WO2003079933A1

WO2003079933A1 - Device for crimping implants

Info

Publication number: WO2003079933A1
Application number: PCT/EP2003/002945
Authority: WO
Inventors: Jürgen HOGE
Original assignee: Phytis Medical Devices Gmbh
Priority date: 2002-03-21
Filing date: 2003-03-20
Publication date: 2003-10-02
Also published as: AU2003223972A1; DE10212707A1

Abstract

The invention relates to a device for crimping implants. Said device comprises a crimping body (26) in the form of pincers with an axially elongated receiving chamber (52) for receiving an implant that is to be crimped and with a wall (54) that surrounds said receiving chamber (52). An actuating part (16) in the form of a pincer sleeve co-operates with the crimping body (26) to modify the size of the receiving chamber (52). The crimping body (26) is positioned in the actuating part (16) so that it can be axially displaced. The size of the receiving chamber (52) of the crimping body (26) can be modified during an axial displacement of the crimping body (26) relative to the actuating part (16) by means of actuating elements (76, 84) in the form of conical areas on the crimping body (26) and on the actuating part (16).

Description

Patent application

Device for compressing implants

Technical field

The invention relates to a device for compressing implants according to the

Preamble of claim 1.

In the medical field, implants are inserted into the body, which have to be compressed beforehand. Examples of such implants to be compressed are stents. A stent is a vascular support that supports the vessel (e.g. a blood vessel) from the inside and widens the cross-section of the vessel to normal size when it is narrowed. The stents are currently predominantly manufactured using appropriately prepared tubes made of metal or composite materials or winding or braiding structures made of metal and / or plastic. Before the stent is inserted into the vessel, it is placed on a support and compressed. This compression is called crimping. The carrier can be a balloon catheter, around which the stent is arranged. The compressed stent is then inserted into the vessel through the catheter to where it is intended to act. The fixation in the vessel is carried out by expanding the stent, for example by means of a balloon catheter, the internal pressure of the balloon catheter being increased, for example, using an isotonic saline solution

Hand pump is increased. The structure of the stent deforms outwards - it grows larger on average - and the stent remains after the catheter has been removed (Release of pressure) dimensionally stable. A similar procedure is preferably used when introducing so-called "self-expandable" implants. In this case, however, the pressure is not applied. The stent opens either due to existing restoring forces or due to the prevailing environmental conditions (flow, temperature, etc.) The vessel is expanded on the one hand and supported on the other by the stents used. In this way, for example, an existing stenosis can be eliminated.

Underlying state of the art

A variety of implants are known which must be compressed prior to insertion into the body. Furthermore, a variety of corresponding compression methods and devices for compressing such implants are known.

Devices for compressing intravascular stents on balloon catheters usually consist of pins, rings or the like, which are in contact with the stent, change their position or shape due to the action of mechanical forces and thereby bring about a diameter reduction of the stent and compress the stent on the balloon catheter ( crimping). Some examples of such known devices are listed below.

EP 0 873 731 discloses a tool for compressing an intravascular stent on a balloon catheter. The tool has a loop holder for a stent. The loop holder is formed by a sheet of flexible material.

At a first end, the sheet has a plurality of elongated strips that are bent and inserted into openings that are at the other end of the sheet, thereby forming a cylindrical opening for the stent. By pulling on the strip, the opening width is reduced and the stent in the opening is compressed. The sheet of flexible material is attached to a support with two parts that can be swiveled so that the Loop recording contracted and the stent is compressed when the two parts are pivoted against each other.

EP 0 938 880 A2 discloses a tool for compressing an intravascular stent on a balloon catheter. The tool contains a flexible loop part, into which the stent is inserted for compression. The free ends of the loop part are connected to the ends of a pair of pliers. By mechanically operating the forceps, the loop part is reduced and the stent is compressed.

EP 0 938 877 A2 discloses a tool for compressing an intravascular

Stents on a balloon catheter. The tool contains a flexible loop part, into which the stent is inserted for compression. One free end of the loop part is fastened in a receiving part. The other free end is attached to a slide, which is guided displaceably in the receiving part. By pushing the pusher into the receiving part, the loop part is reduced and the stent is compressed.

