Device for introducing an implant into a body cavity and arrangement with such a device

Abstract

Device for introducing a radially compressible and expandable implant (10) into a body cavity with a transport wire (11) which has at least one engagement element (12) for positive locking connection with the implant (10) and at least one spacer element (13), characterized in that the spacer element (13) is elastically deformable, arranged on the engagement element (12) and is at least partially compressible by the compressed implant (10) in use.

Description

[0001] The invention relates to a device for introducing an implant into a body cavity according to the preamble of claim 1. The invention further relates to an arrangement with such a device.

[0002] Various devices for delivering implants are known in practice. To deliver radially compressible and expandable implants, such as stents, into a body vessel, transport wires are preferably used. The stent is guided to the treatment site using the transport wire. The transport wire is then removed, leaving only the stent in the body vessel.

[0003] Such a transport wire is known from WO 2013 / 107 783 A1. The known transport wire has a sleeve with radially outwardly projecting lugs, the lugs being able to engage in the openings of a stent's mesh structure. This creates a positive fit between a compressed stent and the transport wire or its sleeve. The positive fit allows the stent to be moved along with the transport wire in both longitudinal directions. Once the stent has reached the treatment site, an external catheter, which holds the stent in its compressed state, is withdrawn, so that the stent preferably expands automatically. During this expansion, the openings of the mesh structure disengage from the lugs of the transport wire's sleeve, thus freeing the stent. The transport wire can then be removed from the body vessel, leaving the stent in place.

[0004] The delivery device according to WO 2013 / 107 783 A1 has proven to be very efficient, particularly for delivering implants with a very small compressed cross-sectional diameter. However, complications can arise in specific situations when retracting the delivery guide wire if the stent has been placed in highly curved body vessels. When guiding guide wires through sharp vessel curves, the wire often adheres to the outer vessel wall. If the stent is then positioned against this outer wall, the guide wire's tabs can become entangled in the stent's mesh openings, thus becoming stuck. This creates a risk of losing the stent's target position. Furthermore, it becomes difficult to advance the delivery guide wire distally through the stent after placement, for example, to begin catheter exchange at a safe location.

[0005] Furthermore, EP 1 374 801 A1 discloses a transport wire which has engagement elements in the form of two cylindrical parts arranged offset along the transport wire, which can, for example, be helically wound coils. A cylindrical intermediate part is arranged between the engagement elements or cylindrical parts, which can be either a helically wound coil or a flexible cylindrical part made of polymer. The implant can be placed on the cylindrical intermediate part.

[0006] Therefore, the object of the invention is to further improve the existing development in order to facilitate the movement of the transport wire after placement of an implant in specific application situations. The object is thus to provide a correspondingly improved device. A further object of the invention is to provide an arrangement with such a device.

[0007] According to the invention, this problem is solved with regard to the device by the subject matter of claim 1 and with regard to the arrangement by the subject matter of claim 16.

[0008] Specifically, the invention is based on the concept of a device for introducing a radially compressible and expandable, preferably self-expanding, implant into a body vessel, wherein the device comprises a transport wire having at least one engagement element for a positive connection with the implant and at least one spacer element. The invention is characterized in that the spacer element is elastically deformable, arranged on the engagement element, and at least partially compressible by the compressed implant during use.

[0009] According to the invention, the spacer element is arranged on the engagement element. This does not preclude the existence of a gap between the engagement element and the spacer element. However, the gap is dimensioned, or rather, is so small, that the spacer element can fulfill a protective function, which will be explained in more detail below.

[0010] The protective function of the spacer element is to prevent the intervention element from becoming entangled in an already implanted implant or its cellular structure. When the transport wire is moved, the spacer element shields the intervention element to such an extent that, even when the transport wire is guided along the vessel wall in vessel bends, the intervention element cannot, for example, engage with the mesh openings of stents. The spacer element thus keeps the intervention element at a distance from such an implant.

[0011] To ensure the positive locking function of the intervention element is not compromised, the spacer element is elastically deformable. This allows a compressed implant to remain positively coupled to the intervention element. The spacer element, which rests against the intervention element, is compressed, at least partially. Specifically, when a stent is positioned on the intervention element in its compressed state, the spacer element can be partially compressed by the stent's mesh elements. The mesh elements can thus be positioned between the prongs of the intervention element, creating a positive locking connection. Once the stent reaches the treatment site and is deployed, the stent's mesh structure expands, causing the mesh elements to move out of the space between the prongs of the intervention element. The spacer element then elastically returns to its original shape.In its original form, the distance element fulfills its protective function.

