Wire-Supported Expandable Catheter Tip

Abstract

The designs and methods disclosed herein are for a blood clot retrieval catheter having a large bore shaft and an expandable distal tip section. The catheter includes a proximal elongate shaft having a distal end, a longitudinal axis, and a shaft braid member comprising a plurality of braided wires. The expandable distal tip section is disposed proximate the distal end of the proximal elongate shaft. The expandable distal tip section can be designed to vary. In one example, the distal tip section includes a longitudinal array of hoops. The plurality of braided wires can be formed integrally with the array of hoops. In another example, the distal tip section can include two sets of opposing ribs. The first rib can be formed from a first wire of the plurality of braided wires and the second rib can be formed from a second wire of the plurality of braided wires.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 344,073, filed on May 20, 2022. All of these contents are incorporated herein by reference.

[0002] (Field of the Invention) The present invention generally relates to devices and methods for removing acute occlusions from blood vessels during endovascular medical procedures. More specifically, the present invention relates to a retrieval catheter having an expandable tip capable of retrieving an object or a plurality of objects.

Background Art

[0003] There are significant challenges associated with the design of blood clot removal devices that can provide high levels of performance. For example, when access involves advancing through the aortic arch (such as coronary artery occlusion or cerebral occlusion), in some patients, due to the configuration of the aortic arch, it becomes difficult to position the guide catheter. These difficult aortic arch configurations are classified as type II or type III aortic arches, with type III aortic arches presenting the greatest obstacle. The problem of tortuosity is even more severe in arteries approaching the brain. For example, it is not uncommon at the distal end of the internal carotid artery for a device to have to continuously advance over a few centimeters of blood vessel having 180° bends, 90° bends, and 360° bends. In the case of pulmonary embolism, access can be obtained through the venous system and then through the right atrium and right ventricle of the heart. The right ventricular outflow tract and pulmonary artery are delicate blood vessels that can be easily damaged by inflexible or high - profile devices.

[0004] The vasculature in regions where blood clots may be present is often fragile and delicate. For example, the blood vessels of the neurovasculature are more fragile than blood vessels of similar size in other parts of the body and are in a soft tissue bed. Excessive tensile forces applied to these blood vessels can result in perforation and bleeding. Pulmonary blood vessels are larger than those of the cerebrovascular system but are also inherently delicate, especially the more distal pulmonary blood vessels. Blood clots not only vary in shape and consistency but can also vary widely in length within any given region of the anatomical structure. For example, a blood clot occluding the middle cerebral artery in a patient with an ischemic stroke can range in length from just a few millimeters to several centimeters.

[0005] Stent-like blood clot retrievers are increasingly being used to remove blood clots from the cerebral blood vessels of patients with acute stroke. These are self-expanding devices that resemble stents attached to the end of a long shaft, which are advanced through a microcatheter and deployed across the blood clot occlusion to capture and retrieve them. Self-expanding devices rely on a pinning mechanism that grips the blood clot by capturing it between the self-expanding stent-like body and the blood vessel wall. This approach has many drawbacks. Stent-like blood clot retrievers maintain their gripping force on the blood clot depending on their outward radial force (RF). If the RF is too low, the stent-like blood clot retriever loses its gripping force on the blood clot, but if the RF is too high, the stent-like blood clot retriever may damage the blood vessel wall and may require an overly strong force to withdraw. Thus, a stent-like blood clot retriever with sufficient radial force to handle all blood clot types can cause vascular trauma and severe patient injury, and a stent-like blood clot retriever with an appropriate radial force to maintain non-traumatic handling may not be able to effectively handle all blood clot types.

[0006] Conventional stent-like blood clot retriever designs do not hold their expanded shape very well when placed under tension within a bend, due to the way their strut elements are connected to each other. This can result in a loss of gripping force on the blood clot when the stent-like blood clot retriever is retracted proximally around a bend in a tortuous blood vessel, and there is a possibility that the captured blood clot may slip out. This occurs because the struts of the stent-like blood clot retriever are placed under tension when retracting. This tension is due to friction between the device and the blood vessel and increases when additional loads, such as the load imposed by the blood clot, are added. In a bend, the struts on the outside of the bend are placed under higher tension than the inner struts. To obtain the lowest possible energy state, the outer surface of the stent moves towards the inner surface of the bend, thereby reducing the tension in the struts but also decreasing the expanded diameter of the stent-like blood clot retriever.

[0007] In order for any device to achieve a high level of success in removing blood clots, restoring flow, and facilitating good patient outcomes, it is necessary to overcome the problems described above. Existing devices do not adequately address these problems. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEMS

[0008] It is an object of the present design to provide an apparatus and method that meet the above needs. The design described herein can include a wire-supported expandable catheter. The catheter can include a proximal elongate shaft including a distal end, a longitudinal axis, and a shaft braiding member having a plurality of braided wires. The catheter can include a distal tip section at the distal end of the elongate shaft. The distal tip section can have a collapsed delivery configuration, an expanded deployment configuration, and a longitudinal array of hoops. The plurality of braided wires of the proximal elongate shaft can be integrally formed with the array of hoops of the distal tip section. Each wire of the plurality of braided wires can branch from the final intersection of the shaft braiding member at the distal end of the proximal elongate shaft so as to form one of the hoops of the longitudinal array of hoops.

