Aspiration catheter systems and methods

Abstract

A medical kit is provided that includes an aspiration catheter tube and a flexible guide structure. The flexible guide structure is structured such that the flexible guide structure can be disposed within a lumen of the aspiration catheter tube as part of an aspiration catheter system. The aspiration catheter tube and flexible guide structure can move independently from one another when the flexible guide structure is disposed within the lumen. The flexible guide structure includes a plurality of rings including a first ring and a second ring. A first connecting member and a second connecting member each connect the first ring to the second ring. The flexible guide structure further including a slit between the first ring and the second ring. The aspiration catheter system can be used for clot aspiration procedures.

Description

ASPIRATION CATHETER SYSTEMS AND METHODS

[0001] The present application relates generally to aspiration catheters and aspiration methods. More specifically, the present application provides an aspiration catheter system that includes a guide structure that may be disposed within an aspiration catheter tube and methods for using same when aspirating a clot in a patient’s neurovascular system.

[0002] Aspiration catheters are medical devices used in the field of interventional cardiology and vascular medicine to treat blood clots, particularly in the context of acute myocardial infarction (heart attack) and ischemic stroke. Typically, an aspiration catheter is a flexible, thin tube that may be coupled to a suction (e.g., vacuum) mechanism, such as a pump or a syringe, and used in a technique known as aspiration thrombectomy to remove a blood clot from a blood vessel. The aspiration catheter can be advanced through a patient’s vascular system to the location of a clot. The tip of the aspiration catheter is positioned directly within, around, or near the clot. Once the aspiration catheter is properly positioned, the suction or aspiration mechanism is activated, which generates negative pressure that allows the aspiration catheter to aspirate the clot into the aspiration catheter. An aspiration catheter may be used with a guiding catheter or other guiding structure that aids with advancing the aspiration catheter through the patient’s vascular system. Typical aspiration catheters and guiding structures, however, leave room for improvement.

[0003] A new and innovative aspiration catheter system is provided with adjustable bending stiffness profiles that enables the aspiration catheter system to be both suitably flexible to advance through a tortuous neurovascular system and suitably stiff to be pushed against a clot during aspiration for efficiently ingesting a clot. The aspiration catheter system includes a flexible guide structure disposed within a lumen of an aspiration catheter tube. The flexible guide structure includes a plurality of rings connected to one another by connecting members, thereby forming slits between each of the adjacent rings. At least one support structure may be integrated into the aspiration catheter tube that contributes to a varied stiffness along the length of the aspiration catheter tube. Different portions of the aspiration catheter tube may have different wall thicknesses, which can also contribute to a varied stiffness along the aspiration catheter tube’s length. The flexible guide structure and the aspiration catheter tube can move independently from one another in a sliding, or telescopic, manner, which allows for adjusting the aspiration catheter system’s bending stiffness profiles and for greater flexibility than the aspiration catheter system’s size would otherwise indicate. For example, in various aspects, the aspiration catheter system can provide as much flexibility as a typical 6F catheter despite having the size of an 8F catheter.

[0004] The flexible guide structure provides the aspiration catheter tube with resistance against collapse or kinking while advancing through a tortuous neurovascular system or as a result of negative pressure during aspiration. The extra support for a given portion of the aspiration catheter tube provided by the flexible guide structure can also be removed by sliding the flexible guide structure proximally relative to the aspiration catheter tube, so that a portion of the aspiration catheter that does not overlap the flexible guide structure has greater flexibility. The aspiration catheter system’s adjustable bending stiffness profiles enable advancing the aspiration catheter system through a tortuous neurovascular system without a guide wire. In at least some aspects, the aspiration catheter system is advanced though the tortuous neurovascular system up to a cerebral artery to ingest a clot. A large inner diameter (e.g., 8F size), lack of a device (e.g., guide wire) that can disturb a clot during aspiration, ability to be pushed into a clot, and support against collapse or kink all contribute to the aspiration catheter system’s strong aspiration power.

[0005] In an example, a medical kit includes an aspiration catheter tube and a flexible guide structure. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring. The flexible guide structure is configured such that the flexible guide structure can be disposed within a lumen of the aspiration catheter tube, and the aspiration catheter tube and the flexible guide structure can move independently from one another when the flexible guide structure is disposed within the lumen.

[0006] In another example, a method includes advancing a catheter system through a blood vessel of a patient. The catheter system includes: an aspiration catheter tube and a flexible guide structure disposed within a lumen of the aspiration catheter tube. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring. The method further includes advancing both a distal end of the aspiration catheter tube and a distal end of the flexible guide structure together through a bend of the blood vessel; and advancing, subsequent to the distal end of the aspiration catheter tube and the distal end of the flexible guide structure advancing past the bend, the distal end of the aspiration catheter tube through the blood vessel independent from the flexible guide structure.

[0007] In another example, a flexible guide structure adapted to be used with an aspiration catheter tube is provided. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring, and the plurality of rings are configured such that the plurality of rings can move, independently from the aspiration catheter tube, within a lumen of the aspiration catheter tube.

[0008] In another example, a clot aspiration method includes advancing a catheter system into a blood vessel of a patient. The catheter system includes an aspiration catheter tube and a flexible guide structure disposed within a lumen of the aspiration catheter tube. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring. The clot aspiration method further includes advancing the catheter system through the blood vessel such that a distal end of the aspiration catheter tube, a distal end of the flexible guide structure, or both abut a proximal end of a clot disposed in the blood vessel or enclose at least a portion of the proximal end of the clot; and aspirating the clot into the catheter system.

[0009] In another example, a clot aspiration method includes advancing a catheter system into a blood vessel of a patient toward a proximal end of a clot disposed in the blood vessel. The catheter system includes an aspiration catheter tube and a flexible guide structure disposed within a lumen of the aspiration catheter tube. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring. The clot aspiration method further includes initiating aspiration of the clot into the catheter system; and advancing, during aspiration of the clot, a distal end of the aspiration catheter tube through the blood vessel and toward a distal end of the clot.

[0010] The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are “coupled” may be unitary with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “about” and “substantially” are defined as largely but not necessarily wholly what is specified-and includes what is specified; e.g., about 90 degrees includes 90 degrees and substantially parallel includes parallel-as understood by a person of ordinary skill in the art. In any disclosed embodiment, the terms “about” and “substantially” may be substituted with “within [a percentage] of” what is specified, where the percentage includes 0.1, 1, 5, and 10 percent.

[0011] Furthermore, all numerical ranges herein should be understood to include all integers, whole or fractions, within the range, inclusive of the ends of the ranges. Moreover, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in that range. For example, a disclosure of from 1 to 10 should be construed as supporting a range of from 1 to 8, from 3 to 7, from 1 to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth.

[0012] Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.

[0013] The terms “comprise” and any form thereof such as “comprises” and “comprising,” “have” and any form thereof such as “has” and “having,” and “include” and any form thereof such as “includes” and “including” are open-ended linking verbs. As a result, an apparatus or system that “comprises,” “has,” or “includes” one or more elements possesses those one or more elements but is not limited to possessing only those elements. Likewise, a method that “comprises,” “has,” or “includes” one or more steps possesses those one or more steps but is not limited to possessing only those one or more steps.

[0014] Any embodiment of any of the apparatuses, systems, and methods can consist of or consist essentially of-rather than comprise / have / include-any of the described steps, elements, and / or features. Thus, in any of the claims, the term “consisting of” or “consisting essentially of” can be substituted for any of the open-ended linking verbs recited above in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb.

[0015] An apparatus or system that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described. Furthermore, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to or configured to perform a particular function encompasses that apparatus, system, or component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted or configured.

[0016] The feature or features of one embodiment may be applied to other embodiments, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the embodiments.

[0017] Some details associated with the embodiments are described above and others are described below.

[0018] Additional features and advantages of the disclosed method and apparatus are described in, and will be apparent from, the following Detailed Description and the Figures. The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the figures and description. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.

[0019] The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers.

[0020] FIG. 1 is a box diagram of a system including a medical kit, according to an aspect of the present disclosure.

[0021] FIG. 2A illustrates a perspective view of a portion of an aspiration catheter system, according to an aspect of the present disclosure.

[0022] FIG. 2B illustrates a front view of the aspiration catheter system of FIG. 2A, according to an aspect of the present disclosure.

[0023] FIG. 3 illustrates an exploded view of a catheter tube, according to an aspect of the present disclosure.

