Wire supported expandable catheter tip

Abstract

The designs disclosed herein are used for a clot retrieval catheter having a large aperture shaft and an expandable distal tip section. The catheter includes a proximal elongate shaft including a distal end, a longitudinal axis, and a shaft braided member including a plurality of braided wires. The expandable distal tip section is positioned proximate the distal end of the proximal elongate shaft. The expandable distal tip section is variable in design. In one example, the distal tip section includes an array of longitudinal cuffs. The plurality of braided wires may be integrally formed with the hoop array. In another example, the distal tip section may include two sets of opposing ribs. A first rib may be formed from a first line of the plurality of braided lines and a second rib may be formed from a second line of the plurality of braided lines.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 344,073, filed on May 20, 2022. The entire contents of that patent application are hereby incorporated by reference. Technical Field

[0003] The present invention generally relates to devices and methods for removing acute blockages from blood vessels during endovascular medical treatment. More specifically, the present invention relates to a retrieval catheter having an expandable tip into which one or more objects may be retrieved. Background Art

[0004] There are significant challenges in designing a clot removal device that can provide a high level of performance. For example, in cases where access involves navigating the aortic arch (such as a coronary artery or blockage), the arch configuration of some patients makes it difficult to position a guide catheter. These difficult arch configurations are classified as type 2 or type 3 aortic arches, with type 3 arches presenting the greatest difficulty. In arteries close to the brain, the tortuosity challenge is even more severe. For example, at the distal end of the internal carotid artery, it is not uncommon for the device to quickly and continuously navigate a vessel segment with a 180° bend, a 90° bend, and a 360° bend in several centimeters of blood vessel. In the case of a pulmonary embolism, access can be obtained through the venous system and then through the right atrium and ventricle of the heart. The right ventricular outflow tract and the pulmonary artery are fragile vessels that are easily damaged by inflexible or high-profile devices.

[0005] The vasculature in areas where a clot may become lodged is often fragile and delicate. For example, neurovascular vessels are more delicate than vessels of similar size elsewhere in the body and are located in soft tissue beds. Excessive tension applied to these vessels may result in perforation and hemorrhage. The pulmonary vessels are larger than those of the cerebral vasculature, but are also delicate in nature, particularly those that are more distal. Clots can vary greatly not only in shape and consistency, but also in length, even in any given area of ​​the anatomy. For example, a clot that obstructs the middle cerebral artery in an ischemic stroke patient can range in length from a few millimeters to several centimeters.

[0006] Stent-like clot retrievers are increasingly used to remove clots from cerebral vessels of acute stroke patients. These stent-like clot retrievers are self-expanding devices, similar in appearance to stents attached to the ends of long shafts, which are advanced through microcatheters and deployed across clot blockages to capture and retrieve clot blockages. They rely on a pinning mechanism to capture clots by capturing the clots between the self-expanding stent-like body and the vessel wall. This method has many disadvantages. Stent-like clot retrievers rely on their outward radial force (RF) to maintain their grip on the clot. If the RF is too low, the stent-like clot retriever will lose its grip on the clot, but if the RF is too high, the stent-like clot retriever may damage the vessel wall and may require excessive force to withdraw. Therefore, stent-like clot retrievers with sufficient radial force to handle all clot types may cause vascular trauma and serious patient injury, and stent-like clot retrievers with appropriate radial force to maintain non-traumatic may not effectively handle all clot types.

[0007] Because of the way its strut elements are connected to each other, conventional stent-like clot retriever designs cannot maintain their expanded shape well when placed under tension in a bend. This may result in a loss of grip on the clot as the stent-like clot retriever is withdrawn proximally near the bend in a curved vessel, and the captured clot may escape. This is because the struts of the stent-like clot retriever are placed under tension as they are retracted. This tension is due to friction between the device and the vessel, and if additional loads (such as those provided by the clot) are applied, the tension increases. At the bend, the struts on the outside of the bend are placed under higher tension than the struts on the inside. In order to obtain the lowest possible energy state, the outer surface of the stent moves toward the inner surface of the bend, which reduces the tension in the struts, but also reduces the expanded diameter of the stent-like clot retriever.

[0008] The above challenges need to be overcome for any device to provide a high level of success in removing clots, restoring blood flow, and promoting good patient outcomes. Existing devices fail to adequately address these challenges. Summary of the invention

[0009] The purpose of this design is to provide a device and method that meets the above needs. The design described herein may include a wire-supported expandable catheter. The catheter may include a proximal elongated shaft, which includes a distal end, a longitudinal axis, and an axis braiding member, and the axis braiding member has multiple braided wires. The catheter may include a distal end section at the distal end of the elongated shaft. The distal end section may have a collapsed delivery configuration, an expanded deployment configuration, and a longitudinal hoop array. The multiple braided wires of the proximal elongated shaft may be formed integrally with the hoop array of the distal end section. Each of the multiple braided wires may be dispersed from the final intersection of the axis braiding member at the distal end of the proximal elongated shaft to form one of the hoops in the longitudinal hoop array.