[0009] In some examples, the distal tip section can include a collapsed inner diameter in the collapsed delivery configuration, which can be smaller than the expanded inner diameter in the expanded deployment configuration.

[0010] In some examples, the wire of each hoop of the longitudinal array of hoops can be connected to the elongate shaft at the final intersection by a pair of axially extending hoop runners. In some examples, each pair of axially extending hoop runners can be evenly spaced around the longitudinal axis. In some examples, each hoop of the longitudinal array of hoops can branch radially from a pair of hoop terminations at the distal ends of each pair of axially extending hoop runners so as to extend circumferentially around the tip section.

[0011] In some examples, a first spacing between a pair of more proximal adjacent hoops of the longitudinal array of hoops can be different from a second spacing between adjacent hoops in a more distal pair of adjacent hoops. In some examples, each hoop of the longitudinal array of hoops can include a peak that is not distally connected and that moves distally when the distal tip section is folded into the collapsed delivery configuration.

[0012] In some examples, each hoop of the longitudinal array of hoops can define a plane perpendicular to the longitudinal axis of the elongated shaft.

[0013] In some examples, the longitudinal array of hoops defines a mouth having a curved profile.

[0014] The designs described herein include a catheter. The catheter can include a proximal elongated shaft including a distal end, a longitudinal axis, and a shaft braid member having a plurality of braided wires. In some examples, the catheter can include a distal tip section extending from the distal end of the elongated shaft. The distal tip section can include two sets of opposing ribs. A first rib of the two sets of opposing ribs can be formed from 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 can be formed from a second wire of the plurality of braided wires of the proximal elongated shaft. The first rib can be spaced approximately 180 degrees about the longitudinal axis from the second rib.

[0015] In some examples, the distal tip section can include a delivery configuration and a blood clot capture configuration. The distal tip section can have a smaller delivery inner diameter in the delivery configuration and can have a larger expanded inner diameter when the blood clot captured in the blood clot capture configuration radially impinges.

[0016] In some examples, the distal tip section can include a collapsed delivery configuration having a collapsed inner diameter and an expanded deployment configuration having an expanded inner diameter heat set to be larger than the collapsed inner diameter.

[0017] In some examples, each rib of the two sets of opposing ribs can have a peak that is not distally connected.

[0018] In some examples, the two sets of opposing ribs can be integrally formed with the plurality of braided wires of the shaft braid member.

[0019] In some examples, each of a plurality of braided wires can branch radially from a final intersection to form a V-shaped pattern.

[0020] In some examples, a plurality of pairs of opposing ribs can define a mouth having a curved profile.

[0021] The designs described herein can include a catheter. The catheter can include a proximal elongate shaft including a distal end, a longitudinal axis, and a shaft braiding member including a plurality of braided wires. The catheter can include a distal tip section at the distal end of the elongate shaft. The distal tip section can have a longitudinal array of offset hoops defining an inclined surface. The catheter can include a distal outer jacket surrounding the longitudinal array of offset hoops. The plurality of braided wires of the proximal elongate shaft can be integrally formed with the array of offset hoops. Each of the plurality of braided wires can branch from a final intersection and extend circumferentially around the tip section. The inclined surface can intersect the longitudinal axis at an acute angle.

[0022] In some examples, the distal tip section can have a collapsed delivery configuration having a collapsed inner diameter and an expanded deployment configuration having an expanded inner diameter heat set to be larger than the collapsed inner diameter.

[0023] In some examples, the distal tip section can have a larger expanded inner diameter when radially impacted by an entrapped blood clot in an expanded blood clot capture configuration and a smaller delivery inner diameter in the delivery configuration. In some examples, the distal tip section can have a substantially circular cross-section having a center radially offset from the longitudinal axis of the elongate shaft when in the expanded deployment configuration.

[0024] In some examples, the distal tip section can have a substantially circular cross-section having a center that substantially coincides with the longitudinal axis of the elongate shaft when in the expanded deployment configuration.

[0025] In some examples, the array of offset hoops can have peaks that move distally and are not distally connected when the distal tip section is folded into the collapsed delivery configuration.

[0026] In some examples, the array of offset hoops follows a curved profile circumferentially around the tip section.

[0027] In some examples, at least a portion of the outer perimeter of one hoop of the array of offset hoops can define a plane that passes through the longitudinal axis at an acute angle.

[0028] In some examples, the distal tip section can include a distal expansion portion configured to expand radially when taking in a blood clot.

[0029] In some examples, the array of offset hoops can define a mouth having a curved profile.

[0030] Other aspects of the present disclosure will become apparent by considering the following detailed description in conjunction with the accompanying figures. Additional features or manufacturing and use steps can be included as will be recognized and understood by those of ordinary skill in the art.

