Mechanical thrombectomy device partially collapsible upon activation of internal actuatable collapsible mechanism during occlusion retrieval

Abstract

A mechanical thrombectomy device includes a self-expanding cage structure that is transitionable from a radially expanded state to a radially partially collapsed state having an outer diameter that is reduced relative to the outer diameter in the radially expanded state. The mechanical thrombectomy device further includes an internal actuatable collapsible mechanism that is internally fixedly attached to the self-expanding cage structure; wherein the inner actuatable collapsible mechanism, when actuated or deployed, applies a radially inward tension to the self-expanding cage, thereby transitioning the self-expanding cage to a radially partially collapsed state.

Description

Technical Field

[0001] The present invention relates to mechanical thrombectomy devices for use in endovascular treatment procedures (e.g., during a thrombectomy procedure to remove a clot). In particular, the present invention relates to a mechanical thrombectomy device that partially collapses radially (i.e., the outer diameter / outer profile is reduced) in response to activation of an internally actuatable collapse mechanism after an obstruction is captured therein, thereby making it particularly suitable for retrieving an obstruction located in a distal vessel.

[0002] Related technologies

[0003] Arteries or blood vessels in the brain may become blocked, resulting in acute ischemic stroke (AIS). Endovascular treatment procedures or therapies include capturing and removing the target blockage using a mechanical thrombectomy device (e.g., a stent) that is navigated through the vasculature. The blockage can be identified in different areas of the vasculature, such as in the brain. One type of brain blockage (commonly referred to as a large vessel occlusion (LVO) or proximal blockage) is located in one of the major arteries of the anatomical structure of the brain (e.g., the internal carotid artery (ICA), the terminal end of the ICA (T-lesions; T blockages), the middle cerebral artery (MCA), the M1 MCA, the vertebral artery, or the basilar artery). The alternatively used term for large vessel blockages is a proximal blockage, wherein the name refers to the fact that these types of blockages are disposed proximally in the vasculature of the brain relative to other types of blockages (and therefore referred to as distal blockages) that are distal to one of the major arteries of the anatomical structure of the brain. Distal obstructions are often caused by accidental fragmentation / fragmentation and / or escape from a retrieval device (eg, stent) during manipulation of the original / primary obstruction that is more proximally positioned relative thereto.

[0004] In order to achieve maximum benefit, the capture of such distal obstructions and the recanalization of these distal vessels are desirable, however, current mechanical thrombectomy devices have several disadvantages and bring significant health risks. When treating obstructions in the distal vessels of the brain, there are additional challenges. One aspect is that the distal vessels are often very curved and require a longer device to enter, which in turn increases the difficulty of navigating and tracking the catheter to these locations, because the catheter often loses pushability. In addition, the tissues around these vessels are fragile / vulnerable, and significant movement of brain structures may occur during removal. The obstructions in these distal vessels are usually treated using conventional mechanical thrombectomy devices (e.g., conventional stents). When conventional mechanical thrombectomy devices (e.g., conventional stents) are used to capture and remove obstructions in the distal vessels, there is a considerable risk of damaging the vessel, rupture or perforator, vasospasm and even bleeding. Another disadvantage of using conventional mechanical thrombectomy devices to treat obstructions in distal vessels is the risk of displacement of the clot captured during removal.

[0005] It would be desirable to develop an improved mechanical thrombectomy device that reduces these risks, thereby improving overall outcomes. Additionally, it would be desirable to develop an improved mechanical thrombectomy device that tightly grips a captured clot, thereby minimizing the risk of accidentally releasing the clot while navigating the tortuous path of a distal vessel, while minimizing the frictional forces exerted on the delicate vessel walls and minimizing the associated risks of complications due to bleeding. Summary of the invention

[0006] One aspect of the present invention relates to an improved mechanical thrombectomy device that minimizes friction or drag with the vessel wall during retrieval of a clot captured therein, and thereby minimizes the potential risk of damage / rupture to the vessel wall.

[0007] Another aspect of the present invention relates to an improved mechanical thrombectomy device, which includes an internally actuatable collapse mechanism, which, when actuated (i.e., under the tension of a force applied in the proximal direction (e.g., pulling a pull wire in the proximal direction)) before the mechanical thrombectomy device is restored / pulled back into the microcatheter / catheter, causes the self-expanding cage structure of the mechanical thrombectomy device to partially collapse radially (i.e., the outer diameter / outer profile is reduced relative to the outer diameter / outer profile when it was in a radially expanded state before actuation of the internally actuatable collapse mechanism).