[0010] In some examples, the distal tip segment can include a collapsed inner diameter in the collapsed delivery configuration, which can be smaller than an expanded inner diameter in the expanded deployed configuration.

[0011] In some examples, the wire of each hoop in the longitudinal hoop array can be connected to the elongated shaft at the final intersection point by a pair of axially extending hoop slides. In some examples, each pair of axially extending hoop slides can be evenly spaced around the longitudinal axis. In some examples, each hoop in the longitudinal hoop array can be radially dispersed from a pair of hoop terminal ends at the distal ends of each pair of axially extending hoop slides to extend circumferentially around the terminal segment.

[0012] In some examples, a first spacing between a more proximally adjacent pair of hoops in the longitudinal hoop array may be different from a second spacing between adjacent hoops in a more distally adjacent pair of hoops. In some examples, each hoop in the longitudinal hoop array may include a distally unconnected peak that moves distally when the distal end segment is folded into the collapsed delivery configuration.

[0013] In some examples, each hoop in the array of longitudinal hoops may define a plane that is perpendicular to the longitudinal axis of the elongated shaft.

[0014] In some examples, the longitudinal array of hoops defines a mouth having a curvilinear profile.

[0015] The design described herein includes a catheter. The catheter may include a proximal elongated shaft having a distal end, a longitudinal axis, and an axis braiding member having a plurality of braided wires. The catheter may include a distal end section extending from the distal end of the elongated shaft. The distal end section may include two sets of opposing ribs. A first rib in the two sets of opposing ribs may be formed by a first wire in the plurality of braided wires of the proximal elongated shaft, and a second rib in the two sets of opposing ribs may be formed by a second wire in the plurality of braided wires of the proximal elongated shaft. The first rib may be spaced approximately 180 degrees from the second rib around the longitudinal axis.

[0016] In some examples, the distal tip segment can include a delivery configuration and a clot capture configuration. The distal tip segment can have a smaller delivery inner diameter in the delivery configuration and a larger expanded inner diameter in the clot capture configuration when radially impacted by an ingested clot.

[0017] In some examples, the distal tip segment can include a collapsed delivery configuration having a collapsed inner diameter and an expanded deployed configuration heat set to have an expanded inner diameter that is greater than the collapsed inner diameter.

[0018] In some examples, each rib in two sets of opposing ribs may have distally unconnected peaks.

[0019] In some examples, two sets of opposing ribs may be integrally formed with the plurality of braided strands of the shaft braid member.

[0020] In some examples, each of the plurality of braided wires may diverge radially from a final intersection point to form a v-shaped pattern.

[0021] In some examples, the set of opposing ribs may define a mouth having a curvilinear profile.

[0022] The designs described herein may include a catheter. The catheter may include a proximal elongated shaft having a distal end, a longitudinal axis, and an axis braiding member including a plurality of braided wires. The catheter may include a distal end segment at the distal end of the elongated shaft. The distal end segment may have a longitudinal offset hoop array defining an oblique plane. The catheter may include a distal outer jacket surrounding the longitudinal offset hoop array. The plurality of braided wires of the proximal elongated shaft may be integrally formed with the offset hoop array. Each of the plurality of braided wires may be dispersed from a final intersection to extend circumferentially around the end segment. The oblique plane may intersect the longitudinal axis at an acute angle.

[0023] In some examples, the distal tip segment can have a collapsed delivery configuration having a collapsed inner diameter and an expanded deployed configuration having an expanded inner diameter that is heat set to be larger than the collapsed inner diameter.

[0024] In some examples, the distal tip segment can have a larger expanded inner diameter when radially impacted by an ingested clot in the expanded clot capture configuration, and can have a smaller delivery inner diameter in the delivery configuration. In some examples, when in the expanded deployed configuration, the distal tip segment can have a substantially circular cross-section with a center radially offset from the longitudinal axis of the elongated shaft.

[0025] In some examples, when in the expanded deployed configuration, the distal tip segment can have a substantially circular cross-section having a center substantially coincident with the longitudinal axis of the elongated shaft.

[0026] In some examples, the offset hoop array may have distally unconnected peaks that move distally when the distal tip segment is folded into the collapsed delivery configuration.

[0027] In some examples, the array of offset hoops follows a curvilinear profile circumferentially around the end segment.