Brief Description of the Drawings

[0031] The above and further aspects of the present invention will be further considered with reference to the following description in conjunction with the accompanying drawings, in which like numbers in the various drawings indicate like structural elements and features. The drawings are not necessarily to scale, and instead, the focus is placed on illustrating the principles of the present invention. The figures depict one or more implementations of the device of the present invention by way of example and not limitation. Those skilled in the art are expected to envision and combine elements from the multiple figures to better suit the user's requirements.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9A

Figure 9B

Figure 9C

Figure 10

Figure 11

Figure 12

Figure 13A

Figure 13B

Figure 13C

DETAILED DESCRIPTION OF THE INVENTION

[0032] Here, specific embodiments of the present invention will be described in detail with reference to the drawings, where the same reference numerals indicate functionally similar or identical elements. The embodiments address many of the deficiencies associated with conventional blood clot retrieval aspiration catheters, such as inadequate or inaccurate deployment to the target site and ineffective blood clot removal.

[0033] The design of this specification can be for a clot retrieval catheter having a large internal lumen and a distal funnel-shaped tip that can self-expand to a diameter larger than the diameter of a coaxially delivered guide or sheath. The design can have a proximal elongated shaft for the catheter shaft and a distal tip having an expandable braided support structure and an outer polymer jacket for imparting atraumaticity to the tip. The braided support can be designed such that the expansion ability is variably concentrated in the axial portion of the tip section. The braid can be easily and repeatedly collapsed for delivery and expand for good clot acceptance and resistance under suction. The braid and tip design of the catheter can be sufficiently flexible to navigate very tortuous areas of the anatomical structure and recover its shape when displaced within a blood vessel to maintain the inner diameter of the lumen.

[0034] Accessing various vessels within a blood vessel, regardless of whether they are coronary, pulmonary, or cerebral vessels, involves well-known procedural steps and the use of numerous 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 with the devices and methods of the present invention in the following description, their functions and exact configurations are not described in detail. Also, these descriptions are often related to thrombectomy treatment in intracranial arteries, but the present disclosure can be similarly adapted to other procedures and other body passages.

[0035] Turning to the figures, FIG. 1 illustrates a possible sequence for approaching an occlusive clot 40 using the clot retrieval catheter 100 of the design disclosed herein. The clot 40 can be approached by the catheter 100 collapsed within a delivery guide sheath 30 or other outer catheter. For further distal navigation using the guide sheath 30, the catheter 100 can be deployed to move more independently distally when the vasculature 10 is too narrow and / or tortuous. The catheter 100 can be very flexible so as to be able to navigate through the neurovascular M1 or other tortuous regions to reach the occlusive clot.

[0036] The clot retrieval catheter 100 can have a flexible elongate shaft 110 that functions as a shaft having a large internal bore (which in some cases can be 0.070 inches or greater), and a distal tip section 210 having a collapsible support braided structure (see also the tip portions 310, 410, 510 described herein). The large bore serves to deliver the catheter to the target site in various ways. These can include over a microcatheter, over a guidewire, using a dilator / access tool, or by itself.

[0037] In most cases, the design of the collapsible funnel-shaped tip can be configured such that the catheter 100 can be delivered (and retrieved rearward) through a generally 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 to have a collapsed delivery outer diameter of about 0.086 inches. The tip can self-expand to an unconstrained position distal to the distal end 32 of the guide sheath 30 and can reach an expanded outer diameter of about 0.132 inches in size. So that the catheter can be delivered independently of remote occlusion, the distal section 210 (see also the tips 310, 410, 510 described herein) must be designed to be resistant to collapse from suction forces, have excellent lateral flexibility in both the expanded and collapsed states, and have a non-traumatic profile to prevent snagging on bifurcations within the blood vessel.

[0038] A more detailed view of the distal portion of the catheter 100 having the distal section 210 in the deployed configuration expanded as a funnel is shown in FIG. 2. The elongate shaft 110 can extend along the longitudinal axis 111. The distal end of the elongate shaft 110 can have a distal end 114, which can be proximate to the distal section 210. The elongate shaft 110 can include a braiding member 120. The braiding member 120 can be formed from a plurality of braiding wires 121 that wrap around the length of the elongate shaft 110. The plurality of braiding wires 121 of the braiding member 120 can function as a skeleton and support for the catheter 100 shaft. The intertwined weave of the plurality of braiding wires 121 can be any number of materials or patterns known in the art and can have varying densities and compositions along the length of the shaft. The distal tip section 210 at the distal end 114 of the elongate shaft 110 can have a collapsed delivery configuration and an expanded deployed configuration.

