阅读说明：本技术 血管内血栓栓塞切除术装置和方法 (Intravascular thromboembolic ablation device and method ) 是由 迈克尔·P·马克斯 莉凯·桂 蒂莫西·约翰·孔科尔 于 2018-09-10 设计创作，主要内容包括：用于增加或恢复身体管腔中的流动的装置和方法。所述装置和方法可以通过从血管移除凝块来治疗例如中风等症状和/或重新打开血管。所述装置可以包括多个接合元件、中心丝和近侧控制元件。所述装置可以包括介于接合元件之间的联结结构。联结结构可以包括构造成在施加纵向载荷时不同地响应的区段。接合元件的位置和它们之间的距离可以同时或依次得到调节,以促进凝块或闭塞物的接合。所述装置可以包括构造成在拉动中心丝以向近侧拉动远侧接合元件时和/或在缩回保持着凝块的装置期间抑制或阻止近侧接合元件被拉回到微导管中。(Devices and methods for increasing or restoring flow in a body lumen. The devices and methods may treat symptoms such as stroke and/or reopen a blood vessel by removing a clot from the blood vessel. The device may include a plurality of engagement elements, a central wire, and a proximal control element. The device may include a coupling structure between the engagement elements. The coupling structure may include segments configured to respond differently upon application of a longitudinal load. The position of the engagement elements and the distance between them may be adjusted simultaneously or sequentially to facilitate engagement of the clot or occlusion. The device may include a wire configured to inhibit or prevent the proximal engaging element from being pulled back into the microcatheter when the wire is pulled to pull the distal engaging element proximally and/or during retraction of the device holding the clot.)

1. A device for removing an obstruction from a body lumen, the device comprising:

a central wire comprising a proximal end and a distal end;

an engagement element at or near a distal end of the central wire; and

a microcatheter at least partially housing the coaptation element during introduction into the body lumen,

wherein, when expanded after denesting from the microcatheter, the coaptation element is configured to inhibit recapturing of the coaptation element in the microcatheter upon application of at least one of a proximal force to the coaptation element or a distal force to the microcatheter.

2. The device of claim 1, wherein the proximal end of the engagement element comprises a stop configured to radially expand when the engagement element is un-sheathed from the microcatheter.

3. The device of claim 2, wherein the stop comprises a ring configured to flex radially outward when the engagement element is un-sheathed from the microcatheter.

4. The device of claim 2, wherein the stop comprises a helical spring wire configured to expand radially outward when the engagement element is un-sheathed from the microcatheter.

5. The device of claim 1, the coaptation element including a leg having a thickness configured to inhibit recapping of the coaptation element in the microcatheter when the leg has been expanded.

6. The device of claim 1, wherein the legs of the coaptation element are angled between 30 ° and 90 ° relative to the longitudinal axis of the microcatheter when the legs have been expanded.

7. The device of claim 1, wherein the engagement element comprises a wire or a strut.

8. The device of claim 1, wherein the coupling element is self-expandable upon uncapping the microcatheter.

9. The device of claim 1, wherein the engagement element is configured to inhibit recapping of the microcatheter upon application of between 50 grams and 450 grams of proximal force.

10. The device of any one of claims 1-9, further comprising a second engaging element located distal to the engaging element.

11. The device according to claim 10, wherein the second engagement element is fixedly attached to a distal end of the central wire.

12. The device of claim 11, wherein the engagement element is slidable on the central wire.

13. The device of claim 10, comprising a coupling connector coupled to the engagement element and the second engagement element, the coupling connector spacing the engagement element and the second engagement element a distance apart.

14. The device of claim 13, wherein the coupling connector is a wire, a hypotube with a slit, or a braid.

15. The device of claim 10, comprising a third engagement element located between the engagement element and the second engagement element.

16. A method of removing at least a portion of an occlusion from a body lumen, the method comprising:

introducing into the body lumen a device comprising an engagement element according to claim 1 at least partially housed in a microcatheter until the engagement element is proximal to the occlusion;

deploying the coaptation element from within the microcatheter such that a distal tip of the microcatheter is proximal to the coaptation element;

engaging at least a portion of the occlusion with the engagement element;

abutting a distal tip of the microcatheter with a proximal end of the engagement element; and

removing the joined occlusion from the body lumen, wherein during the removing, the joining element inhibits recapping of the microcatheter over the joining element.

17. The method of claim 16, wherein the proximal end of the engagement element comprises a stop configured to radially expand when un-jacketing the microcatheter.

18. The method of claim 16, wherein the legs of the coaptation element have a thickness configured to inhibit recapping of the microcatheter when the legs have been expanded.

19. The method of claim 16, wherein the legs of the coaptation element are angled between 30 ° and 90 ° relative to the longitudinal axis of the microcatheter when the legs have been expanded.

20. The method of claim 16, wherein abutting the distal tip of the microcatheter with the proximal end of the engagement element comprises proximally retracting the engagement element.

21. The method of claim 16, wherein abutting the distal tip of the microcatheter with the proximal end of the engagement element comprises advancing the microcatheter distally.

22. The method of claim 21, wherein distally advancing the microcatheter comprises engaging at least a portion of the occlusion with the engaging element.

23. The method of claim 22, wherein removing the engaged occlusion from the body lumen comprises proximally retracting the engaging element.

24. The method of claim 23, wherein removing the engaged occlusion from the body lumen comprises proximally retracting the microcatheter.

25. The method of claim 16, wherein abutting the distal tip of the microcatheter with the proximal end of the engagement element comprises proximally retracting the engagement element and distally advancing the microcatheter.

26. The method of claim 16, wherein abutting the distal tip of the microcatheter with the proximal end of the engagement element comprises at least one of proximally retracting the engagement element or distally advancing the microcatheter.

27. The method according to any one of claims 16 to 26, wherein the device comprises a second engaging element, wherein the positioning comprises positioning the engaging element proximal to the occlusion and the second engaging element distal to a proximal end of the occlusion.

28. The method of claim 27, wherein the second engagement element is distal to a distal end of the occlusion.

29. The method of claim 27, further comprising:

adjusting the position of the engagement element and the second engagement element by at least one of:

holding the microcatheter while pulling the central wire to engage the occlusion between the engaging element and the second engaging element, or

Holding the central wire while pushing the microcatheter to engage the occlusion between the engaging element and the second engaging element.

30. The method of claim 27, further comprising a coupling connector between the engagement element and the second engagement element, wherein the coupling connector engages the occlusion.

31. A device for removing an obstruction from a body lumen, the device comprising:

a central wire comprising a proximal end and a distal end;

a plurality of engagement elements including a distal engagement element, a proximal engagement element, and an intermediate engagement element between the distal engagement element and the proximal engagement element, wherein the distal engagement element is fixedly attached to the distal end of the central wire, and wherein the proximal engagement element and the intermediate engagement element are slidable relative to the central wire; and

an articulation connector comprising a first section coupled to the proximal and intermediate engagement elements and a second section coupled to the intermediate and distal engagement elements, the articulation connector configured to space the engagement elements a distance apart;

wherein the first section is configured to withstand a different axial load than the second section such that upon application of a longitudinal axial load to the coupler connector, the first and second sections are configured to sequentially contract.

32. The device of claim 31, wherein the linking connector comprises a flexible wire configured to flex upon application of the longitudinal axial load.

33. The device of claim 32, wherein the first section comprises a different stiffness than the second section.

34. The apparatus of claim 33, wherein the first section is coarser than the second section.

35. The device of claim 31, wherein the coupling connector comprises a conduit comprising a slit.

36. The device of claim 35, wherein the conduit is configured to shorten when the longitudinal axial load is applied.

37. The device of claim 35, wherein the slit is parallel to a longitudinal axis of the conduit.

38. The device of claim 35, wherein the slit is at an angle to a longitudinal axis of the conduit.

39. The apparatus of claim 35, wherein the slit comprises a helical slit along a longitudinal axis of the conduit.

40. The device of claim 39, wherein the helical slit has different pitches in the first and second sections.

41. The device of claim 35, wherein the slits in the first and second sections differ by one or more of a pattern or density.

42. The device of claim 31, wherein the coupling connector comprises a braid configured to shorten when the central wire is pulled proximally.

43. The device of claim 42, wherein the braids in the first and second sections differ by one or more of braid angle or braid density.

44. The device of claim 31, wherein the proximal engaging element is configured to inhibit re-nesting of the microcatheter over the proximal engaging element upon application of a proximal force.

45. The device of any one of claims 31-44, wherein the second section contracts before the first section contracts upon application of a longitudinal axial load to the coupling connector.

46. The device of any one of claims 31-44, wherein the first section contracts before the second section contracts upon application of a longitudinal axial load to the coupling connector.

47. A method of removing at least a portion of an occlusion from a first location in a body lumen, the method comprising:

introducing the device of claim 31 into the body lumen until the proximal engaging element is proximal of the occlusion and the distal engaging element is distal of a proximal end of the occlusion;

adjusting the position of the plurality of engagement elements by applying a proximal force to:

first reducing the distance between a distal engaging element and an intermediate engaging element to engage at least a portion of the obturator between the distal engaging element and the intermediate engaging element; and is

Reducing the distance between the intermediate and proximal engaging elements to engage at least another portion of the occlusion between the intermediate and proximal engaging elements; and

removing the engaged occlusion from the body lumen.

48. The method of claim 47, further comprising capturing the occlusion between an inner wall of the body lumen and a lateral surface of at least one of the plurality of engaging elements.

Technical Field

The present disclosure relates generally to devices for use in body lumens such as blood vessels and methods of using the same.

Background

Various disease symptoms may be caused at least in part by blockage or occlusion or clotting of a blood vessel. Well-known examples of such symptoms include, but are not limited to, stroke. Other such symptoms include myocardial infarction, limb ischemia, occlusion or clotting of vascular grafts and bypasses, and venous thrombosis.

Stroke is commonly referred to as "brain attack". It often causes a rapid and substantial loss of brain function due to the disturbance of the blood supply to the brain. As a result, mobility difficulties, use of language, vision, and many other biological functions may be temporarily or irreversibly impaired. Stroke is hemorrhagic (due to bleeding) or ischemic (due to insufficient blood supply). Most strokes are ischemic. It is estimated that approximately 700,000 ischemic strokes occur annually in the united states. The main causes of ischemic stroke include the formation of a thrombus (clot) in the blood vessels supplying the brain or an embolus from another source, such as the heart, to the blood vessels supplying the brain. Sometimes thrombosis occurs where there is a preexisting stenosis of a blood vessel in the brain, usually resulting from atherosclerotic disease.

Treatment of acute ischemic stroke focuses on reestablishing blood flow to the brain as quickly as possible. They involve the use of drugs such as tissue plasminogen activator (tPA), thrombolytic agents (clot-breaking drugs). Recent devices such as stent retriever devices (Trevo of Stryker, California, Phomence; Solitaire, California, Covidien, California) and aspiration thrombectomy catheters (Penumbra, California, Alamada) have been approved by the food and drug administration for thrombectomy in acute stroke. These devices do not always achieve complete recanalization or reperfusion. Sometimes they do not open the vessel at all or can only partially open the vessel. They may also take some time to work, where the device needs to be navigated into the intracranial circulation multiple times before the vessel is reopened. In addition, they may break up the clot and allow portions of the clot to exit more distally in the brain circulation. There is a need for a device with a high rate of complete recanalization that fully or partially captures clots that is performed in a more rapid manner.

Disclosure of Invention

The present disclosure relates to devices and methods for removing obstructions from a body lumen.

In some examples, a device for removing an obstruction from a body lumen may include an engaging element and a microcatheter at least partially housing the engaging element. When expanded after denesting from the microcatheter, the coaptation element can be configured to inhibit recapping of the coaptation element in the microcatheter upon application of at least one of a proximal force to the coaptation element or a distal force to the microcatheter.

In some examples, an apparatus for removing an obstruction from a body lumen may comprise: a central wire comprising a proximal end and a distal end; an engagement element at or near the distal end of the central wire; and a microcatheter at least partially housing the engaging element during introduction into the body lumen. When expanded after denesting from the microcatheter, the coaptation element can be configured to inhibit recapping of the coaptation element in the microcatheter upon application of at least one of a proximal force to the coaptation element or a distal force to the microcatheter.

The proximal end of the engagement element may include a stop configured to radially expand when the engagement element is un-sheathed from the microcatheter. The stop may include a ring configured to flex radially outward when the engagement element is un-sheathed from the microcatheter. The stop may include a helical spring wire configured to expand radially outward when the engagement element is un-sheathed from the microcatheter. The coaptation element can include a leg having a thickness configured to inhibit recapping of the coaptation element within the microcatheter when the leg has been expanded. The legs of the coaptation element can be angled between 30 ° and 90 ° relative to the longitudinal axis of the microcatheter when the legs have been expanded. The engagement elements may comprise wires or struts. The coupling element may be self-expandable upon uncapping the microcatheter. The coupling element may be configured to inhibit recapping of the microcatheter upon application of a proximal force of 50 grams to 450 grams. The device may further comprise a second engagement element located distally of the engagement element. The second engagement element may be fixedly attached to a distal end of the central wire. The engagement element may be slidable on the central wire. The device may include a coupling connector coupled to the engagement element and the second engagement element, the coupling connector spacing the engagement element and the second engagement element a distance apart. The coupling connector may be a wire, a hypotube with a slit, or a braid. The device may comprise a third engagement element located between the engagement element and the second engagement element.