[0028] In some examples, at least a portion of a perimeter of a hoop in the offset hoop array may define a plane that passes through the longitudinal axis at an acute angle.

[0029] In some examples, the distal tip segment can include a distal expandable segment configured to expand radially upon ingestion of clot.

[0030] In some examples, the array of offset hoops may define a mouth having a curvilinear profile.

[0031] Other aspects of the present disclosure will become apparent after viewing the following detailed description in conjunction with the accompanying drawings. Additional features or manufacturing steps and use steps may be included as will be understood and appreciated by those of ordinary skill in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above aspects and other aspects of the present invention will be further discussed with reference to the following description and in conjunction with the accompanying drawings, in which similar numbers indicate similar structural elements and features in various figures. The accompanying drawings are not necessarily drawn to scale, but instead, the focus is on illustrating the principles of the present invention. The accompanying drawings depict one or more specific implementations of the device of the present invention only by way of example and not by way of limitation. It is expected that those skilled in the art will be able to conceive and combine elements from multiple drawings to better meet the needs of the user.

[0033] Figure 1 is an illustration of a clot retrieval catheter having an expandable tip advanced through vasculature according to aspects of the present invention;

[0034] Figure 2 A distal portion of a clot retrieval catheter having an expandable tip according to aspects of the present invention is shown;

[0035] Figure 3 A distal portion of a clot retrieval catheter having an expandable tip according to aspects of the present invention is shown;

[0036] Figure 4 According to various aspects of the present invention Figure 3 an end elevational view of a distal portion of a clot retrieval catheter;

[0037] Figure 5 illustrates a distal portion of a clot retrieval catheter having an expandable tip leading to an oblique plane according to aspects of the present invention;

[0038] Figure 6 According to various aspects of the present invention Figure 5 an end elevational view of a distal portion of a clot retrieval catheter;

[0039] Figure 7 is a schematic diagram of a catheter having a distal portion with a symmetrical opening according to aspects of the present invention;

[0040] Figure 8is a schematic diagram of a catheter having an asymmetrically opened distal portion according to aspects of the present invention;

[0041] 9A to 9C is a schematic diagram illustrating a self-expanding catheter for capturing a clot according to aspects of the present invention;

[0042] Fig.10 illustrates a distal portion of a clot retrieval catheter having an expandable tip according to aspects of the present invention;

[0043] Fig.11 illustrates a distal portion of a clot retrieval catheter having an expandable tip according to aspects of the present invention;

[0044] Fig.12 According to various aspects of the present invention Fig.11 a cross-sectional view of a clot retrieval catheter showing details of the outer jacket; and

[0045] FIG. 13A to FIG. 13C is a schematic diagram illustrating a non-self-expanding catheter for capturing a clot according to aspects of the present invention. DETAILED DESCRIPTION

[0046] Specific examples of the present invention are now described in detail with reference to the drawings, wherein like reference numerals indicate functionally similar or identical elements. These examples address many of the deficiencies associated with conventional clot retrieval aspiration catheters, such as the inability to properly or accurately deploy to the target site and ineffective clot removal.

[0047] The design herein can be used for a clot retrieval catheter having a larger lumen and a distal funnel end that can self-expand to a diameter larger than the diameter of the guide or sheath through which the clot retrieval catheter is coaxially delivered. The design can have a proximal elongated shaft for the shaft of the catheter, and a distal end with an expansion braided support structure and an outer polymer jacket to provide the end with atraumatic properties. The braided support can be designed so that the expansion capacity of the axial portion of the terminal segment is adjustable. The braid can be easily collapsed repeatedly for delivery and expansion to achieve good clot reception and suction resistance. The braid and end design of the catheter can be flexible enough to traverse highly tortuous areas of the anatomical structure, and when displaced in a blood vessel, can recover its shape to maintain the inner diameter of the lumen.

[0048] Access to various intravascular vessels (whether coronary, pulmonary or cerebral) involves well-known surgical procedures and the use of many conventional commercially available accessory products. These products, such as angiographic materials, mechanical thrombectomy devices, microcatheters and guidewires, are widely used in laboratories and medical procedures. When these products are used in conjunction with the apparatus and methods of the present invention described below, their functions and exact construction are not described in detail. In addition, although this specification is in many cases in the context of thrombectomy treatment of intracranial arteries, the present disclosure may also be applicable to other procedures and other body passages.

[0049] Turning to the attached figure, Figure 1 A possible sequence of approaching an obstructive clot 40 using a clot retrieval catheter 100 having a design disclosed herein is illustrated. As the catheter 100 collapses within a guide sheath 30 or other outer catheter for delivery, the clot 40 can be approached. When the vasculature 10 becomes too narrow and / or tortuous to be traversed further distally with the guide sheath 30, the catheter 100 can be deployed to advance further distally independently. The catheter 100 can be highly flexible, enabling it to traverse the M1 or other tortuous regions of a neurovascular vessel to reach an obstructive clot.

