MULTIPLE BARREL CLOT REMOVAL DEVICES

A clot removal device comprising a clot engaging structure comprising a plurality of interconnected struts forming an open cell pattern, the clot engaging structure having a radially constrained configuration and a radially expanded configuration, wherein when the clot engaging structure is in the radially expanded configuration, a first portion of the clot engaging structure is rolled about itself in a clockwise direction to form a first barrel, and a second portion of the clot engaging structure is rolled about itself in a counter-clockwise direction to form a second barrel that extends in a side-by-side configuration with the first barrel.

FIELD OF INVENTION

The disclosed inventions are directed to medical devices used to treat and remove obstructions from a blood vessel, such as a blood clot, and more particularly, to embodiments of a multiple barrel clot removal device configured for removing obstructions from a blood vessel.

BACKGROUND

Various surgical devices have been developed for treating and removing vasculature obstructions (also referred to as clots). Vasculature obstructions include clots such as blood clots in the cerebral vasculature which cause embolic strokes and obstructions in various other locations of the vasculature system which can cause various medical conditions such as venous thrombosis or heart attacks. Vasculature obstructions may form in blood vessels by various mechanisms. For instance, emboli may form at a location in the vasculature and become dislodged and then become lodged in a different blood vessel location. For example, emboli occasionally form around the valves of the heart and then are dislodged and follow the blood flow into the distal regions of the body. Such emboli are particularly dangerous should they migrate to the brain neuro vasculature, and cause an embolic stroke.

In general, surgical devices for treating and removing vasculature obstructions are usually delivered through an intravascular catheter. The surgical devices may treat the blood clot in several ways. In one way, the surgical device may be configured and used to open a clear passageway adjacent a thrombus to allow both blood and medication to bypass the clot. Other devices may be configured to pierce and/or remove a thrombus. These thrombi are often found in tortuous vasculature.

Various surgical devices to treat vascular obstructions such as emboli have been previously developed. The use of inflatable balloons to remove emboli has been practiced for many years. For instance, the “Fogarty catheter” has been used, typically in the periphery, to remove clots from arteries found in legs and in arms. These well known devices have been described in some detail in U.S. Pat. No. 3,435,826, to Fogarty and in U.S. Pat. Nos. 4,403,612 and 3,367,101. These patents describe a balloon catheter in which a balloon material is longitudinally stretched when deflated. In procedures for removing emboli using the Fogarty catheter or other similar catheters, it is typical, first, to locate the clot using fluoroscopy. The embolectomy catheter is then inserted and directed to the clot. The distal tip of the balloon catheter is then carefully moved through the center of the clot. Once the balloon has passed through the distal side of the clot, the balloon is inflated. The balloon catheter is then gradually and gently withdrawn. The balloon acts to pull the clot ahead of the balloon.

Removal of emboli using balloon catheters is rife with potential problems. One such problem occurs during removal of a clot. The resistance to such removal often causes the balloon portion of the catheter to evert over the tip of the catheter. Should the user need to partially deflate the balloon during such a deflation, the distal tip of the balloon may become distended and angulate. Another difficulty with balloon catheters is the possibility of damage to the intima of arteries. Inflation pressures can create forces significant enough to score the vessel lining or dislodge plaque lodged on the vessel wall. In the worst case, the balloon may rupture leaving balloon portions in the bloodstream.

Another surgical device for removing clots is described in U.S. Pat. No. 8,852,205, to Brady et al. In one described embodiment, the surgical device includes a dual tube configuration, in which two tubular structures are connected to each other, each tube having a plurality of struts reinforcing its surface. The tubes are connected to a shaft by respective connecting arms. Brady et al.

describes that the ends of the tubes may be open or closed by inwardly facing struts. However, the tubes create a very rigid structure which cannot be easily compressed for placement into an intravascular insertion catheter, since the tubes independently resist compression.

SUMMARY

Exemplary embodiments of the disclosed inventions are directed to a clot removal device that comprises a clot engaging structure, the clot engaging structure comprising a plurality of interconnected struts forming an open cell pattern and having a radially constrained configuration and a radially expanded configuration. When the clot engaging structure is in the radially expanded configuration, a first portion of the clot engaging structure is rolled about itself in a clockwise direction to form a first barrel, and a second portion of the clot engaging structure is rolled about itself in a counter-clockwise direction to form a second barrel that extends in a side-by-side configuration with the first barrel.

