction member, the overall axial / longitudinal shape of the aspiration catheter 205 itself is altered (e.g., meandering, spiraling, or tortuous), so that the central longitudinal axis extending through it is no longer equidistant from the inner wall of the lumen. Those regions 255c of the aspiration catheter that are tortuous, bent, or kinked are in direct physical contact with the inner wall of the blood vessel, thereby stabilizing the aspiration catheter in response to excessive movement of the distal end / tip of the aspiration catheter during aspiration. Figure 4B ).

[0022] at the same time Figure 5A and 5B Another example of an aspiration catheter according to this disclosure is shown, wherein the stabilizing member is a pre-filled outer sheath disposed proximal to the distal end / terminus along the distal segment of the aspiration catheter. In response to the application of an axial compressive force, the pre-filled outer sheath expands radially. See also Figure 5A An outer sheath 255d is disposed proximal to the distal end / terminus of the aspiration catheter 205, surrounding the distal segment. The outer sheath 255d is pre-filled with a deformable material (e.g., a biocompatible gel material). A traction member 245 (e.g., a filament) extends axially through the lumen of the aspiration catheter 205, while being secured within the distal segment of the aspiration catheter 205 at its distal end. In response to actuation of the traction member 245 (e.g., the filament) (e.g., traction in the proximal direction), the pre-filled outer sheath, along with the deformable material contained therein, is longitudinally / axially compressed, thereby expanding radially.

[0023] During operation, when delivered through the blood vessel to the target site proximal to the clot, the traction member 245 (e.g., the filament) is not actuated (i.e., not pulled in the proximal direction), causing the pre-filled outer cannula 255d to remain in a default unstable state (i.e., minimum outer diameter). Therefore, the aspiration catheter 205 along the pre-filled outer cannula 255d to which it is attached is trackable for navigation through the blood vessel to the target site. Figure 5AOnce the aspiration catheter is delivered to the target site in the blood vessel, aspiration (e.g., vacuum or pulsation / circulation) is applied to capture the clot. Simultaneously or prior to aspiration, the traction member 245 (e.g., a filament) is pulled proximally. Subsequently, the pre-filled outer cannula 225d and the deformable material contained therein expand radially upon axial compression, transitioning to a stable state of physical contact with the inner wall of the blood vessel (i.e., maximum outer diameter), thereby stabilizing the aspiration catheter relative to the inner wall of the blood vessel while minimizing movement of the distal tip / end during aspiration. Figure 5B ).

[0024] Figure 6A and Figure 6B The unstable and stable states of another example of the stabilizing structural member of the suction conduit according to this disclosure are depicted, respectively. As an alternative to actuating the stabilizing structural member by applying an axial compressive force to the suction conduit through axial traction on the traction member, in this example, the stabilizing member is thermally actuated. Specifically, the suction conduit 205 has an associated nitinol wire 255e (i.e., a nickel-titanium alloy) that alters the properties or characteristics of the nitinol wire 255e when thermally activated by the circuit 260 to a specified temperature range. See also... Figure 6A In the example, both the nitinol wire 255e and the circuit 260 (e.g., a conductive metal wire) are disposed within the lumen of the suction conduit 205.

[0025] During operation, when delivered through the blood vessel to the target site proximal to the clot, the nickel-titanium wire 255e is in an unstable state (i.e., the martensitic phase temperature is below the austenite transformation completion temperature (A). f This makes the nitinol wire compliant and easy to track, enabling it to navigate through blood vessels to the target site. Once the aspiration catheter is delivered to the target site in the blood vessel, aspiration (e.g., vacuum or pulsation / circulation) is applied to capture the clot. Before or simultaneously with aspiration, in response to thermal actuation (i.e., thermal heating), the nitinol wire transforms to a steady state at 255°C (i.e., the austenite phase – the temperature is heated above the austenite transformation completion temperature (A2). f This hardens the nitinol wire 255e, limiting, reducing, or minimizing excessive movement of the distal end / tip of the suction conduit caused by suction (e.g., vacuum or pulsation / circulation, preferably pulsation / circulation). As a modification, when thermally actuated (i.e., heated), it is in a steady state (i.e., the austenite phase temperature is heated above the austenite transformation completion temperature (A0)). f The nickel-titanium wire can be shaped or formed into a curved, undulating, or spiral shape in the longitudinal / axial direction, such as... Figure 7As shown. Therefore, the stability provided by the hardening of the nickel-titanium wire 255e in the austenitic phase through the curved area of ​​the suction catheter in direct physical contact with the inner wall of the lumen is promoted, supplemented, combined or enhanced by the hardening of the wire in the austenitic phase, which forms a spiral or wave.