[0050] The clot retrieval catheter 100 may have a flexible elongated shaft 110 that serves as a shaft with a large inner caliber (in some cases, it may be 0.070 inches or more) and a distal tip segment 210 (see also tips 310, 410, and 510 described herein) having a collapsible support braid structure. The large caliber facilitates delivery of the catheter to the target site by a variety of methods. These methods may include over a guidewire, over a microcatheter, with a dilator / access tool, or by itself.

[0051] In most cases, the design of the collapsible funnel tip can be configured so that the catheter 100 can be delivered (and retrieved) through a commonly sized outer sheath and guide. For example, a standard 6Fr sheath / 8Fr guide typically has an inner lumen of less than 0.090 inches. Thus, the tip can be designed with a collapsed delivery outer diameter of approximately 0.086 inches. Once the tip is advanced to an unconstrained position distal to the distal end 32 of the guide sheath 30, it can self-expand, and the expanded outer diameter can reach approximately 0.132 inches. Since the catheter can be delivered to the distal obstruction independently, the distal tip segment 210 (also see the tips 310, 410, and 510 described herein) must be designed to resist collapse caused by suction forces, have excellent lateral flexibility in both expanded and collapsed states, and have a non-traumatic profile that prevents obstruction to vascular dispersion points.

[0052] Figure 2A close-up view of the distal portion of the catheter 100 having a terminal segment 210 is illustrated, which presents a funnel shape in an expanded deployment configuration. The elongated shaft 110 may extend along a longitudinal axis 111. The distal end of the elongated shaft 110 may have a distal end 114, and the distal end 114 may be close to the terminal segment 210. The elongated shaft 110 may include a braided member 120. The braided member 120 may be formed by a plurality of braided wires 121 that wrap the length of the elongated shaft 110. The plurality of braided wires 121 of the braided member 120 may be used as the backbone and support of the catheter 100 shaft. The interlaced braiding of the plurality of braided wires 121 may be any number of materials or patterns known in the art, and may have a density and composition that varies along the length of the shaft. The distal terminal segment 210 at the distal end 114 of the elongated shaft 110 may have a collapsed delivery configuration and an expanded deployment configuration.

[0053] The distal end segment 210 may also include a longitudinal hoop array 220 extending around the distal end segment 210. The longitudinal hoop array 220 (also referred to herein as hoop 220 or array of hoop 220) may be continuously formed by a plurality of braided wires 121. For example, the plurality of braided wires 121 may be integrally formed with the array of hoop 220 of the distal end segment 210, such that each braided wire 121 extends continuously from the elongated shaft 110 to the distal end segment 210. Each wire of the plurality of braided wires 121 may be dispersed from the final intersection 218 of the shaft braid member 120 to form one of the hoop 220. In some examples, the catheter 100 may include a hoop slide 221 extending between the final intersection 218 and the hoop 220. For example, at the final intersection 218 of the two braided wires 121, the two braided wires 121 may be turned longitudinally along the longitudinal axis 111 and extend a certain distance as two hoop slides 221 before diverging to form a single hoop 220 extending circumferentially around the end segment 210. This divergence point of the two braided wires 121 used to form the hoop 220 may be referred to as a hoop terminal 223. Referring again to the hoop slides 221, the hoop slides 221 may provide a degree of pushability for the distal tip 210 because their longitudinal orientation may resist axial forces when the catheter 110 is pushed through the target vessel. In some examples, each pair of axially extending hoop slides 221 may be evenly and circumferentially spaced around the longitudinal axis 111.

[0054] Referring to the array of hoops 220 of the distal end segment 210, the spacing between two adjacent hoops can vary depending on where the respective hoops are positioned on the distal end segment 210. For example, a first spacing 224 between a more proximally adjacent pair of hoops in the longitudinal array of hoops 220 can be different from a second spacing 226 between adjacent hoops in a more distally adjacent pair of hoops 220. In some examples, the second spacing 226 of adjacent hoops 220 near the distal end 214 of the distal end segment 210 can be tighter than the first spacing 224 of the more proximally adjacent hoops 220. The tighter spacing at the distal end 214 of the distal end segment 210 can help improve clot retention and reduce its crushability when the distal end segment 210 is in an expanded, deployed configuration. In the expanded, deployed configuration, each hoop in the longitudinal array of hoops 220 can define a plane perpendicular to the longitudinal axis 111 of the elongated shaft 110. Additionally, when the distal tip section 210 is in the expanded deployed configuration, the longitudinal hoop array 220 can form a series of rings concentric with the longitudinal axis 111 .