In some examples, a method of removing at least a portion of an occlusion from a body lumen may include introducing into the body lumen a device for removing the occlusion from the body lumen. The apparatus may include: a central wire comprising a proximal end and a distal end; an engagement element at or near the distal end of the central wire; and a microcatheter at least partially housing the engaging element during introduction into the body lumen. When expanded after denesting from the microcatheter, the coaptation element can be configured to inhibit recapping of the coaptation element in the microcatheter upon application of at least one of a proximal force to the coaptation element or a distal force to the microcatheter. Introducing may include receiving an engaging element at least partially within a microcatheter until the engaging element is proximate the occlusion. The method may further comprise: deploying the coaptation element from within the microcatheter such that a distal tip of the microcatheter is proximal to the coaptation element; engaging at least a portion of the occlusion with the engagement element; abutting a distal tip of the microcatheter with a proximal end of the engagement element; and removing the engaged occlusion from the body lumen. During removal, the coupling element may inhibit recapping of the microcatheter over the coupling element.

The proximal end of the coupling element may include a stop configured to radially expand when uncapping the microcatheter. The legs of the coaptation element can have a thickness configured to inhibit recapping of the microcatheter when the legs have been expanded. The legs of the coaptation element can be angled between 30 ° and 90 ° relative to the longitudinal axis of the microcatheter when the legs have been expanded. Abutting the distal tip of the microcatheter with the proximal end of the engagement element may include proximally retracting the engagement element. Abutting the distal tip of the microcatheter with the proximal end of the engagement element may comprise distally advancing the microcatheter. Advancing the microcatheter distally may comprise engaging at least a portion of the occlusion with the engaging element. Removing the engaged occlusion from the body lumen may include proximally retracting the engaging element. Removing the engaged occlusion from the body lumen may include proximally retracting the microcatheter. Abutting the distal tip of the microcatheter with the proximal end of the engagement element may include proximally retracting the engagement element and distally advancing the microcatheter. Abutting the distal tip of the microcatheter with the proximal end of the engagement element may comprise at least one of proximally retracting the engagement element or distally advancing the microcatheter. The device may comprise a second engagement element, wherein the positioning may comprise positioning the engagement element proximal to the occlusion and positioning the second engagement element distal to the proximal end of the occlusion. The second engagement element may be distal to a distal end of the occlusion. The method may further comprise: adjusting the position of the engagement element and the second engagement element by at least one of: holding the microcatheter while pulling the central wire to engage the occlusion between the engaging element and the second engaging element, or holding the central wire while pushing the microcatheter to engage the occlusion between the engaging element and the second engaging element. The device may further comprise a coupling connector between the engagement element and the second engagement element, wherein the coupling connector engages the obturator.

In some examples, an apparatus for removing an obstruction from a body lumen may comprise: a central wire comprising a proximal end and a distal end; a plurality of engaging elements including a distal engaging element, a proximal engaging element, and an intermediate engaging element between the distal engaging element and the proximal engaging element; and a linking connector comprising a first section coupled to the proximal and intermediate engagement elements and a second section coupled to the intermediate and distal engagement elements. The distal engagement element may be fixedly attached to the distal end of the central wire. The proximal and intermediate engagement elements may be slidable relative to the central wire. The first section and the second section may be configured to contract simultaneously.

In some examples, an apparatus for removing an obstruction from a body lumen may comprise: a central wire comprising a proximal end and a distal end; a plurality of engaging elements including a distal engaging element, a proximal engaging element, and an intermediate engaging element between the distal engaging element and the proximal engaging element; and a linking connector comprising a first section coupled to the proximal and intermediate engagement elements and a second section coupled to the intermediate and distal engagement elements. The distal engagement element may be fixedly attached to the distal end of the central wire. The proximal and intermediate engagement elements may be slidable relative to the central wire. The first section and the second section may be configured to sequentially contract.

In some examples, an apparatus for removing an obstruction from a body lumen may comprise: a central wire comprising a proximal end and a distal end; a plurality of engaging elements including a distal engaging element, a proximal engaging element, and an intermediate engaging element between the distal engaging element and the proximal engaging element; and a linking connector comprising a first section coupled to the proximal and intermediate engagement elements and a second section coupled to the intermediate and distal engagement elements. The distal engagement element may be fixedly attached to the distal end of the central wire. The proximal and intermediate engagement elements may be slidable relative to the central wire. The coupling connector may be configured such that the engagement elements are spaced apart. The first section may be configured to withstand a different axial load than the second section such that upon application of a longitudinal axial load to the coupler connector, the first and second sections may be configured to sequentially contract.

The coupling structure may include a flexible wire configured to flex upon application of the longitudinal axial load. The first section may comprise a different stiffness than the second section. The first section may be thicker than the second section. The coupling connector may include a conduit including a slit. The conduit may be configured to shorten upon application of the longitudinal axial load. The slit may be parallel to the longitudinal axis of the conduit. The slit may be at an angle to the longitudinal axis of the duct. The slit may comprise a helical slit along the longitudinal axis of the conduit. The helical slit may have different pitches in the first and second sections. The slits in the first and second sections may differ by one or more of a pattern or density. The linking connector may include a braid configured to shorten when the central wire is pulled proximally. The braids in the first and second sections may differ by one or more of braid angle or braid density. The proximal engagement element may be configured to inhibit re-nesting of the microcatheter over the proximal engagement element upon application of a proximal force. The second section may contract before the first section contracts upon application of a longitudinal axial load to the coupler connector. The first section may contract before the second section contracts upon application of a longitudinal axial load to the coupler connector.

In some examples, a method of removing at least a portion of an occlusion from a first location in a body lumen may include introducing into the body lumen a device for removing the occlusion from the body lumen. The apparatus may include: a central wire comprising a proximal end and a distal end; a plurality of engaging elements including a distal engaging element, a proximal engaging element, and an intermediate engaging element between the distal engaging element and the proximal engaging element; and a linking connector comprising a first section coupled to the proximal and intermediate engagement elements and a second section coupled to the intermediate and distal engagement elements. The distal engagement element may be fixedly attached to the distal end of the central wire. The proximal and intermediate engagement elements may be slidable relative to the central wire. The coupling connector may be configured such that the engagement elements are spaced apart. The first section may be configured to withstand a different axial load than the second section such that upon application of a longitudinal axial load to the coupler connector, the first and second sections may be configured to sequentially contract. The introduction may be until the proximal engaging element is proximal to the occlusion and the distal engaging element is distal to the proximal end of the occlusion. The method may further comprise: adjusting the position of the plurality of engaging elements by applying a proximal force so as to first reduce the distance between the distal engaging element and the intermediate engaging element to engage at least a portion of the occlusion between the distal and intermediate engaging elements and to reduce the distance between the intermediate engaging element and the proximal engaging element to engage at least another portion of the occlusion between the intermediate engaging element and the proximal engaging element; and removing the engaged occlusion from the first position.

The method may further comprise: capturing the occlusion between an inner wall of the body lumen and a lateral surface of at least one of the plurality of engagement elements.

Drawings

Fig. 1A-B show non-limiting illustrative examples of devices according to some embodiments of the invention.

Fig. 2A-C show another non-limiting illustrative example of a device according to some embodiments of the invention, particularly when the device is located in a body lumen, and show some non-limiting examples of mechanisms to remove an occlusion/clot from a blood vessel according to some embodiments of the invention.

Fig. 3 shows yet another non-limiting illustrative example of an apparatus according to some embodiments of the invention, wherein the apparatus comprises a plurality of engaging elements and connecting wires connecting the engaging elements. The device may be delivered through a microcatheter into a body lumen. The figure also shows that the device can be configured to be retrieved to a microcatheter without elements overlapping each other.

Fig. 4 shows yet another non-limiting illustrative example of an apparatus according to some embodiments of the invention, wherein the apparatus comprises a plurality of engaging elements. In this particular embodiment, the distal engaging element of the device may have a closed end at its distal end. Further, the distal engaging element may be larger in size (length and diameter) than the other engaging elements. However, the stiffness of the distal engagement element may be less than the stiffness of the other engagement elements to avoid vessel damage.

Fig. 5A shows yet another non-limiting illustrative example of an apparatus according to some embodiments of the inventions, wherein the apparatus includes a plurality of engaging elements.

Fig. 5B-D illustrate the detailed location and structure of the connectors at the proximal ends of the proximal, intermediate and distal engaging elements. Fig. 5B-D also show the relationship between the connector, the control conduit compartment, the central wire and the connecting wire.

Fig. 6 shows yet another non-limiting illustrative example embodiment of an apparatus according to some embodiments of the invention, wherein the apparatus comprises a plurality of engaging elements. In this figure, the center wire handle, non-limiting structures and components of the conduit compartment, and connections between the components are shown.

Fig. 7A-C illustrate still other non-limiting embodiments of devices according to the present disclosure, wherein the devices include a plurality of engaging elements. The device may further comprise a control wire, a replacement for the tubing compartment. In the embodiment shown in fig. 7A, the device includes a connecting wire and a control wire. The connecting wire and the control wire may be joined at a proximal end of the proximal engaging element. The control wire may be operably connected to a control wire handle at the proximal end of the device. Fig. 7B illustrates certain non-limiting embodiments of a proximal connector that can link the control wire, the connecting wire, and the legs of the proximal engagement element within the proximal connector. Alternatively, in some such embodiments, a separate connecting wire may not be necessary. Thus, as shown in fig. 7C, the control wire and the connecting wire may be from the same segment of wire, where the connecting wire segment/section is small and flexible and the control wire section is slightly larger and pushable. The control/connecting wire and the leg of the proximal engaging element may be joined via a connector.

FIG. 8A shows yet another non-limiting embodiment of a device according to the present invention, wherein the device comprises a plurality of engaging elements. Among the plurality of engaging elements, some of them are configured to function as receiving elements, while some other engaging elements are configured to function as capturing/lacing elements. Each receiving element and capturing element forms an engaging unit/pair. In some embodiments, the receiving element may be associated with or connected to a spacing filament. The proximal end of the proximal element and the spacer wire are connected to the control conduit compartment. In some embodiments, a pair of receiving elements and capturing elements may be used as an engaging unit/pair. In certain embodiments, the device may comprise a plurality of engagement units/pairs. Fig. 8A shows the engaging unit/pair open and fig. 8B shows the engaging element/pair closed, i.e. the spacing between the catch engaging element and the receiving engaging element is shortened. Fig. 8C-F show detailed connector structures and their relationship to the control conduit compartment, center wire and spacer wire.

Fig. 9A-F illustrate yet another non-limiting embodiment of a method according to the invention, wherein the device shown in fig. 8 is used to treat or remove one or more occlusions from a body lumen. Fig. 9A-C illustrate an embodiment in which a relatively large obturator is removed by a device comprising a plurality of operating units/pairs. Fig. 9D-F show an embodiment in which more than one obturator is removed individually by a plurality of operating units/pairs.

Figure 10 shows yet another non-limiting embodiment of a device according to the present invention, wherein the device comprises a plurality of engaging elements, some of which may serve as receiving elements and some other engaging elements may serve as capturing/tightening elements. The figure shows the coupling element being pulled back into the microcatheter as needed during operation.

Fig. 11A-B illustrate yet another non-limiting embodiment of a device according to the present invention, wherein the device includes a plurality of engaging elements, some of which may serve as receiving elements and some other engaging elements may serve as capturing elements. In certain embodiments, a separate distal engagement element may be added at the end of the central wire to capture clot debris that may be occluded at its distal end. Further, in some embodiments, the distal engaging element may be larger in size and diameter than the other engaging elements. However, the stiffness of the distal engaging element may be less than the stiffness of the other engaging elements.

Figures 12A-E illustrate yet another non-limiting embodiment of a device according to the present invention, wherein the device includes a plurality of engaging elements, some of which may serve as receiving elements and some other engaging elements may serve as capturing/cinching elements. In addition, the device may further comprise a control wire. In some embodiments, the control wire may be operably connected to a handle at a proximal end of the device, whereby an operator may manipulate the control wire, such as pushing or pulling the control wire. All receiving elements are fixed to the spacer wire with a designed spacing between them and they can move freely along the central wire. All capture elements are fixed to the central wire. By controlling one or both of the control wire and the central wire, the spacing between the engaging elements can be adjusted to maximize the engagement and containment of the device against the occlusion. Fig. 12A and 12B illustrate adjustment of the spacing between the engaging elements. Figures 12D-E illustrate views of certain non-limiting embodiments of the proximal connector.

Fig. 13A-F illustrate still further alternative non-limiting embodiments of devices according to the present disclosure, wherein the devices include a plurality of engaging elements. In certain embodiments, two engagement elements (one being a receiving element and the other being a capturing element) form an individual operating unit/pair. The device may comprise a plurality of engagement operating units/pairs. The receiving elements in the different operating units/pairs may be associated or connected to a connecting wire. Further, in certain embodiments, the engagement elements (e.g., at least one receiving element and one capturing element) of the same unit/pair may be connected to or associated with the spacer wire. Fig. 13B shows a device in which the spacing between the engagement elements is reduced. Fig. 13D-F show the relationship of the connector to the engagement element, the connecting wire, the spacer wire and the central wire at various locations of the engagement compartment.

