Aspiration catheter having a stabilizing structure that minimizes the risk of damage to the interior wall of a blood vessel during aspiration - Patent Application 20070122999

Abstract

The aspiration catheter includes a body having a proximal end and an opposite distal tip, with a lumen extending longitudinally therethrough from the proximal end to the distal tip. The aspiration catheter further includes a stabilizing structure that stabilizes the body against the inner wall of the blood vessel so as to minimize movement and / or radial expansion of the body's distal tip while subjected to suction that could otherwise damage the inner wall of the blood vessel.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 447,506, filed February 22, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] FIELD OF THE INVENTION The present disclosure generally relates to an aspiration catheter for use during a clot removal procedure to capture and remove a targeted clot. Preferably, the present disclosure relates to an improved aspiration catheter that undergoes aspiration (e.g., vacuum (i.e., non-cyclic) or pulsatile / cyclic), where the aspiration catheter is configured to minimize the potential risk of damage to the inner wall of the blood vessel by stabilizing the body against the inner wall of the blood vessel so as to minimize distal tip migration and / or radial overextension. [Background technology]

[0003] During endovascular procedures to capture and remove blood clots, suction (e.g., vacuum or pulsatile / cyclic) is often applied to the catheter to improve efficiency. However, when subjected to suction (e.g., vacuum or pulsatile / cyclic), unwanted excessive movement imparted to the distal tip / end of the aspiration catheter poses a significant risk of potential damage to the inner wall of the blood vessel. Therefore, it would be desirable to develop an improved aspiration catheter that provides greater stability during aspiration, thereby reducing or eliminating the risk of potential damage to the inner wall of the blood vessel.

[0004] Additionally, when suction (e.g., vacuum or pulsatile / periodic) is used to capture and remove a clot, the aspiration catheter may be configured with a radially expandable distal section (e.g., a funnel-shaped distal section) to aid in the capture of the clot into the lumen of the body or shaft. However, if the diameter of the clot to be captured exceeds the diameter of the expanded distal end in a radially expanded or deployed state within the blood vessel, the funnel-shaped distal section or aspiration catheter will over-expand radially wider, posing a significant risk of damaging and / or clogging the inner wall of the blood vessel. Therefore, it is desirable to develop an improved aspiration catheter that prevents over-expansion of the radially expandable distal section (e.g., a funnel-shaped distal section). Summary of the Invention [Problem to be solved by the invention]

[0005] In addressing these problems, it would be desirable to develop an improved aspiration catheter that reduces the risk of damaging the inner wall of the blood vessel during aspiration. [Means for solving the problem]

[0006] One aspect of the present disclosure is directed 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 pulsatile / cyclic).

[0007] One aspect of the present disclosure is directed to an improved aspiration catheter for efficiently capturing a target clot therein while providing greater stability against excessive movement of the distal tip / end of the aspiration catheter, thereby minimizing the risk of damage to the inner wall of the blood vessel during aspiration (e.g., vacuum or pulsatile / cyclic).

[0008] A further aspect of the present disclosure is directed to an improved aspiration catheter that is stabilized via a stabilizing structural member, thereby minimizing the risk of damage to the inner wall of the blood vessel resulting from excessive distal / tip movement during aspiration (e.g., vacuum or pulsatile / cyclic).

[0009] Yet a further aspect of the present disclosure is directed to an improved aspiration catheter including a stabilizing structural member to prevent over-expansion of the expandable distal section (e.g., the funnel-shaped distal section), thereby minimizing the risk of damage to the inner wall of the blood vessel and / or the risk of blood clots lodging therein during aspiration (e.g., vacuum or pulsatile / cyclic). [Brief explanation of the drawings]