[0055] As described above, the distal tip segment 210 can have an expanded deployment configuration and a collapsed delivery configuration. 9A to 9C In more detail, the distal end segment 210 can have a collapsed inner diameter 216 in the collapsed delivery configuration that is smaller than the expanded inner diameter 215 in the expanded deployment configuration. Each hoop in the longitudinal hoop array 220 can include a distal unconnected peak 228 that moves distally when the distal end segment 210 is folded into the collapsed delivery configuration.

[0056] Figure 3 A distal portion of a clot retrieval catheter 100 having an expandable tip 310 is illustrated in accordance with aspects of the present invention. Figure 3 The design shown is similar to Figure 2 The design shown, but the distal end section 310 (at Figure 2 The shape and configuration of the distal end segment 210 (referred to as the distal end segment 210) vary. Figure 3 The illustrated example may similarly include a proximal elongated shaft 110 having a distal end 114, a longitudinal axis 111, and a shaft braid member 120 including a plurality of braided wires 121. A distal tip segment 310 may extend from the distal end 114 of the elongated shaft 110. Figure 3In the example shown, the distal end segment 310 may include two sets of opposing ribs 320 that flare outwardly from each other (e.g., open like a book) when the distal end segment 310 is in the expanded configuration. A first rib 330 of the two sets of opposing ribs 320 may be formed by a first wire 331 of the plurality of braided wires 121 of the proximal elongated shaft 110. A second rib 332 of the two sets of opposing ribs 320 may be formed by a second wire 333 of the plurality of braided wires 121 of the proximal elongated shaft 110. The first rib 330 may be spaced approximately 180 degrees from the second rib 332 around the longitudinal axis 111.

[0057] The plurality of braided wires 121 may be integrally formed with the plurality of sets of opposing ribs 320. For example, each braided wire 121 may extend continuously from the elongated shaft 110 to the distal end segment 310. The braided wires 121 of the proximal elongated shaft 110 may diverge as they transition into the distal end segment 310. Each of the plurality of braided wires 121 may diverge radially from the final intersection 318 to form a v-shaped pattern 329. After the final intersection 318, the first rib 330 and the second rib 332 may extend partially around the distal end segment 310. Each rib in the two sets of opposing ribs 320 may include a distal unconnected peak 228 at the distal end 314 of the distal end segment 310, as similarly described in Figure 2 as shown in .

[0058] Figure 4 According to various aspects of the present invention Figure 3 1 is an end elevational view of the distal portion of a clot retrieval catheter of FIG. The figure provides a view of the expanded distal tip segment 310 and the elongated shaft 110. The distal tip segment 310 can have a delivery configuration and a clot capture configuration. The distal tip segment 310 can have a smaller delivery inner diameter 115 in the delivery configuration and can have a larger expanded inner diameter 315 in the clot capture configuration when radially impacted by an ingested clot 40. In this example, the distal tip segment 310 can expand upon contact with a clot. This configuration example is shown in FIG. FIG. 13A to FIG. 13C Alternatively, the distal tip segment 310 may have a collapsed delivery configuration having a collapsed inner diameter 216 and an expanded deployment configuration. The deployed configuration may be achieved by heat setting the material of the opposing ribs 320 to have an expanded inner diameter 215 that is greater than the collapsed inner diameter 216. An example of this configuration is shown in 9A to 9C Shown in.

[0059] Figure 5 The distal portion of a clot retrieval catheter 100 having an expandable tip leading to an inclined plane 413 according to aspects of the present invention is illustrated. The catheter 100 may have a proximal elongated shaft 110 including a distal end 114, a longitudinal axis 111, and a shaft braid member 120 including a plurality of braided wires 121, similar to Figures 2 to 4 The catheter 100 may include a distal tip segment 410 at the distal end 114 of the elongated shaft 110. The distal tip segment 410 is similar to the distal tip segments described above (e.g., distal tip segments 210 and 310), but with variations in shape and design. The distal tip segment 410 may include a longitudinal array of offset hoops 420 defining an oblique plane 413. The oblique plane 413 intersecting the longitudinal axis 111 may be formed at an acute angle 417 so that the distal-most tip 414 of the distal tip segment 410 is directed toward a target (e.g., a clot).