Fig. 14A-E show alternative structures of still further alternative non-limiting and illustrative embodiments of the engaging elements.

Fig. 15A-B show still further alternative non-limiting illustrative embodiments of structures from which the engaging elements may be made.

Fig. 16A-16G illustrate an exemplary device having multiple clot engaging elements configured to sequentially contract.

Fig. 17A-17D illustrate an exemplary two-part device having a proximal engagement element and a distal engagement element.

Fig. 17E illustrates an example device that includes a stop feature.

Fig. 17F illustrates another example device that includes a stop feature.

Detailed Description

The present disclosure relates generally to devices for use in body lumens such as blood vessels and methods of using the same. In some embodiments, the device may be positioned in a body lumen to remove occlusive material, such as blood clots or foreign bodies, from the lumen. Some aspects of the present invention provide devices and methods configured to treat symptoms in blood vessels, including but not limited to stroke. In some embodiments, the devices and methods are configured to treat symptoms associated with ischemic stroke by removing an occlusion/clot from a blood vessel and/or reopening the blood vessel and restoring blood flow therein. Non-limiting examples of blood vessels may include: arteries, veins, and surgically implanted grafts and bypasses that serve as components of the circulatory system.

The term "occlusion" or "clot" generally includes any substance that partially or completely obstructs the lumen of a blood vessel. The occlusion/clot slows or impedes the flow (e.g., the flow of blood or any other biological fluid) traveling through the lumen. Examples of occlusions/clots may include blood occlusions/clots and atherosclerotic plaques as well as fat or foreign matter present in blood vessels.

The term "stroke" generally includes symptoms caused in part by an interruption in the blood supply to the brain. The interference may be caused by an occlusion (e.g., ischemic stroke) and/or a hemorrhage (e.g., hemorrhagic stroke). In particular, ischemic stroke may be caused by partial or substantial occlusion of a blood vessel. Treatment of ischemic conditions may be applied to blood vessels present in the brain as well as in other tissues such as the heart. Thus, the devices and methods disclosed in this application are not limited to use in any particular organ, but may be applied to any blood vessel of the body that would benefit from removing an occlusion/clot to restore blood flow. Furthermore, the devices and methods according to the present invention may be used to treat venous occlusions/clots that may cause other symptoms besides ischemia.

The device may be introduced into the blood vessel through a catheter or microcatheter. "catheters" or "microcatheters" generally comprise tubular structures that can be inserted into a body lumen to allow the application of devices and/or chemicals to the area of the body in need of treatment.

In addition, many different modifications and alterations, which should be apparent to one of ordinary skill in the art based on the disclosure herein, may be made to properly serve a particular therapeutic condition without affecting the scope of the present invention. Therefore, not only the examples disclosed in the present application but also such obvious modifications and variations based on the disclosure herein should be included in the scope of the present invention.

One aspect of the present invention relates to a device for use in a blood vessel, the device comprising a plurality of engaging elements (e.g., two, three, four, or more), a control conduit compartment, a central wire, and/or a control wire. The engaging element may form a self-expanding compartment.

Another aspect of the invention relates to a device for use in a blood vessel, the device comprising a microcatheter, a central wire, a tubing member, and a junction compartment. The engagement compartment may comprise a distal engagement element, an optional intermediate engagement element and a proximal engagement element. The engaging element may be coupled with the connecting wire and/or the spacing wire via a connector. In some embodiments, the distal engagement element may be associated with a central wire. The spacing between the engagement elements may be adjustable. In at least some embodiments, the spacing between adjacent elements can be adjusted by about 0 to 50 mm. In certain embodiments, the distance between the engagement elements may be adjusted by approximately 0mm, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, and 50mm and any range therebetween. In an alternative embodiment, the spacing between the engagement elements may be adjusted to be greater than 50 mm.

In some embodiments, the device may be introduced into a blood vessel. The size of the blood vessels varies greatly, from a diameter of about 0.03 inches (about 1mm) in smaller arteries and veins, to 1.0 inch (about 25mm) in larger arteries, to 1.2 inches (about 30mm) in the aorta. Thus, in some embodiments, the diameter of the device may range from about 0.01 inch (about 0.25mm) to 1.0 inch (about 25mm) to 1.2 inches (about 30mm) when the device is in the expanded state. Further, the diameter of the individual devices may vary as the engaging compartments open (or expand) or close (or contract) during operation. In some other embodiments, the diameter of the device in the collapsed state may range from about 0.01 inches, about 0.02 inches, about 0.03 inches, about 0.04 inches, about 0.05 inches, about 0.06 inches, about 0.07 inches, about 0.08 inches, about 0.09 inches, about 0.10 inches, about 0.12 inches, about 0.14 inches, about 0.16 inches, about 0.18 inches, about 0.20 inches, about 0.30 inches, about 0.40 inches, about 0.50 inches, about 0.60 inches, about 0.70 inches, or any range therebetween.

In some embodiments, the device further comprises a central wire. The center wire may pass through the pipe section and move freely therethrough. In certain embodiments, the central wire is associated with the engagement compartment. More specifically, the central wire may be associated with a distal engaging element, an optional intermediate element and a proximal engaging element. An association generally refers to any type of connection between two objects. Association includes fixation, where movement of one object will be impeded by the other object when the two objects are associated. In other words, once the two objects are associated in a fixed manner, the movement of the two objects may be synchronized. However, association does not necessarily mean that one object is fixed to another. Thus, when two objects are associated but not in a fixed state, movement of one object relative to the other can be unimpeded. Thus, in at least some embodiments, the intermediate element and the proximal engaging element may be associated with the central wire (e.g., they may pass along the central wire), but they may be free to move along the central wire.

According to some embodiments, the central wire is fixed or coupled with the distal engagement element. In some cases, the proximal end or the distal end of the distal engagement element may be coupled to the distal end of the central wire. The association (i.e. connection) between the central wire and the distal engagement element may be done via various means such as welding, gluing or clamping onto the connector. In some embodiments, the joint between the central wire and the distal engaging element is covered by a distal element connector. Alternatively, the connector may consist of a short outer connector tube and a short inner connector tube, wherein the components are fixed between the walls of the pipes and filled with joint medium.

In some embodiments, the central wire may comprise or be in the form of a wire, braid, or cable. The wire may have a uniform diameter or a tapered diameter that varies from the distal end to the proximal end. Various materials may be used to manufacture the center wire, which may include metallic and non-metallic materials. Some non-limiting examples of metallic materials for the central wire may include nickel, titanium, stainless steel, cobalt, chromium, and any alloy of the foregoing metals, such as nitinol (NiTi) or cobalt-chromium alloy. Furthermore, any polymer or plastic having the desired properties as a central filament may be used to produce it. Polymers include, but are not limited to: polyimide, PEEK (polyether ether ketone), nylon, PTFE (polytetrafluoroethylene), PET (polyethylene terephthalate), polypropylene, and the like. Composite coated metals including but not limited to PTFE coated stainless steel, or PTFE coated NiTi may also be used as the center wire. Furthermore, a hydrophilic coating would be applicable. Such a coating may be applied in part to reduce friction between the central wire and the tubing compartment. The central wire may also be made in a composite material such as PTFE or FEP (fluorinated ethylene propylene) tubing on NiTi wire, or PTFE or FEP tubing on stainless steel, etc. The diameter of the central wire may range from about 0.001 inch to 0.1 inch. In certain embodiments, the central wire may have a diameter of about 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01 inches. Alternatively, the diameter of the central wire may be greater than 0.01 inches.

The term "coaptation compartment" generally includes a resilient structure that can be compressed to a small profile/diameter and inserted into a body lumen through a microcatheter and expanded to a larger diameter upon release from the microcatheter to engage and remove at least a portion of a clot/occlusion in order to recanalize an occluded lumen or vessel. The engagement compartment may comprise a distal engagement element, an optional intermediate engagement element and a proximal engagement element. In some embodiments, the engagement element may comprise a plurality of wires. In at least some embodiments, the engaging elements may be formed as a mesh or braid structure. In some other embodiments, the engagement elements may comprise struts made of tubing or sheet material. The struts may be made from laser cut hypotubes or sheet material or photo etched sheet material. A heat treatment may be required to set the struts into a desired shape, such as a conical shape or a cylindrical shape, followed by chemical etching or electropolishing in order to smooth the surface of the element.

The engaging element may be made of an elastic material. Some non-limiting examples of such metallic materials for the joining element include nickel-titanium (NiTi) alloys, stainless steel, titanium and its alloys, and cobalt-chromium (CoCr) alloys. Alternatively, any polymer or plastic having the desired properties for the distal engaging element may be used. In further alternative embodiments, the engagement element may be constructed using two or more different materials, such as a polymer-coated metallic material.

In some embodiments, the overall diameter of the engaging element may vary from about 1mm to 8mm in its expanded state. In some embodiments, the distal engaging elements may have a diameter in their expanded state of about 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, and 8mm or any range therebetween. In some other embodiments, the length of each engagement element may vary from about 2mm to 40 mm. In certain embodiments, the length of each engagement element may be approximately 2mm, 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, and 40mm, and any range therebetween. Further, in alternative embodiments, the length of each engagement element may be greater than 40 mm.

In some embodiments, a marker (such as marker 1770 in fig. 17A) may be added to the device. Such markers may include radiopaque materials that facilitate monitoring of the position and/or movement of the device within the body. Some non-limiting examples of radiopaque markers may include gold, gold alloys, CoCr alloys, platinum, or platinum alloys. The markers may also be in the form of radiopaque coatings. The marker may be added anywhere in the device. In some embodiments, one or more markers may be added at the distal engaging element so that the position of the distal engaging element in the body may be determined. In some embodiments, one or more markers may be added at the proximal engagement element such that the position of the proximal engagement element in the body will be determined. In still other embodiments, any or all of the engagement elements may include indicia. Alternatively, one or more markers may be added to the central wire and/or the conduit compartment. In some embodiments, the markings may be about 0.10 to 4mm long and about 0.001 to 0.030 inches in diameter. However, any variation in any dimension (e.g., length, diameter, size, and mass) as well as in shape of the mark is suitable.

In some embodiments, the device may include one or more conduit compartments. The control duct compartment may comprise a plurality of duct elements. Such duct elements may include a pusher duct and a connecting duct. In at least some embodiments, the pusher tubing may further comprise an inner pusher tubing, an outer pusher tubing, and/or proximal and distal pusher tubing. These pusher tubing components may be attached or secured to one another. The pipe elements may be manufactured using a variety of materials, which may include metallic and non-metallic materials. In some embodiments, the distal pusher tube and/or the outer pusher tube may be made of a lubricious and flexible polymer such as PTFE or PET. When tensile resistance is required, relatively small polyimide or PEEK tubing may be employed. The proximal pusher tube may be made of nitinol superelastic material, stainless steel, CoCr alloy, titanium alloy, or polymer (such as polyimide, PEEK, etc.). To reduce friction between the inner lumen of the microcatheter and the pusher tube, one or more of the tubing elements may also be coated with a lubricious material, such as a PTFE coating, a hydrophilic coating, or the like. The tubing elements may also be made of PTFE or FEP (fluorinated ethylene propylene) tubing over a composite material such as a metal (nitinol, stainless steel, etc.) coil for pushability and flexibility.

The central, control, spacer and connecting wires may be in the form of wires, braids or cables. Some non-limiting examples of metallic materials for the central wire may include nickel, titanium, stainless steel, cobalt, chromium, and any alloy of the foregoing metals, such as nitinol (NiTi), titanium alloy, or cobalt-chromium alloy. Furthermore, any polymer or plastic having the desired properties as a central filament may be used to produce it. Polymers include, but are not limited to: polyimide, PEEK (polyether ether ketone), nylon, PTFE (polytetrafluoroethylene), PET (polyethylene terephthalate), polypropylene, and the like. Composite coated metals including but not limited to PTFE coated stainless steel, or PTFE coated NiTi may also be used as the center wire. A hydrophilic coating may also be applied to reduce friction between the inner lumen of the pusher tubing and the wire.

In some embodiments, the outer diameter of the impeller tube member may be about 0.001 inch (about 0.025mm) to 0.050 inch (about 1.3 mm). In other embodiments, the diameter of the impeller tube member may be less than 0.001 inch (about 0.025mm) or more than 0.050 inch (about 1.3 mm).

In some embodiments, the device may comprise a plurality of engagement elements, such as two, three, four, five, six or more engagement elements. Thus, in embodiments where there are three or more engaging elements in the device, there may be a distal engaging element located most distally, a proximal engaging element located most proximally, and one or more intermediate engaging elements located between the distal and proximal engaging elements, among all of the engaging elements.

The shape, size, and structure/configuration of the engaging element is not limited and may vary to the extent compatible with the blood vessel and suitable for treatment. In certain embodiments, the engaging elements may be generally shaped in the form of a cone or pyramid (as shown in fig. 14A), a cylinder or tube (fig. 14C), an ellipsoid (fig. 14D), or a sphere (fig. 14D), or an umbrella (or parachute) form (fig. 14E), among others, as well as combinations of any of the above forms/shapes. Fig. 14B shows an example. When in cylindrical or tubular form, the engagement element may be open or closed at either end. The individual engaging elements present in the same device may differ from each other, for example in size, structure, material and/or function. Alternatively, some or all of the engaging elements present in the same device may share one or more common characteristics, such as size, structure, material, and function.