[0039] The distal tip section 210 can further include a longitudinal array of hoops 220 extending around the distal tip section 210. This longitudinal array of hoops 220 (also referred to herein as the hoops 220 or the array of hoops 220) can be formed continuously from a plurality of braided wires 121. For example, the plurality of braided wires 121 can be formed integrally with the array of hoops 220 of the distal tip section 210 such that the individual braided wires 121 extend continuously from the elongated shaft 110 to the distal tip section 210. Each wire of the plurality of braided wires 121 can branch from the final intersection 218 of the shaft braiding member 120 to form one of the hoops 220. In some examples, the catheter 100 can include hoop runners 221 extending between the final intersection 218 and the hoops 220. For example, at the final intersection 218 of two braided wires 121, the two braided wires 121 can bend longitudinally along the longitudinal axis 111 and extend a specific distance as two hoop runners 221 before branching to form a single hoop 220 that extends circumferentially around the tip section 210. This branch point of the two braided wires 121 for forming the hoop 220 can be referred to as the hoop end 223. Referring again to the hoop runners 221, the hoop runners 221 can provide a degree of pushability to the distal tip portion 210 because their longitudinal directions can resist axial forces when the catheter 110 is pushed through the target blood vessel. In some examples, each pair of axially extending hoop runners 221 can be evenly and circumferentially spaced around the longitudinal axis 111.

[0040] Referring to the array of hoops 220 of the distal tip section 210, the spacing between two adjacent hoops can vary depending on where the individual hoops are located on the distal tip section 210. For purposes of illustration, a first spacing 224 between a more proximal pair of adjacent hoops in the longitudinal array of hoops 220 can be different from a second spacing 226 between adjacent hoops in a more distal pair of adjacent hoops 220. In some examples, the second spacing 226 of adjacent hoops 220 near the distal end 214 of the distal tip section 210 can be made narrower than the first spacing 224 of adjacent hoops 220 that are more proximal. The narrower spacing at the distal end 214 of the distal tip section 210 can help improve blood clot retention and reduce the frangibility of the distal tip section 210 when the distal tip section 210 is in an expanded deployment configuration. In the expanded deployment configuration, each hoop of the longitudinal array of hoops 220 can define a plane perpendicular to the longitudinal axis 111 of the elongate shaft 110. Further, the longitudinal array of hoops 220 can form a series of rings concentric with the longitudinal axis 111 when the distal tip section 210 is in the expanded deployment configuration.

[0041] As described above, the distal tip section 210 can have an expanded deployment configuration and a collapsed delivery configuration. As will be described in more detail with reference to FIGS. 9A-9C, the distal tip section 210 can have a collapsed inner diameter 216 in the collapsed delivery configuration that is smaller than an expanded inner diameter 215 in the expanded deployment configuration. Each hoop of the longitudinal array of hoops 220 can include a peak 228 that is not distally connected and that moves distally when the distal tip section 210 is folded into the collapsed delivery configuration.

[0042] Figure 3 shows the distal portion of a blood clot retrieval catheter 100 having an expandable tip 310 according to an aspect of the present invention. The design shown in Figure 3 is similar to that shown in Figure 2, but involves variations in the shape and configuration of the distal tip section 310 (referred to as the distal tip section 210 in Figure 2). The example shown in Figure 3 can similarly include a proximal elongated shaft 110 having a distal end 114, a longitudinal axis 111, and a shaft braiding member 120 including a plurality of braided wires 121. The distal tip section 310 can extend from the distal end 114 of the elongated shaft 110. In the example shown in Figure 3, the distal tip section 310 can include two sets of opposing ribs 320 that flare outwardly from each other (e.g., open like a book) when the distal tip section 310 is in an expanded configuration. The first rib 320 from the two sets of opposing ribs 330 can be formed from the first wire 331 of the plurality of braided wires 121 of the proximal elongated shaft 110. The second rib 320 from the two sets of opposing ribs 332 can be formed from the second wire 333 of the plurality of braided wires 121 of the proximal elongated shaft 110. The first rib 330 can be spaced approximately 180 degrees around the longitudinal axis 111 from the second rib 332.

[0043] The plurality of braided wires 121 can be integrally formed with the plurality of sets of opposing ribs 320. For example, the individual braided wires 121 can extend continuously from the elongated shaft 110 to the distal tip section 310. The braided wires 121 of the proximal elongated shaft 110 can branch when transitioning to the distal tip section 310. Each wire of the plurality of braided wires 121 can branch 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 can extend partially around the distal tip section 310. Each rib of the two sets of opposing ribs 320 can include a peak 228 that is not distally connected at the distal end 314 of the distal tip section 310, as similarly shown in Figure 2.

[0044] FIG. 4 is an end elevation view of the distal portion of the blood clot retrieval catheter of FIG. 3, according to an aspect of the present invention. This figure provides a view of the expanded distal tip section 310 and the elongate shaft 110. The distal tip section 310 can have a delivery configuration and a blood clot capture configuration. The distal tip section 310 can have a smaller delivery inner diameter 115 in the delivery configuration and a larger expanded inner diameter 315 when radially impacted by a blood clot 40 captured in the blood clot capture configuration. In this example, the distal tip section 310 can expand when in contact with a blood clot. An example of this configuration is shown in FIGS. 13A-13C. Alternatively, the distal tip section 310 can have a collapsed delivery configuration with a collapsed inner diameter 216 and an expanded deployment configuration. The deployment configuration can be achieved by heat setting the material of the opposing ribs 320 such that it has an expanded inner diameter 215 that is larger than the collapsed inner diameter 216. An example of this configuration is shown in FIGS. 9A-9C.

