Occluder

Abstract

The invention relates to a cylindrical occluder for sealing hollow-cylindrical body vessels, the occluder being able to be positioned minimally invasively in a contracted state and being able to convert to an expanded state in which it has a widened diameter for bearing on the inner wall of a body vessel, wherein the occluder (1) consists of a wire mesh (4), of which the wires are brought together at their ends in such a way that the occluder (1) in the expanded state forms a cage, characterized in that the occluder has, enclosed within it and oriented longitudinally, a sail-shaped insert (6) which consists of one or more elongate wire loops (11, 12) arranged in a row, the proximal end of which wire loops is fixed at the proximal end of the occluder (1), wherein each of the wire loops is covered with a membrane.

Description

[0001] Occluder

[0002] The invention relates to a cylindrical occluder for sealing hollow cylindrical body vessels, which can be positioned in a contracted state in a minimally invasive manner and can be converted into an expanded state in which it has an enlarged diameter for contact with the inner wall of a body vessel, wherein the occluder consists of a wire mesh whose wires are combined at their ends in such a way that the occluder forms a cage in the expanded state.

[0003] It is common practice to implant occluders minimally invasively into body vessels to prevent blood flow. This applies, for example, to the closure of blood vessels during tumor treatment, fistulas or shunts between blood vessels, aneurysms, or even to close the left atrial appendage to prevent thrombus formation. Numerous variants of occluders have been developed for this purpose.

[0004] For example, EP 0 808 138 B1 discloses an occluder in the form of a double umbrella made of a metal mesh of interwoven metal strands. The occluder is placed at the desired location in a patient's vascular system using a catheter and expanded. It is primarily used to close a PFO.

[0005] DE 10 2009 058 132 A1 discloses an occluder having a cylindrical cage structure and containing membranes fitted transversely to the longitudinal direction within the cage, which are suitable for inhibiting or preventing blood flow. Manufactured from a shape-memory material, it allows for transport in a contracted state and placement in an expanded state. A comparable occluder is described in WO 2013 / 005 195 A1.

[0006] It has been shown that a mere cage structure is rarely suitable for preventing unwanted blood flow. The insertion of blocking membranes transverse to the longitudinal direction of an occluder is problematic; the membrane usually has to be sewn in, which is laborious. After placement, the transversely installed membranes can become loose due to the expansion of the cage or become so tense that the expansion and thus the closure of the

[0007] vessel remains incomplete.

[0008] Accordingly, the object of the invention is to provide an occluder with a cage structure that is suitable for sufficiently inhibiting blood flow in a vessel after implantation. An internally inserted membrane must not impede the expansion of the occluder during implementation.

[0009] This task is solved with a cylindrical occluder of the type described above, in which the occluder has a sail-shaped insert enclosed inside and aligned longitudinally, which consists of one or more elongated wire loops arranged in a row, the proximal end of which is fixed to the proximal end of the occluder, each of the wire loops being covered with a membrane.

[0010] According to the invention, the terms distal mean the side of the implant facing away from the treating physician and proximal mean the side facing towards the treating physician.

[0011] A cage is understood to be an occluder made of braided wires that is closed on all sides and whose wire ends are gathered together at both longitudinal ends.

[0012] A wire loop is a longitudinally oval wire structure consisting either of a single wire whose ends are joined and twisted together, or of two wires that are bent upwards and whose ends are twisted together. If several loops are arranged in a row, the wire or wires are twisted together at least once, creating a knot that separates the individual loops. The areas enclosed by the loops are covered with a membrane.

[0013] The occluder according to the invention has a substantially cylindrical shape and consists of a wire mesh. Materials with shape memory properties are used for the wire mesh, for example, spring steel or nickel-titanium alloys, especially nitinol. The wires of the wire mesh are gathered at both ends to form a closed cage. The wire ends are advantageously secured in sleeves made of medical-grade steel.