In some embodiments, the first portion of the clot removal structure terminates along a first edge that does not overlap with a remainder of the first barrel when the clot engaging structure is in the radially expanded configuration, and the second portion of the clot removal structure terminates along a second edge that does not overlap with a remainder of the second barrel when the clot engaging structure is in the radially expanded configuration.

In some embodiments, the first portion of the clot removal structure terminates along a first edge that overlaps with at least a portion of the first barrel when the clot engaging structure is in the radially expanded configuration, and the second portion of the clot removal structure terminates along a second edge that overlaps with at least a portion of the second barrel when the clot engaging structure is in the radially expanded configuration.

In some embodiments, when the clot engaging structure is in the radially expanded configuration, the first barrel has a first barrel diameter, and the second barrel has a second barrel diameter that is smaller than the first barrel diameter.

In some embodiments, the clot engaging structure may further comprise an intermediate portion disposed between the first and second portions, wherein the intermediate portion may comprise a loop and/or a third barrel when the clot engaging structure is in the radially expanded configuration.

In various embodiments, the clot engaging structure is preferably biased to expand, or is otherwise expandable from, the radially constrained configuration to the radially expanded configuration when deployed from a delivery catheter into a blood vessel.

In various embodiments, when the clot engaging structure is delivered to a targeted vascular site proximate a vascular obstruction, and moved or allowed to move from the radially constrained configuration to the radially expanded configuration, the first and second barrels move, be moved, or be allowed to move, respectively, from a radially constrained configuration to a radially expanded configuration to thereby ensnare or encapsulate the vascular obstruction or portions thereof between or within the first and second barrels.

Other and further aspects and features of embodiments of the disclosed inventions will become apparent from the ensuing detailed description in view of the accompanying figures.

DETAILED DESCRIPTION

Various embodiments of the disclosed inventions are described hereinafter with reference to the figures. The figures are not necessarily drawn to scale, the relative scale of select elements may have been exaggerated for clarity, and elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be understood that the figures are only intended to facilitate the description of the embodiments, and are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention, which is defined only by the appended claims and their equivalents. In addition, an illustrated embodiment of the disclosed inventions needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment of the disclosed inventions is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated.

All numeric values are herein assumed to be modified by the term “about,” whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the terms “about” may include numbers that are rounded to the nearest significant figure. The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

The disclosed embodiments herein directed to clot removal devices having multiple barrels. The disclosed clot removal devices, also referred to as stentrievers, are used for removing obstructions (i.e., blood clots) from a blood vessel.

Referring toFIGS. 1 and 2, in one embodiment, the clot removal device10comprises a plurality of elongate barrels12. Each barrel12has a length along a longitudinal axis of each barrel in the direction of the elongate length of each barrel12. The barrels12are arranged substantially side by side and substantially parallel to each other along their length. The barrels12are connected to each other. As shown in the embodiment ofFIGS. 1 and 2, the barrels12may be connected to each other along the length of the outside surface of each barrel12. Alternatively, the barrels12may be connected to each other at only discrete locations along their length or by connecting each barrel12to a common support structure, such as a frame or body.

Each barrel12has a free, unconnected edge14extending along substantially the entire length of the barrel12. Accordingly, the cross-section of each barrel12is an open shape, i.e. there is an unconnected edge14. In the embodiment ofFIGS. 1 and 2, the free, unconnected edge14terminates short of the other side of the barrel (e.g., forming a partial cylinder). As described below for other embodiments, the edge14may overlap the other side (e.g., in a slightly helical shape). Still, in a relaxed state of the device10(i.e., with no outside forces bearing on the barrel), the edge14may be spatially separated (i.e. not in contact, not overlapping), as shown inFIG. 6, or may be spatially together (i.e., in contact, overlapping) as shown inFIG. 5, from any other structure of the clot removal device, as long as the edge14is free and unconnected (i.e., not fixedly attached) from any other structure of the clot removal device.

The elongate barrels12may have any suitable cross-sectional shape, such as the circular cross-section shown in the embodiment ofFIGS. 1 and 2, resulting in each of the barrels12being a partial cylinder. The shape of the barrels12is referred to as a partial cylinder because they do not form a closed cylinder but instead have a free, unconnected edge14along the length of each cylinder. In other words, for an embodiment in which the partial cylinder is a circular cylinder, a cross section of each partial cylinder may be an arc of a circle in the case that the edge14does not overlap, and not a complete circle. In the case that the edge14overlaps, the cross-section may be have a spiral shape, or a portion that is spiraled, such that the edge14overlaps to the inside of the other side of the barrel12(see e.g., the embodiments ofFIGS. 5 and 7).