Furthermore, in some embodiments, there are connecting wires associated with two or more of the engaging elements of the device. In some embodiments, the connecting wire may be connected to or associated with some or some (but not all) of the plurality of engaging elements. In some other embodiments, the connecting wire may be associated with or connected to all of the engaging elements present in the device. The association or connection between the individual engaging elements and the connecting wire may be fixed at a certain position of the connecting wire. When multiple engaging elements are associated with (or connected to) a connecting wire, the type of association/connection of individual engaging elements with the connecting wire may vary, e.g., in a fixed or non-fixed manner, within a single device. Thus, in some embodiments, some (but not all) of the engagement elements associated with or connected to the same connecting wire may be fixed at their respective positions on the connecting wire. The connecting wires may be flexible or soft, which allows the spacing between the engagement elements to be shortened when it is desired to bring the engagement elements closer together. In those cases, the connecting wire may be stretch resistant under tension such that the maximum distance between the engaging elements is also limited by the connecting wire.

The association (including the connection) between the connecting wire and the engaging element, in particular the fixation (or joining) therebetween, may be done via various means such as welding, gluing or clamping. In case the engaging element and the connecting wire are fixed to each other, there may be additional elements like a pipe or a connector. The association (including connection) between the connecting wire and the engaging element, particularly in case the engaging element can move along the central wire, can be done via various ways including a connector. For example, the splice element may receive or attach to short inner and outer element connector tubes. The connecting wire may be attached between the walls of the two conduits, and the center wire may pass through (into) the inner element connector conduit. Therefore, the engaging element can move (slide) along the center wire without being fixed at a certain position.

In some designs, spacer wires may also be present. The engaging element may be fixed to the spacer wire. The spacer wires are stiffer than the connecting wires and therefore do not buckle or become loose. Thus, the spacer wire maintains a fixed spacing or distance between the engagement elements.

The connecting and/or spacing wires may be in the form of round or flat wires, cables or have a braid structure. In some embodiments, the connecting wire is flexible but stretch resistant. Some non-limiting examples of metallic materials for the connecting wire may include nickel, titanium, stainless steel, cobalt, chromium, and any alloy of the foregoing metals, such as nitinol (NiTi), titanium alloy, or cobalt-chromium alloy. Furthermore, any polymer or plastic having the desired properties as a connecting filament may be used for producing it. Polymers include, but are not limited to: polyimide, PEEK (polyether ether ketone), nylon, PTFE (polytetrafluoroethylene), PET (polyethylene terephthalate), polypropylene, and the like. Composite coated metals including but not limited to PTFE coated stainless steel, or PTFE coated NiTi may also be used as connecting wires. Hydrophilic coatings may also be applied.

In certain embodiments, there may be more than one connecting wire. In some such embodiments, the connecting wire may be associated with or connected to all of the engagement elements present in the device. Alternatively, the connecting wire may be associated with or connected to a pair of engaging elements (such as a receiving engaging element and a capturing engaging element). In certain embodiments, there may be two, three, four, five, six, or more connecting wires in a single device. In some other embodiments, the device may have seven or more connecting wires.

In some embodiments, the device may include a proximal end control element that may be associated with the most proximally located engagement element and configured to control the position of the associated engagement element. In certain embodiments, the proximal end control element may be in the form of a conduit compartment or a wire. The proximal end control element may set the boundaries of the proximal-most end of the engagement element. In certain embodiments, the proximal end control element may be operably coupled to a handle that may control movement of the proximal end control element.

In some embodiments where the device comprises a plurality of engagement elements, the device may further comprise a conduit compartment associated with (or connected to) the proximal engagement element of the device. In some embodiments, in addition to the proximal engaging element, other engaging elements may be associated with (or connected to) the conduit by a connecting wire or a spacing wire (both of which may help maintain a desired spacing between the proximal engaging element and the other engaging elements). In some embodiments, the proximal engagement element may be secured around the distal end of the conduit compartment via its proximal end connector. Thus, in such embodiments, movement of the proximal engagement element and other elements secured to the connecting wire or spacer wire is controlled by the conduit compartment.

In an alternative embodiment, the device may comprise a plurality of engagement elements, and further comprise a control wire associated with (or connected to) one or more engagement elements of the device. In some embodiments, the control wire may be associated with a proximal engagement element of the device. The association (or connection) between the control wire and the proximal coupling element may include a fixture or joint that secures the coupling element at a location of the control wire. Thus, movement of the proximal engagement element is controlled by pushing or pulling the control wire.

In some embodiments where more than one engagement element is associated with a control wire, each of the associated engagement elements may be fixed at a respective location on its control wire. In some embodiments where multiple engagement elements (receiving elements) are associated with a control wire, some (but not all) of the associated engagement elements are secured at their respective locations on the control wire or spacer wire via engagement element connector conduits. Those engaging elements can be moved along the central wire to change the spacing between the receiving element and the capturing element.

In some embodiments, the control wire is operably coupled or connected to a handle at the proximal end of the device such that an operator (e.g., a medical practitioner) can control (or move) the control wire via the handle, such as pushing or pulling the control wire. Such control operation of controlling movement of the control wire may result in controlling movement of the engagement elements associated with the control wire and the spacer wire.

The control wire may be in the form of a wire, cable, braid or conduit. Some non-limiting examples of metallic materials for the connecting wire may include nickel, titanium, stainless steel, cobalt, chromium, and any alloy of the foregoing metals, such as nitinol (NiTi), titanium alloy, or cobalt-chromium alloy. Furthermore, any polymer or plastic having the desired properties as a control filament may be used to produce it. Polymers include, but are not limited to: polyimide, PEEK (polyether ether ketone), nylon, PTFE (polytetrafluoroethylene), PET (polyethylene terephthalate), polypropylene, and the like. Composite coated metals including but not limited to PTFE coated stainless steel, or PTFE coated NiTi may also be used as control wires. Hydrophilic coatings may also be applied.

In some embodiments, individual engaging elements may be associated with (or connected to) one or more filaments selected from the group consisting of control filaments, connecting filaments, spacer filaments, and central filaments. Furthermore, when an individual engaging element is associated (or connected) with at least two of the wires, the engaging element may be fixed at a certain position with respect to at least one of the associated/connected wires, while being movable along the other associated/connected wires. Thus, for example, if the engaging element is associated with or fixed to a control wire or spacer wire, the engaging element may still be movable on the other wire.

When an individual engagement element is associated with (or connected to) one or more filaments (e.g., a control filament, a connecting filament, a spacing filament, and a center filament), the position of the individual engagement element can be controlled by controlling one or more of these filaments. Furthermore, the spacing or distance between the engaging elements may also be adjusted via controlling the wires with which they are respectively associated/connected. Thus, when attempting to engage and accommodate an occlusion with a device for removal or treatment of the occlusion from a body lumen, an operator may move a single engagement element or two or more engagement elements as an operating unit/pair. This complex and elaborate mode of operation significantly improves the efficiency of the treatment while minimizing the risk of damaging the body lumen.

The control wire (or the conduit compartment) may be separate from and unattached to the central wire and thus move independently. In some embodiments, there are separate proximal handles configured to control the control wire or conduit compartment and the central wire. The handle may serve as a controller. By manipulating these handles and controlling the central wire and control wire or conduit compartment, the individual engagement elements of the device can be positioned in desired positions, and the spacing/distance between two or more of the engagement elements can also be adjusted in order to maximize grasping/capturing/removal of the occlusion from the body lumen. Alternatively, or in combination with the control wire or the conduit compartment and the central wire, the connecting wire and/or the spacing wire may in some embodiments also be capable of controlling the spacing or distance between two or more engaging elements. For example, the connecting wire may be separate and independently movable from the central wire and the control wire. Thus, it may allow for shortening the spacing/distance between one or more engagement elements. When the central wire is pulled proximally or the control wire or the conduit compartment is pushed distally, the spacing between the receiving element and the capturing element may be shortened in order to cinch or hold the clot. During the pulling of the control wire or the tubing compartment proximally and the holding of the central wire, the distance between the capturing element and the receiving element increases until the connecting wire is under tension. The tensioning of the connecting wire allows the components of the junction compartment to be withdrawn back into the microcatheter without the elements overlapping each other.

In some embodiments, the device may comprise two or more engagement units/pairs, with four or more engagement elements operating together to capture/cinch an occlusion and remove it from a body lumen. In some embodiments, the engagement unit/pair may comprise two engagement elements, one acting as a receiving element and the other as a capturing element. In some embodiments, in the engaging unit/pair, the capturing element may be located distally and the receiving element may be located proximally. The capture element may be formed to be able to engage (e.g. capture or grasp) the occlusion. The capture element may engage the obturator directly with the proximal end of its element body, or by its wire/stay structure along any portion of the stay in contact with the obturator. Alternatively, the obturator may be frictionally engaged between the body lumen and the capture element. Still alternatively, the obturator may be captured, cinched or held between the capture element and the receiving element. All of these mechanisms for capturing, engaging, cinching, or holding the occlusion may work simultaneously to engage and remove the occlusion, e.g., a portion of the occlusion may be frictionally engaged between the capture element and the body lumen, and some other portion of the occlusion may be engaged with the receiving element. Various modes of using multiple engaging elements and body lumens to capture or bind an occlusion may exist, and any such variations are included within the scope of the devices and methods disclosed herein.

In certain embodiments, the distal engaging element may comprise a plurality of wires or struts forming a network such that it may capture an occlusion by itself or in combination with another proximally located engaging or receiving element and/or body lumen. More proximal engaging or receiving elements (although it may also be capable of engaging directly with the occlusion via its wire or strut if desired or necessary) may also be used to ensure or enhance engagement of the occlusion by more distal engaging or capturing elements. For example, in certain instances where the occlusion is relatively large or extends a distance along the body lumen, multiple engaging elements or multiple capture and receiving elements (and often with frictional engagement with the body lumen) may be used to engage the occlusion at more than one location to ensure more complete engagement of the clot. See, for example, the non-limiting and illustrative embodiments shown in fig. 2B and fig. 9A-C. Alternatively, the individual engaging (or operating) units/pairs operate separately to remove the detached occlusion. See, for example, the non-limiting and illustrative embodiments shown in FIGS. 9D-F. Further, alternatively or in combination with at least one of the foregoing modes, the receiving element or the more proximal engaging element may be moved closer to the capturing element or the more distal engaging element, thereby retaining or constricting a clot between two adjacent elements, which may result in a more complete or stronger capture of the occlusion. In certain embodiments, the proximal engaging or receiving element may be shaped such that it can conform to the proximal portion of the more distal engaging or capturing element. In other words, a proximal portion of a distal engaging or capture element may fit within a distal portion of a more proximal engaging or receiving element. Thus, during the treatment procedure and also during removal of the device from the lumen, it may be further ensured that the occlusion is accommodated between the two elements.

In some embodiments, the apparatus may comprise more than two operating units/pairs. Thus, in certain embodiments, the device may comprise three, four, five, six or more operating units/pairs. In certain embodiments, the distal engaging element or distal end of the device may not pass completely beyond an occlusion in the body lumen. Rather, the device may travel into only a portion of the proximal end of the occlusion, for example as seen in fig. 9A-F, and engage only a portion of the occlusion. For example, it may be difficult or impossible to visualize where in the lumen the obstruction (occlusion) extends for how long, i.e., the distal end of the occlusion. In these cases, it may be safer to advance the device alongside or within only a portion of the occlusion, and also engage only a portion of the occlusion. However, in some other cases, the device may be advanced beyond the distal end of the occlusion when it is determined that the advancement may be a safe maneuver.

In some embodiments, the position of the individual engagement elements or the position of the operating units/pairs may be adjusted via movement of at least one selected from the group consisting of: a central wire, a control conduit/wire compartment, a connecting wire, a spacing wire and a control wire. Generally, all of the engagement elements in the device may be associated with (or connected to) the central wire. In some embodiments, only some (but not all) of the engagement elements may be fixed at their respective positions on the central wire, while some other engagement elements may still be movable along the control wire. In some embodiments, all capture elements of the device (from different operating units/pairs) may be fixed at their respective positions in the central wire, while all receiving elements may be movable along the central wire.

For the purpose of illustration, some non-limiting and illustrative examples of the device according to the invention are provided in the following figures. Although a few exemplary applications have been described herein for purposes of illustration, many different modifications and variations will become apparent to those skilled in the art based on the disclosure herein without departing from the scope of the invention. Therefore, not only the examples disclosed in the present application but also such obvious modifications and variations should be included within the scope of the present invention.

Fig. 1 shows one embodiment of a device, wherein the device may comprise a plurality of engaging elements. In some embodiments, the device may include three or more engagement elements. In some embodiments, the device may include a central wire (10), a conduit compartment (27), three or more engagement elements (65, 67, 90), a connecting wire (190). The figure shows four engagement elements, including a distal engagement element (90), a proximal engagement element (65) and two intermediate engagement elements (67). In this example, the most distal engaging element (90) serves as a capture element, and all engaging elements proximal thereto may serve as capture and/or receiving elements. The individual engaging elements may vary in length from 3-25mm when extended. Fig. 1A is in its open state, in which the space between each adjacent engaging element is fully open, the length of the space being labeled "d". Fig. 1B is in its closed state, wherein the spacing between each engaging element is shortened (from "d" to "d 1") for the purpose of holding, cinching or grasping an occlusion or clot.