[0014] The occluder according to the invention is designed to be inserted into hollow cylindrical body vessels and deposited there. The insertion takes place using a conventional catheter or sheath, in which the occluder is transported in a contracted form. For this purpose, the occluder is connected to a dedicated delivery system that allows the occluder to be pushed out of the catheter and brought to its destination and released. Once released, the occluder expands into the predetermined cylindrical shape and, with its enlarged diameter, adheres to the inner wall of the respective body vessel. This expansion also involves the unfolding of the sail-shaped insert, which extends longitudinally within the interior of the cage.

[0015] The sail-shaped insert in the interior of the occluder preferably consists of at least two wire loops with a longitudinally oval orientation, each covered with a membrane. The wire loops can consist of a single wire that is bent back and whose ends are twisted together, or of two single wires that are twisted together at their ends and connected via the membranes. To form the sequential loops, the wire or wires are twisted together at least at one point.

[0016] The sail-shaped insert must be fixed with its proximal end to the proximal end of the occluder. This can be achieved, for example, by suturing it to the proximal end of the occluder. Alternatively, the proximal wire ends of the insert can be secured to the proximal wire ends of the occluder in the proximal sleeve of the occluder. In both cases, a solid connection is created that is designed to last. The distal end of the sail-shaped insert remains freely movable, without being fixed to the distal end of the occluder.

[0017] The membrane material used is usually a body-compatible plastic, preferably Teflon or polyurethane.

[0018] According to one embodiment, the sail-shaped insert can have a longitudinally oval shape over its entire length, such as a lens shape. However, a preferred shape is one in which the insert is twisted multiple times in the center, thus forming two approximately equal-sized segments separated from each other by the twisting knot. Another variant provides for multiple twists such that three or four approximately equal-sized loops or segments are formed, which follow one another. For twisting, the wire loop is preferably twisted multiple times, for example six times, to create a stable structure. It is preferred that the individual segments are not in one plane, but are twisted more or less relative to one another.

[0019] The occluder according to the invention is placed in a known manner using a catheter or a sheath. For this purpose, the occluder is connected to a guidewire / introduction system, which allows the occluder to be pushed out of the catheter and brought to its destination and released. This is preferably done in a known manner using a ball pin and a gripper at the end of the guidewire or introduction system. When placed, the occluder is firmly connected to the gripper, i.e. the gripper is closed. For release, the forceps are opened via a spring mechanism and the catheter and guidewire are retracted. The ball pin is expediently a ball fixed, for example welded, to the proximal sleeve of the occluder, which is held in place by the forceps.

[0020] As already described, the sail-shaped insert is either connected to the proximal end of the occluder with a thread of suture material or is combined with the ends of the occluder in the proximal sleeve via the twisted ends and crimped there.

[0021] Furthermore, and in particular, the occluder can be coated on the front side (at the proximal and / or distal end) with a membrane, preferably made of polyurethane or Teflon. Such a membrane can be applied to the surface of the mesh, for example, by a dip process.

[0022] The invention is explained in more detail in the accompanying figures. They show:

[0023] Fig. 1 shows an occluder according to the invention in plan view without insert;

[0024] Fig. 2 a sail-shaped insert with proximally arranged thread made of surgical suture material;

[0025] Fig. 3 shows the sail-shaped insert from Fig. 2 in a three-dimensional representation; and

[0026] Fig. 4 shows an occluder according to the invention with a sail-shaped insert indicated therein.

[0027] The occluder 1 according to the invention, as shown in Fig. 1, consists of a cylindrical wire mesh 4, the terminal wires of which are combined and fixed in sleeves 2, 3. The sleeves 2, 3 are crimped around the wire ends and provide a permanent hold. The proximal sleeve 3 ends in a pin with a ball 5, which serves to secure the occluder 1 to a guide wire gripper (not shown).

