VALVULOTOME

Abstract

The invention relates to a valvulotome comprising a catheter tube (4) and an expandable basket (5) with cutting elements (7), wherein the catheter tube (4) being designed to accommodate within itself the expandable basket (5) in a non-expanded state, wherein the basket (5) is fixed to the distal end of a wire element (3) extending in the catheter tube (4) and the basket (5) distally comprises an atraumatically configured resilient tip (8).

Claims

1. Valvulotome comprising a catheter tube (4) and an expandable basket (5) with cutting elements (7), wherein the catheter tube (4) being designed to accommodate within itself the expandable basket (5) in a non-expanded state, characterized in that the basket (5) is fixed to the distal end of a wire element (3) extending in the catheter tube (4) and in that the basket (5) distally comprises an atraumatically configured resilient tip (8).

2. Valvulotome according to claim 1, characterized in that the wire element (3) is a braided steel wire strand.

3. Valvulotome according to claim 1, characterized in that the wire element (3) is glued and/or welded to the proximal end of the expandable basket (5).

4. Valvulotome according to claim 1, characterized in that the atraumatically designed tip (8) and the expandable basket (5) are formed in one piece.

5. Valvulotome according to claim 4, characterized in that the atraumatically configured tip (8) and the expandable basket (5) consist of a shape memory material, preferably nitinol.

6. Valvulotome according to claim 5, characterized in that the atraumatically configured tip (8) and the expandable basket (5) are made/cut from a tube.

7. Valvulotome according to claim 6, characterized in that the atraumatically configured tip (8) is provided with a circumferentially running spiral incision (10).

8. Valvulotome according to claim 7, characterized in that incision (10) is provided with webs (12) in the manner of a universal joint.

9. Valvulotome according to claim 1, characterized in that the basket (5) has three struts (6) each provided with one or two cutting elements (7).

10. Valvulotome according to claim 9, characterized in that the struts (6) are brought together distally to form the atraumatically designed tip (8).

11. Valvulotome claim 1, characterized in that the cutting elements (7) have hook-shaped cutters which extend in the plane of the struts (6), with the cutters being flanked by recesses of the struts (6).

12. Valvulotome claim 1, characterized in that the wire element (3) is movably guided in the catheter tube (4).

13. Valvulotome claim 1, characterized in that it comprises a radiopaque marker element in the region of the distal end of the catheter tube (4).

Description

[0026] The invention is explained in more detail by way of the enclosed figures, where

[0027] FIG. 1: shows a valvulotome according to the invention with basket in expanded state,

[0028] FIG. 2: is a planar view of the basket with 3 cutting elements and tip,

[0029] FIG. 3: is a planar view of the basket with 6 cutting elements and tip, and

[0030] FIG. 4: shows a universal joint design of the tip.

[0031] FIG. 1 shows a valvulotome proposed by the present invention together with the introducer sheath 1, the handle 2 for moving the wire element 3. The valvulotome essentially consists of the catheter tube 4, the wire element 3, the cutting basket 5 and the atraumatically designed soft tip 8. As shown in the figure, the cutting basket 5 is extended from the catheter tube 4, expanded, and ready for insertion into a vein to strip the respective venous valves. It comprises three struts 6, each provided with a cutting element 7. The cutting basket 5 itself is distally provided with an atraumatic and soft tip 8. Cutting basket 5 and tip 8 consist of the same material and are manufactured in one piece.

[0032] The wire element 3 is made of a strand of fine steel wires that are braided or twisted together. In this way, the wire element has the flexibility and also the stiffness necessary to move the cutting basket. The wire strand 3 is welded to the proximal end of the cutting basket 5.

[0033] The catheter tube 4 is made of conventional material and therefore requires no further explanation. Expediently, the cutting basket 5 is composed of a shape memory material, particularly nitinol, which allows the basket to be imprinted with the desired shape so that it has an elongated form within the catheter tube and assumes the imprinted expanded shape after being liberated from the catheter tube.

[0034] FIG. 2 is a planar representation of an inventive variant of a cutting basket 5 with distal tip 8. The basket portion shows three struts 6, with each strut 6 carrying a cutting element 7. The cutting edges 7 are designed to form hook-shaped cutters which are curved in the proximal direction of the struts 6. They are located on the plane of the respective strut. The cutters 7 are flanked by recesses of the struts 6. In the process of stripping the venous valves the valves are retained in the recess located in front of the cutting edge and then clipped by retracting the valvulotome.

[0035] Proximal to the cutting basket 5 a tubular segment 9 is arranged, which is triple-perforated and serves to fix the wire strand 3 by welding and/or gluing.

[0036] The atraumatically designed tip 8 is located distal to the cutting basket 5, said tip having a spiral incision 10 and a distal end terminating in four arches 11. As mentioned hereinbefore, the tip 8 is formed from a tube. By providing tip 8 with circumferentially extending spiral incision 10, coil spring properties are imparted on the tip and the terminal arches 11 are given a certain amount of elasticity. The terminal arches 11 are bent inward, that is, they are reshaped toward the tube axis, which prevents the tip 8 from contacting the vessel wall.

[0037] FIG. 3 illustrates a variant of a cutting basket 5 provided with 2 cutters 7 each. These are located, somewhat offset, on opposite sides of the strut, the cutting edges pointing in proximal direction. Providing two cutting edges per strut as shown in this arrangement increases the “hit rate” when stripping the venous valves.

[0038] FIG. 4 shows the universal joint-like design of the incision 10 with webs 12 bridging the incisions. Expediently, two webs 12 are provided per turn, with the webs 12 in adjacent turns being offset from each other by 90°.