Streamlined Treatment of Clot Removal, Angioplasty and Prevention of Restenosis Using a Single Integrated Intravascular Device

Abstract

A single integrated intravascular device including a stentriever and semi-compliant balloon housed therein. After traversing a clot, the device is deployed to a self-expanded state engaging the clot therein, whereupon the device along with the embedded clot is removed. Detecting through imaging a stenosis at an original position of the captured clot, the device is reintroduced to that location and the stentriever is deployed to a self-expanded state. Inflating the semi-compliant balloon enlarges the stentriever to a hyper-expanded state greater than the self-expanded state thereby dilating the vessel while simultaneously completely detaching/releasing the stentriever from a remaining portion of the device. Then the semi-compliant balloon is collapsed and withdrawn along with the remaining portion of the device, while the detachable/releasable portion of the stentriever in the self-expanded state remains in the vessel.

Claims

1. A single integrated intravascular device comprising: a pusher member having a proximal end, an opposite distal end; a self-expanding stentriever comprising an open scaffolding formed by multiple struts secured together; the self-expanding stentriever being transitionable upon withdraw of an externally applied mechanical force between a compressed state having a reduced diameter and a self-expanded state having an enlarged diameter; proximal and distal ends of the self-expanding stentriever being secured to the pusher member at respective proximal and distal securement points; the self-expanding stentriever being detachable or releasable from the pusher member at the respective proximal and distal securement points; a semi-compliant balloon housed within the self-expanding stentriever and secured to the pusher member extending axially through the semi-compliant balloon; wherein the self-expanding stentriever is transitionable between the compressed state and the self-expanded state independently of expansion of the semi-compliant balloon; and an inflation lumen defined axially in the pusher member in fluid communication with the semi-compliant balloon.

2. The device according to claim 1, wherein the self-expanding stentriever is made of a superelastic memory material.

3. The device according to claim 1, wherein some of the multiple struts of the self-expanding stentriever disposed proximate the respective proximal and distal securement points each include a frangible section; the self-expanding stentriever being severable at the frangible sections into a completely detachable portion free from the pusher member and remnant portions remaining secured to the pusher member at the proximal and distal securement points.

4. The device according to claim 1, wherein the proximal and distal ends of the self-expanding stentriever are releasably securable to the pusher member via respective proximal and distal sleeves.

5. A single integrated intravascular device comprising: a pusher member having a proximal end, an opposite distal end; a self-expanding stentriever comprising an open scaffolding formed by multiple struts secured together; the self-expanding stentriever being transitionable upon withdraw of an externally applied mechanical force between a compressed state having a reduced diameter and a self-expanded state having an enlarged diameter; proximal and distal ends of the self-expanding stentriever being secured to the pusher member at respective proximal and distal securement points; the self-expanding stentriever being detachable or releasable from the pusher member at the respective proximal and distal securement points; a semi-compliant balloon housed within the self-expanding stentriever and secured to the pusher member extending axially through the semi-compliant balloon; wherein the self-expanding stentriever is transitionable between the compressed state and the self-expanded state while the semi-compliant balloon is in a deflated state; and an inflation lumen defined axially in the pusher member in fluid communication with the semi-compliant balloon.

6. The device according to claim 5, wherein the self-expanding stentriever is made of a superelastic memory material.

7. The device according to claim 5, wherein some of the multiple struts of the self-expanding stentriever disposed proximate the respective proximal and distal securement points each include a frangible section; the self-expanding stentriever being severable at the frangible sections into a completely detachable portion free from the pusher member and remnant portions remaining secured to the pusher member at the proximal and distal securement points.