[0026] exist Figure 8A and Figure 8B This illustration shows yet another method of applying stability to an aspiration catheter under aspiration (e.g., vacuum or pulsation / circulation) according to the present disclosure, employing a flexible movable hinge. An aspiration catheter 815 is disposed within the lumen of an outer sheath 810, which is positioned proximal to the sheath and connected via a movable hinge 855. The movable hinge 855, preferably made of a flexible biocompatible polymer, isolates the axial movement of the aspiration catheter 815 from the axial movement of the outer sheath 810, while still allowing axial movement of the aspiration catheter 815 under aspiration (e.g., vacuum or pulsation / circulation). The outer sheath 810, where the aspiration catheter 815 is disposed, provides greater stability to reduce excessive axial movement of the distal segment 815 of the aspiration catheter relative to the axial movement provided by the vessel wall. Applying aspiration (e.g., vacuum or pulsation / circulation aspiration, but preferably pulsation / circulation aspiration as indicated by the double arrows) applies axial movement (as shown by the dashed lines) to the aspiration catheter 815 received by the movable hinge 855. Excessive axial movement of the distal segment 815 is reduced by the movable hinge 855 (i.e., not prevented or inhibited), hereinafter referred to as reduced (i.e., non-excessive) axial movement. Vibration, together with the reduced axial movement of the distal segment 815 relative to the outer sheath 810, helps to tear clots (as shown by the tearing of fragments by smaller clots), thereby improving the efficiency of capturing and removing clots, especially fibrin-rich and / or oversized clots.

[0027] The stabilizing structural member can also be a non-circular (e.g., embossed) surface (a separate component attached thereto or a segment of the suction conduit itself), which is arranged along the distal segment of the distal end / proximal end. Figures 9A to 9C An example is shown of an expandable sleeve 955 disposed proximal to the distal end / terminal 915 along the distal segment of the suction conduit 905, the expandable sleeve 955 having an embossed outer surface when expanded. Figure 9CThe cannula 955 can be expanded via an expansion medium received through the expansion lumen 909. Before expansion, the cannula 955 is in an unstable (i.e., minimum outer diameter) state, allowing the aspiration catheter 905 to be tracked and navigated through the blood vessel to the target site. Once the distal end / tip 915 of the aspiration catheter 905 is positioned proximally to the target clot 130, aspiration (e.g., vacuum or pulsation / circulation) is applied to capture the clot therein. The cannula 955 is expanded by filling the expansion medium through the expansion lumen 909 before or simultaneously with the aspiration. In the expanded (i.e., stable) state, the outer surface of the cannula 955 has an embossed profile. Figure 9B and Figure 9C This device stabilizes the aspiration catheter in response to excessive movement of the distal end / tip during aspiration. (Example only.) Figure 9B and Figure 9C The outer surface of the 955 cannula has four ridges or protrusions, but can be modified to have any number of two or more protrusions as needed. The more protrusions, the larger the contact surface area with the vessel wall, thus increasing the stability of the distal end / tip of the aspiration catheter. As mentioned above, as an alternative to an expandable cannula with an embossed outer surface, a portion of the aspiration catheter itself along its distal segment proximal to the distal end / tip may have an embossed outer contour or surface, such as... Figure 9D As shown. Similarly, the number of ridges or ridges can be modified as needed.

[0028] exist Figure 10A and Figure 10B In this configuration, the suction catheter 1005 is isolated within the outer sheath 1070 by a stabilizing member (i.e., an absorbent layer) disposed therebetween, and the suction catheter 1005 is stabilized in response to excessive movement of the distal end / tip 1015. Figure 10A and Figure 10B In the example, the absorbent layer is an air gap 1055 disposed between the outer sheath 1070 and the aspiration catheter 1005, which are secured to each other via a soft elastomeric polymer 1075. The air gap 1055 stabilizes the aspiration catheter 1005 in response to excessive movement of the distal end / tip 1015 during aspiration, while the soft elastomeric polymer 1075 applies an elastomeric return force, thereby restoring the aspiration catheter 1005 to its default position within the outer sheath 1070. Figure 10A and Figure 10B In the preferred example shown, the default position of the aspiration catheter is coaxially centered within the outer sheath 1070.