[0024] FIG. 4A illustrates a perspective view of a portion of a flexible guide structure, according to an aspect of the present disclosure.

[0025] FIG. 4B illustrates a side view of a portion of the flexible guide structure, according to an aspect of the present disclosure.

[0026] FIG. 4C illustrates a magnified view of a portion of a cross section of the flexible guide structure at the plane A-A in FIG. 4B, according to an aspect of the present disclosure.

[0027] FIG. 5 illustrates a perspective view of a pusher structure, according to an aspect of the present disclosure.

[0028] FIG. 6 is a schematic of a length of a tube of the catheter tube, according to an aspect of the present disclosure.

[0029] FIG. 7 is a schematic of a length of the flexible guide structure, according to an aspect of the present disclosure.

[0030] FIG. 8A is a depiction showing the advancement of the aspiration catheter system through arteries of a patient, according to an aspect of the present disclosure.FIG. 8B is a depiction showing the advancement of the aspiration catheter system through arteries of a patient, according to an aspect of the present disclosure.FIG. 8C is a depiction showing the advancement of the aspiration catheter system through arteries of a patient, according to an aspect of the present disclosure.FIG. 8D is a depiction showing the advancement of the aspiration catheter system through arteries of a patient, according to an aspect of the present disclosure.FIG. 8E is a depiction showing the advancement of the aspiration catheter system through arteries of a patient, according to an aspect of the present disclosure.FIG. 8F is a depiction showing the advancement of the aspiration catheter system through arteries of a patient, according to an aspect of the present disclosure.FIG. 8G is a depiction showing the advancement of the aspiration catheter system through arteries of a patient, according to an aspect of the present disclosure.FIG. 8H is a depiction showing the advancement of the aspiration catheter system through arteries of a patient, according to an aspect of the present disclosure.

[0031] FIG. 9A is a schematic depicting a portion of a first clot aspiration method, according to an aspect of the present disclosure.

[0032] FIG. 9B is a schematic depicting a portion of a first clot aspiration method, according to an aspect of the present disclosure.

[0033] FIG. 9C is a schematic depicting a portion of a first clot aspiration method, according to an aspect of the present disclosure.

[0034] FIG. 9D is a schematic depicting a portion of a first clot aspiration method, according to an aspect of the present disclosure.

[0035] FIG. 10A is a schematic depicting a portion of a second clot aspiration method, according to an aspect of the present disclosure.

[0036] FIG. 10B is a schematic depicting a portion of a second clot aspiration method, according to an aspect of the present disclosure.

[0037] FIG. 10C is a schematic depicting a portion of a second clot aspiration method, according to an aspect of the present disclosure.

[0038] FIG. 10D is a schematic depicting a portion of a second clot aspiration method, according to an aspect of the present disclosure.

[0039] FIG. 11 is a flow chart of a method of advancing an aspiration catheter system through a bend in an artery, according to an aspect of the present disclosure.

[0040] FIG. 12 is a flow chart of a first clot aspiration method, according to an aspect of the present disclosure.

[0041] FIG. 13 is a flow chart of a second clot aspiration method, according to an aspect of the present disclosure.

[0042] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to limit the scope of the disclosure. Rather, the detailed description includes specific details for the purpose of providing a thorough understanding of the inventive subject matter. It will be apparent to those skilled in the art that these specific details are not required in every case and that, in some instances, well-known structures and components are shown in block diagram form for clarity of presentation.

[0043] A new and innovative aspiration catheter system is provided with adjustable bending stiffness profiles that enable the aspiration catheter system to be both suitably flexible to advance through a tortuous neurovascular system and suitably stiff to be pushed against a clot during aspiration for efficiently ingesting a clot. A large inner diameter (e.g., 8F size), lack of a device (e.g., guide wire) that can disturb a clot during aspiration, ability to be pushed into a clot, and support against collapse or kink all contribute to the aspiration catheter system’s strong aspiration power. The aspiration catheter system includes a flexible guide structure disposed within a lumen of an aspiration catheter tube. The flexible guide structure includes a plurality of rings connected to one another by connecting members, thereby forming slits between each of the adjacent rings. At least one support structure may be integrated into the aspiration catheter tube that contributes to a varied stiffness along the length of the aspiration catheter tube. Different portions of the aspiration catheter tube may have different wall thicknesses, which can also contribute to a varied stiffness along the aspiration catheter tube’s length. The flexible guide structure and the aspiration catheter tube can move independently from one another, which allows a user to adjust the aspiration catheter system’s bending stiffness profiles for greater flexibility than the aspiration catheter system’s size would otherwise indicate. For example, in various aspects, the aspiration catheter system can provide as much flexibility as a typical 6F catheter despite having the size of an 8F catheter.

[0044] Typical thin aspiration catheter tubes can become susceptible to collapse by negative pressure during aspiration or to kinking by tight vessel (e.g., artery) curvature. Conversely, the flexible guide structure provides the present aspiration catheter tube with resistance against collapse or kinking while advancing through a tortuous neurovascular system or as a result of negative pressure during aspiration. The extra support provided by the flexible guide structure can also be removed for a given portion of the aspiration catheter tube’s length, by withdrawing the flexible guide structure relative to the aspiration catheter tube, thereby leaving such portion of the aspiration catheter tube unsupported by (and not overlapping) the flexible guide structure and increasing such portion’s flexibility, such as the flexibility needed to advance past the ophthalmic artery branch without catching on the “ophthalmic ledge.”

[0045] In some aspects, the aspiration catheter system may be used together with a vacuum source to ingest a clot in a patient’s cerebral artery, such as in the M1 segment of the middle cerebral artery. The aspiration catheter system’s adjustable bending stiffness profiles enable advancing the aspiration catheter system through a tortuous neurovascular system without a guide wire (though a guide wire may be used during at least a portion of the advancing) up to a cerebral artery. A guide wire can disturb a clot during aspiration and thus eliminating the need for a guide wire enhances clot ingestion efficiency.

[0046] FIG. 1 illustrates clot aspiration system 10, which is one example of a system that includes one of the present aspiration catheter systems. Clot aspiration system 10 includes a medical kit 100. Medical kit 100 includes an aspiration catheter tube 102 and a flexible guide structure 104. Flexible guide structure 104 can be disposed within a lumen of aspiration catheter tube 102 to form an aspiration catheter system 200 (FIG. 2), as will be described further below. When aspiration catheter system 200 is in use, and as one of ordinary skill in the art will appreciate, aspiration catheter tube 102 may be in fluid communication with a vacuum source 110 of clot aspiration system 10 through any suitable manner. Vacuum source 110 can generate negative pressure within aspiration catheter system 200. In some aspects, vacuum source 110 may be a manual device, such as a lockable syringe. In other aspects, vacuum source 110 may be an automated device, such as an electromechanical pump. Clot aspiration system 10 further includes a guide wire 112. In some aspects, medical kit 100 may include guide wire 112. In some aspects, guide wire 112 may be omitted from clot aspiration system 10.

[0047] FIGs. 2A and 2B illustrate portions of aspiration catheter system 200. For instance, it will be appreciated that, in FIG. 2A, aspiration catheter system 200 extends well beyond the page and only a distal portion of aspiration catheter system 200 is depicted. Lengths of aspiration catheter tube 102 and flexible guide structure 104 will be described in greater detail below with reference to FIGs. 6 and 7. As shown in FIGs. 2A and 2B, flexible guide structure 104 is structured such that flexible guide structure 104 can be disposed within a lumen 204 (FIG. 3) of aspiration catheter tube 102 such that at least a portion of an exterior surface of flexible guide structure 104 contacts at least a portion of an interior surface of aspiration catheter tube 102. Aspiration catheter tube 102 and flexible guide structure 104 can be moved independently from one another (e.g., telescopically) along double-sided arrow T when flexible guide structure 104 is disposed within lumen 204.

