Sleeve-like medical implant

Abstract

The invention relates to a medical implant, comprising: an electrode arrangement configured to wrap a sleeve, referred to as a sleeve electrode (1), suitable for extravascular or extraneurovascular fixation along in vivo blood vessels or nerve fiber bundles; the sleeve electrode (1) has a longitudinal extension, and an electrical lead-in and lead-out device which electrically connects the sleeve electrode (1) to an implantable supply unit which is designed separately from the sleeve electrode (1), the electrical lead-in and lead-out device being surrounded by an elastic sheath (6) over a section of the longitudinal extension thereof, the elastic sheath (6) is connected in a stationary manner to an in-vivo tissue region (11) by means of a fastening device (8) which can be operatively connected to the elastic sheath (6), characterized in that the elastic sheath (6) has a longitudinal extension and a circumferential edge which is oriented radially about the longitudinal extension and on which the elastic sheath (6) is fastened to the in-vivo tissue region (11). According to the invention, at least one tunnel-shaped opening contour (9) is arranged along at least one cross-sectional plane oriented orthogonally to the longitudinal extent thereof, which opening contour is suitable for locally guiding a fastening device designed as a medical thread (8) and has no structural components protruding radially beyond the circumferential edge of the sheath.

Description

Sleeve-shaped medical implants Technical Field

[0001] This invention relates to a medical implant comprising: an electrode device designed as a sleeve, referred to as a sleeve electrode, suitable for extravascular or extraneural fixation along a blood vessel or nerve fiber bundle in the body; and an electrical introduction and extraction device having a longitudinal extension, the electrical introduction and extraction device electrically connecting the sleeve electrode to a separately designed implantable supply unit, wherein the electrical introduction and extraction device is surrounded by an elastic sheath in a section of its longitudinal extension, the sheath being fixedly connected to a tissue region in the body by a fixation device responsively connected to the elastic sheath. Background Technology

[0002] Document EP3204105B1 discloses a sleeve electrode device, also known as a sleeve electrode, which consists of a flexible, biocompatible, thin-film-shaped carrier substrate, preferably composed of a polyimide film. Multiple individual electrodes are arranged on at least one surface of the carrier substrate. Known sleeve electrodes are used for spatially resolved detection of neuronal electrical signals and for selective electrical stimulation of individual nerve fibers extending within a bundle of nerve fibers. For power and signal supply, all electrodes of the sleeve electrode are connected to wires, which in turn are connected to a separately designed power supply implant. The power supply implant is typically implanted subcutaneously in a surgically accessible area of ​​the body, such as in the chest region or near the clavicle, while the sleeve electrode is implanted a few centimeters away, preferably along the vagus nerve.

[0003] To ensure that the power and signal transmission between the power supply implant and the cuff electrode is as tissue-friendly as possible, the required electrical connection cable must have the smallest possible cross-section and length, sufficient to compensate for relative movement between the implantation sites of the power supply implant and the cuff electrode. Typically, the connection cable is connected to the power supply implant via a detachable, fluid-proof plug, and to the cuff electrode via either electrically fixed contacts or also via a plug. Both connection variations are described in document DE102017209773A1. In both cases, to ensure electrical contact between the multiple electrical conductors located on the cuff electrode side and the connection cable forming the electrical connection cable, a carrier plate made of ceramic material is typically used, on which multiple electrical contacts are arranged by bonding or welding.

[0004] To protect it from moisture or body water intrusion, the contact structure, or at least a portion thereof, is surrounded by a sheath made of a biocompatible electrically insulating material. This sheath, in addition to its sealing function, allows the surgeon to manually manipulate the cuff electrode during implantation due to its macroscopic size and shape. The sheath is preferably made of elastic silicone material and typically has a straight cylindrical or elliptical shape with a longitudinal extension (typically within a range of at least 1 cm) and a diameter of several millimeters. Furthermore, the sheath serves as a mechanical support for the additional fixation of the cuff electrode, which, in the implanted state, tightly surrounds the nerve fiber bundle, preferably the vagus nerve, in a cuff-like manner. To avoid shear forces, especially tension forces, acting directly on the cuff electrode via the connecting cable—forces that may be caused by body movement—the sheath is absorbed or transferred to surrounding tissues by providing additional mechanical fixation to the adjacent tissue area.