[0008] Yet another aspect of the present invention relates to an improved mechanical thrombectomy device which, when radially partially collapsed, constricts / clamps downwardly upon a clot captured therein, thereby minimizing the potential risk of losing its grip (i.e., dislodging) while navigating through tortuous vascular pathways during removal from the body.

[0009] Yet another aspect of the present invention relates to a mechanical thrombectomy device, the mechanical thrombectomy device comprising a self-expanding cage structure capable of transitioning from a radially expanded state to a radially partially collapsed state having an outer diameter reduced relative to an outer diameter when in the radially expanded state. The mechanical thrombectomy device further comprises an internally actuatable collapse mechanism fixedly attached internally to the self-expanding cage structure; wherein the internally actuatable collapse mechanism, when actuated, applies a radially inward tension to the self-expanding cage structure, thereby causing the self-expanding cage structure to transition to the radially partially collapsed state.

[0010] Another aspect of the present invention relates to a method for capturing and removing an obstruction in a blood vessel using the mechanical thrombectomy device described in the previous paragraph. A guide wire is inserted through the blood vessel to the proximal side of the obstruction. Next, a microcatheter is tracked by the guide wire to the proximal side of the obstruction. The guide wire and microcatheter are advanced together or independently and sequentially through the obstruction. The guide wire is then withdrawn from the blood vessel. At this point, the mechanical thrombectomy device is advanced through the microcatheter, and then the mechanical thrombectomy device is actuated, so that the mechanical thrombectomy device is converted to a radially expanded state and the obstruction is captured therein. By applying a radially inward tension inside the self-expanding cage structure, the internally actuable collapse mechanism is deployed, thereby converting from the radially expanded state to a radially partially collapsed state with a reduced outer diameter, while compressing the obstruction captured therein. In the case where the compressed obstruction is captured therein, the self-expanding cage structure is pulled back into the microcatheter when it is in the radially partially collapsed state. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other features of the present invention will become more apparent from the following detailed description and accompanying drawings, in which examples of the present invention are illustrated, wherein like reference numerals refer to similar elements throughout the several views, and in which:

[0012] Figure 1A is a side view of an exemplary mechanical thrombectomy device having an internally actuatable collapse mechanism (e.g., a pull wire) according to the present invention; wherein the mechanical thrombectomy device is depicted in a radially expanded state prior to actuation of the internally actuatable collapse mechanism;

[0013] Figure 1B yes Figure 1A1. A side view of an exemplary mechanical thrombectomy device depicted in a radially partially collapsed state (i.e., outer diameter / outer profile relative to the outer diameter) due to actuation of an internally actuatable collapse mechanism. Figure 1A The outer diameter / outer profile is reduced in the radially expanded state);

[0014] Figure 2A is one with two clots embedded in it Figure 1A A side view of an exemplary mechanical thrombectomy device of; wherein the mechanical thrombectomy device is depicted in a radially expanded state prior to actuation of an internal actuatable collapse mechanism;

[0015] Figure 2B is one with two clots embedded in it Figure 2A 1. Side view of an exemplary mechanical thrombectomy device of FIG. 1; wherein the mechanical thrombectomy device is depicted as being in a radially partially collapsed state (i.e., the outer diameter / outer profile relative to the outer diameter) due to actuation of the internal actuatable collapse mechanism Figure 2A The outer diameter / outer profile is reduced in the radially expanded state), clamping down on the two clots captured therein;

[0016] Figure 3A is where a single clot is trapped. Figure 1A An enlarged side view of an exemplary mechanical thrombectomy device of FIG. 1 ; wherein the mechanical thrombectomy device is depicted in a radially expanded state prior to actuation of an internal actuatable collapse mechanism;

[0017] Figure 3B is where a single clot is trapped. Figure 3A ; wherein the mechanical thrombectomy device is depicted as being in a radially partially collapsed state (i.e., the outer diameter / outer profile relative to the Figure 3A the outer diameter / outer profile of the radially expanded state is reduced) and clamps, grasps or constricts downwardly to physically compress the clot captured therein (e.g., deforms the shape);