[0012] The spacer element can be arranged radially relative to the engagement element. In particular, if the engagement element has lugs, the spacer element may be positioned between the lugs of the engagement element.

[0013] In a preferred embodiment, it is advantageously provided that the spacer element and the engagement element are arranged side by side in the axial direction of the transport wire. In this embodiment, the spacer element exerts its effect, particularly its protective effect, with exceptional efficiency. During axial movement of the transport wire, the spacer element can slide along structures within the body's hollow vessel, which can occur especially when the transport wire moves through strong vessel curvatures. The spacer element thus keeps the engagement element at a distance from such structures within the body's hollow vessel.

[0014] The transport wire can have at least two elastically deformable spacer elements. In particular, two spacer elements can be provided for each engagement element. However, it is also possible, as provided in a further preferred embodiment of the invention, that the transport wire has several engagement elements spaced axially apart from one another. In this case, at least one spacer element can be arranged on at least two, and in particular on all, engagement elements.

[0015] The spacer element is preferably arranged on the proximal side of the intervention element and / or on the distal side of the intervention element. For withdrawing a transport wire from a body vessel, in particular, the arrangement of the spacer element on the proximal side of the intervention element is advantageous. In this way, the spacer element shields the intervention element from a structure within the body vessel in the direction of movement. A particularly low risk of the transport wire displacing an already implanted device is achieved when spacers are arranged on both the proximal and distal sides of the intervention element, i.e., on both sides of the intervention element.

[0016] The spacer element can be positioned directly against the insertion element. In this case, the distance between the spacer element and the insertion element is zero. This offers a particular advantage, especially when guiding the transport wire through a sharp vessel curvature. The absence of a gap between the spacer element and the insertion element ensures that the spacer element maintains its protective function even in highly curved vessel sections. Otherwise, the vessel's curvature and the resulting bend in the transport wire could cause the insertion element to slide along the vessel wall. By directly positioning the spacer element against the insertion element, this effect is avoided.

[0017] In a preferred embodiment, the maximum outer diameter of the spacer element is larger than the inner diameter of the implant in its compressed state. In this embodiment, the spacer element fulfills an additional function. By ensuring that the outer diameter of the spacer element is larger than the inner diameter of the implant in its compressed state, the implant does not fully contact the intervention element when compressed. This reduces the risk of frictional interference, in addition to the positive fit with the intervention element, occurring when the implant is released in highly curved vessel segments. This frictional interference could hinder the expansion of the implant. In other words, the risk of unintentional entanglement between the intervention element and the implant, which can occur when expanding the implant in highly curved vessel segments, is avoided.

[0018] It is also preferred that the maximum outer diameter of the spacer element is larger than the maximum outer diameter of the engagement element minus the wall thickness of the implant. In the case of laser-cut or one-piece lattice implant structures, the wall thickness of the implant corresponds to the height of the lattice elements, specifically the webs. In the case of wire-woven lattice structures, the wall thickness of the implant corresponds to twice the wire diameter.

[0019] It has been shown that such an outer diameter is advantageous so that the spacer element can fulfill its protective function. Therefore, the spacer element can also have a maximum outer diameter that is at least as large as the maximum outer diameter of the engagement element. In a preferred embodiment, it is particularly provided that the maximum outer diameter of the spacer element corresponds approximately to the maximum outer diameter of the engagement element.

[0020] Preferably, the transport wire is arranged or positioned in a catheter so as to be longitudinally displaceable. The device can therefore include a catheter through which an implant can be guided to a treatment site within a hollow body organ, for example, a blood vessel, by means of the transport wire. In preferred embodiments, which are used particularly in the treatment of cerebral blood vessels, the catheter can have an inner diameter of at most 1.34 mm, more specifically at most 1.00 mm, more specifically at most 0.70 mm, more specifically at most 0.53 mm, more specifically at most 0.42 mm.

[0021] The spacer can have a cylindrical or conical outer contour. In particular, a spacer positioned proximal to the intervention element may have a conical outer contour. This facilitates the release of the implant from the intervention element, especially if the spacer tapers proximally. Simultaneously, the conical surface provides a good gliding surface for guiding the spacer along a vessel wall, provided the guide wire is positioned against the vessel wall in a curve. The conical surface thus reduces vessel wall irritation. Additionally, the conical surface can create space for, for example, radiopaque markers positioned at one longitudinal end of the implant. If the spacer is positioned distal to the intervention element, it may have a cylindrical shape. Various combinations of conical and cylindrical shapes are possible.For example, both a cylindrical and a conical spacer element can be arranged on an engagement element. Similar spacer elements, for example, cylindrical or conical on both sides, can also be provided on both sides of the engagement element.

