Systems and methods for intravascular obstruction removal

Abstract

An endovascular device and a method for removing obstructions from a blood vessel using the endovascular device are provided. The endovascular device may include a flexible shaft and an expandable filament mesh structure extending from the flexible shaft. The filament mesh structure includes at least one first expandable segment having a first filament arrangement pattern and at least one second expandable segment having a second filament arrangement pattern different from the first filament arrangement pattern. Furthermore, the gaps in the at least one first expandable segment and the gaps in the at least one second expandable segment may be different in size.

Description

[0001] priority This application claims priority to U.S. Provisional Application No. 62 / 112,862, filed February 6, 2015, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates to intravascular and / or intraluminal medical devices and systems configured to remove obstructions from human blood vessels. The disclosure also relates to methods for removing obstructions from human blood vessels. Summary of the Invention

[0003] This disclosure describes an endovascular and / or endoluminal medical device for retrieving obstructions from human blood vessels. The obstruction may be a blood clot (originating from an embolism or thrombosis). The device may be constructed from an expandable wire mesh structure extending from an elongated axis. This expandable wire mesh structure can utilize different wire arrangement patterns to create a structure with variable gap sizes and / or one or more expandable segments. As a result, when the device expands alongside or within the clot within the blood vessel, the clot can penetrate the wire mesh due to the large gaps, and then be retained within the wire mesh when it is retracted. In other words, the wire mesh can provide a sufficiently large opening to allow expansion through the clot when a radial force is applied to the clot. In some embodiments, the wire mesh can provide a sufficiently small opening to retain the clot during clot retraction when an axial force is applied to the clot. The wire arrangement pattern can be such that the gaps in the distal and proximal ends of the wire mesh can be smaller than at least some of the gaps more centrally located. However, other arrangement patterns may also be used. For example, other arrangement patterns may also be used. For example, the device can be made from only two types of thread arrangement patterns, with the distal thread arrangement pattern having a relatively small opening or gap, and the proximal thread arrangement pattern having a relatively large opening or gap. Attached Figure Description

[0004] Embodiments are illustrated in conjunction with the accompanying drawings, which are incorporated in and form part of this specification, and together with the description, serve to illustrate the features, advantages, and principles of the disclosed embodiments.

[0005] Figure 1 An expandable wire mesh structure with varying wire arrangements to produce gaps of different sizes is described according to the disclosure. Figure 2 The disclosed content depicts an alternating arrangement of woven and straight silk threads in a mesh pattern. Figure 3 An expandable wire mesh structure with alternating braided and intertwined thread connections is depicted according to the disclosure; Figure 4An enlarged view of the intertwined segment that produces a large gap, according to the disclosed content, is shown; Figure 5 The illustration shows a 1×1 weave arrangement transitioning to a 1×3 weave arrangement according to the disclosure; Figure 6 The illustration shows another weaving arrangement based on the disclosed content; Figure 7 A to Figure 7 Figure F illustrates the components of a woven arrangement 7G with uniform gaps; Figure 8 A to Figure 8 Figure F illustrates the transition to a 1×3 woven layout based on the disclosed content. Figure 8 G) is a component of a 1×1 weaving arrangement; Figure 9 A to Figure 9 Figure F illustrates the transition to a 3x3 woven layout based on the disclosed information. Figure 9 G) is a component of a 1×1 weaving arrangement; Figure 10 A to Figure 10 Diagram D illustrates the transition to a 1×2 woven layout based on the disclosed content. Figure 10 E) is a component of the 1×1 weave pattern; Figure 11 A to Figure 11 Diagram D illustrates the transition to a 2×2 woven layout based on the disclosed information. Figure 11 E) is a component of the 1×1 weave pattern; Figure 12 A to Figure 12 Diagram D illustrates the transition to a 1×4 woven layout based on the disclosed information. Figure 12 E) is a component of the 2×2 weave arrangement; Figure 13 The illustration shows an expandable wire mesh made of cable reel threads according to the disclosure; and Figure 14 The illustration shows the clot recovery process based on the disclosure. Detailed Implementation

[0006] One or more embodiments will now be described in detail, and the features of these embodiments are illustrated in the accompanying drawings. Where possible, the same reference numerals are used in all the drawings to denote the same or similar elements.