DE 198 51 846 AI discloses a crimping device for compressing a stent around a catheter. The crimping device has a compression space in which the stent is inserted. The compression space can be reduced from an initial size for inserting the stent to a compression size for compressing the stent. The compression space is defined by an elongated base area and arms formed integrally with the base area. The arms are semicircular and are spaced from one another so that the compression space forms an elongated, cylindrical space which is several

Has areas without wall boundaries. The process of compressing the stent can then be visually monitored through these openings, so that any irregularities can be detected immediately during crimping. The free ends of the arms form receiving areas, into which extensions are inserted, which are provided on the jaws of a mechanically acting crimping tool. The crimp

Pliers have two pliers legs, which are operated manually during crimping. In addition, a soft-elastic tube can be formed in the arms Compression space must be inserted so that the stent is not in direct contact with the arms and an even force distribution is achieved on the stent. In order to protect the stent from damage during compression, which can result from the undefined force effect of the manually operated crimping pliers, a constriction is formed on each arm, which serves as a force limiting means in order to limit the force with which the stent can be compressed , The constrictions act as predetermined breaking points or bending points, which break or give way when the stent is compressed with too much force.

In all of these devices for compressing intravascular stents, the stent to be compressed is introduced into a receiving space of a compression body. The size of the receiving space is then reduced by an actuating part which interacts with the compression body, as a result of which the stent is compressed. To remove the stent from the device, the receiving space is enlarged again and the stent is removed from the device.

Disclosure of the invention

The invention has for its object to provide a device of the type mentioned by which the compression process can be carried out quickly and safely.

The invention is also based on the object of creating a device of the type mentioned at the outset which is simple in construction, safe to use and simple and inexpensive to manufacture.

According to the invention, this object is achieved by a device of the type mentioned at the outset with the features listed in the characterizing part of claim 1.

The device according to the invention for compressing implants is thus constructed similarly to known collets for positioning and holding tools, in which one is provided with radial slots and is radially elastic compressible pliers body is guided axially displaceable relative to a pliers sleeve, a conical surface on the pliers body cooperating with a conical surface on the pliers sleeve such that the pliers body is radially compressed when the pliers body moves axially relative to the pliers sleeve. However, the device according to the invention is not a matter of clamping

Tools, but about compressing implants.

The compression process can be carried out simply, very quickly and reliably by the device according to the invention. When compressing an implant by the device according to the invention, the implant is first introduced into the receiving space in the axial direction. The compression body is then axially displaced in a first direction relative to the actuating part, the size of the receiving space of the compression body being reduced by the actuating means and the implant being compressed. When this compression process is completed, the compression body is axially displaced in a second direction opposite to the first direction relative to the actuating part, the size of the receiving space of the compression body being increased by the actuating means so that the implant is removed again from the device in the axial direction can.

It can be advantageous to compress the implant in succession in a number of compression processes, the implant being introduced into the receiving space to different extents during the various compression processes (depending on the length of the stent to be compressed).

The basic shape of the receiving space of the compression body is preferably adapted to the shape of the implants to be compressed. If the device is designed, for example, for compressing stents with a cylindrical basic shape, the receiving space of the compression body is preferably essentially cylindrical. The compression body itself can be essentially tubular, the outside of the wall of the compression body can be designed in a special way, as will be described later. The wall of the compression body surrounding the receiving space can have one or more longitudinal slots which extend in the axial direction of the receiving space of the compression body. In a preferred embodiment, the wall of the compression body has four such longitudinal slots. In the case of cylindrical stents, this results in a good circular shape of the stent cross section. The longitudinal sections divide the wall of the compression body into longitudinal sections, which move radially towards one another during the compression process and thus reduce the size of the receiving space.

