Patent Application
20250228581
An endovascular thrombectomy involves the removal of a thrombus (blood clot) from a blood vessel, usually under image guidance. A current thrombectomy solution involves using a mesh stent and a “push and fluff” technique. This involves pushing the mesh of the stent radially through the thrombus, and then using a retriever to retrieve the stent and, hence, the thrombus.
While effective, the pressing of a mesh stent radially through the thrombus may cause it to break up into smaller pieces and travel unfettered in the bloodstream. This may increase the risk for embolism. Rotating the mesh stent in an effort to aid in thrombus dislodgment may actually make the situation worse in terms of generating small pieces, and may not serve to fully dislodge pieces of the thrombus from the vessel in situations where they are pressed against the inner wall of the vessel as a result of the mesh expansion.
Accordingly, a need is identified for a solution to the foregoing problem, and perhaps others that have yet to be discovered or understood. The solution would provide an effective device for thrombectomy that dislodges and captures the thrombus while seeking to reduce the creation of small pieces that may travel through the bloodstream, and thereby reduce the risk of embolism.
An object of the disclosure is to provide an effective device for thrombectomy that dislodges and captures the thrombus while seeking to reduce the creation of small pieces that may travel through the bloodstream, and thereby reduce the risk of embolism.
According to a first aspect of the disclosure, an apparatus for engaging a thrombus in a vessel is provided. The apparatus comprises a catheter having a first expandable element. The catheter further includes a plurality of scrapers attached at a distal end portion to the catheter and extending proximally at least partially alongside the first expandable element. A proximal end portion of the plurality of scrapers is unattached to the catheter and adapted to be inserted between the thrombus and the vessel.
In one embodiment, the first expandable element comprises an inflatable balloon. In this or other embodiments, the plurality of scrapers each comprise a shape memory material. Each of the plurality of scrapers may be longer than the first expandable element. The catheter may include a second expandable element distal of the first expandable element. Each of the plurality of scrapers may have a width greater than a thickness. A web may be provided for interconnecting the plurality of scrapers. In any case, each of the plurality of scrapers is adapted to pass into a space between the thrombus and the vessel without buckling.
According to a second aspect of the disclosure, an apparatus for engaging a thrombus in a vessel is provided. The apparatus comprises a catheter including a distal end portion having a first expandable element, the catheter including a plurality of scrapers extending at least partially alongside the first expandable element, a proximal end portion of the plurality of scrapers extending at least partially alongside a second expandable element proximal of the distal end portion, the plurality of scrapers forming a cage lacking any expandable element therein and adapted to capture the thrombus.
In one embodiment, a first end of each of the plurality of scrapers is attached to the first expandable element and a second end of each of the plurality of scrapers is attached to the second expandable element. Each of the plurality of scrapers has a width greater than a thickness. The first and second expandable elements may each comprise an inflatable balloon, and the plurality of scrapers may comprise a shape memory material. Each of the plurality of scrapers may be longer than the first expandable element, and may be adapted for insertion between the thrombus and the vessel without buckling.
Still a further aspect of the disclosure relates to an apparatus for engaging a thrombus in a vessel. The apparatus comprises a catheter including a distal end portion having an expandable element. The catheter includes a plurality of scrapers attached at one end portion to the distal end portion of the catheter and extending at least partially alongside the expandable element, a second opposite end portion of the plurality of scrapers being attached to an elastomeric collar connected to the catheter proximal of the expandable element.
In one embodiment, each of the plurality of scrapers has a width greater than a thickness. The expandable element may comprise an inflatable balloon. The plurality of scrapers may comprise a shape memory material. Each of the plurality of scrapers may be longer than the expandable element, and may be adapted to pass into a space between the thrombus and the vessel without buckling.
Still a further aspect of the disclosure relates to a method of engaging a thrombus in a vessel. The method comprises inserting a first end portion of each of a plurality of scrapers attached at a second end portion to a catheter in a space between the thrombus and the vessel. The method may further comprise rotating the catheter. Prior to the inserting step, the catheter may be advanced distally of the thrombus and the expandable element expanded. The method may further include the step of expanding a balloon distally of the second end portion of the catheter prior to the inserting step.
The above and further advantages of the present disclosure may be better understood by referring to the following description in conjunction with the accompanying drawings in which:
The dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components may be included in one functional block or element. Further, sometimes reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. Moreover, some of the parts depicted in the drawings may be combined into a single function.
In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the presently disclosed invention(s). The disclosed embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, or structures may not have been described in detail so as not to obscure the disclosed inventive concepts.
The invention of this disclosure is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The inventive concepts disclosed are capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
Certain features of the disclosed embodiments that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.
With reference to
As indicated in
Inflatable balloon 12 may include a single or multi-layered balloon wall 28 forming the interior for receiving the inflation fluid. The balloon 12 may be a non-compliant balloon having a balloon wall 28 that maintains its size and shape in one or more directions when the balloon is inflated, and may comprise a plurality of inelastic fibers arranged in one or more layers. The balloon 12 in such case also has a pre-determined surface area that remains constant during and after inflation, also has a pre-determined length and pre-determined diameter that each, or together, remain constant during and after inflation. The balloon 12 (as well as any balloon described herein) can have any of a variety of diameters, ranging from 1-40 mm, such as 2.0-8.0 mm, and may have any of a variety of lengths ranging from 1-300 mm. As outlined further in the discussion that follows, more than one inflatable balloon may be associated with the catheter.