8. The device according to claim 5, wherein the proximal and distal ends of the self-expanding stentriever are releasably securable to the pusher member via respective proximal and distal sleeves.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0010] The foregoing and other features of the present invention will be more readily apparent from the following detailed description and drawings illustrative of the invention wherein like reference numbers refer to similar elements throughout the several views and in which:

[0011] FIG. 1 is a cross-sectional view of an exemplary single integrated intravascular device including a self-expanding stentriever and semi-compliant balloon in accordance with the present invention;

[0012] FIG. 2A depicts the guidewire and microcatheter positioned across the target clot in a vessel;

[0013] FIG. 2B depicts, following proximal withdraw of the guidewire from the vessel, advancement through the lumen of the microcatheter the present inventive single integrated intravascular device of FIG. 1 so that the self-expanding stentriever traverses the target clot in the vessel;

[0014] FIG. 2C depicts, following proximal withdraw of the microcatheter from the vessel, unsheathing and automatic deployment of the self-expanding stentriever to a radially self-expanded state engaging the target clot in the open spaces of the scaffolding;

[0015] FIG. 2D depicts the self-expanding stentriever while in a radially self-expanded state with the clot embedded therein being withdrawn proximally into a larger diameter proximal catheter;

[0016] FIG. 2E depicts the presence of an underlying residual stenosis at the original site in the vessel of the target clot, the guidewire and microcatheter being reintroduced, simultaneously or in succession, into the vessel to a position coinciding with the underlying residual stenosis;

[0017] FIG. 2F depicts, following proximal withdraw of the guidewire from the vessel, reloading of the present inventive single integrated intravascular device of FIG. 1 into the lumen of the microcatheter so that the self-expanding stentriever coincides with the underlying residual stenosis;

[0018] FIG. 2G depicts, following proximal withdraw of the microcatheter from the vessel, unsheathing and automatic deployment of the self-expanding stentriever to a radially self-expanded state at the location of the detected underlying residual stenosis;

[0019] FIG. 2H depicts, inflation of the semi-compliant balloon housed within the self-expanding stentriever, to dilate the vessel at the detected underlying residual stenosis; the self-expanding stentriever is illustrated in a hyper-expanded state larger in diameter than that when in the self-expanded state of FIG. 2G;

[0020] FIG. 2I depicts, following fracture of the frangible sections of the scaffolding of the self-expanding stentriever when deformed by the inflated semi-compliant balloon and thereafter deflating of the semi-compliant balloon, proximal withdraw from the vessel as a single unit the remnant portions of the self-expanding stentriever that remain secured to the pusher shaft along with the deflated balloon, while permanently maintaining in position within the vessel the detachable portion of the self-expanding stentriever in the self-expanded state to prevent restenosis;

[0021] FIG. 2J is an enlarged area of a section II(J) of struts of the self-expanding stentriever in FIG. 2H having a thinner cross-section to promote fracturing when the semi-compliant balloon is inflated causing the self-expanding stentriever to transition to a hyper-expanded state;

[0022] FIG. 3A is a cross-sectional view of an alternative configuration of the present inventive single integrated intravascular device including a self-expanding stentriever and semi-compliant balloon in accordance with the present invention; wherein distal and proximal ends of the self-expanding stentriever are releasably secured to the pusher member via respective distal and proximal sleeves;

[0023] FIG. 3B is a cross-sectional view of the single integrated intravascular device of FIG. 3A after the self-expanding stentriever has been unsheathed from the microcatheter and transitioning to the self-expanded state;

[0024] FIG. 3C is a cross-sectional view of the single integrated intravascular device of FIG. 3A when the semi-compliant balloon has been inflated resulting in radial expansion of the self-expanding stentriever to a hyper-expanded state (having a greater diameter than the self-expanded state in FIG. 3B) simultaneously with a foreshortening axially of the respective proximal and distal ends of the self-expanding stentriever; and

[0025] FIG. 3D is a cross-sectional view of the single integrated intravascular device of FIG. 3A with the proximal and distal ends of self-expanding stentriever released or disengaged from the respective proximal and distal sleeves allowing the released self-expanded stentriever to return to its pre-formed shape.

DETAILED DESCRIPTION OF THE INVENTION

[0026] The terms “distal” or “proximal” are used in the following description with respect to a position or direction relative to the treating physician or medical interventionalist. “Distal” or “distally” are a position distant from or in a direction away from the physician or interventionalist. “Proximal” or “proximally” or “proximate” are a position near or in a direction toward the physician or medical interventionalist. The terms “occlusion”, “clot”, thrombus, or “blockage” are used interchangeably.