[0007] Figure 1 The wire mesh structure associated with the expandable wire mesh structure 100 is described. Figure 1The wire mesh structure depicted includes different wire arrangements that can create gaps of different sizes when the expandable wire mesh structure 100 is in an expanded state. For example, when the expandable member 100 is in an expanded state, the gap 110 in the expandable wire mesh structure 100 can be larger than the gap 105 in the expandable wire mesh structure 100. Additionally, the wires of the expandable wire mesh structure 100 can be used to create cable reels, such as cable reels 90.

[0008] In some implementations, the gap in the first expandable section may differ in size from the gap in the second expandable section by a predetermined amount. For example, the gap in the second expandable section may be approximately three, five, ten, or twenty times larger than the gap in the first expandable section.

[0009] It should be noted that the present invention is not limited to devices with only two types of thread arrangements; alternating thread arrangements can also be used to create structures with openings of different sizes. For example, one embodiment of the device can be made of alternating braided threads and a section of straight or non-braided thread. Figure 2 In this structure, the braided portion between straight yarn segments can serve as a stabilizer, holding the yarns together. Additionally, it can create boundaries between large openings. Specifically, Figure 2 An expandable mesh structure 200 with alternating mesh arrangements is depicted. For example, region 215 of the expandable mesh structure 200 may include braided threads, while region 220 of the expandable mesh structure 200 may include straight (or aligned parallel) threads.

[0010] In yet another embodiment, multiple threads in a large gap section can be intertwined to create even larger openings. Figure 3 This is an illustration of an expandable wire mesh structure 300, in which each pair of threads intertwines between braided sections, resulting in a larger opening. In this embodiment, if particles break and flow to the distal side during the retraction process, the distal braided sections also function as filters. Specifically, in Figure 3 In the depicted embodiment, the expandable mesh structure 300 is shown as having a braided region 324 that transitions to an intertwined region 331 (with intertwined yarn pairs) and then is shown as transitioning (or alternating) back to a braided region 326. When the expandable mesh structure 300 is in an expanded state, the gap 325 may be smaller than the gap 330.

[0011] Figure 4 A close-up view of the expandable wire mesh structure 400 (when in the expanded state) is depicted. Figure 4 As shown, the gap 440 (related to the area of ​​intertwined yarns) can be larger than the gap 435 (related to the weaving arrangement).

[0012] Furthermore, different weave patterns can be used to create different gaps. For example, 1×1 (one thread on one strand) can be used in low-density sections, while 3×1 (three threads on one strand) can be used in sections with larger gaps. Figure 5 Other weaving examples include (but are not limited to) 2×2 (two threads on two strands) with three intertwined yarns, or 2×2 with 4×1, or 1×1 with 3×3. Figure 6 ).

[0013] More specifically, Figure 5 An expandable wire mesh structure 500 is depicted, which includes a 1×1 weave arrangement (in region 545) transitioning to a 1×3 weave arrangement (in region 550). Figure 5 As shown, the gap in region 550 can be larger than the gap in region 545. Figure 6 An expandable mesh structure 600 is depicted, which includes a 1×1 braided arrangement throughout. However, when the expandable mesh structure 600 is in an expanded state, the gaps in region 660 can be larger than the gaps in region 655.

[0014] Figure 7 It depicts pairs of continuously braided threads ( Figure 7 A is related to 701. Figure 7 B is related to 711. Figure 7 C for 721, Figure 7 D is related to 731. Figure 7 E for 741 and Figure 7 (pair 751 in F), together they constitute the expandable wire mesh structure 700 ( Figure 7 The woven fabric with uniform spacing 765 is depicted in G). In the expanded state, the expandable mesh structure 700 includes hollow areas (in... Figure 7 (It is shown as a cylindrical shape). Figure 7 (as well as Figures 8 to 12 The dashed line in ) corresponds to (when from Figure 7 The continuous filaments (as shown in the "front" view) fall into the "back" part of the hollow section.