[0048] FIG. 3 shows an exploded view of aspiration catheter tube 102. Aspiration catheter 102 includes a tube 202 forming a lumen 204. A distal end 203 of tube 202 can also be considered a distal end 203 of aspiration catheter tube 102. Tube 202 may be constructed of a medical-grade material, such as a medical-grade polymer, such as thermoplastic polyurethane (TPU). In some aspects, tube 202 may include a suitable liner to ease advancement of tube 202 through a patient’s neurovascular system, such as a polytetrafluoroethylene liner. In some aspects, a portion of an exterior of tube 202 may be coated with hyaluronic acid. For example, the portion coated with hyaluronic acid may extend proximally 600 mm from distal end 203 of tube 202. A radiopaque marker 208 may be coupled to, or integrated within, tube 202 at distal end 203. Radiopaque marker 208 enables the visualization of distal end 203 of aspiration catheter tube 102 on an x-ray image during a clot aspiration procedure. A coiled support structure 206 may be integrated within a portion of tube 202 as is known in the art. In some aspects, a braided support structure (not shown) may be integrated within a portion of tube 202 as is known in the art. In various aspects, coiled support structure 206 or the braided support structure may include nickel titanium (e.g., nitinol).

[0049] FIGs. 4A to 4C depict various views of flexible guide structure 104. In an example, flexible guide structure 104 includes nickel titanium (e.g., nitinol). Flexible guide structure 104 includes a plurality of rings 222A, 222B, 222C that are connected to one another by a plurality of connecting members 224A, 224B, 224C, 224D, as shown in FIGs. 4A and 4B. For example, ring 222A is connected to ring 222B by connecting members 224A and 224B, and ring 222B is connected to ring 222C by connecting members 224C and 224D. The plurality of rings 222A, 222B, 222C and plurality of connecting members 224A, 224B, 224C, 224D thereby form a plurality of slits 226A, 226B that extend around a circumference of flexible guide structure 104. For example, slit 226A is formed between ring 222A and ring 222B, and slit 226B is formed between ring 222B and 222C. The plurality of slits 226A, 226B allow for minimizing tensile and compression stress in flexible guide structure 104. It should be appreciated that only a small portion of the plurality of rings 222A, 222B, 222C, connecting members 224A, 224B, 224C, 224D, and slits 226A, 226B are indicated with reference numerals to maintain clarity in the figures.

[0050] Connecting members 224A, 224B are arranged in a way that allows for flexible guide structure 104 to have suitable bendability. For example, and with reference to FIG. 4B, a plane B-B (extending into and out of the page) includes a central axis 220 of flexible guide structure 104 and extends through both connecting members 224A and 224B. Stated differently, central axis 220 extends within plane B-B, which extends through both connecting members 224A and 224B. Connecting members 224C, 224D are arranged such that a plane C-C includes central axis 220 of flexible guide structure 104 and extends through both connecting members 224C and 224D. Stated differently, central axis 220 extends within plane C-C, which extends through both connecting members 224C and 224D. Plane B-B and plane C-C are perpendicular to one another.

[0051] A relationship (e.g., ratio) between the lateral surface area of the plurality of rings 222A, 222B, 222C to the lateral area of the plurality of slits 226A, 226B can affect how much of the radial force on aspiration catheter tube 102 during aspiration is reduced. For example, the greater the lateral surface area of the plurality of rings 222A, 222B, 222C compared to the lateral area of the plurality of slits 226A, 226B, the greater the radial force on aspiration catheter tube 102 during aspiration is reduced. This relationship is independent from the length and diameter of flexible guide structure 104.

[0052] Flexible guide structure 104 may include protruding members 228A, 228B extending from the distal-most ring (222A), which defines distal end 231, of flexible guide structure 104. Protruding members 228A, 228B may include radiopaque markers 230A, 230B. Radiopaque markers 230A, 230B enable the visualization of distal end 231 of flexible guide structure 104 on an x-ray image during a clot aspiration procedure. In some aspects, radiopaque markers 230A, 230B may be implemented with flexible guide structure 104 in another suitable manner. For example, radiopaque markers 230A, 230B may be implemented as a ring, similar to radiopaque marker 208, coupled to distal end 231 or may be integrated with ring 222A.

[0053] FIG. 4C illustrates a cross-section of flexible guide structure 104 at a plane A-A that is shown extending into and out of the page in FIG. 4B. A portion of the cross-section including connecting member 224A is magnified. Connecting member 224A includes an inner surface portion 400 having an arc length L1, an outer surface portion 402 having an arc length L2, and sidewalls 404A, 404B. It at least some aspects, arc length L1 of inner surface portion 400 is greater than arc length L2 of outer surface portion 402. The inventor found that having L1 be greater than L2 altered the way flexible guide structure 104 bends such that flexible guide structure 104 has a better bending stiffness than typical aspiration catheters and guiding structures. Each of sidewalls 404A, 404B extends substantially straight from inner surface portion 400 to outer surface portion 402.

[0054] In various aspects, clot aspiration system 10 or medical kit 100 may include a pusher component that may be used to advance or withdraw flexible guide structure 104 relative to aspiration catheter tube 102. In some aspects, the pusher component can be considered part of flexible guide structure 104. The pusher component may include a pusher wire. In at least some aspects, and as illustrated schematically in FIG. 7, the pusher component includes an intermediate structure that couples the pusher wire to a proximal end 706 of flexible guide structure 104. FIG. 5 depicts an example implementation of such a pusher component 500. Pusher component 500 includes a pusher wire 502. Pusher wire 502 may be a guide wire without a tip. Pusher wire 502 is coupled to an intermediate structure 504 at a joint 506, such as with an epoxy. In other aspects, pusher wire 502 may be integral with intermediate structure 504. Intermediate structure 504 includes a distal end 508. Distal end 508 may be coupled to, or integral with, proximal end 706 of flexible guide structure 104. In an example, intermediate structure 504 may be laser cut from a tube of nitinol.

[0055] FIG. 6 is a schematic of a length of aspiration catheter tube 102. A length of aspiration catheter tube 102 can be divided into a first portion 600 and a second portion 602. First portion 600 includes distal end 203 of aspiration catheter tube 102 and has greater flexibility than second portion 602 which includes a proximal end 612 of aspiration catheter tube 102. Contributing to this difference in flexibility is a difference in wall thickness between first portion 600and second portion 602. While each of first portion 600 and second portion 602 have an outer diameter D3, first portion 600 has an inner diameter D1 that is greater than the inner diameter D2 of the second portion 602. In this way, the wall of aspiration catheter tube 102 in first portion 600 is thinner than the wall of aspiration catheter tube 102 in the second portion 602.

[0056] An advantage of catheter system 200 is the large inner diameter of aspiration catheter tube 102. For example, in at least some aspects, aspiration catheter tube 102 may have a French catheter size of 8F. It has been clinically proven that an 8F-sized catheter can ingest clots in the M1 segment of the middle cerebral artery completely. In various aspects, aspiration catheter tube 102 has an outer diameter D3 within a range of about 2.54 to about 2.80 millimeters (mm), inclusive. For example, the outer diameter D3 may be equal to about 2.67 mm. In various aspects, a portion of aspiration catheter tube 102 has an inner diameter within a range of about 2.10 to about 2.56 mm, inclusive. For example, the inner diameter D1 of first portion 600 may be about 2.44 mm. In another example, the inner diameter D2 of second portion 602 may be about 2.29 mm. In these examples, the wall of aspiration catheter tube 102 in first portion 600 may be thinner than a wall of a typical 8F-sized catheter, and the wall of aspiration catheter tube 102 in second portion 602 may be equivalent to a typical thickness of a wall of a typical 8F catheter.

[0057] Aspiration catheter tube 102 may have any suitable length to be used for clot aspiration procedures. In an example, a length of aspiration catheter tube 102 may be about 1300 millimeters (mm). In an example, first portion 600 may have a length within a range of about 40 to about 205 millimeters (mm), inclusive. In an example, second portion 602 may have a length within a range of about 1095 to about 1260 mm, inclusive. In various aspects, first portion 600 can be divided into a third portion 604 and a fourth portion 606. Third portion 604 includes distal end 203 and may be integrated with radiopaque marker 208. In an example, third portion 604 may have a length within a range of about 1 to about 3 mm, inclusive. In an example, fourth portion 606 may have a length within a range of about 37 to about 204 mm, inclusive.

[0058] Also contributing to the difference in flexibility between first portion 600 and second portion 602 is the support structure integrated into tube 202. For example, a fifth portion 608 of aspiration catheter tube 102 may be integrated with coiled support structure 206, whereas a sixth portion 610 of aspiration catheter tube 102 may be integrated with a braided support structure, which is stiffer than coiled support structure 206. In an example, the braided support structure may include coiled support structure 206 plus an additional coiled support structure that crisscrosses coiled support structure 206 to form a braid. In some aspects, the additional coiled support structure may include tungsten. In an example, fifth portion 608, and therefore coiled support structure 206, may have a length within a range of about 20 to about 160 mm, inclusive. In an example, sixth portion 610 may have a length within a range of about 1137 to about 1262 mm, inclusive.