In alternative embodiments, the barrels12may have a partial polygonal cross-section, such as a pentagon, hexagon, heptagon, octagon, etc, or other partially closed shape consisting of line and/or curve segments. The shape is partially closed because it is not connected along the free, unconnected edge of the barrel. As with the circular cylinder shapes, the edge14may overlap or not overlap.

For ease in the illustration, the clot removal device10is shown inFIG. 1as a single sheet of material, such as plate16to better appreciate a perspective view the barrels12aand12b.In this embodiment, the coupling plate16is configured to be connected to a wire or other actuating mechanism for manipulating the clot removal device10, including advancing and withdrawing the clot removal device10within a blood vessel. The coupling plate16has a connector18. In the embodiment ofFIGS. 1 and 2, the connector18comprises an aperture through the coupling plate16. The connector18may be other suitable connectors such as a pin, clip, weld, adhesive, antenna lap joint (as shown inFIG. 3), etc.

The clot removal device10is formed from clot engaging structure20, such as a single, flat sheet of material having interconnected struts forming an open cell pattern as shown inFIG. 3. The clot engaging structure20, and thus the clot removal device10, may be made of any suitable material, such as an appropriate metal or polymer which can be formed into the clot removal device10. For example, the clot engaging structure20is composed of shape memory, self-expandable and biocompatible materials, such as Nitinol. The clot removal device10is preferably manufactured by laser cutting the shape memory material sheet of the clot engaging structure20.

The clot engaging structure20comprises a plurality of interconnected struts25(e.g., undulating elements, wires or the like) forming an open cell27pattern. The struts25may include a plurality of longitudinal undulating elements with adjacent undulating elements being out-of-phase with one another and connected in a manner to form the plurality of diagonally disposed cells27. The clot engaging structure20includes a radially constrained configuration and a radially expanded configuration. When the clot engaging structure20is in the radially expanded configuration, a first portion26of the clot engaging structure20is rolled about itself in a clockwise direction to form a first barrel12a,and a second portion28of the clot engaging structure20is rolled about itself in a counter-clockwise direction to form a second barrel12bthat extends in a side-by-side configuration with the first barrel12a,as shown for example inFIGS. 1-2, 4-7 and 12-15.

The clot engaging structure20further comprises a barrel portion22which is formed into the barrels12(i.e.,12a,12b), and an extension piece24extending from the barrel portion22which forms the coupling plate16. The barrel portion22includes a first edge26which forms the free edge14of a first barrel12aand a second edge28opposing the first edge26which forms the free edge14of the other barrel12b.The clot engaging structure20is formed into the clot removal device10by forming the barrel portion22into the barrels12a-busing a tool such as a mandrel. For instance, the first edge26of the sheet is rolled over the tool to form the first barrel12ahaving a longitudinal axis parallel to the first edge26. The first edge26is positioned by the forming such that it is left free and unconnected from the remainder of the first barrel12aalong the length of the first barrel12a.Then, the second edge28is rolled over a tool to form the second barrel12badjacent and substantially parallel to the first barrel12a.The second edge28is left free and unconnected from the remainder of the second barrel12balong the length of the second barrel12b.

In the embodiment ofFIGS. 1-2 and 4-7, the first edge26and second edge28are rolled in opposite orientations relative to the middle of the sheet, thereby forming a “FIG. 8”-like cross-sectional shape, wherein the first edge26is rolled in a clockwise direction (e.g., downwardly oriented) and the second edge28is rolled in a counter-clockwise direction (e.g., upwardly oriented), from the middle of clot engaging structure20.

In the alternative embodiments depicted inFIGS. 12-15, the first barrel12aand second barrel12bare rolled in the same orientation relative to or towards the middle of the sheet, wherein the first edge26is rolled in a clockwise direction and the second edge28is rolled in a counter-clockwise direction, with both edges26and28being upwardly oriented towards the middle of clot engaging structure20.

Turning now toFIGS. 4-10, the cross-section of the respective barrels12for several alternative embodiments of the clot engaging structure20are shown. Each of the alternative embodiments may have all of the features as described above for the clot removal device10ofFIGS. 1-3, including being formed from a single sheet of material and/or the sheet of material comprising a plurality of struts25and cells27structures, as shown inFIG. 3.