[0015] Figure 8 It depicts pairs of continuously braided threads ( Figure 8 A is related to 802. Figure 8 B is related to 812. Figure 8 C for 822, Figure 8 D contains 832, Figure 8 E for 842 and Figure 8 (for example, in F, pair 852), together they constitute the transition to... Figure 8The 1×3 weave arrangement depicted in the expandable wire mesh structure 800 of G is a 1×1 weave arrangement. For example... Figure 8 As shown in G, when the expandable wire mesh structure 800 is in an expanded state, the gap 870 can be larger than the gap 765.

[0016] Figure 9 It depicts pairs of continuously braided threads ( Figure 9 A is related to 901. Figure 9 B is related to 913. Figure 9 C for 923, Figure 9 D contains 933, Figure 9 E for 943 and Figure 9 (referring to 953 in F), together they constitute the transition to in Figure 9 The 3×3 braided arrangement and 1×1 braided arrangement depicted in the expandable wire mesh structure 900 of G are shown. For example... Figure 9 As shown in G, when the expandable wire mesh structure 900 is in an expanded state, the gap 980 can be larger than the gap 765.

[0017] Figure 10 It depicts pairs of continuously braided threads ( Figure 10 A contains 1004, Figure 10 B contains 1014, Figure 10 In C, 1024, Figure 10 (1034 in D), together they constitute the transition to Figure 10 The 1×2 braided arrangement depicted in the expandable wire mesh structure 1000 of E is a 1×1 braided arrangement. For example... Figure 10 As shown in E, when the expandable wire mesh structure 1000 is in an expanded state, the gap 1090 can be larger than the gap 1085.

[0018] Figure 11 It depicts pairs of continuously braided threads ( Figure 11 A contains 1106, Figure 11 B is related to 1116. Figure 11 C contains 1126, Figure 11 (pair 1136 in D), together they constitute the transformation in Figure 11 The 2×2 braided arrangement and the 1×1 braided arrangement depicted in the expandable wire mesh structure 1100 of E are as follows: Figure 11 As shown in E, when the expandable wire mesh structure 1100 is in an expanded state, the gap 1191 can be larger than the gap 1085.

[0019] Figure 12 It depicts pairs of continuously braided threads ( Figure 12 A contains 1207, Figure 12 B is related to 1217. Figure 12 C contains 1227, Figure 12 (pairs 1237 in D), together they constitute the transformation in Figure 12 The expandable wire mesh structure 1100 of E depicts a 1×4 braided arrangement and a 2×2 braided arrangement. For example... Figure 12 As shown in E, when the expandable wire mesh structure 1200 is in an expanded state, the gap 1191 can be larger than the gap 1292.

[0020] In another embodiment, a larger gap can be created by keeping the same mesh arrangement (e.g., one wire on one wire) but changing the intersection angle. In yet another option, a larger gap can be achieved by reducing the number of wires in a certain part of the arrangement (e.g., by terminating multiple wires at the end of a first section).

[0021] Additionally, in some embodiments, each expandable segment can be configured to expand to a different outer diameter. For example, a first expandable segment can be configured to expand to an outer diameter smaller than the outer diameter of the second expandable segment when it expands. That is, as each segment of the device expands, the device can have multiple different outer diameters along the length of the device.

[0022] Furthermore, expandable segments with different expansion outer diameters can be arranged relative to each other in any desired order along the length of the device. For example, in one embodiment, a first type of expandable segment can be located between a plurality of second type expandable segments. This arrangement can result in an expandable structure with at least two peaks and one valley. However, other arrangements can result in expandable structures with other numbers of peaks and valleys due to expandable segments of different diameters. For example, there can be three valleys and two peaks, or four valleys and three peaks. More generally, there can be one more valley than peak. Alternatively, there can be an equal number of peaks and valleys. Or, there can be one more peak than valley.