[0018] Figure 4 Depicted are preliminary steps in an intravascular treatment or procedure according to any configuration of the present invention, wherein a guidewire is first navigated to a target site in a vessel and a microcatheter is then tracked over the guidewire;

[0019] Figure 5is a side view of yet another exemplary mechanical thrombectomy device having three internally actuatable collapse mechanisms (e.g., three separate pull wires, each of which is actuatable independently of the others) internally connected to a different one of the articulated stent segments; wherein the mechanical thrombectomy device is depicted in a radially expanded state prior to actuation of any one of the three internally actuatable collapse mechanisms;

[0020] Fig. 6A is a side view of the mechanical thrombectomy device of the present invention with a clot captured therein prior to actuation of the internal actuatable collapse mechanism; and

[0021] Figure 6B yes Fig. 6A A side view of a mechanical thrombectomy device after actuation of an internally actuatable collapse mechanism, illustrating that a portion of the mechanical thrombectomy device that coincides with (e.g., is aligned with) a clot has a lesser degree of outer diameter reduction than a portion of the mechanical thrombectomy device that does not coincide with the clot. DETAILED DESCRIPTION

[0022] In the specification, the terms "distal" or "proximal" are used in the following descriptions regarding positioning or direction relative to a treating physician or medical interventionist. "Distal" or "distalward" is a positioning away from or in a direction away from the physician or interventionist. "Proximal" or "proximalward" or "on the proximal side" is a positioning close to or in a direction toward the physician or interventionist. The terms "obstruction", "clot" or "blockage" are used interchangeably.

[0023] The internally actuatable collapse mechanism of the present invention can be used with any desired design or configuration of a mechanical thrombectomy device. In an exemplary configuration of a mechanical thrombectomy device designed as a plurality of articulated stent segments (i.e., unit elements), the number of articulated stent segments (i.e., unit elements) and the specific arrangement / design of the struts associated with each stent segment (i.e., unit element) can be selected as desired, and the specific arrangement / design of the struts can be different or the same for each stent segment. In addition, the internally actuatable collapse mechanism of the present invention can be employed with a dual-structure mechanical thrombectomy device of multiple self-expanding cage structures nested together, which can be delivered to a target site as a single assembled unit but can be actuated independently of each other. For example, a dual-structure mechanical thrombectomy device can be configured to include at least one internal self-expanding cage structure nested within an axial / longitudinal channel of an outermost self-expanding cage structure, wherein each self-expanding cage structure can be actuated independently of each other.

[0024] By way of example, the mechanical thrombectomy device of the present invention is illustrated and described herein as three articulated stent segments. Figure 1A is a side view of an example mechanical thrombectomy device 100 in a radially expanded state having an outer diameter / profile “D” prior to actuation / deployment of an internally actuatable collapse mechanism (depicted as being in a non-actuated / non-deployed state) in accordance with the present invention. Figure 1B , depicts the same mechanical thrombectomy device after actuation / deployment of an internally actuatable collapse mechanism (depicted as being in an actuated / deployed state) causing the mechanical thrombectomy device to be in a radially partially collapsed state (i.e., having a radial outer profile / outer diameter "d", where "d" < "D"). Figure 1A and Figure 1B Clear visualization of the internal actuatable collapse mechanism and its connection points internally to each articulated stent segment, including the self-expanding cage structure of the mechanical thrombectomy device, is provided.

[0025] As previously mentioned, the mechanical thrombectomy device illustrated and described herein has an articulated design that includes three stent segments 115a, 115, 115c (i.e., three unit elements) arranged in series along the axial / longitudinal direction from the proximal end 105 to the opposite distal end 110. Specifically, the distal end of the first stent segment 115a is connected or attached to the proximal end of the second stent segment 115b, and the distal end of the second stent segment 115b is connected or attached to the proximal end of the third stent segment 115c. Each stent segment 115a, 115b, 115c in all example mechanical thrombectomy devices illustrated and described herein is identical in configuration, but not necessarily so. For any particular mechanical thrombectomy device, the configuration and number of struts or arms of each stent segment may be the same or different. The first stent segment 115a is connected at its proximal end to a proximal shaft 130 (eg, a tube) having a passage 135 defined therethrough in an axial / longitudinal direction.