[0005] In practice, additionally securing the sheath to the tissue region adjacent to the vagus nerve has only some advantages. This is because using surgical sutures to secure the sheath between the sleeve electrode and the sheath maintains a relatively constant relative distance, which can effectively absorb the tension acting along the connecting cable. However, rotational movement of the sheath about its longitudinal axis often occurs, and thus the sleeve electrode, which is fixed in position to the vagus nerve, rotates. This results in mechanical material stress, especially within the carrier substrate of the thin-film sleeve electrode, which needs to be reduced or eliminated entirely.

[0006] Document US2015 / 0343198A1 discloses a fixation anchor for securing an intracellular wire, the wire passing through the inner cavity of a flexible housing. To secure the wire within the housing, the housing is provided with a deformable insert capable of securing the wire by compression. Perforations protruding from the outer side of the housing serve as fixation devices for securing the housing to surrounding tissue.

[0007] Document US2008 / 172116A1 describes a sleeve electrode device for installation around a nerve trunk, which has an electrical lead with a spiral fixing structure along its length, and can be applied around a blood vessel or nerve trunk in a winding manner. Summary of the Invention

[0008] The objective of this invention is to further improve a medical implant comprising: an electrode device designed as a sleeve, referred to as a sleeve electrode, suitable for extravascular or extraneural fixation along blood vessels or nerve fiber bundles in the body; and an electrical introduction and extraction device having a longitudinal extension, which electrically connects the sleeve electrode to a separately designed implantable supply unit, wherein the electrical introduction and extraction device is surrounded by an elastic sheath in a section of its longitudinal extension, the sheath being fixedly connected to a tissue region in the body by a fixation device responsively connected to the elastic sheath, such that rotational movement of the sheath about its longitudinal extension is at least reduced or restricted, preferably completely eliminated.

[0009] The solution to the task upon which this invention is based is given in claims 1 and 5. Features that further develop the inventive concept in an advantageous manner are the subject matter of the dependent claims and the further description in conjunction with the embodiments.

[0010] The medical implant according to the invention having the features of the preamble of claim 1 is characterized in that the elastic sheath has a longitudinal extension and a circumferential edge oriented radially about the longitudinal extension, wherein, on the circumferential edge of the sheath, along at least one cross-sectional plane orthogonal to its longitudinal extension orientation, at least one tunnel-shaped opening profile is arranged, the opening profile being suitable for locally guiding a fixation device designed as a medical suture and having no structural components that radially protrude beyond the circumferential edge of the sheath.

[0011] Preferably, along the circumferential edge, in the cross-sectional plane where at least one tunnel-shaped opening profile is arranged, a fully encircling, preferably V-shaped, groove-shaped notch is machined, along which the medical suture can be placed directly, at least partially,. The at least one tunnel-shaped opening profile is preferably defined radially outward by a web that partially bridges the groove-shaped notch, and this web is preferably integrally connected to the elastic sheath, i.e., made of the same material as the elastic sheath itself. The surface of the web of the at least one partially bridging groove-shaped notch is flush with the remaining surface of the sheath, so that the surrounding tissue area is not stimulated by any structural components that radially protrude beyond the at least one tunnel-shaped opening profile.