[0022] The spacer element is preferably ring-shaped or sleeve-shaped and has a central opening through which the transport wire extends. This ensures that the spacer element is arranged completely around the transport wire and thus completely protects the intervention element from sliding along a vessel wall or, in particular, from becoming entangled in an implant placed there.

[0023] In a preferred embodiment, the spacer element can have a compression body with a closed cross-section or a compression body with relief openings in the cross-section to increase flexibility. The spacer element can furthermore be fixedly arranged on the transport wire, in particular by a material-bonded connection and / or by a retaining sleeve and / or by an adhesive bead, wherein the spacer element is fixed between the retaining sleeve and / or adhesive bead and the engagement element.

[0024] Preferably, the spacer element is made of a silicone material, in particular medical-grade silicone material, and has in particular a Shore hardness of at most 90A, in particular at most 80A, in particular at most 60A, in particular at most 50A, in particular at most 40A, in particular at most 30A.

[0025] In a related aspect, an arrangement comprising a previously described device is also disclosed and claimed, wherein the arrangement additionally includes a radially compressible and expandable, in particular self-expanding, implant which is detachably connected to the previously described device.

[0026] The arrangement according to the invention can form an implantation set with the associated implant. The implant can, in particular, be a stent, wherein the stent may have a mesh structure constructed in one piece from struts or a mesh structure woven from wires. The implant and the delivery device can be packaged separately, with the implant being combined with the device to form the arrangement shortly before the implantation procedure. It is also possible that the implant is already mounted on the delivery wire of the device or pre-loaded in a compressed introducer and packaged together as a complete arrangement. A further component of the arrangement can also be an introducer for transferring the implant into a proximal catheter end.The introducer can accommodate the compressed implant and the delivery device, with the delivery device and the implant being slidably arranged within the introducer. After connecting the introducer to a catheter, the implant can be inserted into the catheter using the delivery device.

[0027] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying schematic drawings. These show Fig. 1 a side view of a part of a device according to the invention in a preferred embodiment with a spacer element; Fig. 2 a side view of a device according to the invention in a further embodiment with two spacer elements; Fig. 3 a side view of an arrangement with the device according to Fig. 1 and an implant in a compressed state; Fig. 4 a top view of a spacer element of a device according to the invention, which is formed from a solid material; Fig. 5 a top view of a spacer element of a device according to the invention with relief openings; Fig. 6 a front view of a device according to the invention in its resting state; Fig. 7 a top view of the device according to Fig. 6, wherein the engagement element engages in a compressed implant and the implant at least partially compresses the spacer element; and Fig. 8 a front view of the device according to Fig. 6 with an implant, wherein the implant is in an expanded state.

[0028] Fig. Figure 1 shows a side view of a part of the device according to the invention in a preferred embodiment. The device comprises a transport wire 11 on which an engagement element 12 is arranged. The engagement element 12 is fixedly connected to the transport wire. In particular, the engagement element 12 is not displaceable on the transport wire 11. Rather, the engagement element 12 is fixed in position on the transport wire 11.

[0029] A spacer element 13 is provided on the proximal side of the engagement element 12. It can be seen that the spacer element 13 has an outer diameter that is almost equal to the outer diameter of the engagement element 12.

[0030] The proximal side of the transport wire 11 is the side closest to the user. The proximal section of the transport wire 11 therefore faces the physician, whereas the distal section faces the treatment site.

[0031] The proximal arrangement of the spacer element 13 has the advantage that, when the transport wire 11 is retracted after an implant 10 has been released, the spacer element 13 prevents the intervention element 12 from re-engaging with the implant 10. This is explained below with reference to an arrangement comprising the device according to the invention and an implant 10.

[0032] The spacer element 13 is preferably made of medical-grade silicone. The spacer element is elastically deformable. In particular, a silicone material can be selected for the spacer element 13 that does not flow under pressure but expands back to its original state or resting state even after prolonged compression. Preferably, the spacer element 13 is arranged directly adjacent to the engagement element 12. The spacer element 13 can therefore contact the engagement element 12. If the transport wire 11 has several engagement elements 12, each engagement element 12 preferably has a corresponding spacer element 13. The spacer elements 13 are preferably arranged on the proximal side of each engagement element 12.

[0033] Fig. Figure 2 shows an alternative embodiment of the device according to the invention, in which a spacer element 13 is not only arranged on the proximal side of the engagement element 12. Rather, a further spacer element 13 is provided on a distal side of the engagement element 12.

[0034] The proximal spacer element 13 and the distal spacer element 13 are preferably identical. This reduces production costs.