[0045] FIG. 5 is a view showing the distal portion of a blood clot retrieval catheter 100 having an expandable tip that opens into an inclined surface 413, according to an aspect of the present invention. The catheter 100 can have a proximal elongate shaft 110 that includes a distal end 114, a longitudinal axis 111, and a shaft braid member 120 that includes a plurality of braided wires 121, similar to the design shown in FIGS. 2-4. The catheter 100 can include a distal tip section 410 at the distal end 114 of the elongate shaft 110. The distal tip section 410 is similar to the distal tip sections described above (e.g., distal tip sections 210 and 310), but has variations in shape and design. The distal tip section 410 can include a longitudinal array of offset hoops 420 that define an inclined surface 413. The inclined surface 413 that intersects the longitudinal axis 111 can form an acute angle 417 such that the most distal tip portion 414 of the distal tip section 410 is directed towards a target (e.g., a blood clot).

[0046] The distal tip portion 410 is offset from the longitudinal axis 111, and the membrane for the offset mouth (e.g., outer jacket 180) does not extend completely around the diameter of the distal tip section 410, which can help reduce the likelihood of tip collapse during suction compared to an expandable catheter with a mouth perpendicular to the longitudinal axis 111. The catheter 100 can further include an outer jacket 180 surrounding a longitudinal array of offset hoops 420. The plurality of braided wires 121 of the proximal elongate shaft 110 can be integrally formed with the array of offset hoops 420. Each wire of the plurality of braided wires 121 can branch from the final intersection 418, and beyond the final intersection 418, the plurality of braided wires 121 extend circumferentially around the tip section 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 circumferential curve profile around the distal tip section 410. The array of offset hoops 420 can include distally unconnected peaks 428 that move distally when the distal tip section 210 is folded into a collapsed delivery configuration.

[0047] FIG. 6 is an end elevation view of the distal portion of the clot retrieval catheter 100 of FIG. 5, according to an aspect of the present invention. The end view shows the offset of the distal tip section 410. In the expanded deployed configuration, the distal tip section 410 includes a substantially circular cross-section having a center 432 that is radially offset from the longitudinal axis 111 of the elongate shaft 110, i.e., the center 432 of the distal tip section 410 is offset from the center 117 of the elongate shaft 110. The distal tip section 410 can have a collapsed delivery configuration having a collapsed inner diameter 115 that is approximately equal to the diameter of the elongate shaft 110. The distal tip section 410 can have an expanded deployed configuration having an expanded inner diameter 415 that is heat set to be larger than the collapsed inner diameter 115.

[0048] FIG. 7 is a schematic view of a catheter 100 having a symmetrically opening distal portion according to an aspect 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 section 310 can have a substantially circular cross-section having a center 432 that substantially coincides with the longitudinal axis 111 of the elongate shaft 110. This is shown in the examples of FIGS. 3 and 4 (i.e., the distal tip section 310) and FIG. 2 (i.e., the distal tip section 210). FIG. 8 is a schematic view of a catheter 100 having an asymmetrically opening distal portion according to an aspect of the present invention. This figure shows that in some examples described herein, when the distal tip section 410 is in an expanded deployment configuration, it can have a substantially circular cross-section having a center 432 that is radially offset from the longitudinal axis 111 of the elongate shaft 110. This is shown in the examples of FIGS. 5 and 6 (i.e., the distal tip section 410). Thus, the funnel profiles 434 of FIGS. 7 and 8 have different shapes in the expanded deployment configuration.

[0049] FIGS. 9A-9C are schematic views showing a self-expanding catheter 100 used to capture a blood clot 40 according to an aspect of the present invention. The example shown in the schematic view shows a self-expanding distal tip section 210. This description can apply to the shape of any distal tip section herein, and the distal tip section has an expanded inner diameter 215 that is heat set to be larger than the collapsed inner diameter 216. In FIG. 9A, 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 proximate to the blood clot 40. In FIG. 9B, next, the distal tip section 210 is deployed from the guide sheath 30 and automatically expands to its expanded deployment configuration by heat setting to that configuration. In FIG. 9C, next, the distal tip section 210 is advanced to the blood clot 40 and suction can be applied through the elongate shaft 110 to retract the blood clot from the blood vessel 12.