In some embodiments, all of the plurality of engagement elements (65, 67, and 90) are associated with (or connected to) the central wire (10). Of these, the proximal end of the distal engagement element (90) may be fixed to the distal end (or tip) of the central wire (10), while the other three engagement elements (65 and 67) may slide freely over the central wire. Furthermore, all of the plurality of engaging elements may be associated with a connecting wire (190). In some embodiments, a flexible connecting wire (190) may couple the proximal ends of all of the engagement elements with a preset or equal spacing therebetween. In such an embodiment, the engagement elements are fixed to the connecting wires at their respective locations and the distance is maintained by some manipulation. Additionally, in some embodiments, a proximal end of the proximal engagement element (65) may be secured to a distal end of the conduit compartment (27). The central wire may slide freely within the conduit compartment. In certain embodiments, the device may further include or be operably coupled to a handle (110) at the proximal end of the device such that it can control (e.g., push or pull) the central wire.

Fig. 2 illustrates another embodiment of a method in which a device including a plurality of engaging elements (such as the engaging elements shown in fig. 1) is used to remove or treat an occlusion/clot in a body lumen.

In some embodiments, the device may be introduced into a blood vessel through a microcatheter (30). Upon reaching an occlusion site in a body lumen, and as the device is advanced through the microcatheter (30), the distal engaging element (90) may first be advanced along with the central wire (10). A continuous pushing force on the central wire (10) may keep the connecting wire in tension and pull each engaging element associated with the central wire (190) forward along the microcatheter lumen. Furthermore, continued forward urging during retraction of the microcatheter (30) will allow the operator to disengage the sheathing device and maintain a set distance between the engaging elements. Because the connecting wire (190) may be flexible, but is generally non-stretchable, it allows the engaging elements to move closer to each other when the connecting wire (190) is slack, but prevents the engaging elements from separating beyond a preset distance when the connecting wire (190) is under tension. The coupling elements may be positioned with a preset distance therebetween when un-sleeved from the microcatheter (30).

After uncapping the microcatheter (30), the central wire (10) may remain stable such that the distal engagement element (90) secured at the distal end of the central wire (90) can be stabilized. Friction between the inner lumen of the microcatheter (30) and the surface of the engagement elements (65 and 67) may cause the free sliding engagement elements to move rearward; however, because the connecting filament (190) is non-stretchable, the connecting filament (190) maintains a preset spacing between each element. The coupling element may be self-expanding after uncapping the microcatheter (30). The operator can adjust the spacing between the engagement elements as described below. To engage or retain a clot, the operator may shorten the spacing between the engaging elements by: (i) by pulling the central wire (10) backwards (proximally) while keeping the conduit compartment (27) stable, (ii) by pushing the conduit compartment (27) forwards (distally) while keeping the central wire (10) stable, or (iii) by pulling the central wire (10) backwards (proximally) and pushing the conduit compartment (27) forwards (distally). Such adjustment of the position of the engagement elements and the spacing therebetween may allow at least a portion of the clot to be compressed/constricted or captured in the spacing gap. See, e.g., FIGS. 2B-2C. Alternatively or in combination, the occlusion may be secured via frictional engagement with the body lumen and one or more engagement elements. The occlusion may also be directly engaged with a strut or wire of the engagement element. In addition, the occlusion can be secured and captured between the one or more engagement elements and the body lumen. See also, e.g., FIGS. 2B-2C. In some embodiments, engagement (capture) and accommodation of the occlusion may involve more than one mode. Thus, for example, at least a portion of the occlusion may be captured by direct engagement with one or more engagement elements, and at least some other portion of the occlusion may be captured between the spacing of two or more engagement elements. Additionally, alternatively or in combination, portions of the occlusion may be frictionally captured and secured by the body lumen and the engagement element.

In some embodiments, the central wire may be pulled proximally while maintaining the conduit compartment (27) during a treatment procedure. The distal engaging element may then move back and cinch or hold the clot with the adjacent engaging element. The proximal and/or its adjacent engaging elements are then pushed back (proximally) by the compressed clot, which may in turn compress and cinch the occlusion. The operator may shorten the distance between the engagement elements until the occlusion is securely cinched/grasped by the device. The pattern of securely cinching/gripping the occlusion may include one or more of the following: (1) the occlusion can be cinched or held between the engagement elements, (2) the occlusion can be directly engaged with the wires or struts of the one or more engagement elements, (3) the occlusion can be frictionally received between the body lumen and the one or more engagement elements, and/or (4) the occlusion can be frictionally received between the body lumen and the spacing between the engagement elements.

Once the occlusion is deemed to be firmly grasped or cinched by the device, the device may be pulled out of the body lumen. In some embodiments, such as shown in fig. 1B and 2C, the connecting wire (10) may be thin and flexible, and thus may bend, curl or buckle once the distance between the engaging elements is shortened.

Fig. 3 shows another embodiment of the device, wherein the device may comprise a plurality of engaging elements. In some embodiments, the tubing compartment (27) may be pulled back when it is desired to withdraw the device into the microcatheter (30) during a retrieval procedure. A proximal engagement element (65) secured to the tubing compartment may be pulled into the microcatheter (30). While the connecting wire (190) is maintained in tension, it pulls the coupling elements connected to the connecting wire one by one into the microcatheter. The retrieval mechanism allows the connecting wire to extend to a preset distance between the coaptation elements and prevents multiple coaptation elements from stacking on top of each other so that they can be pulled back into the microcatheter. The stacked splice elements may have too large a diameter to fit within the microcatheter, and they may also be damaged when pulled into the position in which they are stacked.

Fig. 4 shows yet another embodiment of the device, wherein the device may comprise a plurality of engaging elements. In some embodiments, the device may further include a distal engagement element (90) that may also function as a distal filter. In certain embodiments, the distal end (or tip) of the distal engaging element may be closed by a distal connector (150). In some embodiments, the profile of the distal engaging element (90) may be larger in size (length and diameter) than the profiles of the other engaging elements and less rigid than the other engaging elements. This may minimize radial forces of the distal engagement element against the vessel wall. Such a distal engagement element (particularly in the form of a distal filter) may prevent clot debris from traveling downstream. If the clot (or occlusion) breaks during a treatment procedure and debris is generated, the debris can be captured (collected or contained) by the distal filter element (90). Due to the large profile of the distal engagement (filter) element, preferably slightly larger than the diameter of the vessel in the retrieval access, debris may not be able to escape between the engagement element and the vessel wall. In this embodiment, the distal engaging element may also be used to cinch or hold a clot with a more proximal adjacent engaging element.

Additionally, in certain embodiments, the proximal or distal end of the distal engaging element may be fixed to the central wire (10). In addition, there may be a flexible connecting wire (190) that couples (associates or connects) other engaging elements. In some such embodiments, all of the engagement elements are fixed at their respective locations on the connecting wire (190), thereby setting a spacing between each engagement element. In some embodiments, the proximal engagement element (65) may be secured around the distal end of the conduit compartment (27). By this configuration, the position of the proximal engagement element can also be adjusted when pushing or pulling the conduit compartment (27). When the connecting wire is under tension, the intermediate engaging element may be pulled proximally by the conduit compartment and pushed distally by the central wire.

In some other embodiments, all engagement elements are associated with (or connected to) the central wire (10). In some embodiments, only some (but not all) of the engagement elements are fixed to the central wire, while some other engagement elements are free to move over the central wire. Thus, for example, the distal engagement element (90) of fig. 4 may be fixed at a certain position of the central wire, while the proximal engagement element (65) and the middle/middle engagement element (67) may slide freely over the central wire. With this configuration, the distal engaging element may be further controlled when the operator pushes or pulls the central wire via the handle (110), and this may position the most distal extent of the device. Once the distal engaging elements are positioned, the operator may control the connecting wire (190) via the control conduit compartment (27) to further adjust the position of the other engaging elements and the distance/spacing between the engaging elements.

Fig. 5A-D illustrate details of the structure, particularly the connector of the device according to some embodiments of the invention. Fig. 5B shows the proximal engagement element secured to the distal end of the tubing compartment by a connector (41) consisting of an outer connector tube (43) and an inner pusher tube (21). The connecting wire (190) and the leg of the proximal joint element (40) are fixed/bonded between the walls of the two portions of the pipe with a joint medium (42). Similarly, fig. 5C shows the intermediate engagement element connector (44). The connecting wire (190) and the leg of the intermediate coupling element (40) are fixed/coupled between the walls of the two connector conduit portions with a joint medium (42). Fig. 5D shows that the distal connector (80) links the distal tip of the central wire (10), the connecting wire (190) and the leg (40) of the distal engagement element (90) with a short outer v-shaped piece (43) filled with joint medium (42). The central wire (10) passes through the hollow space of the inner connectors (21 and 45), allowing the proximal and intermediate engagement elements (65, 67) to slide freely thereon.

FIG. 6 illustrates a non-limiting exemplary structure of a conduit compartment according to some embodiments of the invention. The conduit compartment may comprise or consist of three main components: an inner distal pusher tube (21), an outer distal pusher tube (23), and a proximal pusher tube (25). All bonded/connected by a linker medium (42). The figure also shows that the proximal end of the central wire is joined to the handle (110) by a joint medium (42). The distal pusher tubing (21, 23) is generally flexible so that the device can be passed through tortuous sections of a blood vessel. The proximal pusher tubing (25) is rigid to ensure that the device can be pushed through a microcatheter.

Fig. 7A-C illustrate yet another embodiment of a device, wherein the device may include a plurality of engaging elements. In some embodiments, the device may include a central wire (10), a control wire (100), and a plurality of self-expandable engagement elements, each of which may be about 2 to about 25mm long or longer in the longitudinal direction. The length of the individual engaging elements when expanded (which may be the same, similar, or different from each other) may be about 1mm, about 2mm, about 4mm, about 5mm, about 6mm, about 7mm, about 8mm, about 9mm, about 11mm, about 12mm, about 13mm, about 14mm, about 15mm, about 16mm, about 17mm, about 18mm, about 19mm, about 20mm, 21mm, 22mm, 23mm, 24mm, and 25 mm. In some embodiments, the length of the individual engaging elements when expanded (which may be the same, similar or different from each other) may be about 25mm or more.

The proximal end of the distal engagement element (90) may be fixed around the distal end of the central wire (10), the structure of this connection being identical to that already shown in fig. 5D. The proximal end of the proximal engagement element (65) and the connecting wire (190) may be secured around the distal end of the control wire (100) by a proximal end connector (41) consisting of an outer connecting conduit (43), an inner connecting conduit (45), and a fitting medium (42), as shown in fig. 7B. The intermediate/engagement element is secured to the connecting wire (190) by connector 44, as shown in fig. 7C, the structure of which is the same as that previously described in fig. 5C. The proximal connector (41) and the intermediate connector (44) are freely slidable on the central wire (10). In some embodiments, a thin flexible connecting wire (190) is coupled to the proximal ends of all of the engaging elements with a preset or equal spacing/distance between each adjacent element. In certain embodiments, the distal section of the control wire may taper into a thinner more flexible section and serve as a connecting wire. In this case, the proximal end of the proximal engagement element may be directly joined to the control wire where the thin section begins, as shown in fig. 7C (i.e., the connecting wire 190 is a section/portion of the control wire 100). The control wire (100) may have a handle (120) attached at the proximal end of the device. The central wire can slide freely within the connectors at the ends of the handle tube and control wire, as well as the intermediate connector. In addition, the device may have a separate handle (110) that may control the movement of the central wire.

In some embodiments, all of the engagement elements are fixed at their respective positions on the connecting wire (100), thereby setting a preset spacing/distance therebetween. On the other hand, while all the engaging elements may be associated with (or connected to) the central wire (10), only the distal engaging element (90) may be fixed at the central wire (10), while the other engaging elements may be freely movable along the central wire. In some such embodiments, the position of each distal and proximal engagement element, and the spacing therebetween, may be adjusted in controlling one or both of the central wire and the control wire in order to securely cinch or grasp the occlusion/clot.

Fig. 8A-F illustrate yet another embodiment of a device, wherein the device may include a plurality of engaging elements. In some embodiments, the device may comprise a plurality of engaging elements, some of which may form an engaging (or operating) unit/pair. The receiving element is connected with a spacing wire (191), which may be stiffer than the previously described connecting wire (190). The spacer wire will not be as flexible or soft so that it will not fold/bend under compression and thus remain elongate. Fig. 8A shows the distance between the receiving element and the catch engaging element being fully opened, while fig. 8B shows the spacing being shortened. Fig. 8D, 8E, 8F show the detailed structure of the proximal receiving engagement element connector (41), the intermediate capture engagement element connector (44) and the distal capture engagement element connector (80), respectively. In some embodiments, the device may comprise a central wire (10), a conduit compartment (27) and a plurality of operating units/pairs. In some embodiments, the device may include two or more pairs of clot-constricting self-expandable engagement elements (each pair including 68 and 69 being considered an operating unit/pair). In each operating unit/pair, there may be at least two or more engaging elements, at least one being a receiving element (e.g. a proximal receiving element and an intermediate receiving element (68)) and at least another being a capturing element (e.g. an intermediate capturing element and a distal capturing element (69)).