[0012] In order to prevent or limit the rotation or self-rotation of the elastic sheath about its longitudinal extension, in the case of a single tunnel-shaped opening profile, the surgical thread is placed in the groove-shaped notch by forming at least one complete loop, wherein the thread passes through the tunnel-shaped opening profile twice in opposite threading directions. The two thread regions continuing from the opening profile are used for fixation in the surrounding tissue region and, after fixation (e.g., by knotting), are respectively pulled away under tension on both sides of the sheath. When the sheath rotates about its longitudinal extension, a clamping force that prevents rotation is formed at the tunnel-shaped opening profile and the thread strands pulled away from both sides of the opening profile, and this clamping force increases significantly as the rotation of the sheath about its longitudinal extension increases, and inhibits or prevents rotation. The measures according to the invention provided on the sheath cooperate with the surgical thread and, based on the self-locking principle, form a clamping force opposite to the direction of the rotational movement between the surgical thread under tension or tensile force and at least one tunnel-shaped opening profile.

[0013] In another preferred embodiment, two tunnel-shaped opening profiles are provided in the same cross-sectional plane of the sheath, and they are preferably arranged in opposite regions along the circumferential edge. In this case, the surgical thread must pass through the two opening profiles such that the medical thread 8 is placed under tensile force along the contact length a against the circumferential edge with a length of U, where the contact length a satisfies: 0.5U ≤ a < U. Of course, the two opening profiles can also be arranged along the circumferential edge with a smaller minimum spacing.

[0014] In order to stably fix the sheath to the surrounding tissue region, in another embodiment, the sheath has at least one tunnel-shaped opening profile in two or more axially spaced cross-sectional planes. In this way, two surgical threads can be used to fix the sheath relative to the sleeve electrode and the surrounding tissue region.

[0015] In another alternative medical implant according to the invention, at least one fixing profile is provided on the circumferential edge of the elastic sheath, preferably in the form of a structural local protrusion beyond the circumferential edge and / or a local depression relative to the circumferential edge. In addition, a joining member is provided that is separately designed from the sheath, which has a joining profile designed with a counter-profile to the fixing structure and also has at least one through-opening for guiding a fixing device designed as a medical thread. In the state where the elastic sheath is fixedly connected to the in-vivo tissue region, the medical thread passes through at least one through-opening of the joining member and is guided and arranged under tensile force along the circumferential edge of the elastic sheath such that the joining member is forcefully joined to the fixing profile of the sheath.

[0016] Preferably, the joining member is designed as a small plate shape and has at least one through-opening through which the medical thread can pass and, when tensile force is applied, fixes the position of the joining member to be joined into the fixing profile of the sheath. A possible special embodiment and its function will be described in detail below with reference to the drawings. Description of the Drawings

[0017] The present invention will now be described by way of example based on embodiments and with reference to the accompanying drawings, without limiting the general concept of the invention. The drawings are as follows.

[0018] Figures 1a and 1b schematically illustrate a known sleeve electrode 1, constructed as a rolled-up sleeve and having a plurality of surface electrodes 1e arranged inside the cylindrical sleeve of the rolled-up sleeve for direct contact with a nerve fiber bundle (not shown), such as the vagus nerve; and a sheath 6 designed according to the invention. Figure 2a shows a cross-section of the sheath according to Figure 1b, Figure 2b shows a cross-section of an alternative embodiment of the sheath having only one tunnel-like fixation structure, Figures 3a and 3b show cross-sections of embodiments of the sheath having alternative tunnel-like fixation structures, and Figures 4a and 4b show alternative embodiments of the sheath designed according to the invention having individual connectors. Detailed Implementation

[0019] Figure 1a schematically illustrates a known sleeve electrode 1, constructed as a wrapped sleeve with multiple surface electrodes 1e disposed inside the cylindrical sleeve of the wrapped sleeve for direct contact with a bundle of nerve fibers (e.g., the vagus nerve, not shown). Each of the multiple electrodes 1e is connected to an individually extending wire 1e1 within a thin-film carrier substrate of the sleeve electrode 1. These wires lead to a plate-like connection structure 2 for further contact and connection to an electrical contact surface 3 disposed on its surface. Electrically introduced or led-out lines 5 are connected to each electrical contact surface 3 by bonding or welding. The multiple electrically introduced or led-out lines are combined into a connecting cable 4, which leads to a separately powered implant (not shown) for further contact.

