Implant insertion system

Abstract

A device for introducing an implant (1) into blood vessels or hollow organs of the human or animal body. The device includes an implant (1), an insertion wire (14) and a release tube (13), wherein the implant (1) is deformable so that it fits into a microcatheter (8) and expands once the external constraint of the microcatheter (8) disappears, adapting to the diameter of the blood vessel or hollow organ, wherein a holding element (2) is arranged on the insertion wire (14) and the holding element (2) has at its periphery at least one groove (3) set into the holding element (2), running along the circumference of the holding element (2) and forming tracks in the form of curved lines, wherein the implant (1) has holding wired (5) extending proximally, which are fitted into the grooves (3).

Claims

1. A device for introducing an implant (1) into blood vessels or hollow organs of a human or animal body, comprising an implant (1) and a release tube (13), wherein the implant (1) is deformable so that it adopts a shape with reduced diameter in a microcatheter (8) and at the site of the implantation it expands once an external constraint of the microcatheter (8) is removed, adapting to the diameter of the blood vessel or hollow organ, and the release tube (13) has a lumen running in the longitudinal direction of the device, through which an insertion wire (14) can be led in lengthwise mobile manner, characterized in that the release tube (13) protrudes into a proximal end of the implant (1), wherein an elastic contact surface is present between an inside of the implant (1) and an outside of the release tube (13), so that a frictional locking is generated between the implant (1) and the release tube (13), bringing about a lengthwise mobility of the implant (1) inside the microcatheter (8) by lengthwise movement of the release tube (13) distally or proximally.

2. The device as claimed in claim 1, characterized in that the elastic contact surface between the inside of the implant (1) and the outside of the release tube (13) is made by an elastic intermediate layer (11).

3. The device as claimed in claim 2, characterized in that the elastic intermediate layer (11) runs in a ring about the release tube (13).

4. The device as claimed in claim 2, characterized in that the elastic intermediate layer (11) consists of the same material as the release tube (13).

5. The device as claimed in claim 2, characterized in that the elastic intermediate layer (11) consists of an elastomer.

6. The device as claimed in claim 5, characterized in that the elastomer is rubber or silicone.

7. The device as claimed in claim 1, characterized in that a release wire (17) is wound around the implant (1) in the region where the release tube (13) protrudes into the proximal end of the implant (1) and in which the elastic contact surface is present between the inside of the implant (1) and the outside of the release tube (13), so that the release wire (17) produces a strengthening of the frictional forces between implant (1) and release tube (13), wherein the release wire (17) is electrolytically corrodible or thermally severable at least at one release site.

8. A device for introducing an implant (1) into blood vessels or hollow organs of a human or animal body, said implant being deformable so that it adopts a shape with reduced diameter in a microcatheter (8) and at a site of the implantation it expands once an external constraint of a microcatheter (8) is removed, said implant having a proximal end a distal end and an inside and an outside, said device comprising a release tube (13), wherein the release tube (13) has a lumen running in the longitudinal direction of the device, through which an insertion wire (14) can be led in lengthwise mobile manner, characterized in that the release tube (13) protrudes into the proximal end of the implant (1), and an elastic pad disposed between the inside of the implant (1) and the outside of the release tube (13), so that a frictional locking is generated between the implant (1) and the release tube (13), bringing about a lengthwise mobility of the implant (1) inside the microcatheter (8) by lengthwise movement of the release tube (13) distally or proximally.

9. The device as claimed in claim 8, characterized in that the elastic pad between the inside of the implant (1) and the outside of the release tube (13) is made by an elastic intermediate layer (11).

10. The device as claimed in claim 9, characterized in that the elastic intermediate layer (11) runs in a ring about the release tube (13).

11. The device as claimed in claim 9, characterized in that the elastic intermediate layer (11) consists of the same material as the release tube (13).

12. The device as claimed in claim 9, characterized in that the elastic intermediate layer (11) consists of an elastomer.