[0010] The above and further aspects of the present disclosure will be further discussed with reference to the following description in conjunction with 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 upon illustrating the principles of the present disclosure. The figures depict one or more implementations of the device by way of example only, and not by way of limitation. [Figure 1A] 1 depicts the distal section of an exemplary aspiration catheter with a stabilizing structure (e.g., a tether) to prevent overexpansion of the radially expandable distal section according to the present disclosure. The aspiration catheter is depicted being delivered to a target site through a blood vessel with the radially expandable distal section housed within an outer guide. [Figure 1B] 1 depicts the radially expanded distal section of the aspiration catheter removed from the outer guide, with the tether preventing over-expansion of the radially expandable distal section resulting from entrapment of excessive blood clot therein. [Figure 2A] 1 depicts the distal section of another embodiment of an aspiration catheter having an axially compressible bellows section as a stabilizing structural member according to the present disclosure, the axially compressible bellows section being illustrated in an unstabilized (i.e., not axially compressed) state. [Figure 2B] 2B depicts the distal section of the exemplary aspiration catheter of FIG. 2A, with the axially compressible bellows section illustrated in a stabilized (ie, axially compressed) state. [Figure 3A]1 depicts the distal section of yet another exemplary aspiration catheter having an external inflatable balloon sleeve as a stabilizing structural member according to the present disclosure, the external inflatable balloon sleeve being illustrated in an unstabilized (i.e., uninflated) state. [Figure 3B] 3B depicts the distal section of the exemplary aspiration catheter of FIG. 3A, with the outer inflatable balloon sleeve illustrated in a stabilized (ie, inflated) state. [Figure 4A] 1 depicts the distal section of yet another embodiment of an aspiration catheter including a pulling member extending axially through the lumen and secured to the distal section, the pulling member illustrated in an undeployed or unactuated state in which the aspiration catheter is in an unstabilized state. [Figure 4B] FIG. 4A depicts the distal section of an exemplary aspiration catheter, with the pull member illustrated in a deployed or actuated state that changes the axial profile of the aspiration catheter to a stabilizing state (e.g., buckling, serpentine, or spiraling). [Figure 5A] 1 depicts the distal section of another embodiment of an aspiration catheter having an external pre-filled gel sleeve as a stabilizing structural member according to the present disclosure, wherein the aspiration catheter extends axially through a lumen and is actuated (i.e., axially compressed) via a pulling member affixed to the distal section of the aspiration catheter, the external pre-filled gel sleeve being illustrated in an unstabilized (i.e., not axially compressed) state prior to pulling the pulling member. [Figure 5B] 3B depicts the distal section of the exemplary aspiration catheter of FIG. 3A, in which the outer pre-filled gel sleeve is illustrated in a stabilized (i.e., axially compressed) state in response to pulling on the pulling member. [Figure 6A]10 depicts the distal section of yet another embodiment of an aspiration catheter including a nitinol wire acting as a stabilizing structural member that can be thermally activated by an electrical circuit. The nitinol wire is illustrated in an unstabilized state (i.e., a martensitic phase temperature above the austenitic transformation finish temperature) so that the distal section of the aspiration catheter remains flexible and trackable. [Figure 6B] 6B depicts the distal section of the exemplary aspiration catheter of FIG. 6B at the target site during aspiration, with the nitinol wire illustrated in a stabilized state (i.e., austenite phase-to-a temperature below the austenite transformation temperature) that hardens the distal section of the aspiration catheter and stabilizes the distal tip / end. [Figure 7] 6A is a modification of FIG. 6A of an exemplary aspiration catheter at a target site during aspiration, where the nitinol wire is set into a curved, spiral, or undulating shape while in a stabilized state (i.e., austenite phase-to-austenite transformation temperature) that hardens the distal section of the aspiration catheter and stabilizes the body against the inner wall of the blood vessel, thereby minimizing movement of the distal tip / end during aspiration. [Figure 8A] 1 is a distal section of yet another exemplary aspiration catheter according to the present disclosure, anchored within the lumen of the outer sheath via a living hinge, the aspiration catheter depicted during delivery to a target site prior to application of suction. [Figure 8B] FIG. 8B is a distal cross-sectional view of the exemplary aspiration catheter of FIG. 8A undergoing suction, depicting the aspiration catheter isolated from the outer sheath by a living hinge such that axial movement (e.g., back and forth movement) of the aspiration catheter when undergoing suction is not transmitted to the outer sheath. [Figure 9A] 1 depicts another exemplary aspiration catheter according to the present disclosure, along its distal section having an inflatable balloon with a knurled outer surface as a stabilizing member according to the present disclosure, the inflatable balloon illustrated in an unstabilized (i.e., uninflated) state as it is delivered through a blood vessel to a target site prior to application of suction. [Figure 9B]FIG. 9B depicts an exemplary aspiration catheter, in which an external inflatable balloon having a knurled outer surface is illustrated in a stabilized (ie, inflated) state positioned at a target site during aspiration. [Figure 9C] FIG. 9C is a radial cross-sectional view along line IX(C)-IX(C) through the knurled external inflatable balloon of FIG. 9B, the external inflatable balloon illustrated in a stabilized (i.e., inflated) state. [Figure 9D] This is a modification of the example of FIG. 9A in which the distal section of the outer surface of the aspiration catheter itself has a knurled surface, rather than an external inflatable balloon. [Figure 10A] 1 depicts the distal section of yet another embodiment of an aspiration catheter according to the present disclosure nested within an outer guide secured together by an elastomeric polymer that forms a gap between the aspiration catheter and the outer guide that acts as a stabilizing structural member that allows but limits movement of the distal tip / end during aspiration. [Figure 10B] 10B is a radial cross-sectional view of the aspiration catheter of FIG. 10A taken along line X(B)-X(B). [Figure 11] An exemplary aspiration catheter system including a vacuum pump fluidly connected to an aspiration catheter delivered to a target site prior to capturing / entrapping a blood clot therein, wherein the aspiration catheter may include any of the stabilizing structural members illustrated above. DETAILED DESCRIPTION OF THE INVENTION

[0011] As used herein, the term "about" or "approximately" in connection with any numerical value or numerical range indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function for its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value; for example, "about 90%" may refer to a range of values ​​of 71% to 99%.

[0012] As used herein, the terms "tubular" and "tube" are intended to be broadly interpreted and are not limited to right cylindrical structures, or structures that are strictly circular in cross section, or structures that are uniform in cross section throughout their length. For example, a tubular structure or tubular system is generally illustrated as a substantially right cylindrical structure. However, a tubular system can have a tapered or curved outer surface without departing from the scope of the present disclosure.

[0013] The documents incorporated by reference into this patent application should be considered an integral part of this application, provided that to the extent that any term is defined in these incorporated documents in a manner that contradicts the definition given herein, either expressly or implicitly, only the definition given herein should be considered.

[0014] 11 illustrates an aspiration catheter 1105 having a proximal hub 1107 in fluid communication with a suction (e.g., vacuum or pulsatile / cyclic) pump 1100 that is delivered through a blood vessel to a target site of a blood clot prior to application of suction (e.g., vacuum or pulsatile / cyclic). Application of suction (e.g., vacuum or pulsatile / cyclic) can cause excessive movement of the distal tip / end of the aspiration catheter 1105 during capture and removal of the clot, posing a significant risk of damaging the inner wall of the blood vessel. The present disclosure is directed to an improved aspiration catheter configured to minimize the potential risk of damage to the inner wall of the blood vessel when subjected to suction (e.g., vacuum (i.e., non-cyclic) or pulsatile / cyclic). In accordance with the present disclosure, one method described herein for minimizing the potential risk of damage to the inner wall of a blood vessel is to stabilize the aspiration catheter against the inner wall of the blood vessel so as to minimize excessive axial movement of the distal tip / end during aspiration. It has also been recognized that there is a risk of potential damage to the inner wall of a blood vessel resulting from overexpansion of the radially expandable distal section (e.g., the funnel-shaped distal section) of the aspiration catheter when it entrains a blood clot that exceeds the diameter of the funnel-shaped distal section and may even become lodged within the blood vessel. This potential risk of damage to the inner wall of a blood vessel is addressed in accordance with the present disclosure by limiting or restricting the overexpansion (i.e., radial expansion) of the radially expandable distal section of the aspiration catheter.

[0015] Some non-limiting examples of stabilizing structures for stabilizing the aspiration catheter against the inner wall of the blood vessel to minimize movement of the distal tip / end of the aspiration catheter when subjected to suction (e.g., vacuum or pulsatile / periodic) are illustrated and described below.