[0026] Conventional self-expanding mechanical thrombectomy devices are compressed or collapsed (the outer profile or outer diameter is reduced) during the removal of a captured clot in the proximal direction only when subjected to an applied radially inwardly applied external compressive force (i.e., when returning / returning / pulling back into the distal end of the microcatheter / catheter). Specifically, when unsheathed from the microcatheter, the conventional mechanical thrombectomy device is in an expanded state, having an outer diameter / outer profile that is greater than the inner diameter lumen of the microcatheter. Therefore, external forces that radially compress the self-expanding cage structure (i.e., reduce its outer diameter / outer profile) are applied only when the conventional mechanical thrombectomy device is pulled back into the smaller inner diameter lumen of the microcatheter. However, the radial partial collapse (i.e., reduction of the outer profile or outer diameter) of the mechanical thrombectomy device of the present invention can be achieved specifically by actuating the internally actuatable collapse mechanism at any desired position or time (e.g., before being removed (i.e., pulled back in the proximal direction) into the microcatheter). In other words, during removal or extraction of a captured clot prior to being withdrawn into a microcatheter, the mechanical thrombectomy device may partially collapse radially (ie, reduce in outer diameter or profile) when subjected to internal tension as the internal collapse mechanism is pulled in the proximal direction.

[0027] Thus, partial collapse of the mechanical thrombectomy device of the present invention can be achieved solely by applying internal tension on the cage structure (i.e., without applying or without applying external compressive forces radially inwardly applied on the outer surface of the self-expanding cage structure during withdrawal into the microcatheter). Furthermore, radial partial collapse of the mechanical thrombectomy device of the present invention caused by actuation of the internally actuatable collapse mechanism can advantageously occur at the location where the clot is captured in the blood vessel prior to withdrawal into the microcatheter (i.e., toward the distal end of the microcatheter). Thus, at the beginning of withdrawal of the captured clot (at a location distal to the distal end of the microcatheter), the mechanical thrombectomy device can radially partially collapse, thereby reducing its outer diameter, reducing friction or drag on the blood vessel wall, thereby minimizing the risk of blood vessel damage or rupture.

[0028] The exemplary internally actuatable collapse mechanism depicted in the drawings and described herein is a pull wire 140 threaded through the channel 135 of the proximal shaft 130. The proximal end of the pull wire 140 extends in the proximal direction through a microcatheter that can be easily manipulated (e.g., pulled in the proximal direction) by an interventional physician outside the body. The pull wire 140 has an axial / longitudinal main segment 145 and one or more branch segments 150 (e.g., branches, fingers) extending from the main segment 145 into the open interior space defined by each stent segment 115a, 115b, 115c. The main segment 145 and the branch segments 150 including the pull wire 140 are depicted as a single integral unit laser cut in a desired configuration from a single piece of material, but may additionally include multiple units or segments that are adhered, laser welded, or otherwise fixedly fastened together as a single unit. The distal end / terminus of each branch segment 150 is fixedly attached (e.g., adhered or welded) to the associated stent segment 115a, 115b, 115c at the connection point 155. Similarly, the number of branch segments 150 and their connection points with each stent segment 115a, 115b, 115c at a specific position can be modified as needed. In the example depicted in the accompanying drawings, each stent segment 115a, 115b, 115c has a single corresponding or associated branch segment 150. However, each stent segment 115a, 115b, 115c may have more than one associated branch segment 150 connected thereto or no branch segment at all. On the contrary, branch segments 150 may be used for all, some, periodic (e.g., every other, every two, etc.) or random selection of stent segments as needed.

[0029] In addition, the extent, degree or amount of radial portion collapse (i.e., the extent of reduction in outer diameter / outer profile) of the mechanical thrombectomy device of the present invention may be controlled by the axial / longitudinal displacement (e.g., pulling) of the pull wire in the proximal direction by the interventionalist. The greater the tension applied to the pull wire (i.e., the greater the displacement in the axial / longitudinal direction), the greater the radial portion collapse of the mechanical thrombectomy device (i.e., the greater the reduction in outer diameter), while the less tension applied to the pull wire (i.e., the less displacement in the axial / longitudinal direction), the less radial portion collapse (i.e., the less reduction in outer diameter of the mechanical thrombectomy device). There is a direct relationship between the tension applied to the pull wire (i.e., the amount of displacement in the axial / longitudinal direction) and the extent / degree of radial portion collapse (i.e., the amount by which the outer diameter of the mechanical thrombectomy device is compressed or reduced).