[0059] FIG. 7 is a schematic of a length of flexible guide structure 104 coupled to pusher structure 500. Flexible guide structure 104 is adapted to snugly fit within lumen 204 of aspiration catheter tube 102. Stated differently, flexible guide structure 104 is able to translate within aspiration catheter tube 102 while also contacting at least a portion of the inner surface of aspiration catheter tube 102. In an example, flexible guide structure 104 may have an outer diameter within a range of about 2.28 to about 2.54 mm, inclusive. For example, flexible guide structure 104 may have an outer diameter of about 2.41 mm. In an example, flexible guide structure 104 may have an inner diameter within a range of about 2.10 to about 2.36 mm, inclusive. For example, flexible guide structure 104 may have an inner diameter of about 2.24 mm.

[0060] In various aspects, flexible guide structure 104 may have a length within a range of about 20 to about 100 mm. In this way, flexible guide structure 104 is adapted so as to have space to be advanced or withdrawn relative to aspiration catheter tube 102 within first portion 600 of aspiration catheter tube 102. In at least some aspects, the outer diameter of flexible guide structure 104 is larger than the inner diameter D2 of second portion 602 such that flexible guide structure 104 cannot be advanced or withdrawn relative to aspiration catheter tube 102 through second portion 602 of aspiration catheter tube 102. For example, a second portion 602 may have a suitable stiffness to navigate a tortuous neurovascular system without the support of flexible guide structure 104. Conversely, first portion 600 may have flexibility that is advantageous for advancing through portions of the tortuous neurovascular system, such as advancing past the ophthalmic artery branch, but can increase the chance of collapse or kinking when advancing through other portions of the tortuous neurovascular system. Flexible guide structure 104 can translate relative to aspiration catheter tube 102 to provide support to first portion 600 and adjust a bending stiffness profile of the first portion 600 of aspiration catheter tube 102.

[0061] In various aspects, pusher structure 500 may have a length of about 1500 mm.

[0062] FIGs. 8A to 8H are a series of depictions showing an example of the advancement of aspiration catheter system 200 through a portion of a patient’s neurovascular system. It will be appreciated that aspiration catheter system 200 can be used in portions of the neurovascular system other than that depicted. In this example, aspiration catheter system 200 can be inserted into an incision in the patient’s groin. For example, a sheath (e.g., 8F sheath) can be inserted into an artery through the groin and aspiration catheter system 200 can be inserted into artery through the sheath. Aspiration catheter system 200 can then be advanced to the patient’s aortic arch. In some aspects, aspiration catheter system 200 may be advanced with the aid of guide wire 112. In other aspects, aspiration catheter system 200 may be advanced without a guide wire 112.

[0063] FIG. 8A depicts a portion of the patient’s neurovascular system including the aortic arch, the right and left subclavian arteries, the right and left internal carotid arteries (ICA in FIG. 8A), and the right and left external carotid arteries (ECA in FIG. 8A). The aortic arch, right and left subclavian arteries, right and left ICAs, and right and left ECAs are not labeled with reference numerals in FIGs. 8B to 8H for improved clarity in these figures, though it should be appreciated that the aortic arch, right and left subclavian arteries, right and left ICAs, and right and left ECAs are depicted similarly in each of FIGs. 8B to 8H.

[0064] Depending on where a clot is located, a particular arterial branch can be targeted. For example, FIGs. 8B and 8C depict the right internal carotid artery being targeted by using guide wire 112 to help guide a distal end 800 of aspiration catheter system 200 through the aortic arch, into the right common carotid artery, and into the right internal carotid artery. As used herein and depicted in the following figures, distal end 800 of aspiration catheter system 200 may include distal end 203 of aspiration catheter tube 102, distal end 231 of flexible guide structure 104, or both.

[0065] The right (or left) internal carotid artery can be tortuous, having curves, kinks, loops, coils, etc., through which aspiration catheter system 200 must be advanced. Prior to aspiration catheter system 200 reaching the ophthalmic artery branch, flexible guide structure 104 may be used to reduce the likelihood of aspiration catheter tube 102 collapsing due to the tight curvature of the right internal carotid artery. In an example, and to reduce the likelihood of collapse, flexible guide structure 104 is advanced through the right internal carotid artery such that flexible guide structure 104 is overlapped with the most tortuous portion of a section of the right internal carotid artery as the aspiration catheter system 200 is advanced through the section. For example, FIGs. 8D to 8F depict aspiration catheter system 200 being advanced through a tight curve of the right internal carotid artery. When aspiration catheter system 200 is advancing through the tight curve (depicted in FIG. 8D), both distal end 203 of aspiration catheter tube 102 and distal end 231 of flexible guide structure 102 are advanced together. After aspiration catheter system 200 is advanced through the tight curve, distal end 203 of aspiration catheter tube 102 may be advanced independent from flexible guide structure 104 (e.g., as depicted in FIG. 8E) so that flexible guide structure 104 remains overlapping with the tight curve to provide support to aspiration catheter tube 102 as more proximal portions of aspiration catheter tube 102 are advanced through the tight curve. Once distal end 203 of aspiration catheter tube 102 is advanced a sufficient amount, distal end 231 of flexible guide structure 104 may be advanced independent from aspiration catheter tube 102 (e.g., as depicted in FIG. 8F). For example, distal end 231 of flexible guide structure 104 may be advanced after a start of second portion 602 of aspiration catheter tube 102 has been advanced through the tight curve. As noted above, second portion 602 of aspiration catheter tube 102 is more rigid than first portion 600. In this way, the likelihood of second portion 602 collapsing is low enough without flexible guide structure 104 so that flexible guide structure 104 may be advanced to support first portion 600 of aspiration catheter tube 102.

[0066] Many typical catheters have difficulty advancing over the ophthalmic artery branch because they are not sufficiently flexible. It has been clinically shown, however, that a flexible 8F catheter tube, such as aspiration catheter tube 102, can be advanced past the branch of the ophthalmic artery. In addition to flexibility, aspiration catheter tube 102 is larger than a diameter of the entrance to the ophthalmic artery, enabling aspiration catheter tube 102 to glide over the entrance of the ophthalmic artery without catching on the “ophthalmic ledge” thereof. As depicted in FIG. 8G, prior to distal end 800 of aspiration catheter system 200 reaching the ophthalmic artery, distal end 203 of aspiration catheter tube 102 is advanced past the ophthalmic artery branch independent from distal end 231 of flexible guide structure 104. Stated differently, in the FIG. 8G depiction, distal end 203 of aspiration catheter tube 102 and distal end 231 of flexible guide structure 104 are advanced together through the internal carotid artery’s curve until distal end 203 and distal end 231 reach the point at which distal end 231 is depicted in FIG. 8G. At that point, distal end 203 of aspiration catheter tube 102 is advanced past the ophthalmic artery branch independent from flexible guide structure 104 so that distal end 203 reaches the point at which distal end 203 is depicted in FIG. 8G. As depicted in FIG. 8H, distal end 231 may then be advanced independent from aspiration catheter tube 102, such as to meet distal end 203 as shown. In various aspects, subsequent to FIG. 8H, distal end 203 of aspiration catheter tube 102 may be advanced independent from flexible guide structure 104 so that flexible guide structure 104 remains overlapping with the internal carotid artery’s curve, as described above.

[0067] Distal end 800 of aspiration catheter system 200 may thereafter be advanced through the remaining portion of the internal carotid artery and into a cerebral artery, such as the middle cerebral artery. In the depicted aspects of FIGs. 9A to 9D and 10A to 10D, distal end 800 is advanced into the M1 segment of the middle cerebral artery. The M1 segment of the middle cerebral artery is laterally located from the middle cerebral artery to the Sylvian fissure’s depths. It is also called the sphenoidal or horizontal segment of the middle cerebral artery. The M1 segment extends in an almost horizontal fashion from the internal carotid artery to a point of middle cerebral artery bifurcation between temporal and frontal lobes.