[0016] 2A and 2B depict an exemplary aspiration catheter according to the present disclosure, including a stabilizing structural member along the distal section of the aspiration catheter proximal to the distal tip / end that radially expands when actuated or deployed via a pull member (e.g., a pull wire). The aspiration catheter 205 in FIG. 2A is depicted while being delivered through a blood vessel to a target site proximal to a target clot prior to application of suction (e.g., vacuum or pulsatile / cyclic). The pull member 245 (e.g., a wire) extends axially through the lumen of the aspiration catheter 205 while being secured (e.g., a collar or anchor) to the distal end of the aspiration catheter 205 within the distal section of the aspiration catheter 205. In the example of FIGS. 2A and 2B, the stabilizing member is an axially compressible section 255a (e.g., a bellows section).

[0017] In operation, when delivered through a blood vessel to a target site proximal to the clot, the pulling member 245 (e.g., wire) is not actuated (i.e., not pulled proximally), so the axially compressible section 255a (e.g., bellows section) remains in a default, unstabilized (i.e., radially contracted) state. Thus, the aspiration catheter 255a, including the axially compressible section 205, has a substantially uniform outer diameter that can be tracked for navigation through the blood vessel to the target site ( FIG. 2A ). Once the aspiration catheter is delivered to the target site within the blood vessel, suction (e.g., vacuum or pulsatile / periodic) is applied to capture the clot. The pulling member 245 (e.g., wire) is actuated by pulling proximally. The axially compressible section 255a (e.g., a bellows section) then transitions to a stabilizing state in which a portion of the axially compressible section 255a physically contacts the inner wall of the blood vessel and radially expands (similar to the expansion of an accordion), thereby stabilizing the distal tip / end of the aspiration catheter when subjected to suction (Figure 2B).

[0018] Another example of an aspiration catheter according to the present disclosure is provided in FIGS. 3A and 3B, in which the stabilizing member is an external, radially expandable sleeve (e.g., external inflatable balloon sleeve 255b) disposed externally along the distal section of aspiration catheter 205 proximal to the distal tip / end. FIG. 3A depicts external inflatable balloon sleeve 255b in an unstabilized (i.e., deflated) state prior to receiving inflation medium via inflation lumen 245′. While in this unstabilized (i.e., deflated) state illustrated in FIG. 3A, aspiration catheter 205 can be delivered through a blood vessel to a target site proximal to the clot. Once properly positioned proximal to the clot within the blood vessel, suction (e.g., vacuum or pulsatile / periodic) is applied to capture the clot. Before, simultaneously with, or after initiation of suction, inflation media is delivered through inflation lumen 245' to transition outer inflatable balloon sleeve 255b to a stabilized (i.e., inflated) state in direct physical contact with the inner wall of the vessel, stabilizing the aspiration catheter against the inner wall of the vessel, thereby minimizing movement of the distal tip / end of the aspiration catheter when subjected to suction (Figure 3B).

[0019] In yet another example of an aspiration catheter according to the present disclosure, the stabilization member is provided by intentionally changing its overall longitudinal / axial shape in response to actuation (i.e., axial pulling) of a pulling member. In this disclosure, the term "changing 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. In the example depicted in FIG. 4B, the depicted altered overall longitudinal / axial shape snakes, spirals, or buckles on alternate sides of the aspiration catheter. Referring to FIG. 4A, the aspiration catheter 205 has a pulling member 245 (e.g., a wire) that is anchored at its distal end to the distal section of the aspiration catheter and extends proximally through the lumen. 4A is depicted in an unstabilized state (i.e., an unaltered overall axial / longitudinal shape in which the central longitudinal axis extending therethrough is substantially equidistant from the inner wall of the lumen). In response to actuation (i.e., proximal pulling) of the pull member (e.g., wire), the aspiration catheter 205 transitions to a stabilized state (i.e., an altered overall axial / longitudinal shape in which the central longitudinal axis extending therethrough is no longer equidistant from the inner wall of the lumen).

[0020] In operation, while being delivered through a blood vessel to a target site proximal to the clot, the pulling member 245 (e.g., wire) is not actuated (i.e., not pulled proximally), so that the aspiration catheter 205 remains in its default, unstabilized state (i.e., an unchanged overall axial / longitudinal shape with a central longitudinal axis extending therethrough that is substantially equidistant from the inner wall of the lumen). Once the aspiration catheter 205 is delivered to a target site within the blood vessel, suction (e.g., vacuum or pulsatile / periodic) is applied to capture the clot. In response to actuating the pulling member, the overall axial / longitudinal shape of the aspiration catheter 205 itself changes (e.g., becomes serpentine, spirals, or buckles) so that the central longitudinal axis extending therethrough is no longer equidistant from the inner wall of the lumen. The region 255c where the aspiration catheter buckles, bends, or curves is 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 tip / end of the aspiration catheter when subjected to suction (Figure 4B).

[0021] 5A and 5B illustrate yet another embodiment of an aspiration catheter according to the present disclosure, in which the stabilizing member is a pre-filled outer sleeve disposed along the distal section of the aspiration catheter proximal to the distal tip / end. In response to the application of an axial compressive force, the pre-filled outer sleeve radially expands. Referring to FIG. 5A, an outer sleeve 255d is disposed around the distal section of the aspiration catheter 205 proximal to its distal tip / end. The outer sleeve 255d is pre-filled with a deformable material (e.g., a biocompatible gel material). A pull member 245 (e.g., a wire) extends axially through the lumen of the aspiration catheter 205 while being secured to the distal end of the aspiration catheter within the distal section of the aspiration catheter 205. In response to actuation (e.g., pulling proximally) of the tensioning member 245 (e.g., a wire), the pre-filled outer sleeve, along with the deformable material contained therein, compresses longitudinally / axially and expands radially.

[0022] In operation, when delivered through a blood vessel to a target site proximal to the clot, the pulling member 245 (e.g., wire) is not actuated (i.e., not pulled proximally), and as a result, the pre-filled outer sleeve 255d remains in its default, unstabilized state (i.e., minimum outer diameter). Thus, the aspiration catheter 205 can be tracked along the pre-filled outer sleeve 255d affixed thereto to guide it through the blood vessel to the target site ( FIG. 5A ). Once the aspiration catheter is delivered to the target site within the blood vessel, suction (e.g., vacuum or pulsatile / periodic) is applied to capture the clot. Simultaneously, or prior to applying suction, the pulling member 245 (e.g., wire) is pulled proximally. The pre-filled outer sleeve 225d and the deformable material contained therein then expand radially when compressed axially, transitioning to a stabilized state (i.e., maximum outer diameter) and physically contacting the inner wall of the vessel, thereby stabilizing the aspiration catheter against the inner wall of the vessel while minimizing movement of the distal tip / end when subjected to aspiration (FIG. 5B).