FIG. 4shows a cross-section of the clot engaging structure20having two barrels12in which the free edge14of each of the barrels12is further from the opposing side of the respective barrel12such that the free edge14is spaced further from the respective barrel12. As shown inFIG. 4, the first portion26terminates along the first edge14that does not overlap with a remainder of the first barrel12a,and the second portion28terminates along a second edge14that does not overlap with a remainder of the second barrel12b,when the clot engaging structure20is in the radially expanded configuration. This provides a larger opening between the free edges14(e.g., less material interaction) and the remainder of the barrel12which may make the barrels12more compressible because the free edges14can be moved a larger distance before contacting the respective other side of the barrels12.

FIG. 5shows a cross-section of the clot engaging structure20having two barrels12in which the free edges14of each of the barrels12overlaps the other side of the barrel12. In this case, the barrels12have a spiral shape, or at least a portion that is spiral shaped, such that the free edge14overlaps to the inside of opposing side of the barrel12. As shown inFIG. 5, the first portion26terminates along the first edge14that overlaps with at least a portion of the first barrel12a,and second portion28terminates along the second edge14that overlaps with at least a portion of the second barrel12bwhen the clot engaging structure20is in the radially expanded configuration.

It should be appreciated that, in any of the embodiments described herein, the barrels12may have all or some barrels12having free edges14that overlap with portions of the barrels, as shown inFIGS. 5, 7, 12 and 15, or all or some barrels12having free edges14that do not overlap with portions of the barrels, as shown inFIGS. 2, 4, 6, 8-10, 12 and 15, when the clot engaging structure20is in the radially expanded configuration.

FIG. 6shows a cross-section of the clot engaging structure20having two barrels12in which the diameter of each barrel12is different. In the embodiment ofFIG. 6, the barrel12ahas a larger diameter than the barrel12bor the barrel12bhas a smaller diameter than the barrel12a,when the clot engaging structure20is in the radially expanded configuration. Accordingly, in any of the embodiments described herein, the barrels12may have the same or similar size and shape, or the barrels12may have different sizes and shapes.

FIG. 7shows a cross-section having two barrels12similar toFIG. 5, except that the free edge14of each barrel overlaps more than the free edges14in the embodiment ofFIG. 5.

FIG. 8shows a cross-section of the clot engaging structure20having two barrels12and including an intermediate portion30disposed between the two barrels12. The intermediate portion30includes a loop and/or a third barrel when the clot engaging structure20is in the radially expanded configuration.

Each of the barrels12and30are the same or similar size in the embodiment ofFIG. 8.

FIG. 9shows a cross-section of the clot engaging structure20having two barrels12and the intermediate portion30, similar to the embodiment ofFIG. 8, except that the two barrels and the intermediate portion30each have a different size.

FIG. 10shows a cross-section of the clot engaging structure20having the barrels12and the intermediate portion30similar to the embodiment ofFIG. 8, except that the intermediate portion30has a larger opening between the edges14of the respective barrels12aand12b.

The operation of each of the embodiments of the clot removal device10is basically the same. The clot removal device10is attached to a wire or actuating mechanism by connecting the wire or actuating device to the connector18. The clot removal device is inserted into an insertion catheter by compressing the barrels12of the clot removal device10. The insertion catheter and clot removal device are inserted into the vasculature of the patient and advanced through the vasculature to position the clot removal device10just distal to the clot. The clot removal device10is removed from the intravascular catheter. This may be done by advancing the clot removal device10relative to the intravascular catheter, or by withdrawing the intravascular catheter relative to the clot removal device10, or by a combination of both (e.g., advancing the clot removal and withdrawing the catheter). The barrels12of the clot removal device10then expand within the blood vessel into the clot. The clot engaging structure20may be biased to expand, or is otherwise expandable from, the radially constrained configuration to the radially expanded configuration when deployed from a delivery catheter into a blood vessel. The clot removal device10is then moved proximally to ensnare the clot by pulling the wire or other actuating mechanism connected to the connector18. The clot removal device10is then withdrawn proximally to remove the clot from the blood vessel. For instance, the clot removal device10and clot may be withdrawn into the insertion catheter, and then the entire assembly including the clot removal device10and catheter are withdrawn from the vasculature.