[0027] The present invention is directed to a single integrated intravascular device that includes a self-expanding stentriever and a semi-compliant balloon. The term “semi-compliant balloon” is herein defined as a balloon that distends approximately 10% of the diameter between the nominal pressure (pressure at labeled diameter) and the rated burst pressure (95% confidence that 99.9% will not fail at or below rated burst). Exemplary semi-compliant balloon materials include, but are not limited to, Polyethylene, Polyolefin Copolymer or Polyamide (Nylon). Heretofore, multiple intravascular treatments (clot removal; angioplasty; prevention of restenosis) were performed in succession, one following the other, each employing a different separate device dedicated exclusively to only one treatment or procedure. With the present inventive single integrated intravascular device, multiple intravascular treatments or procedures may now be carried out in a single streamlined procedure saving time, reducing device exchanges and providing the interventionalist flexibility to permanently deploy a stent scaffold at any point in the thrombectomy procedure. This single integrated intravascular device may be used to carry out multiple intravascular treatments or procedures including clot capture/removal, angioplasty and/or prevention of restenosis.

[0028] Referring to FIG. 1, the present inventive single integrated intravascular device 100 includes a mechanical thrombectomy device (e.g., self-expanding stentriever) 115 comprising an open mesh, cage, scaffolding, or skeleton formed by a plurality of struts connected together with spaces or openings 116 defined therebetween through which the clot may be engaged, captured and over time embed. Self-expanding stentriever 115 is made of an automatically self-expanding material (e.g., a biocompatible superelastic shape memory material such as Nitinol (e.g., Nickel-Titanium)) that may be crimped-down or reduced in diameter to a compressed state receivable within a lumen of a microcatheter, as described in further detail below. Housed within the self-expanding stentriever 115 is a deflated semi-compliant balloon 120. Proximal and distal ends of each of the semi-compliant balloon 120 and self-expanding stentriever 115 are secured (e.g., fused) at respective proximal and distal securement points 117, 117′ to a proximal shaft or pusher member 125. As is illustrated in FIG. 1, a proximal section of the pusher member 125 extends proximally to and axially completely through the semi-compliant balloon 120, while a distal section of the pusher member 125 extends outward beyond the distal end of the semi-compliant balloon 120 and self-expanding stentriever 115. The stiffness of pusher member 125 preferably varies along its axial length from a stiff proximal end relative to a more pliable distal end extending axially beyond the semi-compliant balloon and self-expanding stentriever. Defined axially through a portion of the proximal section of the pusher member 125 and in fluid communication with the semi-compliant balloon 120 is an inflation/deflation lumen 127 for receiving an inflation media (e.g., 50% contrast saline solution) used to inflate/deflate the semi-compliant balloon 120. As is evident from the illustration in FIG. 1, the inflation/deflation lumen 127 is in fluid communication with the semi-compliant balloon, without extending axially beyond the semi-compliant balloon into the distal section of the pusher member 125.

[0029] Heretofore, multifunctional intravascular medical procedures (i.e., clot capture/retrieval; angioplasty; and thereafter implantation of a permanent stent to prevent restenosis) all required different separate medical devices used in successive medical treatments. These separate medical treatments have been streamlined using the present inventive single integrated intravascular device. A general overview of the multifunctional application of the present inventive single integrated intravascular device is provided, the specific details of operating the device follow in the description thereafter. Initially the target clot may be captured using the self-expanding stentriever component of the present inventive single integrated intravascular device and withdrawn into a proximal catheter. Thereafter, imaging may be conducted to determine whether underlying residual stenosis is present at the original site of the target clot. If the presence of underlying residual stenosis is detected at the original site of the target clot, the same single integrated intravascular device 100 may be reloaded into the microcatheter and reintroduced back to the original site of the target clot where the underlying residual stenosis has been detected. At that original site in the vessel angioplasty may be performed on the underlying residual stenosis dilating the opening of the artery to restore blood flow therethrough by inflating the semi-compliant balloon housed within the self-expanding stentriever. With inflation of the semi-compliant balloon the self-expanding stentriever may be detached or released (freed) from the remaining portion of the single integrated intravascular device. The remaining portion of the single integrated intravascular device may thereafter be withdrawn leaving behind permanently in the vessel the detached or released (freed) portion of the self-expanding stentriever while in the self-expanded state to prevent elastic vessel recoil or restenosis.