In certain embodiments, the capture element may comprise a plurality of wires or struts that may be directly engaged with the occlusion. Alternatively or in combination, the capture element may cinch or grasp the occlusion via frictional engagement with the body lumen and/or frictional engagement within a space between the capture element and another engaging (receiving or capturing) element. In at least some embodiments, the capture element has a closed end at its proximal end. The open end of the catch element may face the distal or proximal side of the device. In some embodiments, all capture elements (from different operating units/pairs) may be fixed to the central wire (10) via connectors (47, 80) and the receiving elements are fixed to the spacer wire (191) via connectors (41, 44), while the capture elements may not be connected to the spacer wire. The receiving element may be located proximal to the capture element and may be shaped to follow the shape of the capture element distal thereto. Thus, in some embodiments, the proximal portion of the capture element can fit within the distal portion of its proximally located receiving element.

In certain embodiments, the proximally-located receiving element (68) may be secured to a distal end of the conduit compartment (27). In addition, all receiving elements can also be fixed at their respective positions at the spacing wire (191). Thus, the spacer wires may connect all receiving elements (68) so as to maintain the distance between the receiving elements. Thus, in this configuration, by controlling the duct compartment, it is also possible to control the position of all receiving elements while maintaining the distance therebetween due to the preset distance set by the association with the spacing wire.

In some embodiments, some or all of the capture elements (from different operating units/pairs) may be fixed to the central wire (10). The central wire can slide freely within the conduit compartment (27) and within the connector receiving the splice element. By this configuration, the positions of all the capturing elements can be controlled via the movement of the center wire.

Thus, in some embodiments, the position of the engagement element may be controlled by movement of the central wire and/or the conduit compartment. For example, the spacing between the receiving element and the capturing element may be controlled by sliding a central wire in the conduit compartment. Alternatively or in combination, the pushing or pulling of the conduit compartment may also result in an extension or shortening of the distance between the receiving element and the capturing element.

FIG. 9 illustrates yet another non-limiting embodiment of a method according to the present invention, wherein the device illustrated in FIG. 8 is used to treat or remove one or more occlusions from a body lumen.

In some embodiments, the device may be introduced through the microcatheter (30) by pushing the central wire (10) and the tubing compartment (27). See fig. 9A and D. Spacing wires (191) may maintain spacing between receiving elements (68). The catching elements (69) may be all fixed to the central wire (10). Upon uncapping (see fig. 9B and E), the engagement elements may expand and contract, thereby increasing the distance between the operating units/pairs and also between the individual engagement elements. The distance between the engagement elements and the different operating units/pairs will allow the occlusion (clot) to become stuck in the spacing gap. During the holding of the tubing compartment (27) steady and pulling the central wire proximally (see fig. 9C and F), the catch element (69) moves backwards. The spacing between the capture and receiving elements is entirely shortened and the portion of the occlusion that is lodged in the spacing between the engaging elements is cinched/gripped or held. The device can then be pulled out of the body lumen (e.g., blood vessel).

In certain embodiments, such as shown in fig. 9A-C, relatively large or long lengths of an occlusion may be treated or removed by a device comprising multiple operating units/pairs. In some such cases, more than one operating unit/pair may cooperatively participate in constricting and grasping the occlusion. Alternatively or in combination, more than one occlusion may be treated or removed individually by separate operating units/pairs, as shown in fig. 9D-F. As already explained elsewhere in this application, the mechanism by which the device cinches or grasps (engages, captures or receives) the occlusion can be varied, for example: (1) the occlusion can be captured within the space between the engagement elements, (2) the occlusion can be directly engaged with the wire or strut of the one or more engagement elements, (3) the occlusion can be frictionally received between the body lumen and the one or more engagement elements, and (4) the occlusion can be frictionally received between the body lumen and the space between the engagement elements.

Fig. 10 shows yet another embodiment of the device, wherein the device may comprise a plurality of engaging elements. In some embodiments, when it is desired to withdraw the device into a microcatheter (30) during a retrieval procedure, the tubing compartment (27) may be pulled back, allowing the spacing between the receiving and capturing elements to be increased to prevent them from stacking on top of each other. Thus, all of the coupling elements may be pulled into the microcatheter.

Fig. 11A and B illustrate yet another embodiment of a device, wherein the device may include a plurality of engaging elements. As an alternative design of the device, the device may further comprise an additional element (90) at the distal end of the device in addition to the plurality of operating units/pairs. The additional element may act as a distal filter. In certain embodiments, the distal end of the distal filter element may be closed by a distal connector (150) to more efficiently capture clot debris. In some embodiments, the profile of the distal filter element (90) may be larger in size and diameter than the profiles of the other engagement elements and less rigid than the other engagement elements. This may minimize radial forces of the distal filter element against the vessel wall. The distal-most engagement element (90) may be used to cinch/grip a clot or occlusion, and to capture or filter clot debris. Thus, if the clot (or occlusion) breaks during the retrieval procedure and generates debris, the debris may be captured (collected or contained) in the distal filter element. Due to the large profile of the distal engagement (filter) element, preferably larger than the diameter of the vessel, debris may not escape between the engagement element and the vessel wall. In fig. 11, "x" indicates the position where the capture element (69) may be fixed to the central wire (10), and "x" indicates the position where the receiving element (68) may be fixed to the spacer wire (191), in some embodiments.

Fig. 12 shows yet another embodiment of the device, wherein the device may comprise a plurality of engaging elements. In some embodiments, the device may include a central wire (10), a control wire (100), and a plurality of operating units/pairs, e.g., each unit/pair including two or more pairs of clot engaging elements. In each engagement operating unit/pair, there may be at least one receiving element and one capturing element, and typically the receiving element may be located proximal to the capturing element. In some embodiments, some or all (proximal and middle) receiving elements (68) may be secured to the control wire (100). In some other embodiments, the (distal and intermediate) capture elements (69) may be secured to the central wire (10) via connectors (47, 80). In certain embodiments, the proximal and intermediate receiving elements (68) may be associated with (or connected to) the central wire (10), but freely slide thereon.

In certain embodiments, the control wire (100) may have a handle (120, e.g., a tube type) attached at a proximal end of the control wire, and the central wire may slide freely within the lumen of the handle tube. Furthermore, the central wire (10) may also be operatively coupled to the handle (110). Thus, by controlling one or both of the control and central wires, the spacing between the engaging elements can be adjusted in order to maximize the engagement and containment of the device against the occlusion.

Fig. 12A and B illustrate adjustment of the distance between the engaging elements. For example, in the embodiment of fig. 12B, during holding of the control wire grip and pulling of the central wire (10) proximally, the capture elements (69) will move backwards, shortening the distance between their receiving elements. When the central wire is pulled back (i.e., proximally), the distance between the capture element and the receiving element will shorten, constricting or grasping the clot at various points. As is apparent from the illustration, for example, conversely, by pushing the control wire distally, the receiving element will move forward (distally), thereby shortening the distance between the engaging elements. Thus, by controlling the movement of the central wire (10) and/or the control wire (100), the position of both the capture element and the receiving element can be adjusted, thereby increasing or decreasing the spacing between the engaging elements.

Fig. 12C to E show certain non-limiting embodiments of connectors such as (41) and (44) in which the engaging element (particularly the receiving element) is configured to move along the central wire but is fixed to the control wire. In certain embodiments, short outer connector tubing (43) and short inner connector tubing (45) and joint medium (42) may be used to join the control wire (100), the legs of the distal receiving element (40). The central wire may slide freely within the inner connector tube (45). All capture elements are fixed to the central wire via connectors (47, 80).

The control wire and the spacer wire may be from the same wire, which may be tapered at the distal section acting as the spacer wire to ensure sufficient flexibility of the joint compartment. Thus, in some embodiments, as shown in fig. 12E, control wire (100) is used as spacer wire (190) in the distal portion of the device.

Fig. 13A-F show yet another alternative embodiment of the device, wherein the device may comprise a plurality of operating units/pairs. In some embodiments, all receiving elements (68) are free to slide on the central wire (10) and all catching elements (69) are fixed to the central wire via connectors (47, 80), forming a plurality of pairs of cinching units/pairs. In each engagement operating unit/pair, there may be at least one receiving element and one capturing element, and typically the receiving element may be located proximal to the capturing element. In some embodiments, a relatively thicker or more rigid spacer wire (191) may connect all receiving elements (68) to maintain the spacing between them. Each unit/pair of capture element (69) and receiving element (68) may be connected to a connecting wire (190). All receiving elements can slide freely on the central wire (10). As shown in fig. 13D, the proximal connector (41) connects the spacer wire (191), the connecting wire (190) and the leg portion (40) of the proximal joint element between the inner and outer connection tubes filled with the joint medium (42). Fig. 13E shows a detailed structure of the receiving engagement element connector (44). It connects the connecting wire (190) and the leg (40) receiving the joining element between the inner connecting tube (45) and the outer connecting tube (43) filled with the joint medium (42). Fig. 13F shows a similarly configured connector (44) connecting the spacer wire (191), the connecting wire (190) and the leg receiving the engagement element between the inner connector tube (45) filled with joint medium (42) and the outer connector tube (43). The central wire can slide freely in the inner connector (45). In such an embodiment, the capture element (69) may be secured to the central wire via connectors (47 and 80) and connecting wire (190). All receiving elements are fixed to the spacer wires via connectors (41 and 44).

In addition, a connecting wire (191) links each pair of capture and receiving elements in the same engagement/manipulation unit/pair to maintain a preset spacing between the pairs of engagement elements, particularly when introducing the device through a microcatheter (30). After denesting, and pulling back on the central wire, the distance between the receiving and capturing elements may be reduced, and the occlusion (clot) may be cinched, grasped, or held between the engaging elements. When the device is pulled back into the microcatheter, the connecting wire (190) flexes; the elements of each pair may overlap, however the struts or profiles of the distal ends of the receiving elements and the catching elements may be designed smaller. Thus, if two engaging elements are stacked, they will still be smaller than the diameter of the microcatheter. Thus, the device may be withdrawn back into the microcatheter. In certain embodiments, the microcatheter may act as a stop for all receiving elements when capturing an occlusion (clot) by pulling back on the central wire and capturing element. The advantage of this design is that there is only one handle at the proximal end of the device. The operator need only pull the central wire backwards to shorten the spacing between the receiving and capturing elements to tighten the clot. The position of the engagement element will be self-adjusting and the clot will be engaged and retained.

Fig. 14A-E illustrate non-limiting configurations of the engagement elements. Alternatively, the engagement may be (but is not limited to) the following form/shape: a cone (fig. 14A), a sphere (fig. 14D), an ellipsoid (fig. 14D), a parachute (fig. 14E), a cylinder (fig. 14C), or any combination of the above (e.g., as shown in fig. 14B). The cylindrical form may also be closed or open at the distal or proximal end.

Fig. 15A-B show an alternative non-limiting illustrative embodiment of a structure that may be formed into a splice element. The engagement element may have a proximal leg 40 and the actual engagement element strut 50. Devices according to some embodiments of the invention may be manufactured by various techniques known in the art. For example, the engagement elements/struts may be fabricated from a sheet by a laser cutting or photo etching process. Alternatively, the engaging element may also be made from a length of hypotubing by laser cutting. The struts or laser cut hypotubes shown in fig. 15 may be heat set to the desired shape and size of the engagement element and further chemically polished or electropolished. The components may be assembled into a retrieval device as described herein.

Fig. 16A illustrates an exemplary device comprising a plurality of engaging elements configured to sequentially retract toward one another. In some embodiments, the engagement elements may simultaneously retract toward each other. The device in fig. 16A-16E may have any of the features of the devices described above. Unless otherwise indicated, the device in fig. 16B-16E may have any of the features of the device of fig. 16A, e.g., differing only in the engaging element connecting structure. In some embodiments, the device may include three or more engagement elements, such as a distal engagement element (1690), a proximal engagement element (1665), and a middle or "intermediate" engagement element (1667) between the distal engagement element (1690) and the proximal engagement element (1665). In some embodiments, the device may include more than three engaging elements, such as by having two or more intermediate engaging elements. In some embodiments, the device may include a central wire (1610), a conduit compartment (1627) defined by an outer introducer conduit (1623), and a connecting wire (1619). The central wire (1610) may freely slide within the conduit compartment (1627) relative to the outer actuator conduit 1623. In some embodiments, the device may include an operable coupling with a handle, such as handle (110) in fig. 1A-1B, at a proximal end of the device. The handle may control (e.g., push or pull) the central wire (1610).

In some embodiments, one or more engagement elements (1665, 1667, 1690) may be associated with (or connected to) central wire (1610). As shown in fig. 16A, the distal engagement element (1690) may be fixedly coupled to the central wire (1610), and the intermediate engagement element (1667) and the proximal engagement element (1665) may be free to slide relative to the central wire (1610). One or more engagement elements (1665, 1667, 1690) may also be connected with the connecting wire (1619). For example, as shown in fig. 16A, in the first state, the connecting wire (1619) may couple the proximal ends of all of the engaging elements (1665, 1667, 1690) at a predetermined distance. In some embodiments, the engagement elements (1665, 1667, 1690) may be preset to have equal spacing therebetween in the first state. In some embodiments, the engagement elements (1665, 1667, 1690) may be preset to have different distances therebetween in the first state. In some embodiments, such as shown in fig. 16A, the device may include two connecting wires 1619 positioned generally diametrically opposite one another.