[0029] In the aforementioned example, by stabilizing the aspiration catheter relative to the inner wall of the vessel, the risk of potential damage to the vessel inner wall caused by excessive axial movement of the distal tip / end of the aspiration catheter during aspiration is minimized. There is also a risk of damage to the vessel inner wall during radial expansion of the distal tip / end of the aspiration catheter during clot capture. To aid in clot capture, the aspiration catheter 105 may include a radially self-expanding distal segment 115 (e.g., a distal funnel-shaped segment) that can transition from a non-expanded state (i.e., radial compression / contraction) when encased within the outer guide or sheath 135 to an expanded state (i.e., radial expansion / enlargement) when withdrawn from the outer guide or sheath 135. Due to undesirable radial overexpansion of the radially self-expanding distal segment 115 (e.g., the expandable distal funnel-shaped segment), there is a potential risk of damage to the inner wall of the vessel 140 and the risk of it eventually becoming lodged therein. When an oversized clot is introduced into the aspiration catheter, such unintended radial overexpansion poses a significant risk (where the outer contour of the clot exceeds the inner diameter of the radially self-expanding distal segment when it is in the expanded state) (e.g. Figure 1B (As shown). Figure 1A and Figure 1B An exemplary aspiration catheter 105 having a radially self-expanding distal segment 115 is depicted. Preferably, a frame or skeleton 120, for example made of nitinol, is provided along at least a portion of the self-expanding distal segment 115 of the aspiration catheter 105, preferably along the entire distal edge, to maintain maximum outer diameter when clots are ingested therein. Figure 1A A suction catheter 105 is depicted, wherein a radially self-expanding distal segment 115 is in a non-deployed state and is encased within an outer guide or sheath 135. When in... Figure 1A In the non-deployed state, the aspiration catheter 105 is delivered through the vessel 140 to the target site proximal to the clot 130. Delivery of the external guide 135 and the aspiration catheter 105 to the target site in the vascular system can occur sequentially (i.e., first navigating the external guide 135, then advancing the aspiration catheter 105 distally within it) or simultaneously. Once correctly positioned at the target site, the aspiration catheter 105 is advanced distally (i.e., pushed) until the distal segment 115 protrudes from the distal end of the external guide 135. When withdrawn, the radially self-expanding distal segment 115 automatically transitions from the non-deployed state to the deployed state. Figure 1B According to this disclosure, the tether 125 (e.g., a nitinol tether) serves as a stabilizing structural member to limit, constrain, or reduce the radial expansion of the radially self-expanding distal segment 115 (i.e., to prevent over-expansion) when the clot 130 is ingested therein, thereby minimizing the risk of damage to the inner wall of the vessel 140.

[0030] Various aspects of this disclosure are also provided by the following numbered clauses: Clause 1 A suction catheter includes: a body (105, 205, 815, 905, 1005) having a proximal end and an opposing distal end, wherein a lumen extends longitudinally from the proximal end through the distal end to the distal end; and stabilizing structural members (125, 255a, 255b, 255c, 255d, 255e, 255f, 855, 955, 955', 1055) that stabilize the body (105, 205, 855, 905, 1005) to minimize movement and / or radial expansion of the distal end of the body (105, 205, 815, 905, 1005) during suction.

[0031] Clause 2 The suction catheter according to Clause 1 further includes: an actuating member (245, 260) that, when transitioning from a non-actuated state to an actuated state, changes parameters associated with the body (205); wherein, when the actuating member (245, 260) transitions from the non-actuated state to the actuated state, the stabilizing structural member (255a, 255b, 255c, 255d, 255e, 255f) transitions from an unstable state to a stable state, thereby stabilizing the body (205) to minimize movement of the distal end of the body (205) during suction.

[0032] Clause 3 According to Clause 2, the actuating member is a traction member (245) extending longitudinally within the lumen, the traction member being securely fixed to the distal segment proximal to the distal end; and the traction member (245) is capable of pulling in the proximal direction, changing the parameter of the longitudinal length of the body (205), thereby enabling a transition from a longitudinally elongated state when the traction member (245) is in the non-actuated state to a longitudinally contracted state when the traction member (245) is in the actuated state; and when the traction member (245) is in the actuated state and the body (205) is in the longitudinally contracted state, the stabilizing structural members (255a, 255b, 255c, 255d) expand radially, thereby stabilizing the body (205) and minimizing the movement of the distal end during aspiration.