[0030] A detailed description of the use of the single integrated intravascular device follows below. Because the present inventive single integrated intravascular device employs a semi-compliant balloon, prior to introduction into the body the single integrated device is prepped by removing, purging, or exhausting residual air from the device. Removal of the residual air may be achieved by applying a vacuum using a syringe 110 or other mechanical device connected to a proximal hub 105. The exemplary illustration in FIG. 1 shows a single inflation/deflation lumen 127, however, it is contemplated and within the intended scope of the present invention for separate inflation and deflation lumen (arranged coaxially or side-by-side) to be employed, as desired.

[0031] Once prepped, use of the present inventive single integrated device 100 begins by introducing a guidewire 200 into an artery 205 and advancing the guidewire across the target clot, thrombus, occlusion or blockage 210, as shown in FIG. 2A. Thereafter, a microcatheter 220 having a lumen 225 defined axially therein is tracked over the guidewire 200 until its distal end 230 crosses and emerges distally beyond the target clot 210. Guidewire 200 is then proximally withdrawn from the vessel while maintaining the position of the microcatheter 220 in the vessel 205 traversing the target clot 210. Referring to FIG. 2B, while the self-expanding stentriever 115 is in a compressed state (e.g., sheathed by the microcatheter so as to be crimped-down having a reduced diameter) with the deflated semi-compliant balloon 120 housed therein, the single integrated intravascular device 100 is introduced into the lumen 225 of the microcatheter 220. Guided by imaging, the single integrated intravascular device 100 is advanced through the lumen 225 of the microcatheter 220 using the pusher member 125 so that the self-expanding stentriever 115 traverses the target clot 210. Referring to FIG. 2C, the microcatheter 220 is then retracted or withdrawn proximally while the single integrated intravascular device 100 remains in place within the vessel 205 traversing/crossing the target clot 210. As the microcatheter 220 is proximally retracted from the vessel 205 it unsheathes or frees the self-expanding stentriever 115 disposed therein which automatically transitions to a self-expand state having an enlarged diameter thereby engaging the target clot 210 in the open spaces 116 of the mesh or scaffolding structure. While the scaffolding or skeleton structure of the self-expanding stentriever 115 expands radially outward, the semi-compliant balloon 120 housed therein remains in a deflated state so as not to interfere with engagement and subsequent embedding of the target clot 210. Over time (e.g., approximately 2-5 minutes) the target clot 210 sufficiently embeds in the spacings or openings 116 of the scaffolding of the self-expanding stentriever 115. Thereafter, the target clot 210 embedded in the self-expanding stentriever 115 together with the deflated semi-compliant balloon 120 housed therein are withdrawn proximally as a single unit and received in a proximal catheter 235 having a diameter sufficiently large in size to accommodate the self-expanding stentriever 115 (which in a self-expanded state) without compressing and stripping off the target clot, as depicted in FIG. 2D.

[0032] The functionality of the present inventive single integrated intravascular device does not necessarily end. Now that the self-expanding stentriever 115 and captured target clot 210 therein have been received in the proximal catheter 235 and withdrawn from the vessel 205, the presence of any underlying residual stenosis 215 at the original site of the captured target clot may be detected through imaging.