[0068] With distal end 800 of aspiration catheter system 200 disposed in the M1 segment of the middle cerebral artery, aspiration catheter system 200 may be used to aspirate a clot disposed in the M1 segment. FIGs. 9A to 9D are schematics depicting various aspects of a first clot aspiration method. FIG. 9A depicts a clot 900 disposed in the M1 segment of the middle cerebral artery. A distal end 904 of clot 900 is disposed at a terminus of the M1 segment where the middle cerebral artery branches into the M2 superior trunk and the M2 inferior trunk. The M1 segment, the M2 superior trunk, and the M2 inferior trunk are not labeled in FIGs. 9B to 9D for improved clarity in these figures, though it should be appreciated that the M1 segment, the M2 superior trunk, and the M2 inferior trunk are depicted similarly in each of FIGs. 9B to 9D. In some aspects, distal end 800 of aspiration catheter system 200, including both distal end 203 of aspiration catheter tube 102 and distal end of 231 of flexible guide structure 104, may be advanced to abut a proximal end 902 of clot 900, as depicted in FIG. 9A. In other aspects, distal end 800 of aspiration catheter system 200, including both distal end 203 of aspiration catheter tube 102 and a distal end of 231 of flexible guide structure 104, may be advanced to push into clot 900 (e.g., about 1 mm), as depicted in FIG. 9B, which can reduce the margin of error in making contact between distal end 800 and clot 900. A proximal end 902 of clot 900 may be enclosed within aspiration catheter system 200 after distal end 800 is pushed into clot 900 in these other aspects. Alignment of distal end 203 of aspiration catheter tube 102 and distal end of 231 of flexible guide structure 104 relative to clot 900 can be confirmed by radiopaque markers 208 and 230A, 230B, respectively. In either scenario of FIG. 9A or 9B, aspiration can be initiated (e.g., via vacuum source 110) so that clot 900 is aspirated into (e.g., ingested into) aspiration catheter system 200. Aspiration catheter system 200 may remain stationary while clot 900 is aspirated into aspiration catheter system 200. After a sufficient amount of time for clot aspiration, aspiration catheter system 200 may be withdrawn through the internal carotid artery and out of the patient (e.g., through the sheath at the groin).

[0069] In some aspects of the first clot aspiration method, as depicted in FIG. 9C, distal end 231 of flexible guide structure 104 may be withdrawn independently through aspiration catheter tube 102 as clot 900 is aspirated into aspiration catheter system 200. Withdrawing distal end 231 of flexible guide structure 104 can facilitate the ingestion of clot 902 into aspiration catheter system 200 by pulling clot 900 directly by scratching action (i.e., physical interference between clot 902 and flexible guide structure 104 that, under the aspiration force, causes clot 902 to move with flexible guide structure 140). Once the proximal end 904 of clot 900 fills the cross-sectional area of aspiration catheter system 200 that is under negative pressure, clot 900 will propagate the pulling force of the vacuum aspiration by stress within clot 900. Additionally, withdrawing flexible guide structure 104 will not result in distal end 203 of aspiration catheter tube 102 collapsing due to negative pressure placed on distal end 203 because clot 900 provides support to distal end 203 as clot 900 is aspirated into catheter tube 102.

[0070] In some aspects of the first clot aspiration method, as depicted in FIG. 9D, distal end 231 of flexible guide structure 104 may be pushed into proximal end 904 of clot 900 independent from aspiration catheter tube 102. For example, when aspiration catheter tube 102 is large enough to form a wedge against the vessel wall of the M1 segment, the passage for the negative pressure will remain patent for clot 900 to be pulled into aspiration system 200 through flexible guide structure 104 as flexible guide structure 104 will support the vessel wall of the M1 segment so that the vessel wall does not collapse.

[0071] FIGs. 10A to 10D are schematics depicting various aspects of a second clot aspiration method. FIG. 10A depicts clot 900 disposed in the M1 segment of the middle cerebral artery. A distal end 904 of clot 900 is disposed at a terminus of the M1 segment where the middle cerebral artery branches into the M2 superior trunk and the M2 inferior trunk. The M1 segment, the M2 superior trunk, and the M2 inferior trunk are not labeled in FIGs. 10B to 10D for improved clarity in these figures, though it should be appreciated that the M1 segment, the M2 superior trunk, and the M2 inferior trunk are depicted similarly in each of FIGs. 10B to 10D. Initially, distal end 800 of aspiration catheter system 200, including both distal end 203 of aspiration catheter tube 102 and distal end of 231 of flexible guide structure 104, may be advanced to abut, or push into, proximal end 902 of clot 900, as described above with reference to FIGs. 9A and 9B. Alignment of distal end 203 of aspiration catheter tube 102 and distal end of 231 of flexible guide structure 104 relative to clot 900 can be confirmed by radiopaque markers 208 and 230A, 230B, respectively.

[0072] Aspiration can then be initiated (e.g., via vacuum source 110) so that clot 900 begins to aspirate into (e.g., be ingested into) aspiration catheter system 200. Different from the first clot aspiration method, however, distal end 800 of aspiration catheter system 200 can be advanced during aspiration toward distal end 904 of clot 900 in the second clot aspiration method. In some aspects, as depicted in FIG. 10A, distal end 800 may include both distal end 203 of aspiration catheter tube 102 and distal end of 231 of flexible guide structure 104 as distal end 800 is advanced toward distal end 904 of clot 900. An end point of advancement for distal end 800 may be determined by a medical professional performing the second clot aspiration method. For example, in some aspects, distal end 800 may be advanced all the way to distal end 904 of clot 900, as depicted in FIG. 10B. In other aspects, advancement of distal end 800 may be terminated prior to reaching distal end 904 of clot 900, such as at the position of distal end 800 depicted in FIG. 10A. In some aspects, distal end 231 of flexible guide structure 104 may be withdrawn independently through aspiration catheter tube 102 as clot 900 is aspirated into aspiration catheter system 200, as described above with reference to FIG. 9C.

[0073] In some aspects, as depicted in FIG. 10C, distal end 800 of aspiration catheter system 200 includes only distal end 203 of aspiration catheter tube 102 as distal end 800 is advanced toward distal end 904 of clot 900. Distal end of 231 of flexible guide structure 104 may remain stationary. In such aspects, the end point of advancement for distal end 800 may be determined by a medical professional performing the second clot aspiration method. For example, in some aspects, distal end 800 may be advanced all the way to distal end 904 of clot 900, as depicted in FIG. 10D. In other aspects, advancement of distal end 800 may be terminated prior to reaching distal end 904 of clot 900, such as at the position of distal end 800 depicted in FIG. 10C. After a sufficient amount of time for clot aspiration, aspiration catheter system 200 may be withdrawn through the internal carotid artery and out of the patient (e.g., through the sheath at the groin).

[0074] FIG. 11 is a flow chart of an example method 1100 for advancing an aspiration catheter system (e.g., aspiration catheter system 200) through a bend in a blood vessel (e.g., artery). At block 1102, aspiration catheter system 200 is advanced through a blood vessel of a patient. In some aspects, the blood vessel is a carotid artery of the patient.

[0075] At block 1104, both a distal end (e.g., distal end 203) of the aspiration catheter tube (e.g., aspiration catheter tube 102) and a distal end (e.g., distal end 231) of the flexible guide structure (e.g., flexible guide structure 104) are advanced together through a bend of the blood vessel.

[0076] At block 1106, subsequent to the distal end 231 of the aspiration catheter tube 102 and the distal end 231 of the flexible guide structure 104 advancing past the bend, the distal end 203 of the aspiration catheter tube 102 is advanced through the blood vessel independent from the flexible guide structure 104.

[0077] In some aspects, method 1100 further includes advancing, subsequent to independently advancing the distal end 203 of the aspiration catheter tube 102, the distal end 231 of the flexible guide structure 104 through the aspiration catheter tube 102.

[0078] In some aspects, method 1100 further includes advancing, independent from the flexible guide structure, the distal end of the aspiration catheter tube through the blood vessel and past an ophthalmic artery of the patient. In some aspects, method 1100 further includes advancing, subsequent to independently advancing the distal end of the aspiration catheter tube past the ophthalmic artery, the distal end of the flexible guide structure through the aspiration catheter tube.