[0035] The function of the elastically deformable spacer element 13 is described in Fig. 3 clearly visible. Fig. Figure 3 shows the device according to Fig. 1 as an arrangement with an implant 10. The implant 10 has a grid structure made up of grid elements 10a, which can be, for example, wires. It is also possible that the grid structure is formed in one piece from struts. The struts then form the grid elements 10a. In the embodiment of the implant 10 shown here, radiopaque markers 10b are arranged at its proximal longitudinal end. The radiopaque markers 10b can be formed by sleeves made of a radiopaque material, which are applied to the wires or grid elements 10a, in particular crimped.

[0036] The implant 10 is in Fig. Figure 3 shows the implant in a compressed state, which preferably occurs when the implant is positioned within an introducer or within a catheter. The introducer or catheter exerts a compressive force on the implant and the spacer element 13, which is Fig. 3 is indicated by arrow A. Arrows B show the axial expansion of the spacer element 13 resulting from the radial compression.

[0037] The engagement element 12 preferably has lugs 12a that are oriented radially outwards. In particular, the engagement element 12 can have four lugs 12a that are oriented at right angles to each other and each extend radially outwards from the center of the engagement element 12. Such a design of the engagement element is described in the Fig. 6-8 are discernible. A different number of noses 12a is possible. In particular, the intervention element 12 can also have 3 or 6 circumferentially adjacent noses 12a.

[0038] The lattice structure of the implant 10, consisting of lattice elements 10a, has open cells between the lattice elements 10a. A nose 12a can engage in each of these cells, resulting in a positive fit between the implant 10 and the engagement element 12. The implant 10 is preferably in a compressed state. As shown in Fig. As can be clearly seen in Figure 3, the implant 10 at least partially compresses the spacer element 13, allowing the prongs 12a of the intervention element 12 to penetrate the cells of the implant 10 and thus create a positive fit. The implant 10 is usually held in the compressed position by a catheter that carries the transport wire 11 with the intervention element 12 and the implant 10. For the sake of clarity, a catheter is not shown in the accompanying drawings.

[0039] The implant is preferably self-expanding and expands as soon as the catheter no longer ensures that the implant 10 remains in its compressed state. For example, at a treatment site, the catheter can be withdrawn, thus releasing the implant 10. The implant 10 is preferably self-expanding and expands automatically when the catheter, which acts as an outer boundary, is removed. To release the implant 10, the catheter is withdrawn, thereby exposing the implant 10. This releases the positive-locking connection between the intervention element 12, or its noses 12a, and the implant 10. The elastic spacer element 13 supports the self-expansion of the implant 10 and also expands to its original resting diameter.

[0040] The spacer element 13 can generally be designed as a ring with a central opening 14. The central opening 14 accommodates the transport wire 11. Fig. Figure 4 shows such a design of a spacer element 13 in a top view of the spacer element 13. The central opening 14 serves to fix the spacer element 13 onto the transport wire 11. The surrounding solid material is elastically deformable.

[0041] To further promote the deformation of the spacer element 13, the spacer element can have relief openings 16 that increase the flexibility of the compression body 15 of the spacer element 13. Fig. Figure 5 shows such a design of the spacer element in a top view. It can be seen that the spacer element has a central opening 14 through which the transport wire 11 extends after assembly. Relief openings 16 are arranged around the central opening 14 in the compression body 15. The relief openings 16 extend completely through the spacer element 13 and increase the flexibility of the compression body.

[0042] Fig. Figure 6 shows another top view of a device according to the invention with a transport wire 11, a spacer element 13 and an engagement element 12. The engagement element 12 is in the Fig. 6-8 are arranged in the background. The top view is therefore taken from a proximal perspective of the device.

[0043] Fig. Figure 6 shows the rest state of the distance element 13, which is fully expanded in this state.

[0044] Fig. Figure 7, however, shows the deformation of the spacer element 13 when a compressed implant 10 is positioned. The implant 10 has several grid elements 10a, which can be designed as wires. The grid elements 10a come to rest between the prongs 12a of the intervention element 12, thereby deforming the elastically deformable spacer element 13. In other words, the grid elements 10a partially displace the spacer element 13 or its compression body. When the implant 10 is released, its grid structure expands, with the grid elements 10a moving radially outwards. In doing so, they leave the space between the prongs 12a of the intervention element 12. Simultaneously, the elastic spacer element 13 expands elastically and returns to its resting state (cf. Figure 7). Fig.6) a. In this way, the transport wire 11 can now be withdrawn, whereby the spacer element 13 ensures that the noses 12a of the intervention element 12 can no longer interfere with cells of the grid structure of the implant 10.