[0023] Furthermore, individual filaments can differ from one another in terms of properties, materials, diameter, shape, cross-sectional shape, and radiopaqueness. For example, a single platinum filament can be used to construct a structure visible under a fluorescence microscope, while other filaments can be made of less visible materials, such as nickel. In various embodiments, polymer filaments can be combined with metal filaments to achieve structures with desired mechanical properties. Additionally, flat filaments can be used to reduce the overall profile of the device, or round filaments can be used for better kink resistance. However, the above disclosures allow for the combination of any type of filament from any material, size, and shape. Furthermore, the filaments can be coated or covered. Coating may be desirable to facilitate the delivery of the structure through tight microcatheters. Additionally, the filaments can be coated with drugs to influence treatment or increase adhesion to clots. Finally, segments with small gaps can be coated with an external polymer or other covering to allow for even greater protection of distal showers.

[0024] The expandable mesh can also extend from an elongated shaft. This shaft can be long enough to transport and control the mesh from outside the body. The shaft can be made with a rigid portion at its proximal end to enhance pushing ability and stability, while a flexible portion can be made at its distal end. This distal end can be connected to the expandable mesh at its distal end. The more rigid proximal end can be made of a hollow metal tube or a reinforced polymer structure. The distal end and / or proximal end can also be formed of a reinforced polymer structure with more flexible properties. Alternatively, it can be formed from cut metal tubes. Furthermore, it can be formed, for example, from strands of wire arranged to coil around an assembly, like a cable. If the latter cable-like assembly is used, the wires of the cable can also be used to form the expandable mesh structure. In this case, the connection between the shaft and the expandable portion may no longer be necessary. As a result, the device can be manufactured very flexibly, thus simplifying the assembly process. Figure 13 ). Specifically, Figure 13 An expandable wire mesh 1300 formed from the threads of a cable reel (such as reel 90) is shown.

[0025] There are different ways to expand the expandable wire mesh component extending from the axis described above. One possibility is to make it self-expanding by setting its structure to an expanding shape. If the device is made of metal wire such as nickel, this can be achieved through heat treatment.

[0026] Another alternative is to use one or more pull or control threads that can be connected to the expandable member. These threads can pass through the flexible portion of the shaft and extend to the proximal portion of the shaft, and the mesh member can expand when a force (e.g., tension) is applied to the pull or control threads. In one embodiment, only one core thread can be used and connected to the expandable member at its distal end. In this case, the threads of the expandable member can terminate in a coiled structure. The pull thread can be connected to the coiled structure at the distal end of the expandable member. When the pull thread is pulled, it can cause all the threads of the expandable member to expand, thereby expanding the expandable member. Alternatively, the threads of the expandable member can terminate in other ways. For example, they can be arranged parallel at the distal end. In yet another embodiment, one or more threads can be bent back and themselves serve as pull threads.

[0027] In some implementations, pull-type filament replacement schemes may offer several advantages over self-expanding filaments. First, unlike self-expanding options that can be preset, the amount of expansion can be controlled through use (the greater the pull, the greater the distal expansion). This can be advantageous, for example, if clots are retrieved through vessels of different diameters. Additionally, delivery through tight microcatheters may be easier because the device can be delivered in a non-expanded state. Another additional alternative to expansion of the expandable member is utilizing temperature changes or an electric current that causes the filament to alter its mechanical properties.

[0028] As described above, the disclosed device can be used to remove blockages from blood vessels. Such blockages can be blood clots of various origins, but are not limited to these. For example, the blockage could also be plaque from a foreign object. Alternatively, the device can be sized for use in a catheter rather than in a blood vessel.

