Thrombectomy device

Abstract

The invention relates to a thrombectomy device having a substantially cylindrical stent structure (1) comprised of a plurality of meshes (3, 4) and also two connectors (5, 5′) that are disposed at different meshes (3) at the proximal end of the stent structure (1). The device also has a guide wire (12), which comprises a coupling element (11) to which the connectors (5, 5′) are coupled, and a slit (7), which extends helically over the shell face (8) of the stent structure (1), and a tensioning clip (9) that spans the slit (7) at the proximal end.

Claims

1. A thrombectomy device comprising: a substantially cylindrical stent structure (1) comprised of a shell face (8), a plurality of meshes (3, 4) and two connectors (5, 5′) that are disposed at different meshes (3) at the proximal end of the stent structure (1), and a guide wire (12), which comprises a coupling element (11) to which the connectors (5, 5′) are coupled, wherein the stent structure is characterized by a continuous slit (7) open at a distal end thereof and which extends helically over and throughout the length of the shell face (8) of the stent structure (1), and a single tensioning clip (9) that continuously spans the slit (7) at the proximal end, the tensioning clip (9) being attached to combs at rims (10, 10′) of the mesh structure, wherein the tensioning clip forms an arch that points to the distal end of the stent structure, and wherein the tensioning clip (9) and the connectors (5, 5′) form a loop which converges in the coupling element (11).

2. A device according to claim 1, characterized in that the stent structure comprises a shape-memory material.

3. The device of claim 2, wherein the shape-memory material is Nitinol or a nickel-titanium-chromium alloy.

4. A device as defined in claim 1, characterized in that the stent structure (1) is cut out of a tube and has rectangular or trapezoidal web cross-sections.

5. A device as defined in claim 4, characterized in that the web cross-sections include a small side that forms the shell face (8) of the stent structure (1).

6. A device as defined in claim 1, characterized in that the stent structure (1) is mechanically, hydraulically or electrochemically detachable from the guide wire (12).

7. A device as defined in claim 6, characterized in that the coupling element (11) is configured as a detaching element.

8. A device as defined in claim 6, characterized by two detaching spots.

9. The device of claim 8, with an electrochemical detachment.

10. A device as defined in claim 1, characterized in that the coupling element (11) is peripherally arranged to the connectors.

11. A device as defined in claim 1, characterized in that the distal end of the stent structure (1) is widened-up in a conical or trumpet shape.

12. A device as defined in claim 1 characterized by marker elements.

13. A thrombectomy device comprising: a substantially cylindrical stent structure (1) comprised of a plurality of meshes (3, 4) and two connectors (5, 5′) that are disposed at different meshes (3) at the proximal end of the stent structure (1), and a guide wire (12), which comprises a coupling element (11) to which the connectors (5, 5′) are coupled, wherein the stent structure is characterized by a continuous slit (7) open at a distal end thereof and which extends helically over the shell face (8) of the stent structure (1), and a tensioning clip (9) that continuously spans the slit (7) at the proximal end, the tensioning clip (9) being attached to combs at rims (10, 10′) of the mesh structure, wherein the tensioning clip forms an arch that points to the distal end of the stent structure, and wherein the tensioning clip (9) and the connectors (5, 5′) form a loop which converges in the coupling element (11).

Description

(1) The invention is further elucidated by way of the enclosed drawings, where:

(2) FIG. 1 shows a first variant of the inventive stent structure in a planar, two-dimensional view;

(3) FIG. 2 shows a three dimensional view of the stent structure of FIG. 1;

(4) FIG. 3 shows a planar, two-dimensional representation of a second variant of an inventive stent structure;

(5) FIG. 4 is a three-dimensional representation of the stent structure of FIG. 3 with a guide wire coupled-on;

(6) FIG. 5 is a perspective of an inventive stent structure with two connectors;

(7) FIG. 6 is a representation of the web cross-sections of the stent structure, and

(8) FIG. 7 shows a schematic view of the inventive thrombectomy device.