[0030] If desired, sufficient force (i.e., greater tension) can be applied to the pull wire so that when partially collapsed radially, the mechanical thrombectomy device has a reduced outer diameter that is less than or equal to the inner diameter of the lumen of the microcatheter. In this case, when pulled back into the microcatheter, no radially inward external compressive force is applied to the radially partially collapsed mechanical thrombectomy device in any way. Alternatively, it is also contemplated that a smaller force (i.e., smaller tension or smaller axial / longitudinal displacement) can be applied to the pull wire so that the reduced outer diameter of the radially partially collapsed mechanical thrombectomy device is still greater than the inner diameter of the lumen of the microcatheter. With this alternative design, during removal, when pulled back into the microcatheter, a radially inward external compressive force will be applied to the partially collapsed mechanical thrombectomy device, thereby further reducing its outer profile.

[0031] because Figure 1A and Figure 1B All of the branch segments 150 in the exemplary configuration shown in are connected to the main segment 145 to form an integral single unit, so that pulling in the proximal direction on the proximal end of the single pull wire 140 causes simultaneous radial partial collapse of all of the stent segments 115a, 115b, 115c. However, it is further contemplated that more than one pull wire may be provided, wherein each pull wire may be actuated or deployed independently of one another to cause radial partial collapse of each or some of the stent segments at different times (e.g., sequentially) rather than simultaneously. For example, the internally actuatable collapse mechanism may include three pull wires 140a, 140b, 140c, each of which is separate from one another and can be actuatable independently, such as Figure 5 As shown. The first pull wire 140a is internally connected or attached to the first stent segment 115a; the second pull wire 140b is internally connected or attached to the second stent segment 115b; the third pull wire 140c is internally connected or attached to the third outer cage-shaped stent segment 115c. The timing and extent of the collapse of each stent segment 115a, 115b, 115c can therefore be independently actuated and controlled by pulling the corresponding pull wire 140a, 140b, 140c. The independent actuation of each of the corresponding pull wires 140a, 140b, 140c can be sequentially (i.e., in sequence), randomly, or perhaps some but not all are actuated simultaneously. In addition, it is also possible that in use, one or more pull wires associated with a particular articulated stent segment are never actuated. The internally actuatable collapse mechanism can be configured to include any number of one or more puller wires connected to one or more stent segments, wherein the timing and / or decision whether to actuate each puller wire can be independently controlled as desired.

[0032] In the case of multiple pull wires, each pull wire can be actuated or deployed independently of the others so as to control the extent, degree or amount of radial partial collapse (i.e., the extent, degree or amount of reduction in outer diameter or outer profile) of the associated articulated stent segment based on the extent, degree or amount of tension applied to that particular pull wire (i.e., displacement in the axial / longitudinal direction). That is, the greater the axial / linear displacement in the proximal direction on the pull wire (i.e., the greater the applied tension), the greater the radial partial collapse (i.e., the greater the radial reduction in outer profile / outer diameter) of the stent segment to which the pull wire is connected. Thus, the extent, degree or amount of radial reduction of each stent segment can be independently controlled by manipulating the associated pull wires connected thereto internally.

[0033] Furthermore, given the fact that the extent, degree, or amount of radial portion collapse can be controlled based on the axial / longitudinal displacement of the pull wire (i.e., the tension applied thereto), the extent, degree, or amount of tension (i.e., axial / longitudinal displacement) applied to any single pull wire after capturing a clot can also vary in multiple stages depending on the positioning or location of the mechanical thrombectomy device and the clot captured therein when navigating through the vessel during retrieval. For example, where the mechanical thrombectomy device is positioned in a vessel at a location where a clot is captured therein, a first stage of axial / longitudinal displacement (i.e., a first predetermined tension) can be applied to the pull wire in the proximal direction, thereby causing an initial radial portion collapse (e.g., an initial reduction in outer diameter). When navigating tortuous vasculature, upon reaching the distal end / tip of the microcatheter, the mechanical thrombectomy device may undergo a further radial partial collapse (i.e., a further reduction in outer diameter relative to the initial reduction in outer diameter) actuated by applying a second stage of axial / longitudinal displacement on the same pull wire that is greater than the first stage of axial / longitudinal displacement (i.e., a second predetermined tension greater than the first predetermined tension). This multi-stage collapse (e.g., two-stage collapse) by varying the tension applied to the same pull wire at different locations or positions within the vessel by the mechanical thrombectomy device ensures that a clot embedded therein is not displaced when the mechanical thrombectomy device is pulled back into the microcatheter during retrieval.