[0033] Clause 4 According to Clause 3, the stabilizing structural member is: (i) a buckling portion (255c) of the body (205) on alternating sides of the longitudinal centerline when the traction member (245) is in the actuated state and the body (205) is in the longitudinally contracted state; (ii) a longitudinally compressible bellows segment (255a) of the body (205) having multiple discrete portions, capable of radial expansion when the traction member (245) is in the actuated state and the body (205) is in the longitudinally contracted state; or (iii) an expandable or pre-filled deformable sheath (255b, 255d) disposed proximally around the body (205) at the distal end.

[0034] Clause 5 According to Clause 2, the stabilizing structural member is a nitinol wire (255e, 255f) associated with the body (205), and the actuating member is a circuit (260) that changes the temperature parameter, thereby enabling a transition from a non-actuated state at a temperature below the austenite transformation completion temperature to an actuated state at a temperature above the austenite transformation completion temperature; wherein when the circuit (260) is in the non-actuated state at the temperature below the austenite transformation completion temperature, the nitinol wire (255e, 255f) is in a martensitic phase with lower stiffness, but when the circuit (260) is in the actuated state at the temperature above the austenite transformation completion temperature, the nitinol wire (255e, 255f) is in an austenitic phase with higher stiffness, thereby stabilizing the body (205) and minimizing the movement of the distal end of the body (205) during suction.

[0035] Clause 6 According to Clause 5, the aspiration conduit, when in the austenitic phase, is shaped as a curved, undulating, or spiral shape.

[0036] Clause 7 According to Clause 1, the suction catheter wherein the body (815) is disposed within an outer sheath (810) connected to the body via a movable hinge (855), the movable hinge serving as a stabilizing structural member that isolates the distal end of the body (815) from the outer sheath (810) such that axial movement of the body (815) during suction is not transmitted to the outer sheath (810).

[0037] Clause 8 According to Clause 1, the aspiration conduit wherein the stabilizing structural member is either an embossed outer surface (955') that is part of the body (905) itself or an inflatable balloon (955) disposed around it.

[0038] Clause 9 The suction catheter according to Clause 1 further includes an outer sheath (1070) disposed around the body (1005) and secured to the body via an elastomeric polymer that defines an air gap therebetween. The elastomeric polymer serves as a stabilizing structural member for the body (1005), thereby minimizing movement of the distal end of the body (1005) during suction; wherein the elastomeric polymer restores the body (1005) to a substantially centered position within the outer sheath (1070).

[0039] Clause 10 The aspiration catheter according to Clauses 1 to 9, wherein the body (105) of the aspiration catheter has a radially self-expanding distal segment (115) including the distal end; wherein the stabilizing structural member is a tether (125) associated with the radially self-expanding distal segment (115) that restricts the radial expansion of the radially self-expanding distal segment during aspiration to prevent over-expansion.

[0040] Clause 11 A method for using a suction catheter, the suction catheter comprising a body (105, 205, 815, 905, 1005) having a proximal end and an opposing distal end, wherein a lumen extends longitudinally from the proximal end through it to the distal end; and stabilizing structural members (125, 255a, 255b, 255c, 255d, 255e, 255f, 855, 955, 955', 1055) stabilizing the body (105, 205, 855, 905, 1005) to allow the body (105, 205, 815, 905, 1005) to... The method includes the steps of: navigating the aspiration catheter through a blood vessel to a target site, wherein the distal end is positioned proximal to the target clot; applying aspiration to the body (105, 205, 815, 905, 1005) to capture the clot into the lumen; and simultaneously applying the aspiration, stabilizing the body (105, 205, 815, 905, 1005) relative to the inner wall of the blood vessel via the stabilizing structural members (125, 255a, 255b, 255c, 255d, 255e, 255f, 855, 955, 955', 1055) to minimize the movement and / or radial expansion of the distal end during the aspiration, thereby minimizing the risk of damage to the inner wall of the blood vessel.

[0041] Clause 12 According to the method described in Clause 11, the stabilization step includes changing parameters associated with the body (205) in response to the actuating member (245, 260) associated with the body (205) transitioning from a non-actuated state to an actuated state; and when the actuating member (245, 260) transitions from the non-actuated state to the actuated state, the stabilizing structural member (255a, 255b, 255c, 255d, 255e, 255f) transitions from an unstable state to a stable state, thereby stabilizing the body (205) to minimize the movement of the distal end of the body (205) during suction.