[0020] To protect against moisture and to stabilize the mechanical fixation of the sleeve electrode 1 within the body, as well as for its manipulation, a sheath 6 made of an elastic biocompatible material (preferably silicone) is arranged in the region of the connecting structure 2. In the illustrated case, this sheath is designed to be elliptical. It should be noted that the dimensional representation of the sleeve electrode 1 and the sheath 6 in Figure 1a is not literal but is used for better illustration. The sheath 6 has a circumferential groove 7 on its surface into which a surgical suture 8 can be inserted to secure the sheath 6 to the directly adjacent tissue region 11.

[0021] Figure 1b shows an extension of the sleeve 6 shown in Figure 1a according to the invention, such that a tunnel-shaped opening profile 9 is arranged along a preferably V-shaped slot-shaped notch 7, which is formed by a web 10 that partially bridges the slot-shaped notch 7. A further slot-shaped notch 7 with the same arrangement of tunnel-shaped opening profile 10, shown in dashed lines in Figure 1b, is intended to illustrate a preferred extension of the sleeve 6.

[0022] Figure 2a shows a cross-section of the sheath 6 in the region of the slotted notch 7 according to Figure 1b, where the illustration of the radially inner conductor structure is omitted. In two opposite regions surrounding the slotted notch 7, two tunnel-shaped opening profiles 9 are arranged, each opening profile being defined radially outward by a web 10 that is flush with the remaining circumferential edge of the sheath 6.

[0023] A surgical suture 8 is used to secure the sheath 6 to the directly adjacent tissue region 11. This suture passes through two tunnel-like opening profiles 9 as shown in FIG. 2a, and each half rests against the circumferential edge of a V-shaped groove notch 7. The surgical suture 8 is preferably secured within the tissue region 11 by a knot, such that the tensioned suture 8 presses the sheath 6 into the tissue region 11 in a fixed position. The surgical suture 8 here contacts a corresponding boundary edge 12 of the abdominal plate 10. When the sheath 6 rotates about its longitudinal extension, the clamping force generated by the interaction between the boundary edge 12 and the surgical suture 8 serves to resist or prevent rotational movement.

[0024] Figure 2b shows a cross-sectional view of one embodiment of the sheath 6 along the grooved notch 7, which has only one tunnel-shaped opening profile 9. To prevent rotational movement of the sheath 6 about its longitudinal extension, in this case, the surgical suture 8 forms at least one complete loop wrapped around the grooved notch 7. The suture end regions (which are subsequently knotted to secure within the tissue region 11) emerging from both sides of the tunnel-shaped opening profile 9 contact the two boundary edges 12 of the abdominal plate 10. In this case, when the sheath 6 rotates about its longitudinal extension, the clamping force generated by the interaction between the boundary edges 12 and the surgical suture 8 acting under tension thereon also prevents or blocks the rotation of the sheath 6.

[0025] Figure 3a shows a schematic cross-sectional view of an alternative embodiment of the sheath 6 designed according to the present invention, which has two arc-shaped tunnel-like opening profiles 9 through which a surgical suture 8 is passed and secured in the surrounding tissue 11. As an alternative to the arc-shaped tunnel-like opening profiles 9, they can also be designed as straight lines, as shown in Figure 3b, where the sheath 6 has only one tunnel-like opening profile 9 through which the surgical suture 8 is passed and knotted with the surrounding tissue area 11. Preferably, the tunnel-like opening profile 9 has a maximum opening width w, 0.1 mm ≤ w ≤ 1 mm, and a tunnel length l, 0.5 mm ≤ l ≤ 2 mm.

[0026] Figures 4a and 4b show a sleeve 6 in side and cross-sectional views, respectively, with four blind holes in the form of recesses 13 on its circumferential edge. These recesses serve as a fixing profile 14 into which a separate engagement member 15 can be engaged. This engagement member has an engagement profile 16 designed to be opposite to the fixing profile 14. The engagement profile 16 is designed in the form of four protrusions 17.