13. The device as claimed in claim 12, characterized in that the elastomer is rubber or silicone.

14. The device as claimed in claim 8, characterized in that a release wire (17) is wound around the implant (1) in the region where the release tube (13) protrudes into the proximal end of the implant (1) and in which an elastic contact surface is present between the inside of the implant (1) and the outside of the release tube (13), so that the release wire (17) produces a strengthening of the frictional forces between implant (1) and release tube (13), wherein the release wire (17) is electrolytically corrodible or thermally severable at least at one release site.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention shall now be explained more closely as an example with the aid of the following representations. There are shown:

(2) FIG. 1a, b: a device with distal insertion wire tip according to a first embodiment of the invention;

(3) FIG. 2a, b: a device without distal insertion wire tip according to the first embodiment of the invention,

(4) FIG. 3a, b: the holding element in transverse and longitudinal cross section according to the first embodiment of the invention;

(5) FIG. 4: a holding element in longitudinal cross section with secured implant according to the first embodiment of the invention;

(6) FIG. 5: a device according to the invention in longitudinal cross section according to a second embodiment of the invention;

(7) FIGS. 6-11: different variants of a release tube according to the second embodiment of the invention, and

(8) FIG. 12: a variant of the second embodiment of the invention in which a release wire is used.

DETAILED DESCRIPTION OF THE INVENTIONS

(9) FIG. 1a shows the basic layout of the device of the invention according to the first embodiment of the invention, where the specific properties of the holding element cannot be seen in this representation. The device is composed of an implant 1, an insertion wire 14 and a release tube 13. The implant 1 consists of a braiding, in which individual wires 4 of a radiopaque material are interwoven in order to ensure the radiopacity of the implant 1. At the proximal end, the implant 1 is coupled to the insertion wire 14, which has a holding element not represented here in further detail. The holding wires emerging from the proximal end of the implant 1 are fixed in the holding element, wherein the release tube 13 prevents the holding wires from being loosened from the holding element. The insertion wire 14 runs in the distal direction through the implant 1 and has at the distal end an insertion wire tip 9. The implant 1 is advanced through a microcatheter 8. At the proximal end, the insertion wire 14 and the release tube 13 are held together by a torquer 7.

(10) FIG. 1b shows the implant 1 of FIG. 1a in the released state. The release tube 13 has been retracted, so that the holding wires could become loosened from the holding element of the insertion wire 14. The insertion wire tip 9 still runs through the implant 1, but it can be retracted together with the insertion wire 14 and release tube 13.

(11) FIGS. 2a and 2b show an embodiment which corresponds fundamentally to the one from FIGS. 1a and 1b, but here there is no distal insertion wire tip 9.

(12) FIG. 3a shows the holding element 2 in cross section. The holding element 2 is basically substantially cylindrical and thus rotationally symmetrical. A number of grooves 3 have been recessed in the holding element 2, the number of grooves 3 being four in the example chosen here. However, it is also possible to make more grooves 3 in the holding element, such as 8-32 grooves 3. The grooves 3 are open on the outside, so that it is possible to insert a holding wire 5.

(13) The course of the grooves 3 is shown in FIG. 3b, which is a longitudinal cross section through the holding element 2. The holding element 2 is fastened to the insertion wire 14. The grooves 3 have a wave-shaped course, and so the holding wires 5 can be inserted such that a sufficiently strong frictional locking is produced, preventing the implant 1 from being pulled out in the longitudinal direction. On the other hand, the grooves 3 are open radially outward, so that a radial exiting of the holding wires 5 is easily possible as soon as a release tube 13 pulled over the holding element 2 and the holding wires 5 has been removed. The grooves 3 of the holding element 2 located at the edge are only suggested in FIG. 3b, but they have the same wave-shaped course as the other grooves 3.

(14) The overall principle of the releasing is further illustrated in FIG. 4, showing the proximal implant end 12. In the representation chosen here and in FIG. 3b, contrary to the representations chosen in FIGS. 1a, b and 2a, b, left corresponds to distal, while the device continues to the right in the proximal direction. The implant 1 is composed of a plurality of braiding wires 6. Of the braiding wires 6, some braiding wires 6 have a lengthened proximal end, the lengthening producing the holding wire 5 which is inserted into a groove 3. The number of holding wires 5 normally corresponds to the number of grooves 3. Thanks to a wave-shaped course of the groove 3, a corresponding wave shape is also imposed on the holding wire 5, so that the holding wire 5 is held in the groove 3 by means of frictional locking. The stiffness of the holding wire 5 should be attuned to the device so that an unintentional pulling of the holding wire 5 out from the groove 3 is virtually impossible for the pushing or pulling forces typically occurring in the implantation process. Typically, every 2nd, 4th, or 8th braiding wire 6 is formed longer, so that a holding wire 5 is produced. Furthermore, some of the braiding wires 6 have a platinum coil 10, which serves to heighten the radiopacity of the implant 1.