FIGS. 11A-Cillustrate exemplary use of the clot removal device10according to the disclosed inventions. The clot removal device10disposed in a target site of a patient's blood vessel70(e.g., within a lumen72and adjacently located to a clot75); the device10is radially constrained by a catheter80, as shown inFIG. 11A. The clot removal device10is either pushed distally relative to a catheter80, or the catheter80is withdrawn proximally relative to the clot removal device10(or some of each) (not shown), in order to deploy the clot removal device10out of the catheter80and into the lumen72of the blood vessel70, and allow the no-longer radially constrained clot removal device10to radially expand within the blood vessel70in order to engage, ensnare and encapsulate the clot75. When the clot removal device10is deployed, the barrels12of device10expand (decompress), and unroll due to radial expansion forces.

The clot removal device10, in particular, the barrels12may assume a variety of orientations relative to the clot75when deployed within the patient's blood vessel70, such as for example the orientations ofFIGS. 11B-C or any range therebetween. For example, the device10may assume an orientation having barrels12aand12bin contact with the blood vessel70when deployed, so that the barrels12a-bassist the device10to overcome resistive forces36of the clot75, which in turn allows the device to penetrate the clot75at least at two points of entry76a-b, in order to engage, ensnare and/or capture the clot75, as shown inFIG. 11B. In another example, the device10may assume an orientation having one of the barrels12ain contact with the blood vessel70when deployed, the barrel12awill further assist the device10to overcome resistive forces36of the clot75by pushing the barrel12bfurther into the clot75engaging, ensnaring and/or capturing the clot75, as shown inFIG. 11C.

In yet another example, the device10may assume any orientation in a range between the orientations ofFIGS. 11B-C, which in turns may provide a combination of the advantages of said orientations ofFIGS. 11B-Cto the device10(e.g., multiple points of entry to the clot and/or assistance to overcome the resistive forces of the clot).

FIG. 12shows a cross-section of another embodiment of the clot engaging structure20, in which the first portion26terminates along the first edge14that does not overlap with a remainder of the first barrel12a,and the second portion28terminates along a second edge14that does not overlap with a remainder of the second barrel12b,respectively, when the clot engaging structure20is in the radially expanded configuration. This embodiment provides a larger opening between the free edges14(e.g., less material interaction) and the remainder of the barrels12, which may make the barrels12more compressible because the free edges14can be moved a larger distance before contacting the respective other side of the barrels12. In this embodiment, the clot engaging structure20includes a space or separation between barrels12aand12b(e.g., barrels12are not in contact with each other), when the clot engaging structure20is in the radially expanded configuration.

FIG. 13shows a cross-section of yet another embodiment of the clot engaging structure20, in which the first portion26terminates along the first edge14that overlaps with at least a portion of the first barrel12a,and second portion28terminates along the second edge14that overlaps with at least a portion of the second barrel12b,respectively, when the clot engaging structure20is in the radially expanded configuration. In this embodiment, the clot engaging structure20includes a space or separation between barrels12aand12b(e.g., barrels12are not in contact with each other), when the clot engaging structure20is in the radially expanded configuration.

FIG. 14shows a cross-section of still another embodiment of the clot engaging structure20, in which the first portion26terminates along the first edge14that does not overlap with a remainder of the first barrel12a,and the second portion28terminates along a second edge14that does not overlap with a remainder of the second barrel12b,respectively, when the clot engaging structure20is in the radially expanded configuration. In this embodiment, the first portion26of the barrel12ais in contact with at least one point or section29of the second portion28of the second barrel12b,when the clot engaging structure20is in the radially expanded configuration.

FIG. 15shows a cross-section of yet another embodiment of the clot engaging structure20, in which the first portion26terminates along the first edge14that overlaps with at least a portion of the first barrel12a,and second portion28terminates along the second edge14that overlaps with at least a portion of the second barrel12b,respectively, when the clot engaging structure20is in the radially expanded configuration. In this embodiment, the first portion26of the barrel12ais in contact with at least one point or section29of the second portion28of the second barrel12b,when the clot engaging structure20is in the radially expanded configuration.

It will be appreciated that the use of the various clot removal devices10shown inFIGS. 1-15may also be used in other suitable medical applications. Furthermore, it should be apparent to those of ordinary skill in the art that many modifications may be made to the illustrated and herein described embodiments may be made without departing from the scope of the appended claims, and that the proper scope of the disclosed inventions should be limited only as defined in the appended claims, and their full legal equivalents, so as to encompass all such modifications and equivalents.