[0060] The distal tip 410 is offset from the longitudinal axis 111, which can help reduce the likelihood of tip collapse during aspiration compared to expandable catheters having a mouth that is perpendicular to the longitudinal axis 111 because the membrane (e.g., outer jacket 180) used to offset the mouth does not extend completely around the diameter of the distal tip segment 410. The catheter 100 can also include an outer jacket 180 surrounding a longitudinal array of offset hoops 420. The plurality of braided wires 121 of the proximal elongated shaft 110 can be integrally formed with the array of offset hoops 420. Each of the plurality of braided wires 121 can diverge from a final intersection 418, where beyond the final intersection 418, the plurality of braided wires 121 extend circumferentially around the tip segment 410. In other words, the plurality of braided wires 121 can interrupt their braided orientation at the final intersection 418, bend, and continue distally to follow a curved profile circumferentially around the distal tip segment 410. The array of offset hoops 420 may include distal unconnected peaks 428 that move distally when the distal tip section 210 is folded into the collapsed delivery configuration.

[0061] Figure 6 According to various aspects of the present invention Figure 5 FIG. 4 is an end elevation view of the distal portion of the clot retrieval catheter 100 of FIG. The end view shows the offset of the distal tip segment 410. In the expanded deployed configuration, the distal tip segment 410 includes a substantially circular cross-section having a center 432 radially offset from the longitudinal axis 111 of the elongated shaft 110, i.e., the center 432 of the distal tip segment 410 is offset from the center 117 of the elongated shaft 110. The distal tip segment 410 may have a collapsed delivery configuration having a collapsed inner diameter 115 approximately equal to the diameter of the elongated shaft 110. The distal tip segment 410 may have an expanded deployed configuration having an expanded inner diameter 415 that is heat set to be larger than the collapsed inner diameter 115.

[0062] Figure 7is a schematic diagram of a catheter 100 having a symmetrically opened distal portion according to aspects of the present invention. The figure shows that in some examples described herein, when the catheter 100 is in a collapsed delivery configuration or an expanded deployment configuration, the distal tip segment 310 can have a substantially circular cross-section having a center 432 substantially coinciding with the longitudinal axis 111 of the elongated shaft 110. This Figure 3 and Figure 4 (ie, distal tip segment 310) and Figure 2 (ie, distal tip segment 210 ) is shown in the example. Figure 8 is a schematic diagram of a catheter 100 having an asymmetrically opened distal portion according to aspects of the present invention. The figure shows that in some examples described herein, when in an expanded deployed configuration, the distal tip segment 410 can have a substantially circular cross-section with a center 432 radially offset from the longitudinal axis 111 of the elongated shaft 110. This Figure 5 and Figure 6 (ie, distal tip segment 410). Thus, Figure 7 and Figure 8 The funnel profile 434 in has a different shape in the expanded deployed configuration.

[0063] 9A to 9C is a schematic diagram illustrating a self-expanding catheter 100 for capturing a clot 40 according to various aspects of the present invention. The example shown in the schematic diagram depicts a self-expanding distal tip segment 210. This description is applicable to any distal tip segment shape herein, wherein the distal tip segment is heat set to have an expanded inner diameter 215 that is larger than the collapsed inner diameter 216. Fig.9A In the embodiment, the catheter 100 is deployed through the blood vessel 12 through the guide sheath 30 until the distal end 32 of the guide sheath 30 is close to the clot 40. Fig. 9B In, the distal tip section 210 is then deployed from the introducer sheath 30 and automatically expands into its expanded deployed configuration due to heat setting. Fig. 9C In the embodiment of the present invention, the distal tip section 210 is then advanced to the clot 40 , suction is applied through the elongated shaft 110 , and the clot can be retrieved from the blood vessel 12 .

[0064] Fig.10 Illustrated is a distal portion of a clot retrieval catheter 100 having an expandable tip in accordance with aspects of the present invention. Fig.10 The example shown is basically similar to Figure 3 However, in Figure 3 In the design of , the distal tip section 310 can be considered a self-expanding design because it is heat set into the expanded deployed configuration; Fig.10The design in the embodiment instead includes a low shear distal tip segment 510 that expands upon contact with a clot 40. For example, the distal expandable segment 530 of the distal tip segment 510 can maintain a nominal distal inner diameter 516 until the distal end 514 of the distal tip segment 510 contacts the clot 40. Upon contact with the clot 40, the distal tip segment 510 can be advanced while providing suction around the clot 40 for retrieval. In addition, Fig.10 The design shown may include a final intersection 518 similar to Figure 3 The final intersection 318 in the clot 40 may include two sets of opposing ribs 520 that flare outward when contacting the clot 40, which are similar to the two sets of opposing ribs 320; may include a first rib 531, which is similar to the first rib 330; may include a second rib 532, which is similar to the second rib 332; a distal unconnected peak 528, which is similar to the distal unconnected peak 328; and the opposing ribs 520 may include a v-shaped pattern 529, which is similar to Figure 3 The chevron pattern in 329.