[0029] One embodiment of the method for removing an obstruction from a blood vessel using the disclosed device may include inserting a device having an expandable structure into the blood vessel. The expandable segment may include at least one end region with a gap, the gap of which is at most one-third the size of the gap in the central region. The expandable structure can then be positioned in a desired location. For example, the expandable structure can be moved such that at least the central region coincides with the obstruction (e.g., aligned with the obstruction, adjacent to the obstruction, completely within the obstruction, or partially within the obstruction). Once aligned, the expandable structure can be expanded, for example by pulling or controlling a suture, to embed some or all of the obstruction in the central region. The expandable structure containing the embedded obstruction can then be withdrawn from the blood vessel.

[0030] Figure 14The figure illustrates one implementation of a method for clearing blockages from blood vessels. However, it should be noted that although the method is illustrated in the context of clearing clots from cerebral blood vessels, in other embodiments, the device can also be used to clear various other types of blockages. In one embodiment, the method of using the device may include one or more of the following aspects: 1) Imaging can be used to identify the location of clots. For example, Figure 14 A depicts a clot 1408 located in blood vessel 1409, where the clot 1408 obstructs blood flow.

[0031] 2) Using minimally invasive catheter insertion techniques, an 8Fr guiding catheter can be placed at the internal carotid artery.

[0032] 3) Place the 3FRr microcatheter, guided by the guidewire, on both sides of the clot (the tip of the microcatheter can be positioned distally relative to the clot). For example... Figure 14 As shown in Figure B, the microcatheter 1415 can be advanced into the blood vessel 1409 to reach the clot 1408, so that the opening of the microcatheter 1415 is located on the distal side of the clot 1408.

[0033] 4) Remove the guidewire while keeping the microcatheter in place.

[0034] 5) Advance the expandable member through the microcatheter. An axis can be used to advance the expandable mesh to the tip of the microcatheter. For example, this can be achieved by... Figure 14 The microcatheter 1415 shown in C delivers the expandable member 1417 (in its unexpanded state) to the clot 1408.

[0035] 6) While the expandable member is held in place (its tip is at the distal end of the clot), the microcatheter is pulled back, resulting in the expandable member being unsheathed next to the clot.

[0036] 7) The pull wire can be pulled to expand the expandable member. The user can select the amount of expansion necessary to penetrate the clot. For example, expandable member 1417 can be... Figure 14 As shown in Figure D, it expands through clot 1408.

[0037] 8) It can inflate the balloon guiding catheter and aspirate the guiding catheter to reverse blood flow.

[0038] 9) Both the microcatheter and the expandable component can be retracted. When pulling the device through a larger blood vessel, the user may need to expand the expandable component. The expandable component and microcatheter can be retracted via a guide catheter. Figure 14 As shown in E, the expandable member 1417 and the block 1408 can then be retrieved.

[0039] In addition to the uses described above, this expandable component can also be used to retrieve other foreign substances from body cavities. For example, it can be used to retrieve pulmonary embolisms, kidney stones, etc.

[0040] Additionally, in some embodiments, the device may include a flexible shaft made of 12 threads. In this embodiment, six of the threads may be arranged clockwise, while the other six may be arranged counterclockwise.

[0041] In some implementations, the non-woven sections of the expandable member may include intertwined pairs.

[0042] In some implementations, these threads do not intersect substantially in the non-woven sections of the expandable member.

[0043] In some implementations, different types of weaving can be used in the same expandable member.

[0044] The following technical description is exemplary and is not intended to limit the embodiments of the present invention described above.

[0045] Intravascular devices (or intraluminal expandable components) include any expandable component that can be inserted into a lumen, catheter, or blood vessel.

[0046] A wire mesh structure includes any structure that is at least wholly or partially made of wire, regardless of whether the structure is made of metal, polymer or any other material.

[0047] A thread arrangement pattern is the configuration of the threads. In its broadest sense, the pattern need not have any regular rhythm. In some implementations, the configuration may include repetition; in others, it may have no repetition at all.

[0048] A gap includes any interstitial space, such as any form of void, space, hole, partition, or slit.

[0049] Woven fabrics are structures such as those with multiple strands of yarn that overlap or interweave diagonally in spinning or weaving.