[0034] Thus, the number of pull wires and the independent control of each pull wire (ie, the timing of actuation of each pull wire and / or the range, degree or amount of tension applied to each pull wire) can be varied as desired.

[0035] In operation, the guidewire 405 is navigated through the blood vessel to the proximal side of the target clot. Thereafter, the microcatheter 410 is tracked by the guidewire 405 to the proximal side of the target clot, such as Figure 4As shown. The microcatheter 410, together with the guidewire 405 disposed within its lumen, traverses the target clot. Thereafter, the guidewire 405 is withdrawn from the microcatheter 410 in the proximal direction, and the mechanical thrombectomy device of the present invention is advanced in the distal direction through the lumen of the microcatheter 410 across the target clot. As Figure 2A illustrated, the microcatheter 410 is then withdrawn in the proximal direction, whereby the deployed mechanical thrombectomy device radially self-expands to an outer profile or outer diameter "D" that captures the target clot therein. Subsequently, the internal actuatable collapsing mechanism is actuated or deployed by the interventional physician pulling the proximal end of the pull wire 140 in the proximal direction (as Figure 2B indicated by the arrow in). In doing so, those stent segments 115a, 115b, 115c having associated branch segments 150 attached to the pull wire 140 through connection points 155 radially partially collapse (i.e., reduce the outer profile or outer diameter "d", where D > d). The reduced diameter "d" resulting from the actuation of the internal actuatable collapsing mechanism (e.g., pulling the pull wire 140 in the proximal direction) clamps down or constricts on the clot 200 captured therein, thereby tightening its grip, thus minimizing the risk of displacement during removal while navigating through the vasculature.

[0036] In Figure 3A and Figure 3B are shown enlarged views of exemplary mechanical thrombectomy devices that capture only a single clot therein, to illustrate the compression, squeezing, or constriction of the captured clot when the internal actuatable collapsing mechanism is deployed. Before the internal actuatable collapsing mechanism is deployed, the mechanical thrombectomy device that has been withdrawn from the microcatheter has an expanded outer profile or outer diameter "D". Once the clot is captured, in response to the tension applied to the pull wire 140 (i.e., pulling in the proximal direction), the stent segments 115a, 115b, 115c of the mechanical thrombectomy device that are connected to the pull wire partially collapse (i.e., the outer diameter or outer profile "d" decreases, as Figure 3B depicted therein, where d < D). The reduced outer diameter or outer profile "d" of the mechanical thrombectomy device in this radially partially collapsed state minimizes the frictional force or resistance applied to the vessel wall during removal of the captured clot. Additionally, the radial partial collapse of the mechanical thrombectomy device compresses, squeezes, or constricts the clot captured therein, thereby tightening its grip, thus minimizing the potential risk of displacement during removal. Figure 3B The enlarged view of clearly shows the咬紧的radially partially collapsed cage structure of the mechanical thrombectomy device that compresses (e.g., physically deforms or reform shapes) the clot captured therein.

[0037] It should be noted that there is an unclear term "咬紧的" in the original text which might need further clarification in the source language to ensure an accurate translation. The above translation attempts to render the text as accurately as possible based on the available context.​​​It should also be noted that when the internal actuatable collapse mechanism is deployed, the radially partially collapsed stent segment in which a clot is captured has a lesser reduction in outer diameter relative to another stent segment that does not or does not contain any captured clot. Fig. 6A is a side view of a mechanical thrombectomy device of the present invention with a clot captured therein prior to actuation of the internally actuatable collapse mechanism. Figure 6B As depicted in , stent segments of a mechanical thrombectomy device having a captured clot therein experience a lesser degree of outer diameter reduction relative to those stent segments of the mechanical thrombectomy device in which no clot is present.