According to a first aspect of the disclosure, the catheter 10 may be adapted to dislodge, or scrape, a thrombus from within a vessel and capture the same for recovery. As illustrated in
Regardless of the number, shape, and size, the fingers 30 at a distal end 30a are attached to a tip 32 of the catheter 10 distal of the balloon 12 (which may be initially uninflated and folded), and through which tip the guidewire 26 may pass via lumen 19. The fingers 30 overlie and extend along the balloon 12, including the barrel portion 16 (which in
In use, and with reference to
With the scrapers or fingers 30 deployed in this manner, the catheter 10 may then be drawn or pulled proximally, as indicated by arrow P. This movement causes the free ends 30b of the fingers 30 to enter into an interstitial space between the thrombus and the inner wall of the vessel V without buckling or folding, thus capturing the thrombus T between the fingers and also aiding in dislodging it from the vessel. Since the fingers 30 do not move radially within the thrombus T in this version, and only engage it peripherally, the thrombus is less likely to break into multiple small pieces.
As indicated by action arrow R, the catheter 10 may also be bodily rotated with the fingers 30 in the deployed position (such as to and fro to a limited degree, for example, but full rotation is of course possible). This rotation of the catheter 10 causes the deployed fingers 30 to move circumferentially along the inner wall of the vessel V and thereby potentially aid in dislodging and capturing the thrombus T. This movement may also be combined with the retraction or advance of the catheter 10 to aid in dislodgement and capture, as necessary for a particular situation.
As indicated in
Turning to
In the above embodiments, the fingers 30, 130, 230 may be laser cut from a single tube. This provides each finger with a degree of curvature in a circumferential direction. Once formed, the free ends (e.g., proximal end 30b of finger 30) may be deburred or rounded to eliminate any sharp edges, thereby ensuring an atraumatic presentment along the inner wall of the vessel when the thrombus is engaged as previously described.
Still further embodiments of thrombectomy catheters are shown in
In use, the catheter 300 may be advanced through a thrombus such that it lies between the uninflated balloons 312a, 312b. The balloons 312a, 312b may then be inflated to cause the fingers 330 to pass radially through the thrombus into an interstitial space with the vessel. This may serve to capture the thrombus between the fingers 330, but with minimal disruption (possibly only dividing the thrombus into two halves in the case of two fingers 330, as shown). The catheter 300 may also be rotated once the fingers 330 are expanded to assist in scraping and dislodgement of the thrombus, as indicated by arrow R.
In any case, individual pieces of a thrombus created as a result of using the catheter 300 for performing a thrombectomy are prevented from traveling upstream or downstream in the vessel by the inflated balloons 312a, 312b, and may potentially be aspirated through a port in the catheter shaft 314. The balloons 312a, 312b may be deflated to allow the fingers 330 to compress around and capture the thrombus (or portions thereof) for removal from the vessel, such as by an aspiration catheter (not shown).
The webbing 402 may be expandable or elastic to allow the fingers 430 to expand outwardly as described above on inflation of the associated balloon. As examples, the webbing 402 may comprise a polymer sheet or film (such as, for example, PTFE, PET, Nylon, PEBAX or the like), but could also take the form of a polymer or metal mesh or other porous material. The webbing 402 may also extend to the free ends of the fingers 430, or may terminate proximally thereof.
In still a further embodiment of a catheter 500 adapted to perform a thrombectomy, which includes an expandable element, such as balloon 512, and fingers 530 connected at a distal end to a tip 532 of the catheter. The proximal ends of fingers 530 are connected to a connector, such as a collar 540 proximal of the balloon 512, which helps to prevent deflection during rotation of the catheter 500.
The collar 540 may comprise a flexible material, such as an elastomer. The collar 540 may be connected directly to the shaft 514, such as by welding or adhesive. The fingers 530 in this embodiment may be formed of a non-shape memory material, such as for example stainless steel, but could also be formed of a shape memory material.
In use, the catheter 500 once passed through a thrombus may be used to actuate or expand the balloon 512, thus pressing the fingers 530 radially outwardly to form a cage 550 for capturing the thrombus therein. Rotation of the catheter 500 (arrow R) may be done to scrape or dislodge the thrombus, as indicated by arrow R, which the collar 540 allowing for flexibility in the movement of fingers 530 to avoid causing damage to the vessel while allowing for movement into a space between the thrombus and the inner wall of the vessel to capture the former. The balloon 512 may then be deflated to capture the thrombus between the fingers 530, and the catheter 500 withdrawn to complete the thrombectomy.
Summarizing, this disclosure may be considered to relate to the following items:
As used herein, the following terms have the following meanings:
“A”, “an”, and “the” as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, “a compartment” refers to one or more than one compartment.
“About,” “substantially,” or “approximately,” as used herein referring to a measurable value, such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/−20% or less, preferably +/−10% or less, more preferably +/−5% or less, even more preferably +/−1% or less, and still more preferably +/−0.1% or less of and from the specified value, in so far such variations are appropriate to perform in the disclosed invention. However, it is to be understood that the value to which the modifier “about” refers is itself also specifically disclosed.
“Comprise”, “comprising”, and “comprises” and “comprised of” as used herein are synonymous with “include”, “including”, “includes” or “contain”, “containing”, “contains” and are inclusive or open-ended terms that specifies the presence of what follows, e.g., component or the like does not exclude or preclude the presence of additional, non-recited components, features, element, members, steps, known in the art or disclosed therein.
Although the invention has been described in conjunction with specific embodiments, many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it embraces all such alternatives, modifications, and variations that fall within the spirit and scope of the appended claims. It is to be fully understood that certain aspects, characteristics, and features, of the invention, which are, for clarity, illustratively described and presented in the context or format of a plurality of separate embodiments, may also be illustratively described and presented in any suitable combination or sub-combination in the context or format of a single embodiment. Conversely, various aspects, characteristics, and features, of the invention which are illustratively described and presented in combination or sub-combination in the context or format of a single embodiment may also be illustratively described and presented in the context or format of a plurality of separate embodiments.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/054394 | 10/11/2021 | WO |