[0050] FIG. 10 shows the distal portion of a blood clot retrieval catheter 100 having an expandable tip according to an aspect of the present invention. The example shown in FIG. 10 is substantially similar to the design shown in FIG. 3. However, in the design of FIG. 3, the distal tip section 310 can be considered a self-expanding design in that it is heat set to an expanded deployment configuration. Instead, the design of FIG. 10 includes a low-shear distal tip section 510 that expands when it contacts the blood clot 40. For example, the distal expansion portion 530 of the distal tip section 510 can maintain a nominal tip inner diameter 516 until the distal end 514 of the distal tip section 510 contacts the blood clot 40. When contacting the blood clot 40, the distal tip section 510 can advance while suction is provided to surround the blood clot 40 for retrieval. Otherwise, the design shown in FIG. 10 can include a final intersection 518 similar to the final intersection 318 of FIG. 3. Similar to the two sets of opposing ribs 320, it can include two sets of opposing ribs 520 that expand outward when contacting the blood clot 40. It can include a first rib 531 similar to the first rib 330. It can include a second rib 532 similar to the second rib 332. The opposing ribs 520 and the non-distally connected peak 528 similar to the non-distally connected peak 328 can include a V-shaped pattern 529 similar to the V-shaped pattern 329 of FIG. 3.

[0051] FIG. 11 shows the distal portion of a blood clot retrieval catheter 100 having an expandable tip according to an aspect of the present invention. The example shown in FIG. 11 is substantially similar to the design shown in FIG. 5. However, in the design of FIG. 5, the distal tip section 410 can be considered a self-expanding design in that it is heat-set to an expanded deployed configuration. Instead, the design of FIG. 11 includes a low-shear distal tip section 610 that expands during retrieval of the blood clot 40. For example, the distal expansion portion 630 of the distal tip section 610 can maintain a nominal tip inner diameter 616 until the distal end 614 of the distal tip section 610 contacts the blood clot 40. Upon contact with the blood clot 40, the distal tip section 610 can advance while suction is provided to surround the blood clot 40 for retrieval. Otherwise, the design shown in FIG. 11 can include a bevel angle 617 similar to the acute angle 417 of FIG. 5, can include a final intersection 618 similar to the final intersection 418, can include a longitudinal array of offset hoops 620 similar to the longitudinal array of offset hoops 620, and can include a non-distally connected peak 628 similar to the non-distally connected peak 428. The longitudinal array of hoops 620 can define a mouth having a curved profile 613. This curved profile 613 can also be present for the opposing ribs 320 (see FIG. 3) and the array of offset hoops 420 (see FIG. 5).

[0052] FIG. 12 is a cutaway view of the blood clot collection catheter 100 of FIG. 11 showing details of the outer jacket 180 according to an aspect of the present invention. The image is a cutaway view of FIG. 11, but it will be understood that the jacket 180 can be applied to any of the catheter 100 designs described herein. The jacket 180 can prevent proximal fluid from entering the expanded tip during aspiration and collection of blood clots, allowing for a more efficient direction of the suction force while preventing distal movement of blood clot fragments or other debris during the procedure. In one example, the jacket 180 can be formed from a highly elastic material such that when in the expanded deployed configuration, the radial force exerted by expanding the expandable tip is sufficient to stretch the membrane over the funnel-shaped contour of the tip. One example can be the use of a ductile elastomer, which has the advantage of being soft and flexible and having resistance to tearing and puncturing due to high fracture strain. Alternatively, the jacket 180 can be loosely fitted to the catheter 100 and can be folded over the edge of the distal tip section such that it can move more freely when the distal tip section is expanded and collapsed.

[0053] Figures 13A - 13C are schematic views showing a non - self - expanding catheter 100 used to capture a blood clot 40 according to an aspect of the present invention. The example shown in the schematic view shows a non - self - expanding distal tip section 510. This description can apply to any distal tip section described herein, where the distal tip section is not heat - set to have an expanded configuration, but instead, a distal expansion portion (e.g., expansion portion 430) expands to an expanded inner diameter 415 when it contacts the blood clot 40. The distal tip section 410 can have a larger expanded inner diameter 415 when radially impacted by the captured blood clot 40 in the expanded blood clot capture configuration and a smaller delivery inner diameter 115 in the delivery configuration. In Figure 13A, the catheter is deployed through the guide sheath 30 through the blood vessel 12 until the distal end 32 of the guide sheath 30 is close to the blood clot 40. At this point, the distal tip section 410 has a collapsed inner diameter 416. In Figure 13B, next, the distal tip section 510 is deployed from the guide sheath 30. In Figure 13C, the distal tip section 510 is then advanced to the blood clot 40, and the distal tip section 510 expands as the most distal tip portion 414 of the distal tip section 510 is advanced over the blood clot 40. Suction can be applied through the elongate shaft 110 to withdraw the blood clot 40 from the blood vessel 12.

[0054] The present invention is not necessarily limited to the described examples and can vary in its construction and details. The terms "distal" and "proximal" are used throughout the foregoing description and are intended to refer to the position and direction relative to the treating physician. Thus, "distal" or "distally" refers to a position away from or a direction away from the physician. Similarly, "proximal" or "proximally" refers to a position close to or a direction towards the physician. Further, unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" include plural referents.

[0055] As used herein, the term "about" or "substantially" with respect to any numerical value or numerical range indicates a preferred dimensional tolerance that allows a part of a component or a set of components to function for its intended purpose described herein. More specifically, "about" or "substantially" may refer to a range of values of ±20% of the recited value. For example, "about 90%" may refer to a range of values from 71% to 99%.