[0065] Fig.11 Illustrated is a distal portion of a clot retrieval catheter 100 having an expandable tip in accordance with aspects of the present invention. Fig.11 The example shown is basically similar to Figure 5 However, in Figure 5 In the design of , the distal tip section 410 can be considered a self-expanding design because it is heat set into the expanded deployed configuration; Fig.11 The design in the embodiment instead includes a low shear distal tip segment 610 that expands during retrieval of the clot 40. For example, the distal expandable section 630 of the distal tip segment 610 can maintain the nominal distal inner diameter 616 until the distal end 614 of the distal tip segment 610 contacts the clot 40. Upon contacting the clot 40, the distal tip segment 610 can be advanced while providing suction around the clot 40 for retrieval. In addition, Fig.11 The design shown may include a bevel 617 similar to Figure 5 may include a final intersection 618 similar to final intersection 418; may include a longitudinal array of offset hoops 620 similar to the longitudinal array of offset hoops 620; may include distally unconnected peaks 628 similar to distally unconnected peaks 428. The longitudinal array of hoops 620 may define a mouth having a curved profile 613. The curved profile 613 may also provide for the opposing ribs 320 (see Figure 3 ) and an array of offset hoops 420 (see Figure 5 ).

[0066] Fig.12 According to various aspects of the present invention Fig.11A cross-sectional view of the clot retrieval catheter 100 is shown showing details of the outer jacket 180. Although the image is Fig.11 , but it should be understood that the jacket 180 can be applied to any of the catheter 100 designs described herein. During aspiration and retrieval of clots, the jacket 180 can prevent proximal fluid from entering the expanded end, thereby allowing the aspiration force to be more effectively directed while preventing clot fragments or other debris from migrating distally during surgery. In one example, the jacket 180 can be formed of a highly elastic material so that the radial force applied by expanding the expandable end is sufficient to stretch the membrane into the funnel-shaped profile of the end when in the expanded and deployed configuration. An example can be the use of a ductile elastomer, which has the following advantages: soft and flexible to resist tearing and puncture due to high failure strains. Alternatively, the jacket 180 can be loosely fitted to the catheter 100 and folded over the edge of the distal end segment so that the distal end segment can move more freely when expanded and collapsed.

[0067] FIG. 13A to FIG. 13C is a schematic diagram illustrating a non-self-expanding catheter 100 for capturing a clot 40 according to various aspects of the present invention. The example shown in the schematic diagram depicts a non-self-expanding distal tip segment 510. This description may be applied to any distal tip segment described herein, wherein the distal tip segment is not heat set to have an expanded configuration, but rather a distal expandable segment (e.g., expandable segment 430) expands to an expanded inner diameter 415 upon contacting a clot 40. The distal tip segment 410 may have a larger expanded inner diameter 415 in the expanded clot capture configuration when radially impacted by an ingested clot 40, and may have a smaller delivery inner diameter 115 in the delivery configuration. Fig.13A In the embodiment, the catheter is deployed through the blood vessel 12 through the guide sheath 30 until the distal end 32 of the guide sheath 30 is close to the clot 40. At this point, the distal tip section 410 has a collapsed inner diameter 416. Fig. 13B In, the distal tip section 510 is then deployed from the introducer sheath 30. Fig. 13C , the distal tip segment 510 is then advanced to the clot 40, wherein the distal tip segment 510 expands as the distal-most tip 414 of the distal tip segment 510 is advanced over the clot 40. Suction is applied through the elongated shaft 110, and the clot 40 can be retrieved from the blood vessel 12.

[0068] The present invention is not necessarily limited to the examples described, the configurations and details of which may vary. The terms "distal" and "proximal" are used throughout the foregoing description and refer to positions and directions relative to the treating physician. Similarly, "distal" or "toward the distal side" refers to a position away from the physician or in a direction away from the physician. Similarly, "proximal" or "toward the proximal side" refers to a position close to the physician or in a direction toward the physician. In addition, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the / said" include plural references.

[0069] As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a value range of ±20% of the recited value, for example, "about 90%" can refer to a value range of 71% to 99%.

[0070] In describing the example embodiments, terminology has been employed for the sake of clarity. Therefore, not all possible combinations are listed, and such variations are generally obvious to those skilled in the art and are intended to fall within the scope of the following claims. Without departing from the scope and spirit of the present invention, it is intended that each term contemplates its broadest meaning as understood by those skilled in the art, and includes all technical equivalents that operate in a similar manner to achieve similar purposes. It should also be understood that reference to one or more steps of a method does not exclude the presence of additional method steps or intermediate method steps between those explicitly identified steps. Similarly, some steps of the method may be performed in an order different from that described herein without departing from the scope of the disclosed technology.