[0079] In some aspects, method 1100 further includes aspirating a clot (e.g., clot 900) positioned in a second blood vessel into the aspiration catheter system 200. In some aspects, the second blood vessel is a cerebral artery of the patient. In some aspects, the cerebral artery is a middle cerebral artery of the patient. In some aspects, the second blood vessel is the M1 segment of the patient’s middle cerebral artery. In some aspects, method 1100 further includes, prior to aspirating the clot 900, advancing both the distal end 203 of the aspiration catheter tube 102 and the distal end 231 of the flexible guide structure 104 together to abut a proximal end (e.g., proximal end 902) of the clot 900 or enclose the proximal end 902 of the clot 900. In some aspects, method 1100 further includes, during aspiration of the clot 900, withdrawing the distal end 231 of the flexible guide structure 104 back through at least a portion of the blood vessel independent from the distal end 203 of the aspiration catheter tube 102. In some aspects, method 1100 further includes, prior to aspirating the clot 900, advancing the distal end 231 of the flexible guide structure 104 to abut proximal end 902 of the clot 900, or enclose the proximal end 902 of the clot 900, independent from the distal end 203 of the aspiration catheter tube 102. In some aspects, method 1100 further includes, during aspiration of the clot 900, advancing both the distal end 203 of the aspiration catheter tube 102 and the distal end 231 of the flexible guide structure 104 together past the proximal end 902 of the clot and to a distal end 904 of the clot 900. In some aspects, method 1100 further includes, during aspiration of the clot 900, advancing the distal end 203 of the aspiration catheter tube 102 past the proximal end 902 of the clot 900 and to the distal end 904 of the clot 900 independently from the distal end 231 of the flexible guide structure 104.

[0080] FIG. 12 is a flow chart of an example clot aspiration method 1200. Clot aspiration method 1200 may correspond to the first clot aspiration method described above in reference to FIGs. 9A to 9D. At block 1202, an aspiration catheter system (e.g., aspiration catheter system 200) is advanced into a blood vessel (e.g., artery) of a patient. In some aspects, the blood vessel is a cerebral artery of a patient. In some aspects, the cerebral artery is a middle cerebral artery of the patient. In some aspects, the blood vessel is the M1 segment of the patient’s middle cerebral artery.

[0081] At block 1204, the aspiration catheter system 200 is advanced through the blood vessel such that a distal end (e.g., distal end 203) of the aspiration catheter tube 102, a distal end (e.g., distal end 231) of the flexible guide structure 104, or both abut a proximal end (e.g., proximal end 902) of a clot (e.g., clot 900) disposed in the blood vessel or enclose at least a portion of the proximal end 902 of the clot 900.

[0082] At block 1206, the clot 900 is aspirated into the aspiration catheter system 200. In some aspects, method 1200 further includes, during aspiration of the clot, withdrawing the distal end 231 of the flexible guide structure 104 back through at least a portion of the blood vessel independent from the distal end 203 of the aspiration catheter tube 102. In some aspects, aspirating the clot 900 is initiated when only the distal end 203 of the aspiration catheter tube 102 abuts, or encloses at least a portion of the proximal end 902 of, the clot 900. In some aspects, aspirating the clot 900 is initiated when only the distal end 231 of the flexible guide structure 104 abuts, or encloses at least a portion of the proximal end 902 of, the clot 900.

[0083] FIG. 13 is a flow chart of an example clot aspiration method 1300. Clot aspiration method 1300 may correspond to the second clot aspiration method described above in reference to FIGs. 10A to 10D. At block 1302, an aspiration catheter system (e.g., aspiration catheter system 200) is advanced into a blood vessel (e.g., artery) of a patient toward a proximal end (e.g., proximal end 902) of a clot (e.g., clot 900) disposed in the blood vessel. In some aspects, the blood vessel is a cerebral artery of a patient. In some aspects, the cerebral artery is a middle cerebral artery of the patient. In some aspects, the blood vessel is the M1 segment of the patient’s middle cerebral artery.

[0084] At block 1304, aspiration of the clot 900 into the aspiration catheter system 200 is initiated. In some aspects, a distal end (e.g., distal end 231) of the flexible guide structure 104 abuts, or encloses at least a portion of, the proximal end 902 of the clot 900 when aspiration of the clot 900 is initiated. In some aspects, at least a portion of the proximal end 902 of the clot 900 is disposed within the aspiration catheter tube 102 when aspiration of the clot 900 is initiated. In some aspects, the at least a portion of the proximal end 902 of the clot 900 is also disposed within the flexible guide structure 104 when aspiration of the clot 900 is initiated.

[0085] At block 1306, a distal end (e.g., distal end 203) of the aspiration catheter tube 102 is advanced, during aspiration of the clot, through the blood vessel and toward a distal end (e.g., distal end 904) of the clot 900. In some aspects, advancing the distal end 203 of the aspiration catheter tube 102 through the blood vessel and toward the distal end 904 of the clot 900 includes advancing the distal end 231 of the flexible guide structure 104 together with the distal end 203 of the aspiration catheter tube 102. Stated differently, in such aspects, the distal end 203 of the aspiration catheter tube 102 and the distal end 231 of the flexible guide structure 104 are advanced together, during aspiration of the clot, through the blood vessel and toward the distal end 904 of the clot 900.

[0086] It is noted that the order of one or more blocks (or operations) described with reference to FIGs. 11 to 13 may be changed, certain blocks may be combined with other blocks, additional blocks may be added, and some of the block may be omitted. It is also noted that one or more blocks (or operations) described with reference to FIGs. 11 to 13 may be combined with one or more blocks (or operations) described with reference to another of the figures. For example, one or more blocks (or operations) of FIGs. 12 or 13 may be combined with one or more blocks (or operations) of FIG. 11.

[0087] In one or more aspects, the present aspiration catheter system may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other processes or devices described elsewhere herein. In a first aspect, a medical kit includes an aspiration catheter tube and a flexible guide structure. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring. The flexible guide structure is configured such that the flexible guide structure can be disposed within a lumen of the aspiration catheter tube, and the aspiration catheter tube and the flexible guide structure can move independently from one another when the flexible guide structure is disposed within the lumen.

[0088] In a second aspect, in combination with the first aspect, a first portion of the aspiration catheter tube has a greater inner diameter than a second portion of the aspiration catheter tube.

[0089] In a third aspect, in combination with the second aspect, the first portion includes a distal tip of the aspiration catheter tube.

[0090] In a fourth aspect, in combination with one or more of the first aspect through the third aspect, a first arc length of the first connecting member along an inner surface of the flexible guide structure is greater than or equal to a second arc length of the first connecting member along an outer surface of the flexible guide structure.

[0091] In a fifth aspect, in combination with one or more of the first aspect through the fourth aspect, a central axis of the flexible guide structure is included in a first plane that extends through both the first and second connecting members.

[0092] In a sixth aspect, in combination with the fifth aspect, the plurality of rings of the flexible guide member further include: a third ring, a third connecting member, and a fourth connecting member. Each of the third and fourth connecting members connect the second ring to the third ring, and the central axis of the flexible guide structure is included in a second plane that extends through both the third and fourth connecting members.

[0093] In a seventh aspect, in combination with one or more of the first aspect through the sixth aspect, the aspiration catheter includes a coiled support structure integrated within a body of the aspiration catheter tube.

[0094] In an eighth aspect, in combination with the seventh aspect, the coiled support structure includes nickel titanium (NiTi).

[0095] In a ninth aspect, in combination with one or more of the first aspect through the eighth aspect, the aspiration catheter tube has an outer diameter within a range of 0.100 to 0.110 inches, inclusive.

[0096] In a tenth aspect, in combination with one or more of the first aspect through the ninth aspect, a portion of the aspiration catheter tube has an inner diameter within a range of 0.083 to 0.101 inches, inclusive.

[0097] In an eleventh aspect, in combination with one or more of the first aspect through the tenth aspect, the flexible guide structure has an outer diameter within a range of 0.090 to 0.100 inches, inclusive.

[0098] In a twelfth aspect, in combination with one or more of the first aspect through the eleventh aspect, the flexible guide structure has an inner diameter within a range of 0.083 to 0.093 inches, inclusive.

[0099] In a thirteenth aspect, in combination with one or more of the first aspect through the twelfth aspect, the flexible guide structure includes nickel titanium (NiTi).

[0100] In a fourteenth aspect, in combination with one or more of the first aspect through the thirteenth aspect, the medical kit further includes a pusher component integral with, or configured to be coupled to, the flexible guide structure.