[0038] Therefore, although the basic novel features of the present invention as applied to its preferred embodiments have been shown, described and pointed out, it should be understood that various omissions, substitutions and changes in form and detail may be made to the illustrated system / device and its operation by those skilled in the art without departing from the spirit and scope of the present invention. For example, it is clearly intended that all combinations of those elements and / or steps that perform substantially the same functions in substantially the same manner to achieve the same results are within the scope of the present invention. It is also fully expected and conceivable that elements are replaced from one described embodiment to another. It should also be understood that the drawings may not be drawn to scale, but they are merely conceptual in nature. Therefore, it is intended to be limited only as indicated by the scope in the appended claims.

[0039] Each issued patent, pending patent application, publication, journal article, book, or any other reference cited herein is each incorporated by reference in its entirety.

Claims

1. A mechanical thrombectomy device, comprising: a self-expanding cage structure capable of transitioning from a radially expanded state to a radially partially collapsed state having an outer diameter that is reduced relative to the outer diameter when in the radially expanded state; and An internally actuatable collapse mechanism is internally and fixedly attached to the self-expanding cage structure; wherein the internally actuatable collapse mechanism applies a radially inward tension to the self-expanding cage structure when actuated, thereby converting the self-expanding cage structure to the radially partially collapsed state.

2. A mechanical thrombectomy device according to claim 1, wherein the internally actuatable collapse mechanism is at least one pull wire, the at least one pull wire comprising a main segment and a plurality of branch segments, wherein each branch segment has a first end connected to the main segment and an opposite second end fixedly connected internally to the self-expanding cage structure.

3. The mechanical thrombectomy device according to claim 2, wherein the main segment and the plurality of branch segments constituting the at least one pull wire are formed of a single wire or a plurality of wire segments fixedly fastened together to form a single unit.

4. A mechanical thrombectomy device according to claim 1, wherein the self-expanding cage structure includes a plurality of articulated stent segments; and the internally actuatable collapse mechanism is at least one pull wire including a main segment and a plurality of branch segments; each of the plurality of branch segments has a first end connected to the main segment and a relative second end fixedly connected internally to one of the plurality of articulated stent segments.

5. A mechanical thrombectomy device according to claim 4, wherein each of the plurality of articulated stent segments has one branch segment of the plurality of branch segments associated therewith that is internally attached to each articulated stent segment.

6. A mechanical thrombectomy device according to claim 4, wherein the internally actuatable collapse mechanism is a plurality of pull wires that can be actuatable independently of each other; each of the plurality of pull wires is internally connected to a different one of the plurality of articulated stent segments.

7. A mechanical thrombectomy device according to claim 1, wherein the internally actuatable collapse mechanism is a plurality of pull wires that can be actuatable independently of each other; and wherein the self-expanding cage structure comprises a double structure, the double structure comprising an internal self-expanding cage structure, which is arranged in the internal axial channel of the outermost self-expanding cage structure, wherein each self-expanding cage structure can be deployed independently of each other; and the plurality of pull wires comprise a first pull wire and a second pull wire, the first pull wire being internally attached to the outermost self-expanding cage structure, and the second pull wire being internally attached to the inner self-expanding cage structure; wherein the first pull wire and the second pull wire can be actuatable independently of each other to cause the outermost self-expanding cage structure and / or the corresponding one of the internal self-expanding cage structure to partially collapse radially.

8. A method for capturing and removing an obstruction in a blood vessel using a mechanical thrombectomy device, the mechanical thrombectomy device having a self-expanding cage structure that is capable of converting from a radially expanded state to a radially partially collapsed state in which the outer diameter is reduced relative to the outer diameter when in the radially expanded state; and the mechanical thrombectomy device also includes an internally actuatable collapse mechanism that is internally fixedly attached to the self-expanding cage structure; and wherein the internally actuatable collapse mechanism, when actuated, applies a radially inward tension to the self-expanding cage structure, thereby converting the self-expanding cage structure to the radially partially collapsed state, the method comprising the following steps: inserting a guidewire through the blood vessel proximal to the obstruction; tracking a microcatheter over the guidewire to the proximal side of the obstruction; advancing the guidewire and the microcatheter together or independently and sequentially through the obstruction; withdrawing the guide wire from the blood vessel; advancing the mechanical thrombectomy device through the microcatheter; actuating the mechanical thrombectomy device, thereby converting the mechanical thrombectomy device to the radially expanded state and capturing the obstruction in the mechanical thrombectomy device; deploying the internal actuatable collapse mechanism to apply radially inward tension within the self-expanding cage structure, thereby converting the self-expanding cage structure from the radially expanded state to the radially partially collapsed state of reduced outer diameter while compressing the obstruction captured therein; and The self-expanding cage structure in the collapsed state of the radial portion is pulled back into the microcatheter with the compressed obstruction captured therein.