[0028] The wire mesh 4 of the occluder 1 is made of a shape-memory material, specifically nitinol, which allows the occluder to be transported in a contracted state within a catheter. After leaving the catheter, the occluder 1 expands and rests with its enlarged circumference against the inner wall of the vessel to be worn. It remains fixed in this position due to its expansion force.

[0029] By bundling the wires of the occluder 1 at the ends, the wire mesh 4 becomes denser and is thus suitable for inhibiting blood flow in the respective blood vessel. Fig. 2 shows the sail-shaped insert 6 with the two wires 7, 8, which are twisted together several times to form a knot at 9 in the center. A thread 10 made of surgical suture material at the proximal end of the insert 6 serves to secure it to the proximal end of the occluder 1. The twisted ends of the wires 7, 8 are not shown. A covering or membrane made of polyurethane film forms the sail structure, which in the illustrated case consists of two loops or segments 11, 12.

[0030] The sail-shaped insert 6 is expediently inserted into the occluder 1 through the wire mesh 4, which, due to its shape memory properties, can be easily stretched and returns to its predetermined shape after insertion. Placement within the occluder 1 during manufacturing, i.e., before closing the proximal end, is also possible; in this case, the sail-shaped insert can be crimped directly to the wire ends of the occluder 1 and the sleeve 3.

[0031] Fig. 3 shows the sail-shaped insert from Fig. 2 in a three-dimensional representation. It is clear that the two segments of the insert 6 do not run in one plane, but are twisted relative to each other and also have curvatures.

[0032] Fig. 4 shows an occluder 1 according to the invention with a sail-shaped insert 6 arranged therein. For clarity, the two segments 11, 12 are shown in one plane. It is understood that the sail-shaped insert is fixed to the occluder 1 only at its proximal end; the distal end is freely movable. This is necessary because the occluder 1, in its contracted state with a small diameter, has a greater length than the insert 6 in this state.

Claims

Patent claims 1. Cylindrical occluder for sealing hollow cylindrical body vessels, which can be positioned minimally invasively in a contracted state and converted into an expanded state in which it has an enlarged diameter for contact with the inner wall of a body vessel, wherein the occluder (1) consists of a wire mesh (4) whose wires are combined at their ends such that the occluder forms a cage in the expanded state, characterized in that the occluder (1) has an internally enclosed and longitudinally aligned sail-shaped insert (6) which consists of one or more elongated wire loops (11, 12) arranged next to one another, the proximal end of which is fixed to the proximal end of the occluder (1), wherein each of the wire loops is covered with a membrane.

2. Cylindrical occluder according to claim 1, characterized in that the wire mesh (4) consists of a material with shape memory properties, in particular nitinol.

3. Cylindrical occluder according to claim 1 or 2, characterized in that the ends of the occluder (1) are combined with sleeves (2, 3) made of medical steel.

4. Cylindrical occluder according to claim 3, characterized in that the proximal sleeve (8) is provided with a ball pin (5).

5. Cylindrical occluder according to one of the preceding claims, characterized in that the wires (7, 8) of the wire loops (11, 12) consist of a shape memory material, in particular Nitinol, and are twisted together at the ends 6. Cylindrical occluder according to one of the preceding claims, characterized in that the wires (7, 8) are twisted into two loops (11, 12) in such a way that two sail-shaped segments are obtained.

7. Cylindrical occluder according to one of claims 1 to 5, characterized in that the wires (7, 8) are twisted into three or more loops.

8. Cylindrical occluder according to one of the preceding claims, characterized in that the membrane consists of Teflon or polyurethane.

9. Cylindrical occluder according to one of the preceding claims, characterized in that the proximal ends of the wire loops (11, 12) are connected to the proximal ends of the Occluders are summarized and fixed together.

10. Cylindrical occluder according to one of claims 1 to 8, characterized in that the sail-shaped insert (6) is fixed with suture material (10) at the proximal end of the occluder (1). 11 . Cylindrical occluder according to one of the preceding claims, characterized in that the proximal and / or distal end of the occluder (1) is coated with a membrane.

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