[0027] In addition, the connector 15 has a central opening 18 through which the surgical suture 8 passes to form a loop that completely surrounds the sheath 6, and its end 19 is knotted and secured in the adjacent tissue area 11.

[0028] The geometric design of the joining profile 16 on the one hand and the fixed profile 14 with the opposite profile design on the other hand are designed under the premise of forming a shape-locking connection, and are not subject to any design restrictions.

[0029] List of reference numerals: 1 sleeve electrode, 1e surface electrode, 1el wire, 2 connection structure, 3 bonding / welding connection, 4 connecting cable, 5 electrical inlet and outlet lines, 6 sheath, 7 slotted notch, 8 fixation device, surgical line, 9 tunnel-shaped opening contour, 10 abdominal plate, 11 tissue area, 12 boundary edge, 13 depression, 14 fixation contour, 15 joint, 16 joint contour, 17 protrusion, 18 opening, 19 line end.

Claims

1. A medical implant comprising: an electrode device configured as a sleeve, referred to as a sleeve electrode (1), suitable for extravascular or extraneural fixation along a bundle of blood vessels or nerve fibers in the body; and an electrical inlet and outlet device having a longitudinally extending electrical inlet and outlet device electrically connecting the sleeve electrode (1) to an implantable supply unit separately configured relative to the sleeve electrode (1), wherein, The electrical introduction and extraction device is surrounded by an elastic sheath (6) along a segment of its longitudinal extension, the elastic sheath being fixedly connected to an in vivo tissue region (11) by a fixation device (8) operatively connected to the elastic sheath (6), characterized in that the elastic sheath (6) has a longitudinal extension and a circumferential edge oriented radially around the longitudinal extension; on the circumferential edge of the sheath (6), at least one tunnel-shaped opening profile (9) is arranged along at least one cross-sectional plane orthogonal to its longitudinal extension orientation, the opening profile being suitable for a fixation device locally guiding a medical suture (8) and not having structural components that radially protrude beyond the circumferential edge of the sheath.

2. The medical implant according to claim 1, characterized in that, A slotted notch (7) is provided along the circumferential edge in the cross-sectional plane of the opening profile (9) having at least one tunnel-shaped structure; and the at least one tunnel-shaped opening profile (9) is formed by a web (10) that partially bridges the slotted notch (7).

3. The medical implant according to claim 1 or 2, characterized in that, The medical thread (8) passes through the at least one tunnel-shaped opening profile (10) in such a way that the medical thread (8) is held against a circumferential edge of length U under tension along a contact length a, wherein for a, 0.5U≤a≤U is satisfied.

4. The medical implant according to any one of claims 1 to 3, characterized in that, The at least one tunnel-shaped opening profile (10) has a maximum opening width w of 0.1mm≤w≤1mm and a tunnel length l of 0.5mm≤l≤2mm.

5. The medical implant according to the preamble of claim 1, characterized in that, The elastic sheath (6) has a longitudinal extension and a circumferential edge oriented radially around the longitudinal extension, on which at least one fixed profile (14) is provided, and a separate connector (15) is provided, which has a connecting profile (17) designed opposite to the fixed profile (14), the connector (15) having at least one through opening (18) for guiding a fixation device configured as a medical suture (8), and in a state where the elastic sheath (6) is fixedly connected to the in vivo tissue region (11), the medical suture (8) passes through at least one through opening (18) of the connector (15) and is held against the circumferential edge of the elastic sheath (6) under tension, such that the connector (15) is forcefully engaged on the fixed profile (14) of the sheath (6).

6. The medical implant according to claim 5, characterized in that, The fixed profile (14) is constructed as a structural local protrusion extending beyond the circumferential edge and / or a local depression relative to the circumferential edge.

7. The medical implant according to claim 5 or 6, characterized in that, The joint (15) is plate-shaped and has at least one through opening (18).

8. The medical implant according to any one of claims 1 to 7, characterized in that, The sheath (6) is constructed in an elliptical shape.

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