[0023] 6A and 6B depict, respectively, unstabilized and stabilized states of yet another embodiment of a stabilizing structure of an aspiration catheter according to the present disclosure. As an alternative to actuating the stabilizing structure by axially pulling a pull member that applies an axial compressive force to the aspiration catheter, in this example, the stabilizing structure is thermally actuated. Specifically, the aspiration catheter 205 is associated with a nitinol wire 255e (i.e., a nickel-titanium alloy) that changes its properties or characteristics when thermally activated to a specified temperature range by an electrical circuit 260. Referring to the example of FIG. 6A, the nitinol wire 255e and the electrical circuit 260 (e.g., a conductive metal wire) are both disposed within the lumen of the aspiration catheter 205.

[0024] In operation, while being delivered through a blood vessel to a target site proximal to a clot, the nitinol wire 255e is in an unstabilized state (i.e., above the austenite transformation finish temperature (A f) so that the nitinol wire is flexible and easily trackable for navigation through the blood vessel to the target site. Once the aspiration catheter is delivered to the target site within the blood vessel, suction (e.g., vacuum or pulsatile / cyclic) is applied to capture the clot. Prior to or simultaneously with the application of suction, in response to thermal actuation (i.e., thermal heating), the nitinol wire 255e reaches a stabilized state (i.e., below its austenite transformation finish temperature (A f )), thereby hardening the nitinol wire 255e and limiting, reducing, or eliminating excessive movement of the distal tip / end of the aspiration catheter resulting from aspiration (e.g., vacuum or pulsatile / cyclic, preferably pulsatile / cyclic). Alternatively, when thermally actuated (i.e., thermally heated), the nitinol wire in a stabilized state (i.e., above its austenite transformation finish temperature (A f ) above the austenite phase temperature) can be configured or formed to have a curved, undulating, or helical shape in the longitudinal / axial direction, as depicted in Figure 7. As a result, the stability provided by the hardening of the helical or wavy shaped nitinol wire 255e while in the austenite phase is facilitated, complemented, compounded, or reinforced by the bent regions of the aspiration catheter that are in direct physical contact with the inner wall of the lumen.

[0025] Yet another approach to providing stability to an aspiration catheter while undergoing suction (e.g., vacuum or pulsatile / cyclical) in accordance with the present disclosure is illustrated in FIGS. 8A and 8B , employing a flexible living hinge. The aspiration catheter 815 is disposed within the lumen of an outer sheath 810, which is disposed adjacent to the aspiration catheter 815 and connected via a living hinge 855. The living hinge 855, preferably made from a flexible, biocompatible polymer, isolates the axial movement of the aspiration catheter 815 from that of the outer sheath 810 while still allowing axial movement of the aspiration catheter 815 when subjected to suction (e.g., vacuum or pulsatile / cyclical). The outer sheath 810 within which the aspiration catheter 815 is disposed provides greater stability relative to that provided by the inner wall of the blood vessel, limiting excessive axial movement of the distal section 815 of the aspiration catheter. Application of suction (e.g., vacuum or pulsatile / periodic, but preferably pulsatile / periodic suction as indicated by the double arrow) imparts axial movement to the aspiration catheter 815, which is housed by the living hinge 855 (as indicated by the dashed line). Excessive axial movement of the distal section 815 is reduced (i.e., without preventing or inhibiting all axial movement) by the living hinge 855 and is hereafter referred to as reduced (i.e., non-excessive) axial movement. The vibration along with the reduced axial movement of the distal section 815 relative to the outer sheath 810 helps to dislodge the clot (as depicted by the smaller dislodged portion of the clot), improving the efficiency of clot capture and removal (particularly fibrin-rich and / or oversized clots).

[0026] The stabilizing structure may also be a non-circular (e.g., knurled) surface, either a separate component attached thereto or a section of the aspiration catheter itself, disposed along the distal section proximal to the distal tip / end. Figures 9A-9C illustrate an example of an expandable sleeve 955 disposed along the distal section of the aspiration catheter 905 proximal to the distal tip / end 915, the expandable sleeve 955 having a knurled outer surface when inflated (Figure 9C). The sleeve 955 is expandable via an inflation medium received through the inflation lumen 909. Prior to inflation, the sleeve 955 is in an unstabilized (i.e., minimum outer diameter) state so that the aspiration catheter 905 can be tracked and guided through the blood vessel to the target site. Once the distal tip / end 915 of the aspiration catheter 905 is positioned proximal to the target clot 130, suction (e.g., vacuum or pulsatile / periodic) is applied to capture the clot therein. Prior to or simultaneously with the application of suction, sleeve 955 is inflated by filling it with inflation medium via inflation lumen 909. In the inflated (i.e., stabilized) state, the outer surface of sleeve 955 has a knurled profile (FIGS. 9B and 9C) that stabilizes the aspiration catheter in response to excessive movement of the distal tip / end during aspiration. By way of example only, the outer surface of sleeve 955 in FIGS. 9B and 9C has four ridges or bumps, but can be modified to have any number of bumps greater than or equal to two, as desired. A greater number of bumps increases the surface area of ​​contact with the inner wall of the blood vessel, thus increasing the stability of the distal tip / end of the aspiration catheter. As mentioned above, as an alternative to having an inflatable sleeve with a knurled outer surface, a portion of the aspiration catheter itself along its distal section proximal to the distal tip / end can have a knurled outer profile or surface, as depicted in FIG. 9D. Again, the number of ridges or bumps can be varied as desired.

[0027] 10A and 10B, the aspiration catheter 1005 is stabilized in response to excessive movement of the distal tip / end 1015 by insulating the aspiration catheter 1005 within the outer sheath 1070 with a stabilizing member (i.e., an absorbent layer) disposed therebetween. In the example of FIGS. 10A and 10B, the absorbent layer is a void 1055 disposed between the outer sheath 1070 and the aspiration catheter 1005, which are secured to one another via a soft elastomeric polymer 1075. The void 1055 stabilizes the aspiration catheter 1005 in response to excessive movement of the distal tip / end 1015 during aspiration, while the soft elastomeric polymer 1075 provides an elastomeric return force that restores the aspiration catheter 1005 to its default position within the outer sleeve 1070. In the preferred example depicted in FIGS. 10A and 10B, the default position of the aspiration catheter is coaxially centered within the outer sleeve 1070.