[0042] Clause 13 According to the method described in Clause 12, the parameter to be changed is the longitudinal length of the body; and the actuating member is a traction member (245) extending longitudinally in the lumen, the traction member being securely fixed to the distal segment; wherein the step of stabilizing axial movement includes: changing the longitudinal length of the body (205) in response to pulling the traction member (245) in the proximal direction, the body (205) changing from a longitudinally elongated state when the traction member (245) is in an actuated state to a longitudinally contracted state when the traction member (245) is in an actuated state; and in response to the change in the longitudinal length of the body (205) when the traction member (245) is in the actuated state and the body (205) is in the longitudinally contracted state, causing the stabilizing structural members (255a, 255b, 255c, 255d) to expand radially, thereby stabilizing the body (205) and minimizing the movement of the distal end under suction.

[0043] Clause 14 According to the method described in Clause 13, the stabilizing structural member is: (i) a buckling portion of the body (205) on alternating sides of the longitudinal centerline when the tension member (245) is in the actuated state and the body (205) is in the longitudinally contracted state; (ii) a longitudinally compressible bellows segment (255a) of the body (205) having multiple discrete portions, capable of radial expansion when the tension member (245) is in the actuated state and the body (205) is in the longitudinally contracted state; or (iii) an expandable or pre-filled deformable sleeve (255b, 255d) disposed on the outside of the body (205) at the proximal side of the distal end.

[0044] Clause 15 According to the method described in Clause 12, the stabilizing structural member is a nitinol wire (255e, 255f) associated with the body (205), and the actuating member is a circuit (260) that changes the temperature parameter, thereby enabling a transition from a non-actuated state at a temperature below the austenite transformation completion temperature to an actuated state at a temperature above the austenite transformation completion temperature; wherein the step of stabilizing the body (205) relative to the inner wall of the container includes: raising the temperature of the nitinol wire (255e, 255f) via the circuit (260) from a non-actuated state at a temperature below the austenite transformation completion temperature to an actuated state at a temperature above the austenite transformation completion temperature; and in response to raising the temperature of the nitinol wire (255e, 255f) via the circuit (260), causing the nitinol wire (255e, 255f) in the body (205) to... The stiffness of 255f increases from a lower stiffness state in the martensitic phase when the temperature of the body (205) is below the austenite transformation completion temperature to a higher stiffness state in the austenitic phase when the temperature of the nitinol wires (255e, 255f) is above the austenite transformation completion temperature; wherein the higher stiffness state of the nitinol wires (255e, 255f) in the body (205) serves as a stabilizing structural member for the body (205) so as to minimize the movement of the distal end when the suction is applied.

[0045] Clause 16 According to the method described in Clause 15, the nickel-titanium wire, when in the austenitic phase, is shaped into a curved, undulating, or spiral shape.

[0046] Clause 17 According to the method described in Clause 11, the body (815) is disposed within an outer sheath (810) connected to the body via a movable hinge (855), the movable hinge serving as a stabilizing structural member that isolates the distal end of the body (815) from the outer sheath (810), such that axial movement of the body (815) during suction is not transmitted to the outer sheath (810).

[0047] Clause 18 According to the method described in Clause 11, the stabilizing structural member is either an embossed outer surface (955') that is part of the body (905) itself or an inflatable bladder (955) disposed around it.

[0048] Clause 19 According to the method described in Clause 11, the aspiration conduit further includes an outer sleeve (1070) disposed around the body (1005) and secured together via an elastomeric polymer (1075) therebetween defining an air gap (1055) which serves as a stabilizing structural member for stabilizing the body (1005) thereby minimizing movement of the distal end during aspiration; wherein the elastomeric polymer (1075) restores the body (1005) to a substantially centered position within the outer sleeve (1070).

[0049] Clause 20 The method according to any one of Clauses 11 to 19, wherein the navigation step comprises the following steps: advancing the aspiration catheter toward the target clot in a distal direction through the outer guide (135); and engaging the target clot with the aspiration catheter during aspiration, and causing the radially expandable distal segment to radially rotate from a radially contracted state to a radially expanded state; wherein the stabilization step comprises preventing excessive radial expansion of the distal end of the body via a tether (125) serving as a stabilizing structural member to minimize the risk of damage to the vascular endothelium.