Claims

1. An intraluminal device, the intraluminal device comprising: Flexible shaft; and An expandable filament mesh structure is formed by an arrangement of filaments extending from the flexible shaft. The expandable filament mesh structure includes at least one first expandable section having a first filament arrangement pattern and at least one second expandable section having a second filament arrangement pattern different from the first filament arrangement pattern. Wherein, due to the difference between the first filament arrangement pattern and the second filament arrangement pattern, the gap size in the at least one first expandable segment is different from the gap size in the at least one second expandable segment; Wherein, at least a portion of the at least first expandable segment is woven, and at least a portion of the at least second expandable segment is non-woven; Wherein, the at least one second expandable section comprises at least two non-woven sections spaced apart by woven sections; and The flexible shaft comprises multiple strands of continuous coiled filaments, and the expandable filament mesh structure is formed by the filaments.

2. The intraluminal device according to claim 1, wherein, The at least one first expandable section includes at least two woven sections spaced apart by non-woven sections.

3. The intraluminal device according to claim 1 or 2, wherein, The gap of the at least one second expandable section in the non-woven fabric is greater than the gap of the at least one first expandable section in the woven fabric.

4. The intraluminal device according to claim 1, wherein, The multi-strand yarns include yarns with different cross-sectional shapes.

5. The intraluminal device according to claim 1, wherein, The multi-stranded threads include threads made of different materials.

6. The intraluminal device according to claim 1, wherein, The multi-strand filament includes at least one filament, the at least one filament having a different radiopaqueness from at least one other filament in the multi-strand filament.

7. The intraluminal device according to any one of claims 1 to 2, further comprising a control wire extending through the flexible shaft and the expandable filament mesh structure, the expandable filament mesh structure being configured to apply force to the control wire to expand the expandable filament mesh structure.

8. The intraluminal device according to claim 1, wherein, The gap in the at least one second expandable segment is at least three times larger than the gap in the at least one first expandable segment.

9. The intraluminal device according to claim 1, wherein, The gap in the at least one second expandable segment is at least five times larger than the gap in the at least one first expandable segment.

10. The intraluminal device according to claim 1, wherein, The at least one second expandable segment has a larger gap than the at least one first expandable segment, and wherein the expandable filament mesh structure has the filament arrangement pattern of the first expandable segment at its opposite proximal and distal ends.

11. The intraluminal device according to claim 1, wherein, During expansion, the at least one second expandable segment has an outer diameter larger than that of the at least one first expandable segment.

12. The intraluminal device according to claim 11, wherein, The at least one second expandable segment includes a plurality of second expandable segments, and at least one first expandable segment is located between the plurality of second expandable segments, thereby obtaining an expandable structure having at least two peaks and one valley.

13. The intraluminal device according to claim 11, wherein, The at least one first expandable segment includes a plurality of first expandable segments, and wherein the at least one second expandable segment includes a plurality of second expandable segments, and wherein each second expandable segment is located between two first expandable segments, thereby obtaining an expandable structure having a plurality of peaks and a plurality of valleys.

14. The intraluminal device according to claim 1, wherein, The gap in the at least one second expandable segment is at least ten times larger than the gap in the at least one first expandable segment.

15. The intraluminal device according to claim 1, wherein, The gap in the at least one second expandable segment is twenty times larger than the gap in the at least one first expandable segment.

16. The intraluminal device according to claim 1, wherein, The threads of the at least one first expandable segment are woven according to a first weaving pattern, and the threads of the at least one second expandable segment are woven according to a second weaving pattern, the difference between the first weaving pattern and the second weaving pattern causing the gap size in the at least one first expandable segment to be different from the gap size in the at least one second expandable segment.

17. The intraluminal device according to claim 1, wherein, The difference between the first and second silk thread arrangement patterns is that, compared to the silk threads forming the first silk thread arrangement pattern, the silk threads forming the second silk thread arrangement pattern are intertwined.

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