[0028] In the aforementioned example, the risk of potential damage to the inner wall of the blood vessel resulting from excessive axial movement of the distal tip / end of the aspiration catheter during aspiration is minimized by stabilizing the aspiration catheter against the inner wall of the blood vessel. There is also a risk of damaging the inner wall of the blood vessel during radial expansion of the distal tip / end of the aspiration catheter during capture of the target clot. To assist in clot capture, the aspiration catheter 105 may include a radially self-expandable distal section 115 (e.g., a distal funnel section) that can transition from a non-deployed state (i.e., a radially compressed / contracted state) while contained within the outer guide or sheath 135 to a deployed state (i.e., a radially expanded / expanded state) upon removal from the outer guide or sheath 135. The risk of potential damage to the inner wall of the blood vessel 140, and possibly eventual lodging within the blood vessel, may arise due to undesired radial overexpansion of the radially self-expandable distal section 115 (e.g., an expandable distal funnel section). Such undesirable radial overexpansion poses a significant risk (as shown in FIG. 1B ) when the aspiration catheter entraps an excessively large clot (the outer profile of the clot exceeds the outer profile of the inner diameter of the radially self-expandable distal section while in the deployed state). FIGS. 1A and 1B depict an exemplary aspiration catheter 105 having a radially self-expandable distal section 115. A frame or skeleton 120, preferably made of Nitinol, is provided along at least a portion, and preferably along the entire distal edge, of the self-expandable distal section 115 of the aspiration catheter 105 to maintain a maximum outer diameter during clot entrapment in the distal section 115. FIG. 1A depicts the aspiration catheter 105 with the radially self-expandable distal section 115 in an undeployed state while housed within an outer guide or sheath 135. It is while in the undeployed state shown in FIG. 1A that the aspiration catheter 105 is delivered through a blood vessel 140 to a target site proximal to the clot 130.Delivery of the outer guide 135 and the aspiration catheter 105 to the target site in the vasculature can occur sequentially (i.e., the outer guide 135 is introduced first, followed by distal advancement of the aspiration catheter 105 therein) or simultaneously. Once properly positioned at the target site, the aspiration catheter 105 is advanced (i.e., pushed) distally until the distal section 115 emerges from the distal end of the outer guide 135. Upon removal from the sheath, the radially self-expandable distal section 115 automatically transitions from a non-deployed state to a deployed state ( FIG. 1B ). According to the present disclosure, the tether 125 (e.g., a nitinol wire) acts as a stabilizing structural member to limit, restrict, or reduce the extent of radial expansion (i.e., prevent overexpansion) of the radially self-expandable distal section 115 as it traps a blood clot 130 therein, thereby minimizing the risk of damage to the inner wall of the blood vessel 140.

[0029] Aspects of the disclosure are also provided by the following numbered paragraphs: Clause 1 1. A suction catheter comprising: a body (105, 205, 815, 905, 1005) having a proximal end and an opposite distal tip, the body (105, 205, 815, 905, 1005) having a lumen extending longitudinally therethrough from the proximal end to the distal tip; and a stabilizing structural member (125, 255a, 255b, 255c, 255d, 255e, 255f, 855, 955, 955', 1055) that stabilizes the body (105, 205, 855, 905, 1005) to minimize movement and / or radial expansion of the distal tip of the body (105, 205, 815, 905, 1005) while under suction.

[0030] Clause 2 The suction catheter described in clause 1 further comprises an actuation member (245, 260) that changes a parameter associated with the main body (205) when transitioning from an inactive state to an active state, and when the actuation member (245, 260) transitions from the inactive state to the active state, the stabilization structural members (255a, 255b, 255c, 255d, 255e, 255f) transition from an inactive state to a stabilization state that stabilizes the main body (205) so as to minimize movement of the distal tip of the main body (205) when subjected to suction.

[0031] Clause 3 An aspiration catheter as described in clause 2, wherein the actuating member is a tensioning member (245) extending longitudinally within a lumen fixedly attached to the distal section proximal to the distal tip, the tensioning member (245) being capable of being pulled proximally to change the longitudinal length parameters of the body (205) which is movable from a longitudinally extended state when the tensioning member (245) is in an unactuated state to a longitudinally contracted state when the tensioning member (245) is in an actuated state, and the stabilizing structural members (255a, 255b, 255c, 255d) radially expand when the tensioning member (245) is in an actuated state and the body (205) is in a longitudinally contracted state, stabilizing the body (205) and minimizing movement of the distal tip when suction is applied.

[0032] Clause 4 The aspiration catheter of clause 3, which is characterized by: (i) buckling (255c) of the body (205) on alternate sides of the longitudinal centerline when the tensioning member (245) is in an actuated state and the body (205) is in a longitudinally contracted state; (ii) a longitudinally compressible bellows section (255a) of the body (205) having multiple radially expandable individual portions when the tensioning member (245) is in an actuated state and the body (205) is in a longitudinally contracted state; or (iii) a sleeve (255b, 255d) pre-filled with an expandable or deformable material disposed externally around the body (205) proximal to the distal tip.

[0033] Clause 5 3. The aspiration catheter of claim 2, wherein the stabilizing structural member is a nitinol wire (255e, 255f) associated with the main body (205), the actuating member is an electrical circuit (260) that changes a temperature parameter at which the main body can transition from an inactive state at a temperature below the austenite transformation finish temperature to an active state at a temperature above the austenite transformation finish temperature, and when the electrical circuit (260) is in an inactive state at a temperature below the austenite transformation finish temperature, the nitinol wire (255e, 255f) is in a martensite phase having a lower stiffness, while when the electrical circuit (260) is in an active state at a temperature above the austenite transformation finish temperature, the nitinol wire (255e, 255f) is in an austenite phase having a higher stiffness, stabilizing the main body (205) and minimizing movement of the distal tip of the main body (205) when subjected to aspiration.

[0034] Clause 6 6. The aspiration catheter of clause 5, wherein the nitinol wire is shape-set into a curved, undulating, or helical shape while in the austenite phase.