[0033] If residual stenosis 215 is detected during imaging, the single integrated intravascular device 100 may be cleaned and reloaded into the microcatheter 220. Similar to that in FIG. 2A (but the target clot 210 has already been captured and removed from the vessel), the guidewire 200 and microcatheter 220, either successively (one after the other) or simultaneously at the same time, are reintroduced and tracked through the vessel 205 to the detected underlying residual stenosis 215, as illustrated in FIG. 2E. Guidewire 200 is then proximally withdrawn from the vessel leaving the microcatheter 220 in position coinciding with the underlying residual stenosis 215. While the self-expanding stentriever 115 is in the compressed state (i.e., crimped-down having a reduced diameter) with the deflated semi-compliant balloon 120 housed therein, the single integrated intravascular device 100 is reloaded into the microcatheter 220 and advanced so that the self-expanding stentriever 115 coincides with the underlying residual stenosis 215, as shown in FIG. 2F. Referring to FIG. 2G, microcatheter 220 is withdrawn proximally from the vessel 205 unsheathing the self-expanding stentriever 115 allowing it to automatically enlarge radially to the self-expanded state. With the self-expanding stentriever 115 in the self-expanded state, the syringe 110 dispenses under pressure the inflation media through the inflation lumen 127 of the pusher member 125 filling the semi-compliant balloon 120. Self-expanding stentriever 115 may be configured so that some portions of the scaffolding or struts include weakened or frangible sections 111 disposed at multiple strut locations proximate the proximal and distal securement points to the pusher member 125. The frangible sections 111 of the self-expanding stentriever may be designed as sections of the struts having a thinner cross-section (as depicted in FIG. 2J), or as struts with focal stress risers (notches).

[0034] As the semi-compliant balloon 120 inflates imposing a radially outward force, the self-expanding stentriever 115 hyper-expands to a diameter larger than the self-expanding state while adopting the curved contour of the inflated semi-compliant balloon, as shown in FIG. 2H. The inflated balloon enlarges or dilates the narrow opening of the vessel in which there is a build-up of plaque improving blood flow therethrough.

[0035] At some point during inflation of the semi-compliant balloon 120, sufficient radially outward force is imposed to deform the frangible sections 111 of the self-expanding stentriever 115 causing the frangible sections 111 to fracture or break. Fracturing of the frangible sections 111 completely frees or releases a detachable portion 130′ of self-expanding stentriever 115 from that that of remnant portions 130 of the self-expanding stentriever 115 that remain secured to the pusher member 125 at respective proximal and distal securement points. A negative pressure is applied using the syringe 110 expelling the inflation media via the inflation/deflation lumen 127 of the pusher member 125 so that the collapsed semi-compliant balloon 120 may be withdrawn from the vessel. As the semi-compliant balloon 120 collapses, the detachable portion 130′ of the self-expanding stentriever transitions from the hyper-expanded state (FIG. 2H) back to the smaller diameter self-expanded state (FIG. 2I). FIG. 2I further depicts the severed detachable portion 130′ of the self-expanding stentriever maintained in the vessel 205 in the self-expanded state, while the remnant portions 130 secured to the pusher member 125 together with the deflated semi-compliant balloon 120 are proximally withdrawn from the vessel as a single unit. Detachable portion 130′ of the self-expanding stentriever 115 in the self-expanded state remains permanently in the vessel at the position in which residual stenosis was detected to prevent restenosis. Accordingly, the probability of restenosis (re-narrowing of the opening of the artery) that occurs (typically within approximately 6-12 months) following dilation of the vessel opening by the inflated balloon is prevented or reduced by the detachable portion of the self-expanding stentriever permanently remaining in place in the vessel.