The longitudinal slots preferably extend from a first end of the compression body only over a partial region of the compression body. As a result, the longitudinal sections are connected to one another at the other end, so that the compression body can be formed in one piece in this way. In the vicinity of the second end, at which the longitudinal sections are connected to one another, connecting means for connecting the compression body to an actuating element can then be provided. These connecting means can contain a thread which interacts with a thread on the actuating element. The actuating element can contain a lever mechanism, the actuation of a lever of the lever mechanism causing the axial displacement of the compression body, or it can also take place hydraulically or pneumatically.

The actuating means for changing the size of the receiving space of the compression body in the event of an axial displacement of the compression body relative to the actuating part can contain inclined surfaces, similar to the collets mentioned above. In this case, a conical surface provided on the compression body can interact with a surface part on the actuating part, which can also be conical.

The outside of the wall of the compression body can be designed in such a way that a conical region adjoins a cylindrical region. In such an embodiment, it has been shown that, with multiple use of the Device according to the invention, in the area of the transition between the conical area and the cylindrical area due to friction effects, a burr can form, which can restrict the quality of further compression processes. In a preferred embodiment, the longitudinal slots are therefore widened in the region of the transition between the conical region and the cylindrical region. This can be done by providing a small hole or circular erosion at this point when using hardened steel.

In many cases, implants to be compressed have a sensitive outer surface. This is the case, for example, with coated stents. In order that the compression process can be carried out as gently as possible, a protective insert made of elastic material that can be inserted into the compression body is preferably used. It can be a silicone tube part. In addition to mechanical protection, the protective insert also protects the implant from possible

Abrasion particles of the compression body.

When producing a compression body for a device according to the invention, the initially compact compression body can be drilled out (eroded), the bore forming a cylindrical receiving space for the implant.

Then the longitudinal slots are created in the wall of the compression body. When using this manufacturing process, it has been shown that the receiving space does not have an exactly cylindrical shape later in the compressed state of the compression body, so that the implant cannot be compressed uniformly over the entire compression length. It has been shown that this can be remedied if the inside of the wall of the compression body is processed in a state in which the size of the receiving space of the compression body corresponds to the size of the fully compressed implant. In the case of a compression body provided with longitudinal slots, this is the compressed state of the compression body. It has also been shown that it is sufficient for the cylindrical design if the inside of the wall of the compression body is reworked by drilling or by means of wire EDM. An embodiment of the invention is explained below with reference to the accompanying drawings.

Brief description of the drawings

Fig. 1 is a schematic representation and shows an embodiment of a

Device for compressing implants with a compression body and an actuating part for actuating the compression body.

2A is a schematic illustration and shows the compression body of FIG. 1 in a side view.

FIG. 2B shows the compression body of FIG. 1 in a front view.

Fig. 3 shows the actuating part of Fig. 1 in a side view.

Preferred embodiment of the invention

For a better overview, matching parts are the same in all figures

Provide reference numerals.

A housing is designated by 10. The housing has a housing passage 14 arranged about an axis 12. At the left end of the housing in FIG. 1, an actuating part in the form of a pliers sleeve 16 is provided. The pliers sleeve 16 is connected to an intermediate piece 20 (sliding guide) via a first threaded connection 18. The intermediate piece 20 is connected to the housing 10 via a second threaded connection 22. The interior of the pliers sleeve 16 and the interior of the intermediate piece 20 are arranged coaxially around the axis 12 and, together with the housing passage 14, form a continuous channel 24. In the channel 24, a compression body in the form of a tong body 26 is arranged to be axially displaceable. At the right end in FIG. 1, the Zangenköφer 26 is connected to an actuating rod 30 via a threaded connection 28. The actuating rod 30 extends out of the right end of the housing 10 in FIG. 1.

A lever device 34 is connected to the housing 10 at the right end of the housing 10 in FIG. 1 via a threaded connection 32. The lever device 34 has an actuating lever 36 which is articulated in a steering point 38 on a lever housing 40. The actuating lever 36 is articulated in a steering point 42 to a link 44. The handlebar 44 is also in a steering point 46 with the

Actuating rod 30 articulated. The actuating rod 30 is secured against loosening or twisting by a lock nut with the lever device 34. The lever device 34 (or the actuating rod 30 or the actuating lever 36) represents an actuating element by means of which the tong body 26 can be displaced axially in the tong sleeve 16.