[0045] The spacer element 13 is generally preferably fixed to the transport wire 11 by means of an adhesive. However, it is also possible to provide a further sleeve that is firmly connected to the transport wire 11 and holds the spacer element 13 to the transport wire 11 in a form-fitting and force-fit manner. In particular, the spacer element 13 can be arranged between such a further sleeve and the engagement element 12.

[0046] To ensure sufficiently high elasticity, the Shore hardness of the spacer element 13 is specified as being less than 60A, in particular less than 50A, in particular less than 40A, and in particular at most 30A. The spacer element 13, or the silicone sleeve forming the spacer element 13, can be transparent or colored. It is also possible to integrate radiopaque particles into the spacer element 13, thus facilitating the implantation of an implant under radiographic guidance.

[0047] If a silicone material is used for the spacer element 13, it is preferred to produce it by extruding a silicone tube, which is then cut to the appropriate length. Alternatively, a silicone cord can also be produced, which is cut to the desired length of the spacer element 13, with the central opening 14 and / or the relief openings 16 then being introduced, for example, by punching or drilling.

[0048] Another alternative option is to provide silicone sheets that can be processed by laser cutting. Using laser cutting, silicone rings or silicone sleeves can be produced that form the spacer element 13. Reference sign 10 implants 10a Grid element 10b X-ray marker 11 Transport wire 12 Intervention element 12a Nose 13 spacer element 14 central opening 15 compression bodies 16 relief openings

Claims

[1] Device for introducing a radially compressible and expandable implant (10) into a body cavity with a transport wire (11) which has at least one engagement element (12) for positive connection with the implant (10) and at least one spacer element (13), characterized by , that the spacer element (13) is elastically deformable, is arranged on the engagement element (12) and is at least partially compressible by the compressed implant (10) in use. [2] Device according to claim 1, characterized by , that the spacer element (13) and the engagement element (12) are arranged next to each other in the axial direction of the transport wire. [3] Device according to claim 1 or 2, characterized by that the transport wire (11) has at least two elastically deformable spacer elements (13). [4] Device according to any one of the preceding claims, characterized by, that the transport wire (11) has several axially spaced engagement elements (12), wherein at least one spacer element (13) is arranged on at least two, in particular on all, engagement elements (12). [5] Device according to any one of the preceding claims, characterized by , that the spacer element (13) is arranged on the proximal side of the engagement element (12) and / or on the distal side of the engagement element (12). [6] Device according to any one of the preceding claims, characterized by , that the distance element (13) is in contact with the engagement element (12). [7] Device according to any one of the preceding claims, characterized by , that the maximum outer diameter of the spacer element (13) is larger than the inner diameter of the implant (10) in the compressed state. [8] Device according to claim 7, characterized by, that the maximum outer diameter of the spacer element (13) is larger than the maximum outer diameter of the engagement element (12) minus the wall thickness of the implant. [9] Device according to any one of the preceding claims, characterized by , that the maximum outer diameter of the spacer element (13) corresponds approximately to the maximum outer diameter of the engagement element (12). [10] Device according to any one of the preceding claims, characterized by , that the transport wire (11) can be arranged or is arranged in a longitudinally displaceable manner in a catheter, wherein the catheter has an inner diameter of at most 1.34 mm, in particular at most 1.00 mm, in particular at most 0.70 mm, in particular at most 0.53 mm, in particular at most 0.42 mm. [11] Device according to any one of the preceding claims, characterized by , that the spacer element (13) has a cylindrical outer contour or a conical outer contour. [12] Device according to any one of the preceding claims, characterized by , that the spacer element (13) is ring-shaped or sleeve-shaped and has a central opening (14) through which the transport wire (11) extends. [13] Device according to any one of the preceding claims, characterized by , that the spacer element (13) has a compression body (15) that is closed in cross-section or a compression body (15) that has relief openings (16) in cross-section to increase flexibility. [14] Device according to any one of the preceding claims, characterized by , that the spacer element (13) is fixedly arranged on the transport wire (11), in particular by a material-bonded connection and / or by a retaining sleeve, wherein the spacer element (13) is fixed between the retaining sleeve and the engagement element (12). [15] Device according to any one of the preceding claims, characterized by, that the spacer element (13) is made of a silicone material, in particular medical silicone material, and in particular has a Shore hardness of at most 90A, in particular at most 80A, in particular at most 60A, in particular at most 50A, in particular at most 40A, in particular at most 30A. [16] Arrangement comprising a device according to one of the preceding claims and a radially compressible and expandable implant (10) which is detachably connected to the device for delivery into a body cavity.

Images