[0035] Clause 7 An aspiration catheter as described in clause 1, wherein the main body (815) is disposed within an outer sheath (810) connected to the main body via a living hinge (855), and the living hinge (855) acts as a stabilizing structural member that isolates the distal tip of the main body (815) from the outer sheath (810), such that axial movement of the main body (815) while under suction is not transmittable to the outer sheath (810).

[0036] Article 8 10. The aspiration catheter of claim 1, wherein the stabilizing structure is a knurled outer surface (955') of a portion of the body (905) itself, or an inflatable balloon (955) disposed therearound.

[0037] Article 9 The suction catheter described in clause 1 further comprises an outer sleeve disposed around the main body (1005) and secured to the main body via an elastomeric polymer, wherein the elastomeric polymer defines a gap between the outer sleeve (1070) and the main body (1005) that acts as a stabilizing structural member to stabilize the main body and minimize movement of the distal tip of the main body (1005) when suction is applied, and the elastomeric polymer restores the main body (1005) to a position substantially centered within the outer sleeve (1070).

[0038] Article 10 An aspiration catheter as described in any one of clauses 1 to 9, wherein the body (105) of the aspiration catheter has a radially self-expandable distal section (115) including a distal tip, and the stabilizing structural member is a tether (125) associated with the radially self-expandable distal section (115) and which limits the radial expansion of the radially self-expandable distal section (115) while under suction and prevents over-expansion.

[0039] Article 11 1. A method for using an aspiration catheter, the method comprising: a body (105, 205, 815, 905, 1005) having a proximal end and an opposite distal tip, the body (105, 205, 815, 905, 1005) having a lumen extending longitudinally therethrough from the proximal end to the distal tip; and a stabilizing structural member (125, 255a, 255b, 255c, 255d, 255e, 255f, 855, 955, 955', 1055) that stabilizes the body (105, 205, 855, 905, 1005) to minimize movement and / or radial expansion of the distal tip of the body (105, 205, 815, 905, 1005) while receiving aspiration, the method comprising: guiding the aspiration catheter through the blood vessel to the target site while the aspiration catheter is positioned proximal to the blood vessel; applying suction to the body (105, 205, 815, 905, 1005) to capture the clot within the lumen; and stabilizing the body (105, 205, 815, 905, 1005) against the interior wall of the blood vessel via a stabilizing structural member (125, 255a, 255b, 255c, 255d, 255e, 255f, 855, 955, 955', 1055) while applying suction to minimize movement and / or radial expansion of the distal tip during aspiration to minimize risk of damage to the interior wall of the blood vessel.

[0040] Article 12 The method of clause 11, wherein stabilizing includes altering a parameter associated with the body (205) in response to an actuation member (245, 260) associated with the body (205) transitioning from an inactive state to an active state, and when the actuation member (245, 260) transitions from an inactive state to an active state, the stabilizing structural members (255a, 255b, 255c, 255d, 255e, 255f) transition from an inactive state to a stabilizing state that stabilizes the body (205) to minimize movement of the distal tip of the body (205) when suction is applied.

[0041] Article 13 13. The method of claim 12, wherein the changed parameter is the longitudinal length of the body, the actuating member is a tensioning member (245) extending longitudinally within the lumen that is fixedly secured to the distal section, and stabilizing axial movement includes changing the longitudinal length of the body (205) in response to pulling the tensioning member (245) in the proximal direction, wherein the body (205) transitions from a longitudinally extended state when the tensioning member (245) is in an unactuated state to a longitudinally contracted state when the tensioning member (245) is in an actuated state, and radially expanding the stabilizing structural members (255a, 255b, 255c, 255d) in response to the change in the longitudinal length of the body (205) when the tensioning member (245) is in an actuated state and the body (205) is in a longitudinally contracted state to stabilize the body (205) and minimize movement of the distal tip when suction is applied.

[0042] Article 14 14. The suction catheter of claim 13, wherein the stabilizing structural member is (i) buckling of the body (205) on alternate sides of the longitudinal centerline when the tensioning member (245) is in an actuated state and the body (205) is in a longitudinally contracted state, (ii) a longitudinally compressible bellows section (255a) of the body (205) having multiple individual radially expandable portions when the tensioning member (245) is in an actuated state and the body (205) is in a longitudinally contracted state, or (iii) a sleeve (255b, 255d) pre-filled with an expandable or deformable material disposed externally around the body (205) proximal to the distal tip.

[0043] Article 15 The stabilizing structural member is a nitinol wire (255e, 255f) associated with the body (205), the actuating member is an electrical circuit (260) that changes a temperature parameter that allows transition from an inactive state below the austenite finish temperature to an active state above the austenite finish temperature, and stabilizing the body (205) against the inner wall of the blood vessel includes increasing the temperature of the nitinol wire (255e, 255f) via the electrical circuit (260) to .... 13. The method of claim 12, comprising: in response to increasing the temperature of the ears (255e, 255f), increasing the stiffness of the nitinol wires (255e, 255f) within the body (205) from a lower stiffness state in a martensite phase when the temperature of the body (205) is below an austenite finish temperature to a higher stiffness state in an austenite phase when the temperature of the nitinol wires (255e, 255f) is above an austenite finish temperature, wherein the higher stiffness state of the nitinol wires (255e, 255f) within the body (205) acts as a stabilizing structural member that stabilizes the body (205) to minimize distal tip movement when suction is applied.

[0044] Article 16 16. The method of clause 15, wherein the nitinol wire is shape-set into a curved, undulating, or helical shape while in the austenite phase.

[0045] Article 17 The method of claim 11, wherein the main body (815) is disposed within an outer sheath (810) connected to the main body via a living hinge (855), and the living hinge (855) acts as a stabilizing structural member isolating the distal tip of the main body (815) from the outer sheath (810), such that axial movement of the main body (815) during application of suction is not transmittable to the outer sheath (810).

[0046] Article 18 12. The method of clause 11, wherein the stabilizing structure is a knurled outer surface (955') of a portion of the body (905) itself, or an inflatable balloon (955) disposed therearound.

[0047] Article 19 The method of claim 11, wherein the suction catheter further comprises an outer sleeve (1070) disposed around the body (1005) and secured via an elastomeric polymer, the elastomeric polymer (1075) defining a gap (1055) between the outer sleeve (1070) and the body (1005) that acts as a stabilizing structural member to stabilize the body (1005) and minimize movement of the distal tip when suction is applied, and the elastomeric polymer (1075) restores the body (1005) to a substantially centered position within the outer sleeve (1070).