In the exemplary embodiment shown, the compression body is essentially tubular in the form of the tong body 26. As can best be seen from FIG. 2, the tong body 26 has an enlarged head part 48 and a fuselage part 50. The Zangenköφer 26 is designed such that an axially elongated receiving space 52 for receiving an implant to be compressed is formed in the interior of the Zangenköφer 26. The receiving space 52 continues through a bore in the actuating rod 30, so that even long stents with even longer balloon catheters can be inserted and compressed. The exemplary embodiment shown is provided for compressing cylindrical stents. The is accordingly

Receiving space 52 of the compression body 26 is essentially cylindrical.

Four axial longitudinal slots 56, 58, 60 and 62 are provided in the wall 54 of the receiving space 52 of the pliers body 26, of which only the longitudinal slots 56 and 58 can be seen in FIG. 2A. The longitudinal slots 56, 58, 60 and 62 extend from the left end of the pliers body 26 in FIG. 2A, at which they are open, over an axial partial region of the pliers body 26 and end in the body part 50 of the pliers body. köφers 26. Through the longitudinal slots 56, 58, 60 and 62, the wall 54 of the Zangenköφers 26 is divided into four longitudinal sections 64, 66, 68 and 70. Since the longitudinal slots 56, 58, 60 and 62 do not extend to the right end of the pliers body 26 in FIG. 2, the longitudinal sections are connected to one another on the right part of the fuselage part 50 in FIG. 2A.

In the receiving space 52 of Zangenköφer 26, a protective insert made of elastic material in the form of a silicone hose 72 is used. The silicone hose 72 lies against the inside of the wall 54. 2A so that the silicone tube 72 cannot slip through the pliers body 26 to the right in FIG. 2A, the receiving space 52 ends in a shoulder (recess) 74 in the wall 54.

On the head part 48, the pliers body 26 is provided with a surface which extends obliquely relative to the axis 12 in the form of a conical region 76 on the outside of the wall 54. The conical region 76 merges into a cylindrical region 78. In the region of the transition between the conical region 76 and the cylindrical region 78, the longitudinal slots 56, 58, 60 and 62 are provided with an enlargement in the form of a bore. Such a bore 80 is shown by way of example in the longitudinal slot 58 in FIG. 2A. The bore 80 (cross bore) serves to prevent burr formation and thus a negative change in the axial diameter.

The actuating part in the form of a pliers sleeve 16 is shown separately in FIG. 3. At the left end in FIG. 3, the pliers sleeve 16 is provided with a surface which extends obliquely relative to the axis 12 in the form of a conical region 82 on the inside of the wall 84 of the pliers sleeve 16. The conical area 82 of the pliers sleeve 16 is complementary to the conical area 76 of the pliers body 26.

To stabilize the device, the housing 10 can be attached to a holder (not shown), which in turn is attached, for example, to a table or a base plate. The described device can be placed in a relaxed state and in a tensioned (or compressed) state. In Fig. 1 the device is shown in the relaxed state. In this relaxed state, the tong body 26 in the tong sleeve 16 is withdrawn to the right in FIG. 1. The Zangenköφer 26 is relaxed, so that the diameter of the receiving space 52 is relatively large. In order to put the device in the tensioned state, the lever 36 is pivoted clockwise in FIG. 1, as a result of which the tong body 26 is displaced to the left in FIG. 1 via the handlebar 44 and the actuating rod 30. During this movement of the tong body 26, the conical regions 76 and 82 of the tong body 26 and the tong sleeve 16 act together, so that the longitudinal sections 64, 66, 68 and 70 move radially towards one another, thereby reducing the size of the receiving space 52 becomes. The reduced receiving space 52 is indicated in FIG. 2A by broken lines 86 and 88. The conical regions 76 and 82 of the tong body 26 and the tong sleeve 16 thus form actuating means by means of which the size of the receiving space 52 can be changed relative to the tong sleeve 16 when the tong body 26 is axially displaced.