The proximal engagement element (1665) may be secured to the distal end of the outer introducer tube (1623) by a proximal engagement element connector (1641). The proximal junction element connector (1641) may include an outer connector conduit (1643) and/or an inner pusher conduit (1621). The legs (1640) of the proximal engagement element (1665) and the connecting wire (1619) may be secured (e.g., bonded) between an inner wall of the outer connector tube (1643) and an outer wall of the inner pusher tube (1621), for example, with a bonding medium such as an adhesive, solder (1642), friction, welding, and/or the like.

The intermediate engagement element (1667) may be coupled (e.g., fixed or bonded) to the connecting wire (1619) by an intermediate engagement element connector (1644). The intermediate junction element connector (1644) may comprise an outer connector tube (1643) and/or an inner connector tube (1645). The legs (1640) of the proximal engagement element (1667) and the connecting wires (1619) may be secured (e.g., bonded), such as with a bonding medium such as an adhesive, solder (1642), friction, welding, and/or the like, between an inner wall of the outer connector tube (1643) and an outer wall of the inner connector tube (1645). The central wire (1610) passes through the hollow space of the inner connector (1621, 1645). Thus, proximal engagement element (1665) and intermediate engagement element (1667) may move with connecting wire (1619), but may slide freely relative to central wire (1610).

The proximal end of the distal engagement element (1690) may be secured to the distal end (or tip) of the central wire (1610) via a distal engagement element connector (1680). The distal engagement element connector (1680) may join (e.g., secure, bond, and/or the like) the distal end of the central wire (1610), the distal tip of the connecting wire (1619), and the legs (1640) of the distal engagement element (1690) with the outer connector tube (1643), for example, via a joining medium such as solder (1642) filled within the outer connector tube (1643), adhesive, welding, friction, and/or the like.

The distal engagement element (1690) may serve as a capture element and the engagement elements (1665, 1667) proximal to the distal engagement element (1690) may serve as a capture element and/or a receiving element. When in the extended configuration, the individual engaging elements may vary in length between about 3mm to about 25 mm. Fig. 16A shows the device in its open state, where the space between each adjacent engagement element (1665, 1667, 1690) is fully open, and the connecting wire (1619) is under tension or substantially under tension. The connecting wire (1619) may be flexible. The device may have a closed state, similar to the device shown in fig. 16G, in which the spacing between each engagement element (1665, 1667, 1690) is shortened for the purpose of holding, cinching, and/or grasping an occlusion or clot, with the connecting wires (1619) flexed or folded.

The distance between the elements (1665, 1667, 1690) may be lengthened or maintained by the user pushing on the central wire (1610) and stabilizing the outer actuator tube (1623). Once the device has been advanced to a desired location, such as when a clot is between the proximal engagement element (1665) and the distal engagement element (1690) (e.g., the proximal end of the distal engagement element (1690) or the distal end of the distal engagement element (1690)), the spacing between the engagement elements (1665, 1667, 1690) can be reduced by a user pulling proximally on the central wire (1610) and/or pushing distally out the actuator tube (1623). This manipulation may contract the connecting wire (1619), thereby bringing the engaging elements (1665, 1667, 1690) together to capture a clot therebetween. Connecting wire (1619) may include one or more filaments configured to be axially compressed by pulling on central wire (1610) and/or pushing (or stabilizing) outer pusher tubing (1623). The connecting wire (1619) may include a metal wire (nitinol, stainless steel, and/or the like), a plastic wire, and the like. The thin connector wires may have an outer diameter ranging from about 0.005 inches (about 0.13mm) to about 0.02 inches (about 0.51mm), such as about 0.005 inches (about 0.13mm), about 0.006 inches (about 0.15mm), about 0.007 inches (about 0.18mm), about 0.008 inches (about 0.20mm), about 0.009 inches (about 0.23mm), about 0.01 inches (about 0.25mm), about 0.012 inches (about 0.30mm), about 0.014 inches (about 0.36mm), about 0.016 inches (about 0.41mm), about 0.018 inches (about 0.46mm), or about 0.02 inches (about 0.51 mm). In some embodiments, the outer diameter of the connecting wire may vary gradually or stepwise along its length.

If the connecting wire (1619) has uniform stiffness along the length of the wire (1619), all of the engagement elements (1665, 1667, 1690) may be brought together simultaneously or substantially simultaneously when the device is actuated to contract the connecting wire (1619). Simultaneous contraction of the connecting wire (1619) between the proximal engagement element (1665) and the intermediate engagement element (1667) and between the intermediate engagement element (1667) and the distal engagement element (1690) may result in loss of clot. For example, if the clot has not been first engaged between the intermediate engagement element (1667) and the distal engagement element (1690), the clot may not move backwards in the blood vessel, and the engagement elements (1665, 1667, 1690) may slide through the clot as the distal and intermediate engagement elements (1667, 1690) are pulled proximally and simultaneously towards the proximal engagement element (1665).

In some embodiments, the stiffness or axial compression force of the connecting wire (1619) may be varied along its length such that the clot engaging elements (1665, 1667, 1690) are sequentially brought together. For example, differential axial compression forces may allow a user to first bring the distal engagement element (1690) and the intermediate engagement element (1667) together, and then bring the intermediate engagement element (1667) and the proximal engagement element (1665) together.

In fig. 16A, the stiffness of the connecting wire (1619) from the proximal engaging element (1665) to the intermediate engaging element (1667) may be higher than the stiffness of the connecting wire (1619) from the intermediate engaging element (1667) to the distal engaging element (1690). The difference in stiffness may be due to, for example, the material, thickness, shape setting (if applicable), and/or the like of the connecting wire (1690) in those different sections. As shown in fig. 16F (device in second state) and 16G (device in third state), when the user pulls the connecting wire (1610) proximally and/or pushes the outer pusher conduit (1623) distally, the gap between the intermediate and distal engagement elements (1667, 1690) may close in the second state, and then the gap between the intermediate and proximal engagement elements (1665, 1667) closes in the third state. This sequential contraction of the connecting wire (1619) may allow for better capture of the clot during the retrieval procedure. The clot may first be engaged between the intermediate and distal engagement elements (1667, 1690) and then pulled back to then be further engaged between the intermediate and proximal engagement elements (1665, 1667).

In some embodiments, the connecting wire (1619) may be more rigid between the intermediate and distal engaging elements (1667, 1690) than between the intermediate and proximal engaging elements (1665, 1667) such that the intermediate and proximal engaging elements (1665, 1667) are first approximated together and then the distal and intermediate engaging elements (1667, 1690) are approximated together.

The device can be deployed using a method such as that shown in fig. 2A-C to remove an occlusion or clot in a body lumen. To engage or retain a clot, the operator may shorten the spacing or gap between the engagement elements (1665, 1667, 1690) by: (i) by pulling the central filament (1610) backwards (proximally) while keeping the conduit compartment (1627) stable, (ii) by pushing the conduit compartment (1627) forwards (distally) while keeping the central filament (1610) stable, or (iii) by pulling the central filament (1610) backwards (proximally) while pushing the conduit compartment (1627) forwards (distally). Such adjustment of the position of the engagement elements (1665, 1667, 1690) and the spacing therebetween may allow at least a portion of the clot to be compressed/constricted or captured in the spacing gap, such as shown in fig. 2B-2C. Alternatively or in combination, the occlusion may be secured via frictional engagement with the body lumen and one or more engagement elements (1665, 1667, 1690). The obturator may also be directly engaged with a strut or wire of an engagement element (1665, 1667, 1690). In some embodiments, engagement (capture) and accommodation of an occlusion may involve more than one mode disclosed herein. The pattern of securely cinching/gripping the occlusion may include one or more of the following: (1) the occlusion can be cinched or held between the engagement elements, (2) the occlusion can be directly engaged with the wires or struts of the one or more engagement elements, (3) the occlusion can be frictionally received between the body lumen and the one or more engagement elements, and/or (4) the occlusion can be frictionally received between the body lumen and the spacing between the engagement elements.

In some embodiments, during a treatment procedure, the distal engagement element (1690) may first move backward and may cinch up or hold a clot with an adjacent engagement element, such as an intermediate engagement element (1667). Adjacent engaging elements, such as one or more intermediate engaging elements, may then be simultaneously or sequentially pushed rearwardly (proximally) toward the proximal engaging element (1690), which in turn may further compress and/or cinch the occlusion. The user may shorten the distance between the engagement elements until the occlusion is securely cinched/grasped by the device. Once the occlusion is deemed to be firmly grasped or cinched by the device, the device may be pulled proximally out of the body lumen.

Other types of couplings or connecting structures may be used to connect the engagement elements (1665, 1667, 1690). In some embodiments, the coupling structure may have different axial compression loads along its length such that the engagement elements sequentially approach each other as the central wire (1610) is pulled and/or the outer pusher conduit (1623) is pushed.

As shown in fig. 16B-16D, the coupling structure may include or be formed from a tube having a slit along its length. A device comprising a conduit as a coupling structure, which may be more rigid than a device comprising a flexible wire as a coupling structure, may advantageously omit the inner connector tube at the intermediate junction element, thereby reducing the number of parts for assembling the device. The tubing may comprise or be made of metal (such as nitinol, stainless steel, and/or the like), plastic, and the like. The duct may start from a sheet rolled into a tube (e.g., after cutting a slit). In some embodiments, a laser may be used to cut the slits. The pattern of the slits may vary, such as vertical, horizontal, slanted, helical, combinations thereof, and/or the like. In fig. 16B, the conduit (1618) includes a slit (1628) oriented in a direction substantially parallel to the longitudinal axis of the conduit (1628) and/or parallel to the connecting wire (1610). In fig. 16C, the conduit (1617) includes a slit (1627) oriented at an angle relative to the longitudinal axis of the conduit (1628) and/or relative to the connecting wire (1610). The angle may be, for example, between about 5 ° and about 85 ° relative to the longitudinal axis (e.g., about 5 °, about 10 °, about 15 °, about 20 °, about 25 °, about 30 °, about 35 °, about 40 °, about 45 °, about 50 °, about 55 °, about 60 °, about 65 °, about 70 °, about 75 °, about 80 °, about 85 °, and ranges therebetween). In fig. 16D, the conduit (1616) may have a helical or spiral slit 1626 along the longitudinal axis of the conduit (1628) and/or for the connecting wire (1610). The angle of the spiral or helical slit may be, for example, between about 5 ° and about 85 ° relative to the longitudinal axis (e.g., about 5 °, about 10 °, about 15 °, about 20 °, about 25 °, about 30 °, about 35 °, about 40 °, about 45 °, about 50 °, about 55 °, about 60 °, about 65 °, about 70 °, about 75 °, about 80 °, about 85 °, and ranges therebetween).

The distance between the engagement elements (1665, 1667, 1690) may be shortened by pulling on the central wire (1610) and/or stabilizing (or pushing) the outer actuator tube (1623). The conduits (1618, 1617, 1616) may experience axial loads along their length as a user pulls on the central wire (1610) and/or holds the outer pusher conduit (1623) steady and/or pushes the outer pusher conduit (1623). The compression may cause the conduit (1618, 1617, 1616) to deform at or near the slit (1628, 1627, 1626). In some embodiments, the conduit (1618, 1617, 1616) may shorten under axial compression loads. Shortening may allow the position of the intermediate and/or distal engagement elements (1667, 1690) to be changed relative to the proximal engagement element (1665) and the distance between the elements (1665, 1667, 1690) to be shortened. In some variations, the conduits (1618, 1617, 1616) may have a corrugated shape, which may also be shortened by axial loads. In addition to the capturing action of the engagement elements (1665, 1667, 1690), the radial expansion of the shortened conduits (1618, 1617, 1616) may help carry and/or hold the clot against the vessel wall and/or more strongly hold the clot during withdrawal of the device, which may improve capture and/or removal of the clot.

The slits (1628, 1627, 1626) may vary between the proximal and intermediate engagement elements (1665, 1667) and between the intermediate and distal engagement elements (1667, 1690). The slits (1628, 1627, 1626) may vary in cutting pattern, pitch/angle, density, thickness, material, shape setting (if applicable), and/or the like. In some embodiments, the section of the conduit (1618, 1617, 1616) between the intermediate and distal engagement elements (1667, 1690) may be subjected to a lower compressive load than the section of the conduit (1618, 1617, 1616) between the intermediate and proximal engagement elements (1666, 1667) prior to retraction (e.g., shortening). Upon pulling the central wire (1610) and/or pushing the outer pusher conduit (1623), the gap between the intermediate and distal engagement elements (1667, 1690) may decrease before the gap between the intermediate and proximal engagement elements (1665, 1667) decreases. In some embodiments, the section of the conduit (1618, 1617, 1616) between the intermediate and proximal engagement elements (1665, 1667) may be subjected to a lower axial compressive load than the section of the conduit (1618, 1617, 1616) between the intermediate and distal engagement elements (1667, 1690) prior to retraction (e.g., shortening). In some embodiments, the conduits (1618, 1617, 1616) allow for simultaneous contraction.