[0050] The descriptions contained herein are exemplary and are not intended to limit the scope of this disclosure in any way. As described herein, this disclosure contemplates numerous variations and modifications of aspiration catheters that reduce the risk of damage to the inner wall of blood vessels during aspiration. Modifications and variations that will be apparent to those skilled in the art based on the teachings of this disclosure are intended to fall within the scope of the appended claims.

Claims

1. A suction catheter, comprising: A body having a proximal end and an opposing distal end, wherein a lumen extends longitudinally from the proximal end through it to the distal end; and A stabilizing structural member that stabilizes the body to minimize movement and / or radial expansion of the distal end of the body during suction.

2. The aspiration catheter according to claim 1 further comprises: An actuating member, when transitioning from a non-actuated state to an actuated state, changes parameters associated with the body; When the actuating member transitions from the non-actuated state to the actuated state, the stabilizing structural member transitions from the unstable state to the stable state, thereby stabilizing the body and minimizing the movement of the distal end of the body during suction.

3. The aspiration catheter according to claim 2, wherein the actuating member is a traction member extending longitudinally within the lumen, the traction member being securely fixed to a distal segment proximal to the distal end; and the traction member is capable of being pulled in the proximal direction, changing the parameter of the longitudinal length of the body, thereby enabling a transition from a longitudinally elongated state when the traction member is in the non-actuated state to a longitudinally contracted state when the traction member is in the actuated state; and when the traction member is in the actuated state and the body is in the longitudinally contracted state, the stabilizing structural member expands radially, thereby stabilizing the body and minimizing the movement of the distal end during aspiration.

4. The aspiration catheter according to claim 3, wherein the stabilizing structural member is: (i) a buckling portion of the body on alternating sides of the longitudinal centerline when the traction member is in the actuated state and the body is in the longitudinally contracted state; (ii) a longitudinally compressible bellows segment of the body having a plurality of discrete portions, capable of radial expansion when the traction member is in the actuated state and the body is in the longitudinally contracted state; or (iii) an expandable or pre-filled deformable sheath disposed proximally around the body at the distal end.

5. The suction conduit of claim 2, wherein the stabilizing structural member is a nitinol wire associated with the body, and the actuating member is a circuit that changes the temperature parameter, thereby enabling a transition from a non-actuated state at a temperature below the austenite transformation completion temperature to an actuated state at a temperature above the austenite transformation completion temperature; wherein when the circuit is in the non-actuated state at a temperature below the austenite transformation completion temperature, the nitinol wire is in a martensitic phase with lower stiffness, but when the circuit is in the actuated state at a temperature above the austenite transformation completion temperature, the nitinol wire is in an austenitic phase with higher stiffness, thereby stabilizing the body and minimizing the movement of the distal end of the body during suction.

6. The suction catheter according to claim 5, wherein when in the austenitic phase, the nickel-titanium wire is shaped into a curved, undulating, or spiral shape.

7. The suction catheter of claim 1, wherein the body is disposed within an outer sheath connected to the body via a movable hinge, the movable hinge serving as a stabilizing structural member that isolates the distal end of the body from the outer sheath, such that axial movement of the body during suction is not transmitted to the outer sheath.

8. The suction catheter of claim 1, wherein the stabilizing structural member is an embossed outer surface of the body itself or an inflatable balloon disposed therearound it.

9. The aspiration catheter of claim 1, further comprising an outer sheath surrounding the body and secured to the body via an elastomeric polymer defining an air gap therebetween, the elastomeric polymer serving as a stabilizing structural member for stabilizing the body, thereby minimizing movement of the distal end of the body during aspiration; wherein the elastomeric polymer restores the body to a substantially centered position within the outer sheath.

10. The aspiration catheter of claim 1, wherein the body of the aspiration catheter has a radially self-expanding distal segment including the distal end; wherein the stabilizing structural member is a tether associated with the radially self-expanding distal segment, the tether limiting the radial expansion of the radially self-expanding distal segment during aspiration to prevent over-expansion.