The described device for compressing an implant in the form of a stent works as follows:

In the relaxed state (FIG. 1) of the device, the stent, which is applied, for example, to a balloon catheter, is introduced from the left in FIG. 1 into the receiving space 52 of the forceps body 26 to a desired length. The lever 36 is then pivoted clockwise in Fig. 1, so that the Zangenköφer 26 is moved to the left in Fig. 1, whereby the receiving space 52 is reduced in the desired manner and compresses the stent around the balloon catheter. When the desired compression has occurred, the lever 36 is pivoted counterclockwise in Fig. 1, so that the Zangenköφer 26 is moved to the right in Fig. 1, whereby the receiving space 52 is enlarged in the desired manner, so that the stent in again the receiving space 52 can be pushed in. The entire

Compression of the stent take place in several work steps, the stent then being inserted further and further into the receiving space 52 with each work step. A specific method of manufacturing the device, in particular the pliers body 26, can be of particular importance. Without paying particular attention to the manufacture of the pliers body 26, it has been shown that the shape of the receiving space 52 does not always meet expectations in the tensioned state. An advantageous shape in cylindrical receiving spaces can be achieved in that the inside of the wall 54 of the Zangenköφers 26 is machined in the tensioned state, in particular drilled (eroded in the case of hardened material).

The dimensions of the individual parts will essentially vary according to the

Align the dimensions of the implants to be compressed. It is within the ability of a person skilled in the art to suitably choose such dimensions so that they are not described in detail here.

Claims

claims

1. Device for compressing implants, containing

(a) a compression body (26) with an axially elongated receiving space (52) for receiving an implant to be compressed and one of the

Recording space (52) surrounding wall (54), and

(b) an actuating part 1 (16) which interacts with the compression body (26) to change the size of the receiving space (52) of the compression body (26),

characterized in that

(c) the compression body (26) is arranged axially displaceably in the actuating part (16), and

(d) actuating means (76, 84) are provided, by means of which the size of the receiving space (52) of the compression body (26) can be changed relative to the actuating part (16) when the compression body (26) is axially displaced.

2. Apparatus according to claim 1, characterized in that the receiving space (52) of the compression body (26) is substantially cylindrical.

3. Device according to claim 1 or 2, characterized in that the compression body (26) is substantially tubular.

4. Device according to one of claims 1-3, characterized in that the wall (54) surrounding the receiving space (52) of the compression body (26) is provided with at least one longitudinal slot (56,58,60,62).

5. The device according to claim 4, characterized in that the longitudinal slot or slots (56, 58, 60, 62) extend from a first end of the compression body (26) over a portion of the compression body (26).

6. Device according to one of claims 1-5, characterized by an actuating element (30; 34; 36), through which the compression body (26) axially in the

Actuating part (16) is displaceable.

7. The device according to claim 6, characterized in that the compression body (26) in the vicinity of a second end has connecting means (32) for connecting the compression body with the actuating element (30; 34; 36).

8. Device according to one of claims 1-7, characterized in that the actuating means contain at least one inclined surface (76; 84) provided on the compression body (26) and / or on the actuating part (16).

9. The device according to claim 8, characterized in that the outside of the wall (54) of the compression body (26) has a conical region (76) at least over a portion.

10. The device according to claim 9, characterized in that the outside of the wall (54) of the compression body (26) has a cylindrical region (78) which adjoins the conical region (76).

11. The device according to claim 10, characterized in that the or the

Longitudinal slots (56,58,60,62) in the region of the transition between the conical region (76) and the cylindrical region (78) of the Have an extension (80) on the outside of the wall (54) of the compression body (26).

12. Device according to one of claims 1-11, characterized by a in the Komprimierköφer (26) insertable protective insert (72) made of elastic material.

13. A method for producing a compression body (26) for a device according to one of claims 1-11, characterized in that the inside of the wall (54) of the compression body (26) is processed in a state in which the size of the receiving space ( 52) of the compression body (26)

Size of the fully compressed implant corresponds.

14. The method according to claim 12, characterized in that the inside of the wall (54) of the compression body (26) is machined by drilling or eroding.