[0101] In a fifteenth aspect, in combination with one or more of the second aspect through the fourteenth aspect, a method includes advancing a catheter system through a blood vessel of a patient. The catheter system includes: an aspiration catheter tube and a flexible guide structure disposed within a lumen of the aspiration catheter tube. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring. The method further includes advancing both a distal end of the aspiration catheter tube and a distal end of the flexible guide structure together through a bend of the blood vessel; and advancing, subsequent to the distal end of the aspiration catheter tube and the distal end of the flexible guide structure advancing past the bend, the distal end of the aspiration catheter tube through the blood vessel independent from the flexible guide structure.

[0102] In a sixteenth aspect, in combination with the fifteenth aspect, the method further includes advancing, subsequent to independently advancing the distal end of the aspiration catheter tube, the distal end of the flexible guide structure through the aspiration catheter tube.

[0103] In a seventeenth aspect, in combination with one or more of the fifteenth aspect through the sixteenth aspect, the blood vessel is a carotid artery of the patient.

[0104] In an eighteenth aspect, in combination with one or more of the fifteenth aspect through the seventeenth aspect, the method further includes advancing, independent from the flexible guide structure, the distal end of the aspiration catheter tube through the blood vessel and past an ophthalmic artery of the patient.

[0105] In a nineteenth aspect, in combination with the eighteenth aspect, the method further includes advancing, subsequent to independently advancing the distal end of the aspiration catheter tube past the ophthalmic artery, the distal end of the flexible guide structure through the aspiration catheter tube.

[0106] In a twentieth aspect, in combination with one or more of the fifteenth aspect through the nineteenth aspect, the method further includes aspirating a clot positioned in a second blood vessel into the catheter system.

[0107] In a twenty-first aspect, in combination with the twentieth aspect, the second blood vessel is a cerebral artery of the patient.

[0108] In a twenty-second aspect, in combination with one or more of the twentieth aspect through the twenty-first aspect, the method further includes prior to aspirating the clot, advancing both the distal end of the aspiration catheter tube and the distal end of the flexible guide structure together to abut a proximal end of the clot or enclose the proximal end of the clot.

[0109] In a twenty-third aspect, in combination with the twenty-second aspect, the method further includes during aspiration of the clot, withdrawing the distal end of the flexible guide structure back through the blood vessel independent from the distal end of the aspiration catheter tube.

[0110] In a twenty-fourth aspect, in combination with one or more of the twentieth aspect through the twenty-first aspect, the method further includes prior to aspirating the clot, advancing the distal end of the flexible guide structure to abut a proximal end of the clot, or enclose the proximal end of the clot, independent from the distal end of the aspiration catheter tube.

[0111] In a twenty-fifth aspect, in combination with one or more of the twentieth aspect through the twenty-first aspect, the method further includes during aspiration of the clot, advancing both the distal end of the aspiration catheter tube and the distal end of the flexible guide structure together past a proximal end of the clot and to a distal end of the clot.

[0112] In a twenty-sixth aspect, in combination with one or more of the twentieth aspect through the twenty-first aspect, the method further includes during aspiration of the clot, advancing the distal end of the aspiration catheter tube past a proximal end of the clot and to a distal end of the clot independently from the distal end of the flexible guide structure.

[0113] In a twenty-seventh aspect, a flexible guide structure adapted to be used with an aspiration catheter tube is provided. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring, and the plurality of rings are configured such that the plurality of rings can move, independently from the aspiration catheter tube, within a lumen of the aspiration catheter tube.

[0114] In a twenty-eighth aspect, in combination with the twenty-seventh aspect, a first arc length of the first connecting member along an inner surface of the flexible guide structure is greater than or equal to a second arc length of the first connecting member along an outer surface of the flexible guide structure.

[0115] In a twenty-ninth aspect, in combination with one or more of the twenty-seventh aspect through the twenty-eighth aspect, a central axis of the flexible guide structure is included in a first plane that extends through both the first and second connecting members.

[0116] In a thirtieth aspect, in combination with the twenty-ninth aspect, the plurality of rings of the flexible guide member further include a third ring, a third connecting member, and a fourth connecting member. Each of the third and fourth connecting members connect the second ring to the third ring, and the central axis of the flexible guide structure is included in a second plane that extends through both the third and fourth connecting members.

[0117] In a thirty-first aspect, in combination with one or more of the twenty-seventh aspect through the thirtieth aspect, each of the plurality of rings has an outer diameter within a range of 2.28 to 2.54 millimeters (mm), inclusive.

[0118] In a thirty-second aspect, in combination with one or more of the twenty-seventh aspect through the thirty-first aspect, each of the plurality of rings has an inner diameter within a range of 2.10 to 2.36 mm, inclusive.

[0119] In a thirty-third aspect, in combination with one or more of the twenty-seventh aspect through the thirty-second aspect, the flexible guide structure includes nickel titanium (NiTi).

[0120] In a thirty-fourth aspect, in combination with one or more of the twenty-seventh aspect through the thirty-third aspect, the flexible guide structure further includes a pusher component integral with, or configured to be coupled to, the plurality of rings.

[0121] In a thirty-fifth aspect, a clot aspiration method includes advancing a catheter system into a blood vessel of a patient. The catheter system includes an aspiration catheter tube and a flexible guide structure disposed within a lumen of the aspiration catheter tube. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring. The clot aspiration method further includes advancing the catheter system through the blood vessel such that a distal end of the aspiration catheter tube, a distal end of the flexible guide structure, or both abut a proximal end of a clot disposed in the blood vessel or enclose at least a portion of the proximal end of the clot; and aspirating the clot into the catheter system.

[0122] In a thirty-sixth aspect, in combination with the thirty-fifth aspect, the method further includes, during aspiration of the clot, withdrawing the distal end of the flexible guide structure back through the blood vessel independent from the distal end of the aspiration catheter tube.

[0123] In a thirty-seventh aspect, in combination with the thirty-fifth aspect, aspirating the clot is initiated when only the distal end of the aspiration catheter tube abuts, or encloses the proximal end of, the clot.

[0124] In a thirty-eighth aspect, in combination with one or more of the thirty-fifth aspect through the thirty-sixth aspect, aspirating the clot is initiated when only the distal end of the flexible guide structure abuts, or encloses the proximal end of, the clot.

[0125] In a thirty-ninth aspect, a clot aspiration method includes advancing a catheter system into a blood vessel of a patient toward a proximal end of a clot disposed in the blood vessel. The catheter system includes an aspiration catheter tube and a flexible guide structure disposed within a lumen of the aspiration catheter tube. The flexible guide structure includes: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member; and a slit between the first ring and the second ring. Each of the first and second connecting members connect the first ring to the second ring. The clot aspiration method further includes initiating aspiration of the clot into the catheter system; and advancing, during aspiration of the clot, a distal end of the aspiration catheter tube through the blood vessel and toward a distal end of the clot.

[0126] In a fortieth aspect, in combination with the thirty-ninth aspect, a distal end of the flexible guide structure abuts, or encloses at least a portion of, the proximal end of the clot when aspiration of the clot is initiated.

[0127] In a forty-first aspect, in combination with the thirty-ninth aspect, at least a portion of the proximal end of the clot is disposed within the aspiration catheter tube when aspiration of the clot is initiated.

[0128] In a forty-second aspect, in combination with the forty-first aspect, the at least a portion of the proximal end of the clot is also disposed within the flexible guide structure when aspiration of the clot is initiated.

[0129] In a forty-third aspect, in combination with one or more of the thirty-ninth aspect through the forty-second aspect, advancing the distal end of the aspiration catheter tube through the blood vessel and toward the distal end of the clot includes advancing the distal end of the flexible guide structure together with the distal end of the aspiration catheter tube.

[0130] In a forty-fourth aspect, in combination with one or more of the thirty-ninth aspect through the forty-third aspect, the blood vessel is a cerebral artery of the patient.

[0131] Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.

[0132] The above specification and examples provide a complete description of the structure and use of illustrative embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. As such, the various illustrative embodiments of the products, systems, and methods are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiment. For example, elements may be omitted or combined as a unitary structure, and / or connections may be substituted. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and / or functions, and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments.

[0133] The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.

Claims

1. A medical kit comprising: an aspiration catheter tube; and a flexible guide structure comprising: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member, wherein each of the first and second connecting members connect the first ring to the second ring; and a slit between the first ring and the second ring; wherein the flexible guide structure is configured such that the flexible guide structure can be disposed within a lumen of the aspiration catheter tube, and wherein the aspiration catheter tube and the flexible guide structure can move independently from one another when the flexible guide structure is disposed within the lumen.