As shown in fig. 16E, the attachment structure may comprise an attachment braid or tubular structure (1615). The braid (1615) may comprise or be made of metal (such as NiTi, stainless steel, and/or the like), plastic, and the like. In some embodiments, braid (1615) comprises a plurality of wires or filaments braided into a tubular braid. In some embodiments, the tubular structure (1615) may be laser cut from a hypotube or other type of conduit. The strut thickness, wire thickness, braid pattern, braid angle, density, shape setting (if applicable), and/or other properties of the braid or tubular structure (1615) may optionally be varied such that sections of the tubing (1618, 1617, 1616) between the intermediate and distal engagement elements (1667, 1690) and sections of the tubing (1618, 1617, 1616) between the intermediate and proximal engagement elements (1665, 1667) may be subjected to lower axial compressive loads than before contraction (e.g., shortening), or such that sections of the tubing (1618, 1617, 1616) between the intermediate and proximal engagement elements (1665, 1667) and sections of the tubing (1618, 1617, 1616) between the intermediate and distal engagement elements (1667, 1690) may be subjected to lower axial compressive loads than before contraction (e.g., shortening). In some embodiments, braids 1615 are allowed to contract simultaneously.

In some embodiments, the coupling structures may comprise different coupling structures. For example, the section between the intermediate and proximal engagement elements (1667, 1665) may comprise a different one of a wire, a tube containing a longitudinal slit, a tube containing an angled slit, a tube containing a helical slit, or a braid, and the section between the intermediate and distal engagement elements (1667, 1690) may comprise a wire, a tube containing a longitudinal slit, a tube containing an angled slit, a tube containing a helical slit, or a braid. The inherent nature of compression upon application of an axial load between different types of coupling structures may provide sequential compression without changing one type of coupling structure.

In some embodiments where the device includes more than three engagement elements, the stiffness of the linking structure may vary between each engagement element. For example, the stiffness between the proximal engaging member and the second proximal-most engaging member may be different from the stiffness between the second proximal-most engaging member and the third proximal-most engaging member, which may be different from the stiffness between the third proximal-most engaging member and the distal engaging member. In some embodiments, the stiffness may be continuous in the same direction (e.g., more stiff, or less stiff, less stiff). In some embodiments, the changes in stiffness may alternate (e.g., more, less, more, or less stiff, more, less stiff). The principles disclosed herein may also be applied to five or more engaging elements.

The principles herein may be applied to two engagement elements. For example, an initial axial load between the proximal and distal engaging elements may cause the coupling structure to contract a first amount, and a further axial load between the proximal and distal engaging elements may cause the coupling structure to contract a second amount different from the first amount. The coupling structure may be shortened, which may help carry and/or hold the clot against the vessel wall and/or more strongly hold the clot during withdrawal of the device, which may improve capture and/or removal of the clot.

The coupling structures disclosed herein may resist different axial loads along the length of the coupling structure. For example, a section of the linking structure may resist an axial load of about 5 grams, or about 10 grams, or about 15 grams, or about 20 grams, or about 25 grams, or about 30 grams, or about 35 grams, or about 40 grams, or about 45 grams, or about 50 grams, or any range between these values.

Fig. 17A-17F illustrate an embodiment of a device comprising two engagement elements: a distal engagement element (1790) and a proximal engagement element (1765). The device may include features such as those described in U.S. patent application No.13/191,306 and U.S. patent application No.13/543,657, which are incorporated by reference herein in their entirety for all purposes. In some embodiments, the device may include only one engagement element or a plurality of engagement elements (e.g., as described herein and/or in U.S. patent application No.14/638,994, which is incorporated herein by reference in its entirety for all purposes). The leg (1740) of the proximal and/or distal engagement element (1765, 1790) may include an indicia (1770), such as at a distal end of the leg 1740. The indicia may also be located at other portions of the device. In some embodiments, the device may include a central wire (1710) and a microcatheter (1730). When the device includes more than one engagement element, the device may optionally include a coupling wire (1719). The central wire (1710) may have a taper such that a distal portion of the central wire (1710) may have a smaller outer diameter than the remainder of the central wire (1710). The device of fig. 17A-17F may advantageously omit or have no outer injector conduits. The absence of an outer pusher conduit may allow the distal end of the device, including the proximal engagement element (1765) and the distal engagement element (1790), to reach a more distal portion of the vessel lumen, such as a small branch artery, which may be too small to be accessed by a device containing an outer pusher conduit.

The central wire (1710) may slide freely within the microcatheter (1730). In some embodiments, the device may further comprise an operable coupling with a handle, such as handle (110) in fig. 1A-1B, at the proximal end of the device. The handle may control (e.g., push or pull) the central wire (1710). As shown in fig. 17A, a distal engagement element (1790) may be secured to the distal tip of the central wire (1710). The proximal engagement element (1765) may be set to a predetermined distance from the distal engagement element (1790). The two engagement elements may be coupled with a coupling wire or structure (1719), such as a wire in fig. 17A-17C, a suture, a braid (1715) in fig. 17D, a conduit having a slit as disclosed herein, and/or the like.

As shown in fig. 17B, the proximal engagement element (1765) may be secured to the proximal engagement element connector (1741). The proximal engaging member connector (1741) may include an outer connector tube (1743) and/or an inner connector tube (1745). The legs (1740) and the tie wires (1719) of the proximal engagement element (1765) may be secured (e.g., bonded) between the inner wall of the outer connector tube (1743) and the outer wall of the inner connector tube (1745), for example, with a bonding medium such as adhesive, solder (1642), friction, welding, and/or the like. The proximal engagement element (1765) may slide freely over the central wire (1710). As shown in fig. 17B, the proximal end of the distal engagement element (1790) may be secured to the distal end (or tip) of the central wire (1710) via a distal engagement element connector (1780). The distal engagement element connector (1780) may couple (such as by securing, bonding, and/or the like) the distal end of the central wire (1710), the coupling wire (1719), and the leg (1740) of the distal coupling element (1790) with the outer connector tubing (1743), such as using a coupling medium such as adhesive, solder (1642), friction, welding, and/or the like.

To introduce the device into a body lumen within the microcatheter (1730), the distal engagement element (1790) can be pushed distally along the microcatheter (1730). The coupling wire (1719) may be under tension, which may pull the proximal engagement element (1765) through the microcatheter (1730). During a clot retrieval procedure, a proximal engagement element (1765) may be placed at the proximal end of the clot, and a distal engagement element (1790) may be distal to the proximal end of the clot or distal to the clot (while the device is still within the distal end of the microcatheter (1730)). The proximal and distal engagement elements (1765, 1790) may expand or open when the microcatheter (1730) is uncapped during retention of the central wire (1710). The clot can be at least partially between the proximal and distal engagement elements (1765, 1790). The un-sheathing may stop when the proximal end of the proximal engagement element (1765) has just left the distal end of the microcatheter (1730).

The spacing between the engaging elements may be reduced by the user pulling proximally on the central wire (1710), thereby bringing the engaging elements closer together to capture a clot therebetween, such as shown in fig. 17C. The clot can be engaged by the distal engagement element (1790), pulled back, and grasped between the proximal and distal engagement elements (1765, 1790). When in the extended configuration, the individual engaging elements may vary in length between about 3mm to about 25 mm. The flexible coupling wire (1719) may flex when the distal engagement element (1790) is pulled rearward. In devices having only one engagement element, the clot may be engaged by the engagement element and removed proximally through the device. Alternatively or additionally, the spacing between the engagement elements (1765, 1790) may be reduced by pushing the microcatheter (1730) forward. This may push the proximal engagement element (1765) towards the distal engagement element (1790). Pushing the microcatheter (1730) forward may be done during stabilization or fixation of the central wire (1710). The spacing between the engagement elements (1765, 1790) may also be reduced by simultaneously pulling on the central wire (1710) during pushing of the microcatheter (1730).

In some embodiments, the strut or foot design of the proximal engagement element (1765) may be configured to make it difficult to pull the proximal engagement element (1765) back into the microcatheter (1730). For example, the struts or feet of the proximal engagement element (1765) may be rigid and/or thick enough, and/or angled enough (e.g., between about 30 ° and about 90 ° (e.g., about 30 °, about 35 °, about 40 °, about 45 °, about 50 °, about 55 °, about 60 °, about 65 °, about 70 °, about 75 °, about 80 °, about 85 °, about 90 °, and ranges therebetween)) such that upon expansion, the struts may resist contraction and are pulled back into the microcatheter (1730). In some embodiments, thicker struts of the proximal engagement element (1765) may allow for lower angles. A proximal engagement element (1765) comprising a lower angle may be pushed more easily through the microcatheter (1730). In some embodiments, a higher angle of the proximal engagement element (1765) may allow for thinner struts. The angles disclosed herein may be relative to the longitudinal axis of the central wire (1710), the longitudinal axis of the microcatheter (1730), and/or the longitudinal axis of the proximal engagement element (1765). The distal tip of the microcatheter (1730) may prevent the expanded proximal engagement element (1765) from moving back into the microcatheter (1730) and the device becomes "locked" at the distal tip of the microcatheter (1730). The "locking" may improve and/or more ensure engagement of the clot between the proximal and distal engagement elements (1765, 1790). With the relative positions of the microcatheter tip and the distal and proximal engagement elements (1765, 1790) locked, the device can be removed from the artery with the clot engaged.

The device may additionally or alternatively include a stop feature at a proximal end of the proximal engagement element (1765). The stop feature may have any shape (e.g., ring, clip, and/or the like) and/or size, and may be configured to radially expand (such as automatically expand (e.g., due to a shape setting)) upon denesting of the microcatheter (1730). During pulling back of the distal engagement element (1790) to engage the clot, the stop feature may facilitate the proximal engagement element (1765) being stopped by the end of the microcatheter (1730). A clot removal procedure with the proximal end of the proximal engagement (1765) resting on the distal tip of the microcatheter (1730) may allow a clot to be more tightly engaged between the proximal and distal engagement elements (1765, 1790). Inhibiting or preventing the re-entry of the proximal engagement element (1765) of the captured clot into the microcatheter (1730) may reduce the risk of the captured clot falling off completely or in small parts (e.g., release of small emboli). Such a procedure may reduce or eliminate the outer pusher tubing so that the device may be advanced into smaller body lumens (such as small branch arteries) than would otherwise be necessary to remove occlusions in those lumens. This potential advantage can be achieved without significantly increasing trauma to the body lumen wall.

As shown in fig. 17E, the stopper feature may include a ring (1772). When the proximal engagement element (1765) is outside of the microcatheter (1730), the ring 1772 can flex radially outward. In some embodiments, the ring may open automatically. The stop feature may also be a helical spring wire (1774), such as shown in fig. 17F. Other examples of stop features include any configuration made of shape memory alloy (e.g., nitinol cage), wire having a predetermined three-dimensional shape, and the like. In some embodiments, the stop feature has a diameter when expanded that is greater than a diameter of the distal end of the microcatheter.

The strut design of the leg (1740) of the other stopper features and/or proximal engagement element (1765) disclosed herein may resist a pull-out force of about 50 grams, about 100 grams, about 150 grams, about 200 grams, about 250 grams, about 300 grams, about 350 grams, about 400 grams, about 450 grams, or any range between these values.

In some embodiments of devices having more than two engaging elements, struts of the legs of the proximal engaging element or other stop features at the proximal end of the proximal engaging element may be included to inhibit or prevent the expanded proximal engaging element from being pulled back into the microcatheter when the central wire is pulled to move the distal engaging element proximally and/or push the microcatheter to capture clots.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Term(s) for

As used herein, the relative terms "proximal" and "distal" are defined from the perspective of the delivery system. Thus, proximal refers to the direction of the handle portion of the delivery system, while distal refers to the direction of the distal tip.

While certain embodiments and examples have been described herein, those skilled in the art will appreciate that many aspects of the delivery systems shown and described in this disclosure may be variously combined and/or modified to form yet further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. A wide variety of designs and approaches are possible. The features, structures, or steps disclosed herein are not required or essential to all of them.

For the purposes of this disclosure, certain aspects, advantages, and novel features are described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

Moreover, although illustrative embodiments have been described herein, the scope of any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations, and/or alterations are based on the present disclosure as would be appreciated by those in the art. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. Further, the acts of the disclosed processes and methods may be modified in any manner, including by reordering acts and/or inserting additional acts and/or deleting acts. It is intended, therefore, that the specification and examples be considered as exemplary only, with a true spirit and scope being indicated by the following claims and their full scope of equivalents.

Unless specifically stated otherwise, or otherwise understood in the context of usage, conditional language, such as "may", "might", "may", "for example", etc., as used herein, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements, blocks, and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for determining (with or without author input or prompting) whether such features, elements, and/or states are included or are to be performed in any particular embodiment.

The methods disclosed herein may include certain actions taken by the practitioner; however, these methods may also include any third party instructions, either explicit or implicit, for these actions. For example, actions such as "advancing a self-expanding stent" include "instructing to advance a self-expanding stent".

The ranges disclosed herein also encompass any and all overlaps, sub-ranges, and combinations thereof. Language such as "up to," "at least," "greater than," "less than," "between," and the like includes the recited number. Numbers beginning with terms such as "about" or "approximately" include the number recited and should be interpreted on a case by case basis (e.g., as reasonably accurate as possible in certain instances, e.g., ± 1%, ± 5%, ± 10%, ± 15%, etc.). For example, "about 0.01 inch" includes "0.01 inch". Phrases that begin with terms such as "substantially" include the recited phrase and should be interpreted based on the context (e.g., as much as reasonably possible in certain circumstances). For example, "substantially linear" includes "linear".