9. A method according to claim 8, wherein the internally actuatable collapse mechanism is at least one pull wire, and the at least one pull wire includes a main segment and a plurality of branch segments, wherein each branch segment has a first end connected to the main segment and a relative second end connected internally to the self-expanding cage structure.

10. The method of claim 9, wherein the main segment and the plurality of branch segments constituting the at least one pull wire are formed of a single wire or a plurality of wire segments fixedly fastened together to form a single unit.

11. A method according to claim 8, wherein the self-expanding cage structure includes a plurality of articulated stent segments; and the internally actuatable collapse mechanism is at least one pull wire including a main segment and a plurality of branch segments; each of the plurality of branch segments has a first end connected to the main segment and a relative second end internally connected to an articulated stent segment among the plurality of articulated stent segments.

12. The method of claim 11, wherein each of the plurality of articulated stent segments has one of the plurality of branch segments associated therewith that is internally attached thereto.

13. The method of claim 11, wherein the internally actuatable collapse mechanism is a plurality of pull wires that can be actuatable independently of one another; each of the plurality of pull wires being internally connected to a different one of the plurality of articulated stent segments.

14. A method according to claim 13, wherein the deployment step includes independently controlling the amount of tension applied to each of the multiple pull wires in the proximal direction, thereby independently adjusting the range of reduction in outer diameter for each articulated stent segment connected to each pull wire among the multiple articulated stent segments when converting to the radial partially collapsed state.

15. A method according to claim 8, wherein the self-expanding cage structure comprises a double structure, the double structure comprising an internal self-expanding cage structure, which is nested in the internal axial channel of the outermost self-expanding cage structure, wherein each self-expanding cage structure can be deployed independently of each other; and the internally actuatable collapse mechanism comprises a first pull wire and a second pull wire, the first pull wire is internally attached to the outermost self-expanding cage structure, and the second pull wire is internally attached to the inner self-expanding cage structure; wherein the deployment step comprises independently pulling the first pull wire and / or the second pull wire in the proximal direction, thereby respectively applying internal tension internally, thereby converting the outermost self-expanding cage structure and / or the inner self-expanding cage structure into the radially partially collapsed state.

16. A method according to claim 15, wherein the deployment step also includes independently controlling the amount of tension applied to each of the first pull wire and the second pull wire in the proximal direction, thereby independently adjusting the range of reduction in the outer diameter for each of the outermost self-expanding cage structure and / or the inner self-expanding cage structure connected to the first pull wire and the second pull wire when converting to the radial partially collapsed state.

17. The method of claim 8, wherein the deploying step comprises the following steps: The amount of tension applied to the inner actuatable collapse mechanism in the proximal direction is controlled, and thus the extent of the reduction in the outer diameter of the self-expanding cage structure when transitioning to the radially partially collapsed state is controlled.

18. The method of claim 17, wherein the amount of tension applied to the inner collapsible mechanism in the proximal direction is applied in more than one stage depending on the position of the self-expanding cage structure during retrieval through the blood vessel.

19. The method of claim 18, wherein the amount of tension applied to the inner collapsible mechanism in the proximal direction is applied in two stages; wherein the two stages include: (i) a first stage of applying a first predetermined axial tension to the internal collapsible structure when the self-expanding cage structure is located at the capture site of the obstruction in the blood vessel; and (ii) a second stage of applying a second predetermined axial tension to the internal collapsible structure proximal to the capture site of the obstruction but before entering the distal end of the microcatheter; wherein the second predetermined axial tension is greater than the first predetermined tension.

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