(9) FIGS. 1 and 3 show two variants of an inventive cylindrical stent structure 1 with the individual meshes 3 and 4 and the connectors 5 and 5′. The meshes 3 and 4 are of two different types, one type (3) having a wave shape, the other type (4) having a bulbous shape with two tips. When co-acting, these two shapes provide the overall structure with both stability and flexibility.

(10) In the planar, two-dimensional representation of FIGS. 1 and 3, a slit or channel 7 extends through the stent structure, said slit or channel being bridged by the tensioning dip 9 at the proximal end of the structure. The slit 7 is confined by the lateral faces 10 and 10′ of the mesh structure. The slit 7 does not extend in parallel to the longitudinal axis of the structure, but obliquely to the longitudinal axis which in the three-dimensional is represented as a helically-shaped course along the shell face ((see FIG. 2/4).

(11) The representation shown in FIGS. 1 and 3 is a planar, two-dimensional representation of a cut-open stent structure 1; and the three-dimensional representations are reflected in FIGS. 2 and 4. In the planar, two-dimensional representation, the meshes 3 immediately adjacent to the meshes 3′ in such a manner that it results in an overall tubular structure comprising a slit or channel 7 extending circumferentially roughly half around the shell face 6.

(12) The variants of FIGS. 1 and 3 differ in the shape of the connectors 5 and 5′, which in the case of FIG. 3 are configured longer and converged in a coupling element 11 (see FIG. 4). The coupling element 11 may, for example, be an electrolytically corrodible system that permits detaching the stent structure 1 from the guide wire 12 (see FIG. 4). In the variant according to FIG. 2, two detaching elements 6, 6′ may be provided for electrolytic detachment.

(13) Both embodiments have in common that the slit 7 is bridged by the dip 9. The clip 9 attaches to the combs lying at the rims 10, 10′ of the mesh structure, and with its arch it points to the distal side of the stent structure. This allows for unproblematic pulling-in of the stent structure into a catheter. Together with the adjacent connectors 5 and 5′, the tensioning arch 9 forms a capture sling and/or opening of a capture cage converging in the coupling element 11 (FIG. 4). To this effect, the distal end the stent structure may also be occluded with a mesh structure.

(14) In the representations of FIGS. 2 and 4, which are a three-dimensional representation of the stent structures of FIGS. 1 and 3, the webs of the stent structure that lie on the rear side are shown bright. What can be seen here is the slit 7 extending at the proximal end of the structure under the tensioning clip 9 and winding towards the right side around the shell face 8 of the stent structure. The slit 7 terminates in its distal position on the bottom side of the stent structure 1, thus describing a rotation by about 180°.

(15) FIG. 5 shows a three-dimensional representation of an inventive stent structure, wherein the connectors 5 and 5′ are provided with inwardly directed hooks engaging into a corresponding take-up of a coupling element 11 of a guide wire 12. As long as the coupling element with the proximal end of the connectors 5 and 5′ is located in a catheter, the stent structure 1 is coupled to the guide wire. On pushing it out from the catheter, the connection between the connectors 5, 5′ and the coupling element 11 disappears and the structure is released as a stent for retention in the vascular system. The disengagement, however, will occur only in special cases (of emergency), for example if the device cannot be retracted ready into the catheter.

(16) Clearly recognizable in FIG. 5 is the loop-type structure composed of the clip 9 and the connectors 5, 5′ as well as the course of webs of the stent structure along the shell face 8 which with their edges serve to take an impact on the thrombus material to be removed and which shear it off from the vessel wall.

(17) FIG. 6 illustrates these two preferred embodiments of the webs 14 with a rectangular and a trapezoidal cross-section, with the small side each pointing to the shell face 8 of the stent structure 1 and to the vessel wall 13, respectively. These variants ensure the required stability of the mesh net on the one hand and a good shear and displacement effect on the thrombus on the other hand.

(18) FIG. 7 schematically shows the set-up of an inventive thrombectomy device comprising the guide wire 12, the coupling element 11, the area of the proximal tie-up to the connectors 5, 5′, the effective range with the shell face 8 and the distal area 13 with a trumpet-shaped expansion.

(19) Equal reference numbers in these figures represent equal factual circumstances.