[0056] When describing exemplary embodiments, technical terms are used for clarity. As a result, not all possible combinations are listed, and such variations are often obvious to those skilled in the art and are intended to be within the scope of the following claims. Each term is intended to have its broadest meaning as understood by those skilled in the art and is intended to include all technical equivalents that act in a similar manner to achieve a similar purpose without departing from the scope and spirit of the present invention. It should also be understood that a reference to one or more steps of a method does not exclude the presence of additional method steps or method steps intervening between those explicitly identified. Similarly, some steps of a method can be performed in an order different from that described herein without departing from the scope of the disclosed technology.

[0057] 〔Embodiment〕 (1) A catheter comprising a proximal elongated shaft comprising a distal end, a longitudinal axis, and a shaft braiding member comprising a plurality of braided wires, a distal tip section at the distal end of the elongated shaft, the distal tip section comprising a collapsed delivery configuration, an expanded deployment configuration, and a longitudinal array of hoops, the plurality of braided wires of the proximal elongated shaft being integrally formed with the array of hoops of the distal tip section, Each wire of the plurality of braided wires branches from the final intersection of the shaft braiding member at the distal end of the proximal elongate shaft so as to form one of the hoops of the longitudinal array of hoops of the catheter. (2) The catheter according to embodiment 1, wherein the distal tip section further comprises a collapsed inner diameter in the collapsed delivery configuration that is smaller than the expanded inner diameter in the expanded deployment configuration. (3) The catheter according to embodiment 1, wherein the wires of each hoop of the longitudinal array of hoops are connected to the elongate shaft at the final intersection by a pair of axially extending hoop runners. (4) The catheter according to embodiment 3, wherein each pair of axially extending hoop runners are equally spaced about the longitudinal axis. (5) The catheter according to embodiment 3, wherein each hoop of the longitudinal array of hoops branches radially from a pair of hoop terminations at the distal ends of each pair of axially extending hoop runners so as to extend circumferentially around the tip section.

[0058] (6) The catheter according to embodiment 1, wherein a first spacing between a first pair of adjacent hoops of the longitudinal array of hoops is different from a second spacing between adjacent hoops within a second pair of adjacent hoops that are more distal. (7) The catheter according to embodiment 6, wherein each hoop of the longitudinal array of hoops comprises a peak that is not distally connected and that moves distally when the distal tip section is folded into the collapsed delivery configuration. (8) The catheter according to embodiment 1, wherein each hoop of the longitudinal array of hoops defines a plane perpendicular to the longitudinal axis of the elongate shaft. (9) A catheter comprising a proximal elongate shaft having a distal end, a longitudinal axis, and a shaft braiding member comprising a plurality of braided wires; a distal tip section extending from the distal end of the elongate shaft and comprising two sets of opposing ribs. Of the two sets of opposing ribs, a first rib is formed from a first wire of the plurality of braided wires of the proximal elongate shaft, and a second rib of the two sets of opposing ribs is formed from a second wire of the plurality of braided wires of the proximal elongate shaft, the first rib being spaced approximately 180 degrees around the longitudinal axis from the second rib, a catheter. (10) The distal tip section further includes a delivery configuration and a blood clot capture configuration, The distal tip section has a smaller delivery inner diameter in the delivery configuration and a larger expanded inner diameter when a blood clot captured in the blood clot capture configuration radially impinges, the catheter of embodiment 9.

[0059] (11) The distal tip section further includes a collapsed delivery configuration having a collapsed inner diameter and an expanded deployment configuration heat set to have an expanded inner diameter larger than the collapsed inner diameter, the catheter of embodiment 9. (12) Each rib of the two sets of opposing ribs includes a peak not connected distally, the catheter of embodiment 9. (13) The two sets of opposing ribs are integrally formed with the plurality of braided wires of the shaft braiding member, the catheter of embodiment 9. (14) Each wire of the plurality of braided wires branches radially from a final intersection to form a V-shaped pattern, the catheter of embodiment 9. (15) A catheter comprising: a proximal elongate shaft having a distal end, a longitudinal axis, and a shaft braiding member comprising a plurality of braided wires; a distal tip section at the distal end of the elongate shaft, the distal tip section comprising a longitudinal array of offset hoops defining an inclined surface; and a distal outer jacket surrounding the longitudinal array of offset hoops. The plurality of braided wires of the proximal elongated shaft are integrally formed with the array of offset hoops, and each wire of the plurality of braided wires branches from a final intersection and extends circumferentially around the tip section. The inclined surface intersects the longitudinal axis at an acute angle, catheter.

[0060] (16) The distal tip section further includes a collapsed delivery configuration having a collapsed inner diameter and an expanded deployment configuration having an expanded inner diameter heat-set to be larger than the collapsed inner diameter, the catheter according to embodiment 15. (17) The distal tip section further comprises a larger expanded inner diameter when radially impacted by an entrapped blood clot in an expanded blood clot capture configuration and a smaller delivery inner diameter in a delivery configuration, the catheter according to embodiment 15. (18) In the expanded blood clot capture configuration, the distal tip section further comprises a substantially circular cross-section having a center radially offset from the longitudinal axis of the elongated shaft, the catheter according to embodiment 17. (19) The array of offset hoops comprises a peak not connected distally that moves distally when the distal tip section is folded into a collapsed delivery configuration, the catheter according to embodiment 15. (20) The array of offset hoops follows a curved profile circumferentially around the tip section, the catheter according to embodiment 15.