(15) The release tube 13 is pulled over both the holding element 2 and the proximal implant end 12. This ensures on the one hand that a releasing of the implant 1 cannot occur before the release tube 13 has been pulled down from the holding element 2 enough so that all of the grooves 3 are exposed. On the other hand, the fact that the release tube 13 is also pulled over the proximal implant end 12 ensures that even after releasing of the implant from the microcatheter the braiding wires 6 are held together at the proximal end 12 and a retraction into the microcatheter 8 still remains possible if needed, as long as the release tube 13 has not been retracted.

(16) FIGS. 5-11 show the second embodiment of the invention. The release tube 13 comprises at its distal end one or more pads 11, which are made from an elastic material and create a sufficiently strong frictional locking between pad 11 and implant 1 so that an advancement and retraction of the implant 1 is possible by moving the release tube 13. The implant 1 in the representation chosen here is located inside the microcatheter 8, i.e., in its compressed form. The insertion wire 14 extends here through the entire implant, so that the insertion wire tip 9 lies distally to the distal end of the implant, but an insertion wire tip 9 is not obligatory. In contrast to the representation which was chosen in FIGS. 3a, 3b and 4, in the representation of FIGS. 5-11 proximal lies to the left and distal to the right. At the proximal end of the device, the insertion wire 14 and the release tube 13 are held by means of a torquer 7.

(17) Once the implant 1 has arrived at the target location, it can be pushed distally out from the microcatheter 8 or the microcatheter 8 can be retracted proximally, so that the implant 1 expands radially and adapts to the inner wall of the vessel. As in the first embodiment of the invention, the release principle is thus based on the fact that a releasing occurs by an expansion of the implant 1 in the radial direction, while sufficiently large frictional forces are generated in the axial direction to prevent a releasing of the implant 1 in the axial direction.

(18) FIGS. 6-11 show different variants of release tubes 13. In the embodiment represented in FIG. 6, a proximal section 15 of the release tube 13 has a larger cross section, while a further distally situated middle section 16 has a smaller cross section. This means that on the one hand the middle section 16 of the release tube 13 is quite flexible and can be advanced easily during the transport through narrow-lumen blood vessels, while on the other hand the release tube 13 can also be retracted easily in the proximal direction, since the proximal section 15 has a larger cross section and thus limits the lengthwise stretchability of the release tube 13. According to FIG. 6, the pad 11 is made from the tube material itself, i.e., no pad 11 needs to be arranged additionally on the release tube 13.

(19) FIG. 7 shows a similar embodiment, in which the middle section 16 likewise has a smaller cross section than the proximal section 15 of the release tube 13. In contrast to the representation shown in FIG. 6, however, two pads 11 are arranged here separately, surrounding the release tube 13 like a ring.

(20) FIG. 8 shows a further variant, in which the proximal section 15 likewise has a larger cross section than the further distally situated middle section 16 of the release tube 13, but here only one pad 11 has been arranged surrounding the release tube 13 in a ring, being longer in configuration than the individual pads of FIG. 7.

(21) FIGS. 9, 10 and 11 correspond to FIGS. 6, 7 and 8, but the release tube 13 has no shoulder and, seen from the distal end, has a uniform cross section.

(22) FIG. 12 shows a variant in which a frictional locking is produced between the implant 1 and the release tube 13 by winding a release wire 17 about the implant 1. The release wire 17 ties the implant 1 between two pads 11 such that a fixation of the implant 1 on the release tube 13 is produced. Thus, even without a microcatheter, the implant 1 remains secured on the release tube 13 until an electrical voltage is applied and produces an electrolytic corrosion of the release wire 17 at a designated release site and the release wire is detached from the implant 1. After this, the implant 1 can expand and the microcatheter, the release tube 13, the insertion wire 14 as well as the remaining ends of the release wire 17 are retracted. To enable an electrical voltage source to be applied to the release wire 17, the two ends of the release wire 17 run in the proximal direction.