Claims

1. A catheter, comprising: a proximal elongated shaft comprising a distal end, a longitudinal axis, and a shaft braid member comprising a plurality of braided wires; as well as a distal tip segment at the distal end of the elongated shaft, the distal tip segment comprising a collapsed delivery configuration, an expanded deployed configuration, and a longitudinal hoop array; The plurality of braided wires of the proximal elongated shaft are integrally formed with the array of ferrules of the distal tip section, and Each of the plurality of braided wires diverges from a final intersection of the shaft braid member at the distal end of the proximal elongated shaft to form one of the hoops in the longitudinal array of hoops.

2. The catheter of claim 1, wherein the distal tip segment further comprises a collapsed inner diameter in the collapsed delivery configuration, the collapsed inner diameter being smaller than the expanded inner diameter in the expanded deployment configuration.

3. The catheter of claim 1, said wire of each hoop in said longitudinal array of hoop being connected to said elongated shaft at said final intersection point by a pair of axially extending hoop slides.

4. The catheter of claim 3, each pair of axially extending hoop slides being evenly spaced about the longitudinal axis.

5. The catheter of claim 3, each hoop in the longitudinal array of hoop being radially divergent from a pair of hoop terminal ends at the distal end of each pair of axially extending hoop slides to extend circumferentially around the terminal segment.

6. The catheter of claim 1, a first spacing between a more proximally adjacent pair of hoops in the longitudinal array of hoops being different than a second spacing between adjacent hoops in a more distally adjacent pair of hoops.

7. The catheter of claim 6, each hoop in the longitudinal array of hoop comprising a distal unconnected peak that moves distally when the distal tip segment is folded into the collapsed delivery configuration.

8. The catheter of claim 1, each hoop in the longitudinal array of hoop defining a plane perpendicular to the longitudinal axis of the elongated shaft.

9. A catheter, comprising: a proximal elongated shaft comprising a distal end, a longitudinal axis, and a shaft braid member comprising a plurality of braided wires; as well as a distal tip section extending from the distal end of the elongated shaft, the distal tip section comprising two sets of opposing ribs; A first rib of the two sets of opposing ribs is formed by a first wire of the plurality of braided wires of the proximal elongated shaft, and a second rib of the two sets of opposing ribs is formed by a second wire of the plurality of braided wires of the proximal elongated shaft, the first rib being spaced apart from the second rib by approximately 180 degrees around the longitudinal axis.

10. The catheter of claim 9, the distal tip segment further comprising a delivery configuration and a clot capture configuration; The distal tip segment has a smaller delivery inner diameter in the delivery configuration and a larger expanded inner diameter in the clot capture configuration when radially impacted by an ingested clot.

11. The catheter of claim 9, the distal tip segment further comprising a collapsed delivery configuration having a collapsed inner diameter and an expanded deployed configuration heat set to have an expanded inner diameter greater than the collapsed inner diameter.

12. The catheter of claim 9, each rib in the two sets of opposing ribs comprising distally unconnected peaks.

13. The catheter of claim 9, the two sets of opposing ribs being integrally formed with the plurality of braided wires of the shaft braid member.

14. The catheter of claim 9, each of the plurality of braided wires radially diverging from a final intersection point to form a v-shaped pattern.

15. A catheter, comprising: a proximal elongated shaft comprising a distal end, a longitudinal axis, and a shaft braid member comprising a plurality of braided wires; a distal tip segment at the distal end of the elongated shaft, the distal tip segment comprising an array of longitudinally offset hoops defining an oblique plane; as well as a distal outer jacket surrounding the array of longitudinally offset hoops; The plurality of braided wires of the proximal elongated shaft are integrally formed with the offset hoop array, each wire of the plurality of braided wires diverging from a final intersection point to extend circumferentially around the tip section, The inclined plane intersects the longitudinal axis at an acute angle.

16. The catheter of claim 15, the distal tip segment further comprising a collapsed delivery configuration having a collapsed inner diameter and an expanded deployed configuration having an expanded inner diameter heat set to be larger than the collapsed inner diameter.

17. The catheter of claim 15, the distal tip segment further comprising a larger expanded inner diameter in the expanded clot capture configuration when radially impacted by an ingested clot, and a smaller delivery inner diameter in the delivery configuration.

18. The catheter of claim 17, wherein in the expanded clot capture configuration, the distal tip segment further comprises a substantially circular cross-section, the center of the substantially circular cross-section being radially offset from the longitudinal axis of the elongated shaft.

19. The catheter of claim 15, the offset hoop array comprising distal unconnected peaks that move distally when the distal tip segment is folded into a collapsed delivery configuration.

20. The catheter of claim 15, the array of offset hoops following a curvilinear profile circumferentially around the tip section.

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