[0036] Instead of designing the struts of the self-expanding stentriever to have frangible sections 111 that break or fracture when deformed, the self-expanding stentriever may alternatively be releasably secured to the pusher member. By way of illustrative example, FIG. 3A depicts an alternative configuration, wherein the self-expanding stentriever 315 (while in a crimped state) with the deflated semi-compliant balloon 320 disposed therein together are advanced through the microcatheter 370 to a target site in the vessel. Proximal and distal end struts of the self-expanding stentriever 315 are secured to the pusher member 325 via proximal and distal sleeves or end caps 385, 385′, respectively, that remain fixed in position axially relative to one another. When the microcatheter 370 is withdrawn proximally, the self-expanding stentriever 315 no longer constrained by the microcatheter automatically self-expands increasing in diameter to a self-expanded state, as shown in FIG. 3B. Despite such expansion, the distal and proximal end struts of the self-expanding stentriever 315 nevertheless remain constrained or secured by the proximal and distal sleeves 385, 385′. Thus, the self-expanding stentriever 315 while in the self-expanded state may be employed similar to that described above with respect to FIGS. 2A-2J to engage and remove the target clot. If, subsequent to removing the target clot, through imaging a stenosis is detected at the site of the removed target clot, the device may be cleaned and reloaded into the vessel to the target site, once again following the description and procedure above regarding the design of FIGS. 2A-2J. Once the self-expanding stentriever is positioned at the target site the microcatheter 370 is proximally withdrawn. The unsheathing of the crimped-down self-expanding stentriever 315 increases its diameter to a self-expanded state, nevertheless the distal and proximal end struts of the self-expanding stentriever remain secured to the pusher member 325 beneath the respective proximal and distal sleeves 385, 385′. Referring to FIG. 3C, the semi-compliant balloon 320 is inflated causing the self-expanding stentriever 315 to transition to a hyper-expanded state (i.e., having a diameter greater than that in a self-expanded state when the self-expanding stentriever is unsheathed by the microcatheter but remains secured by the proximal and distal sleeves 385, 385′, as shown in FIG. 3B). Inflation of semi-compliant balloon 320 to the hyper-expanded state, increases in diameter (direction traverse to the axial direction—as denoted by the larger arrows) and, in turn, causes a foreshortening of the self-expanding stentriever (axial direction—as denoted by the smaller arrows drawn towards one another) to such extent that the distal and proximal end struts of the self-expanding stentriever are freed from or disengage (no longer secured by) the proximal and distal sleeves 385, 385′. Once released or detached from the proximal and distal sleeves (as shown in FIG. 3D), the distal and proximal end struts of the self-expanding stentriever expand automatically in diameter to their pre-formed shape in direct physical contact with the inner wall of the vessel at the target site of the stenosis. Thereafter, semi-compliant balloon 320 may be deflated and removed proximally along with the sleeves 385, 385′ and pusher member 325, while the detached (freed) self-expanding stentriever 315 permanently remains in physical contact with the inner wall of the vessel 305 at the target site.

[0037] Regardless of the particular design or configuration of the device, if the self-expanding stentriever is substantially “waisted” indicating an inability to embed into the target clot while the presence of an underlying stenosis is probable, the step of removing the target clot may be bypassed entirely. In such case, the interventionalist may proceed directly to inflating the semi-compliant balloon causing the self-expanding stentriever to transition to a hyper-expanded state and detaching/releasing itself from the pusher member, without attempting to remove or withdraw the clot. After deflation, the semi-compliant balloon is withdrawn together with the pusher member, leaving in place at the site of the stenosis the detached/released self-expanding stentriever in the self-expanded state in physical contact against the wall of the vessel.

[0038] Thus, the present inventive single integrated intravascular device is used to perform multifunctional treatment including: (i) capturing and removing the target clot; (ii) dilating the narrowed opening of a vessel in which an underlying residual stenosis is detected beneath the target clot after removal; and/or (iii) permanently maintaining the detachable/releasable (freed) self-expanding stentriever in the vessel at the location of the detected underlying residual stenosis to prevent restenosis.

[0039] Thus, while there have been shown, described, and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions, substitutions, and changes in the form and details of the systems/devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, it is expressly intended that all combinations of those elements and/or steps that perform substantially the same function, in substantially the same way, to achieve the same results be within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated. It is also to be understood that the drawings are not necessarily drawn to scale, but that they are merely conceptual in nature. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

[0040] Every issued patent, pending patent application, publication, journal article, book or any other reference cited herein is each incorporated by reference in their entirety.