[0048] Article 20 The method of any one of clauses 11 to 19, wherein guiding includes advancing the suction catheter distally toward the target clot through the outer guide (135), engaging the target clot with the suction catheter while receiving suction and radially self-transitioning the radially expandable distal section from a radially contracted state to a radially expanded state, and stabilizing includes preventing radial over-expansion of the distal tip of the body via a tether (125) acting as a stabilizing structural member to minimize the risk of damage to the inner wall of the blood vessel.

[0049] The descriptions contained herein are by way of example and are not intended to limit the scope of the present disclosure in any way. As described herein, the present disclosure contemplates many variations and modifications of aspiration catheters that reduce the risk of damage to the inner wall of a blood vessel during aspiration. Modifications and variations that are obvious to those skilled in the art from the teachings of the present disclosure are intended to be within the scope of the following claims.

[0050] [Embodiment] (1) A suction catheter, a body having a proximal end and an opposite distal tip, the body having a lumen extending longitudinally therethrough from the proximal end to the distal tip; a stabilizing structure that stabilizes the body to minimize movement and / or radial expansion of the distal tip of the body while under suction. (2) further comprising an actuation member that changes a parameter associated with the body when transitioning from an inactive state to an active state; 2. The aspiration catheter of claim 1, wherein when the actuation member transitions from the unactuated state to the actuated state, the stabilization structure transitions from an unstabilized state to a stabilizing state that stabilizes the body to minimize movement of the distal tip of the body when subjected to suction. (3) The aspiration catheter of embodiment 2, wherein the actuation member is a tensioning member extending longitudinally within the lumen that is fixedly affixed to a distal section proximal to the distal tip, the tensioning member being proximally pullable to change the parameter of the longitudinal length of the body that is transitionable from a longitudinally extended state when the tensioning member is in the unactuated state to a longitudinally contracted state when the tensioning member is in the actuated state, and the stabilizing structure member radially expands when the tensioning member is in the actuated state and the body is in the longitudinally contracted state to stabilize the body and minimize movement of the distal tip when subjected to aspiration. (4) The aspiration catheter of embodiment 3, wherein the stabilizing structural member is (i) buckling of the body on alternate sides of the longitudinal centerline when the tensioning member is in the actuated state and the body is in the longitudinally contracted state, (ii) a longitudinally compressible bellows section of the body having multiple individual radially expandable portions when the tensioning member is in the actuated state and the body is in the longitudinally contracted state, or (iii) a sleeve pre-filled with an expandable or deformable material disposed externally around the body proximal to the distal tip. (5) The aspiration catheter of embodiment 2, wherein the stabilizing structural member is a nitinol wire associated with the body, and the actuating member is an electrical circuit that changes the parameter of the temperature at which the body can transition from an inactive state below an austenite transformation finish temperature to an active state above an austenite transformation finish temperature, such that when the electrical circuit is in the inactive state below the austenite transformation finish temperature, the nitinol wire is in a martensite phase having a lower stiffness, and when the electrical circuit is in the active state above the austenite transformation finish temperature, the nitinol wire is in an austenite phase having a higher stiffness, stabilizing the body and minimizing movement of the distal tip of the body when subjected to the aspiration.

[0051] (6) The aspiration catheter of claim 5, wherein the nitinol wire is shape-set into a curved, undulating, or helical shape while in the austenite phase. (7) An aspiration catheter as described in embodiment 1, wherein the body is disposed within an outer sheath connected to the body via a living hinge, and the living hinge acts as the stabilizing structural member isolating the distal tip of the body from the outer sheath, such that the axial movement of the body while subjected to the aspiration is not transmittable to the outer sheath. (8) An aspiration catheter as described in embodiment 1, wherein the stabilizing structural member is an inflatable balloon disposed on or around a knurled outer surface of a portion of the body itself. (9) The aspiration catheter of embodiment 1, further comprising an outer sleeve disposed around the body and secured to the body via an elastomeric polymer, wherein the elastomeric polymer defines a gap between the outer sleeve and the body that acts as a stabilizing structural member to stabilize the body and minimize movement of the distal tip of the body when subjected to suction, and the elastomeric polymer restores the body to a substantially centered position within the outer sleeve. (10) An aspiration catheter as described in embodiment 1, wherein the body of the aspiration catheter has a radially self-expandable distal section including the distal tip, and the stabilizing structural member is a tether associated with the radially self-expandable distal section, which limits the radial expansion of the radially self-expandable distal section while receiving the aspiration and prevents overexpansion.

[0052] (11) A method for using a suction catheter comprising: a body having a proximal end and an opposite distal tip, the body having a lumen extending longitudinally therethrough from the proximal end to the distal tip; and a stabilizing structure that stabilizes the body to minimize movement and / or radial expansion of the distal tip of the body while receiving suction, the method comprising: navigating the aspiration catheter through a blood vessel to a target site with the distal tip positioned proximal to a target clot; applying suction to the body to capture the clot within the lumen; and simultaneously applying the suction, stabilizing the body against the inner wall of the blood vessel via the stabilizing structural member so as to minimize the movement and / or the radial expansion of the distal tip during the suction and minimize the risk of damage to the inner wall of the blood vessel. (12) The method of embodiment 11, wherein the stabilizing includes altering a parameter associated with the body in response to an actuation member associated with the body transitioning from a non-actuated state to an actuated state, and when the actuation member transitions from the non-actuated state to the actuated state, the stabilizing structure member transitions from a non-stabilized state to a stabilizing state that stabilizes the body to minimize movement of the distal tip of the body when subjected to suction. (13) The method of claim 1, wherein the modified parameter is a longitudinal length of the body, the actuating member is a tension member extending longitudinally within the lumen that is fixedly secured to the distal section, and stabilizes the axial movement. changing the longitudinal length of the body in response to pulling the tensioning member in a proximal direction, the body transitioning from a longitudinally extended state when the tensioning member is in the unactuated state to a longitudinally contracted state when the tensioning member is in the actuated state; and radially expanding the stabilizing structure in response to the change in the longitudinal length of the body when the tensioning member is in the actuated state and the body is in the longitudinally contracted state to stabilize the body and minimize movement of the distal tip when subjected to suction. (14) The method of embodiment 13, wherein the stabilizing structure is (i) buckling of the body on alternate sides of the longitudinal centerline when the tensioning member is in the actuated state and the body is in the longitudinally contracted state, (ii) a longitudinally compressible bellows section of the body having multiple discrete portions that are radially expandable when the tensioning member is in the actuated state and the body is in the longitudinally contracted state, or (iii) a sleeve pre-filled with an expandable or deformable material disposed externally around the body proximal to the distal tip. (15) The stabilizing structural member is a nitinol wire associated with the body, and the actuating member is an electrical circuit that changes the parameter of the temperature at which the body can transition from an inactive state below an austenite finish temperature to an active state above an austenite finish temperature, thereby stabilizing the body against the interior wall of the blood vessel. increasing the temperature of the nitinol wire via the electrical circuit transitioning from the inactive state at a temperature below the austenite finish temperature to the active state at a temperature above the austenite finish temperature; 13. The method of claim 12, comprising: in response to increasing the temperature of the nitinol wire via the electrical circuit, increasing the stiffness of the nitinol wire within the body from a lower stiffness state in a martensite phase when the temperature of the body is below the austenite transformation finish temperature to a higher stiffness state in an austenite phase when the temperature of the nitinol wire is above the austenite transformation finish temperature, wherein the higher stiffness state of the nitinol wire within the body acts as the stabilizing structural member that stabilizes the body to minimize movement of the distal tip when the suction is applied.