Claims

1. A catheter comprising: a proximal elongate shaft having a distal end, a longitudinal axis, and a shaft braid member comprising a plurality of braided wires; a distal tip section at the distal end of the elongate shaft, the distal tip section comprising a collapsed delivery configuration, an expanded deployment configuration, and a longitudinal array of hoops; the plurality of braided wires of the proximal elongate shaft being integrally formed with the array of hoops of the distal tip section; a catheter, wherein each wire of the plurality of braided wires branches from a final intersection of the shaft braid member at the distal end of the proximal elongate shaft so as to form one of the hoops of the longitudinal array of hoops.

2. The catheter according to claim 1, wherein the distal tip section further comprises a collapsed inner diameter in the collapsed delivery configuration that is smaller than an expanded inner diameter in the expanded deployment configuration.

3. The catheter according to claim 1, wherein the wire of each hoop of the longitudinal array of hoops is connected to the elongate shaft at the final intersection by a pair of axially extending hoop runners.

4. The catheter according to claim 3, wherein each pair of axially extending hoop runners is equally spaced about the longitudinal axis.

5. The catheter according to claim 3, wherein each hoop of the longitudinal array of hoops branches radially from a pair of hoop terminations at the distal ends of a pair of axially extending hoop runners so as to extend circumferentially around the tip section.

6. The catheter according to claim 1, wherein a first spacing between a first pair of adjacent hoops of the longitudinal array of hoops is different from a second spacing between adjacent hoops within a second pair of adjacent hoops that are more distal.

7. The catheter according to claim 6, wherein each hoop of the longitudinal array of hoops comprises a peak that is not distally connected and that moves distally when the distal tip section is folded into the collapsed delivery configuration.

8. The catheter according to claim 1, wherein each hoop of the longitudinal array of hoops defines a plane perpendicular to the longitudinal axis of the elongate shaft.

9. A catheter comprising: a proximal elongate shaft having a distal end, a longitudinal axis, and a shaft braid member comprising a plurality of braided wires; 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 from 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 from a second wire of the plurality of braided wires of the proximal elongated shaft, and the first rib is spaced approximately 180 degrees around the longitudinal axis from the second rib. A catheter. **Claim 10** The distal tip section further includes a delivery configuration and a blood clot capture configuration. The distal tip section has a smaller delivery inner diameter in the delivery configuration and a larger expanded inner diameter when a blood clot captured in the blood clot capture configuration radially collides. The catheter according to claim 9. **Claim 11** The distal tip section further includes a collapsed delivery configuration having a collapsed inner diameter and an expanded deployment configuration heat set to have an expanded inner diameter larger than the collapsed inner diameter. The catheter according to claim 9. **Claim 12** Each rib of the two sets of opposing ribs includes a peak that is not distally connected. The catheter according to claim 9. **Claim 13** The two sets of opposing ribs are integrally formed with the plurality of braided wires of the shaft braiding member. The catheter according to claim 9. **Claim 14** Each wire of the plurality of braided wires branches radially from a final intersection to form a V-shaped pattern. The catheter according to claim 9. **Claim 15** A catheter comprising: A proximal elongated shaft having a distal end, a longitudinal axis, and a shaft braiding member comprising a plurality of braided wires; A distal tip section at the distal end of the elongated shaft, the distal tip section comprising a longitudinal array of offset hoops defining an inclined surface; A distal outer jacket surrounding the longitudinal array of offset hoops; The plurality of braided wires of the proximal elongated shaft are integrally formed with the array of offset hoops, and each wire of the plurality of braided wires branches from a final intersection and extends circumferentially around the tip section. The inclined surface intersects the longitudinal axis at an acute angle. A catheter. **Claim 16** The catheter according to claim 15, wherein the distal tip section further includes a collapsed delivery configuration having a collapsed inner diameter and an expanded deployment configuration having an expanded inner diameter heat set to be larger than the collapsed inner diameter. **Claim 17** The catheter according to claim 15, wherein the distal tip section further comprises a larger expanded inner diameter when radially impacted by an entrapped blood clot in an expanded blood clot capture configuration and a smaller delivery inner diameter in the delivery configuration. **Claim 18** The catheter according to claim 17, wherein in the expanded blood clot capture configuration, the distal tip section further comprises a substantially circular cross-section having a center radially offset from the longitudinal axis of the elongate shaft. **Claim 19** The catheter according to claim 15, wherein the array of offset hoops comprises peaks not connected distally that move distally when the distal tip section is folded into the collapsed delivery configuration. **Claim 20** The catheter according to claim 15, wherein the array of offset hoops follows a curved profile circumferentially around the tip section.

Images