2. The medical kit of claim 1, wherein a first portion of the aspiration catheter tube has a greater inner diameter than a second portion of the aspiration catheter tube.

3. The medical kit of claim 2, wherein the first portion includes a distal tip of the aspiration catheter tube.

4. The medical kit of claim 1, wherein a first arc length of the first connecting member along an inner surface of the flexible guide structure is greater than or equal to a second arc length of the first connecting member along an outer surface of the flexible guide structure.

5. The medical kit of claim 1, wherein a central axis of the flexible guide structure is included in a first plane that extends through both the first and second connecting members.

6. The medical kit of claim 5, wherein the plurality of rings of the flexible guide member further comprise: a third ring; a third connecting member; and a fourth connecting member; wherein each of the third and fourth connecting members connect the second ring to the third ring; and wherein the central axis of the flexible guide structure is included in a second plane that extends through both the third and fourth connecting members.

7. The medical kit of claim 1, wherein the aspiration catheter comprises a coiled support structure integrated within a body of the aspiration catheter tube.

8. The medical kit of claim 7, wherein the coiled support structure includes nickel titanium (NiTi).

9. The medical kit of claim 1, wherein the aspiration catheter tube has an outer diameter within a range of 0.100 to 0.110 inches, inclusive.

10. The medical kit of claim 1, wherein a portion of the aspiration catheter tube has an inner diameter within a range of 0.083 to 0.101 inches, inclusive.

11. The medical kit of claim 1, wherein the flexible guide structure has an outer diameter within a range of 0.090 to 0.100 inches, inclusive.

12. The medical kit of claim 1, wherein the flexible guide structure has an inner diameter within a range of 0.083 to 0.093 inches, inclusive.

13. The medical kit of claim 1, wherein the flexible guide structure includes nickel titanium (NiTi).

14. The medical kit of claim 1, further comprising a pusher component integral with, or configured to be coupled to, the flexible guide structure.

15. A method comprising: advancing a catheter system through a blood vessel of a patient, the catheter system comprising: an aspiration catheter tube; and a flexible guide structure disposed within a lumen of the aspiration catheter tube, the flexible guide structure comprising: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member, wherein each of the first and second connecting members connect the first ring to the second ring; and a slit between the first ring and the second ring; advancing both a distal end of the aspiration catheter tube and a distal end of the flexible guide structure together through a bend of the blood vessel; and advancing, subsequent to the distal end of the aspiration catheter tube and the distal end of the flexible guide structure advancing past the bend, the distal end of the aspiration catheter tube through the blood vessel independent from the flexible guide structure.

16. The method of claim 15, further comprising advancing, subsequent to independently advancing the distal end of the aspiration catheter tube, the distal end of the flexible guide structure through the aspiration catheter tube.

17. The method of claim 15, wherein the blood vessel is a carotid artery of the patient.

18. The method of claim 15, further comprising advancing, independent from the flexible guide structure, the distal end of the aspiration catheter tube through the blood vessel and past an ophthalmic artery of the patient.

19. The method of claim 18, further comprising advancing, subsequent to independently advancing the distal end of the aspiration catheter tube past the ophthalmic artery, the distal end of the flexible guide structure through the aspiration catheter tube.

20. The method of claim 15, further comprising aspirating a clot positioned in a second blood vessel into the catheter system.

21. The method of claim 20, wherein the second blood vessel is a cerebral artery of the patient.

22. The method of claim 20, further comprising, prior to aspirating the clot, advancing both the distal end of the aspiration catheter tube and the distal end of the flexible guide structure together to abut a proximal end of the clot or enclose the proximal end of the clot.

23. The method of claim 22, further comprising, during aspiration of the clot, withdrawing the distal end of the flexible guide structure back through the blood vessel independent from the distal end of the aspiration catheter tube.

24. The method of claim 20, further comprising, prior to aspirating the clot, advancing the distal end of the flexible guide structure to abut a proximal end of the clot, or enclose the proximal end of the clot, independent from the distal end of the aspiration catheter tube.

25. The method of claim 20, further comprising, during aspiration of the clot, advancing both the distal end of the aspiration catheter tube and the distal end of the flexible guide structure together past a proximal end of the clot and to a distal end of the clot.

26. The method of claim 20, further comprising, during aspiration of the clot, advancing the distal end of the aspiration catheter tube past a proximal end of the clot and to a distal end of the clot independently from the distal end of the flexible guide structure.

27. A flexible guide structure adapted to be used with an aspiration catheter tube, the flexible guide structure comprising: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member, wherein each of the first and second connecting members connect the first ring to the second ring; and a slit between the first ring and the second ring; wherein the plurality of rings are configured such that the plurality of rings can move, independently from the aspiration catheter tube, within a lumen of the aspiration catheter tube.

28. The flexible guide structure of claim 27, wherein a first arc length of the first connecting member along an inner surface of the flexible guide structure is greater than or equal to a second arc length of the first connecting member along an outer surface of the flexible guide structure.

29. The flexible guide structure of claim 27, wherein a central axis of the flexible guide structure is included in a first plane that extends through both the first and second connecting members.

30. The flexible guide structure of claim 29, wherein the plurality of rings of the flexible guide member further comprise: a third ring; a third connecting member; and a fourth connecting member; wherein each of the third and fourth connecting members connect the second ring to the third ring; and wherein the central axis of the flexible guide structure is included in a second plane that extends through both the third and fourth connecting members.

31. The flexible guide structure of claim 27, wherein each of the plurality of rings has an outer diameter within a range of 2.28 to 2.54 millimeters (mm), inclusive.

32. The flexible guide structure of claim 27, wherein each of the plurality of rings has an inner diameter within a range of 2.10 to 2.36 mm, inclusive.

33. The flexible guide structure of claim 27, wherein the flexible guide structure includes nickel titanium (NiTi).

34. The flexible guide structure of claim 27, further comprising a pusher component integral with, or configured to be coupled to, the plurality of rings.

35. A clot aspiration method comprising: advancing a catheter system into a blood vessel of a patient, the catheter system comprising: an aspiration catheter tube; and a flexible guide structure disposed within a lumen of the aspiration catheter tube, the flexible guide structure comprising: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member, wherein each of the first and second connecting members connect the first ring to the second ring; and a slit between the first ring and the second ring; advancing the catheter system through the blood vessel such that a distal end of the aspiration catheter tube, a distal end of the flexible guide structure, or both abut a proximal end of a clot disposed in the blood vessel or enclose at least a portion of the proximal end of the clot; and aspirating the clot into the catheter system.

36. The method of claim 35, further comprising, during aspiration of the clot, withdrawing the distal end of the flexible guide structure back through the blood vessel independent from the distal end of the aspiration catheter tube.

37. The method of claim 35, wherein aspirating the clot is initiated when only the distal end of the aspiration catheter tube abuts, or encloses the proximal end of, the clot.

38. The method of claim 35, wherein aspirating the clot is initiated when only the distal end of the flexible guide structure abuts, or encloses the proximal end of, the clot.

39. A clot aspiration method comprising: advancing a catheter system into a blood vessel of a patient toward a proximal end of a clot disposed in the blood vessel, the catheter system comprising: an aspiration catheter tube; and a flexible guide structure disposed within a lumen of the aspiration catheter tube, the flexible guide structure comprising: a plurality of rings including a first ring and a second ring; a first connecting member; a second connecting member, wherein each of the first and second connecting members connect the first ring to the second ring; and a slit between the first ring and the second ring; initiating aspiration of the clot into the catheter system; and advancing, during aspiration of the clot, a distal end of the aspiration catheter tube through the blood vessel and toward a distal end of the clot.

40. The method of claim 39, wherein a distal end of the flexible guide structure abuts, or encloses at least a portion of, the proximal end of the clot when aspiration of the clot is initiated.

41. The method of claim 39, wherein at least a portion of the proximal end of the clot is disposed within the aspiration catheter tube when aspiration of the clot is initiated.

42. The method of claim 41, wherein the at least a portion of the proximal end of the clot is also disposed within the flexible guide structure when aspiration of the clot is initiated.

43. The method of claim 39, wherein advancing the distal end of the aspiration catheter tube through the blood vessel and toward the distal end of the clot includes advancing the distal end of the flexible guide structure together with the distal end of the aspiration catheter tube.

44. The method of claim 39, wherein the blood vessel is a cerebral artery of the patient.

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