[0053] 16. The method of claim 15, wherein the nitinol wire is shape-set into a curved, undulating, or helical shape while in the austenite phase. (17) The method of embodiment 11, wherein the body is disposed within an outer sheath connected to the body via a living hinge, the living hinge acting as the stabilizing structural member isolating the distal tip of the body from the outer sheath, such that the axial movement of the body during application of suction is not transferable to the outer sheath. (18) The method of embodiment 11, wherein the stabilizing structure is an inflatable balloon disposed on or around a knurled outer surface of a portion of the body itself. (19) The method of embodiment 11, wherein the suction catheter further comprises an outer sleeve disposed around the body and secured via an elastomeric polymer, the elastomeric polymer defining a gap between the outer sleeve and the body that acts as the stabilizing structure to stabilize the body and minimize movement of the distal tip when the suction is applied, and the elastomeric polymer restores the body to a substantially centered position within the outer sleeve. (20) The inducing advancing the aspiration catheter in the distal direction through an outer guide toward the target clot; engaging the target clot with the aspiration catheter while receiving aspiration, and radially self-transitioning the radially expandable distal section from a radially contracted state to a radially expanded state; The method of embodiment 11, wherein the stabilizing includes preventing radial over-expansion of the distal tip of the body via a tether acting as the stabilizing structural member so as to minimize the risk of damage to the inner wall of the blood vessel.

Claims

1. 1. A suction catheter comprising: a body having a proximal end and an opposite distal tip, the body having a lumen extending longitudinally therethrough from the proximal end to the distal tip; a stabilizing structure that stabilizes the body to minimize movement and / or radial expansion of the distal tip of the body while under suction.

2. an actuation member that changes a parameter associated with the body when transitioning from an inactive state to an active state; 2. The aspiration catheter of claim 1, wherein when the actuation member transitions from the unactuated state to the actuated state, the stabilizing structure transitions from an unstabilized state to a stabilizing state that stabilizes the body to minimize movement of the distal tip of the body when subjected to suction.

3. 3. The aspiration catheter of claim 2, wherein the actuation member is a pull member extending longitudinally within the lumen that is fixedly affixed to a distal section proximal to the distal tip, the pull member being pullable proximally to change the parameter of the longitudinal length of the body that is transitionable from a longitudinally extended state when the pull member is in the unactuated state to a longitudinally contracted state when the pull member is in the actuated state, and the stabilizing structure member radially expands when the pull member is in the actuated state and the body is in the longitudinally contracted state to stabilize the body and minimize movement of the distal tip when subjected to suction.

4. 4. The aspiration catheter of claim 3, wherein the stabilizing structure is: (i) buckling of the body on alternate sides of a longitudinal centerline when the tensioning member is in the actuated state and the body is in the longitudinally contracted state; (ii) a longitudinally compressible bellows section of the body having multiple discrete portions that are radially expandable when the tensioning member is in the actuated state and the body is in the longitudinally contracted state; or (iii) a sleeve pre-filled with an expandable or deformable material disposed externally around the body proximal to the distal tip.

5. 3. The aspiration catheter of claim 2, wherein the stabilizing structural member is a nitinol wire associated with the body, and the actuating member is an electrical circuit that changes the parameter of the temperature at which the body can transition from an inactive state below an austenite finish temperature to an active state above an austenite finish temperature, wherein when the electrical circuit is in the inactive state below the austenite finish temperature, the nitinol wire is in a martensite phase having a lower stiffness, and when the electrical circuit is in the active state above the austenite finish temperature, the nitinol wire is in an austenite phase having a higher stiffness, stabilizing the body and minimizing movement of the distal tip of the body when subjected to the aspiration.

6. The aspiration catheter of claim 5 , wherein while in the austenite phase, the nitinol wire is shape-set into a curved, undulating, or helical shape.

7. 2. The aspiration catheter of claim 1, wherein the body is disposed within an outer sheath connected to the body via a living hinge, the living hinge acting as the stabilizing structural member isolating the distal tip of the body from the outer sheath such that the axial movement of the body while under suction is not transferable to the outer sheath.

8. 10. The aspiration catheter of claim 1, wherein the stabilizing structure is an inflatable balloon disposed on or around a portion of the knurled outer surface of the body itself.

9. 2. The aspiration catheter of claim 1, further comprising an outer sleeve disposed around the body and secured to the body via an elastomeric polymer, the elastomeric polymer defining a gap between the outer sleeve and the body that acts as the stabilizing structure to stabilize the body and minimize movement of the distal tip of the body when subjected to suction, the elastomeric polymer restoring the body to a substantially centered position within the outer sleeve.

10. 2. The aspiration catheter of claim 1, wherein the body of the aspiration catheter has a radially self-expandable distal section that includes the distal tip, and the stabilizing structure is a tether associated with the radially self-expandable distal section that limits radial expansion of the radially self-expandable distal section while subjected to the aspiration, preventing overexpansion.

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