11. A method of using a suction catheter, the suction catheter comprising a body having a proximal end and an opposing distal end, wherein a lumen extends longitudinally from the proximal end through the lumen to the distal end; and a stabilizing structural member, said stabilizing structural member stabilizing the body to minimize the movement and / or radial expansion of the distal end of the body during suction; the method includes the following steps: The aspiration catheter is guided through the blood vessel to the target site, wherein the distal end is positioned proximal to the target clot. Apply suction to the body to capture the clot into the lumen; and While the aspiration is being applied, the body is stabilized relative to the inner wall of the blood vessel via the stabilizing structural member in order to minimize the movement and / or radial expansion of the distal end during the aspiration, thereby minimizing the risk of damage to the inner wall of the blood vessel.

12. The method of claim 11, wherein the stabilization step includes changing a parameter associated with the body in response to an actuating member associated with the body transitioning from a non-actuated state to an actuated state; and when the actuating member transitions from the non-actuated state to the actuated state, the stabilizing structural member transitions from an unstable state to a stable state, thereby stabilizing the body to minimize movement of the distal end of the body during suction.

13. The method of claim 12, wherein the changed parameter is the longitudinal length of the body; and the actuating member is a traction member extending longitudinally in the lumen, the traction member being securely fixed to the distal segment; The step of stabilizing axial movement includes: In response to the longitudinal length of the body being changed by pulling the traction member in the proximal direction, the body changes from a longitudinally elongated state when the traction member is in the non-actuated state to a longitudinally contracted state when the traction member is in the actuated state. as well as In response to the change in the longitudinal length of the body when the traction member is in the actuated state and the body is in the longitudinally contracted state, the stabilizing structural member is radially expanded to stabilize the body and minimize the movement of the distal end during suction.

14. The method of claim 13, wherein the stabilizing structural member is: (i) a buckling portion of the body on alternating sides of the longitudinal centerline when the traction member is in the actuated state and the body is in the longitudinally contracted state; (ii) a longitudinally compressible bellows segment of the body having a plurality of discrete portions, capable of radial expansion when the traction member is in the actuated state and the body is in the longitudinally contracted state; or (iii) an expandable or pre-filled deformable material sleeve disposed on the outside of the body on the proximal side of the distal end.

15. The method of claim 12, wherein the stabilizing structural member is a nitinol wire associated with the body, and the actuating member is a circuit that changes the temperature parameter, thereby enabling a transition from a non-actuated state at a temperature below the austenite transformation completion temperature to an actuated state at a temperature above the austenite transformation completion temperature; wherein, The steps of stabilizing the body relative to the inner wall of the container include: The temperature of the nitinol wire is increased by transitioning it from the non-actuated state at a temperature below the austenite transformation completion temperature to the actuated state at a temperature above the austenite transformation completion temperature via the circuit; and In response to raising the temperature of the nitinol wire via the circuit, the stiffness of the nitinol wire in the body is increased from a lower stiffness state (martensitic phase) when the temperature of the body is below the austenite transformation completion temperature to a higher stiffness state (austenitic phase) when the temperature of the nitinol wire is above the austenite transformation completion temperature; wherein the higher stiffness state of the nitinol wire in the body serves as a stabilizing structural member for stabilizing the body, so as to minimize the movement of the distal end during the application of the suction.

16. The method of claim 15, wherein when in the austenitic phase, the nickel-titanium wire is shaped into a curved, undulating, or spiral shape.

17. The method of claim 11, wherein the body is disposed within an outer sheath connected to the body via a movable hinge, the movable hinge serving as a stabilizing structural member that isolates the distal end of the body from the outer sheath, such that axial movement of the body during the application of the suction is not transmitted to the outer sheath.

18. The method of claim 11, wherein the stabilizing structural member is an embossed outer surface of the body itself or an inflatable bladder disposed therearound it.

19. The method of claim 11, wherein the aspiration catheter further comprises an outer sheath surrounding the body and secured together via an elastomeric polymer defining an air gap therebetween, the elastomeric polymer serving as a stabilizing structural member for stabilizing the body, thereby minimizing movement of the distal end during aspiration; wherein the elastomeric polymer restores the body to a substantially centered position within the outer sheath.

20. The method of claim 11, wherein the navigation step comprises the following steps: The suction catheter is advanced toward the target clot in the distal direction through the outer guide; as well as During suction, the target clot is engaged with the suction conduit, and the radially expandable distal segment is radially rotated from a radially contracted state to a radially expanded state. The stabilization step includes preventing excessive radial expansion of the distal end of the body via a tether that serves as a stabilizing structural member, thereby minimizing the risk of damaging the vascular endothelium.

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