WO2008034452A1

WO2008034452A1 - Percutaneous implant

Info

Publication number: WO2008034452A1
Application number: PCT/EP2006/009112
Authority: WO
Inventors: Thomas Frello
Original assignee: Bmc Ventures A/S
Priority date: 2006-09-20
Filing date: 2006-09-20
Publication date: 2008-03-27

Abstract

The inventions refers to a percutaneous implant (1) comprising a first end (4) and a second end (2), having the first end (4) under the skin (3) and the second end (2) outside the skin (3) . To decrease the risk of infection and for using the implant for a long time, the first end (4) of the implant is fixed to an ectopic biological material.

Description

Percutaneous Implant

The invention refers to a percutaneous implant comprising a first end and a second end, having the first end under the skin and the second end outside the skin.

Percutaneous implants often cause infection problems, which do not occur in connection with fully implanted foreign bodies, like for example artificial hip or back implants .

Skin cells are spreading until they are surrounded by neighbouring skin cells. Thereby they expel dead tissue by growing so as to surround it. By wound healing for example the skin always grows from the edges of the wound under the crust, until the crust falls off. In the same manner skin tends to grow down along the im- pla-nt which penetrates the skin. Therefore, the wound which occurred during the implanting will not be sealed by new skin cells and the risk of infections will be increased.

However, a fairly good sealing of the area where the implant penetrates the skin can be achieved if the implant consists of a bio-compatible material and if the implant is mechanically stable in relation to the skin.

Jansen J.A., de Groot K.: "Guinea pig and rabbit model for the histological evaluation of permanent percutaneous implants", Biomaterials 1988, Vol. 9(3), 268-72, discloses that an implant can be stabilised in relation to the skin, if the lower part of the implant is fixed in a bone and if the distance to the covering skin is small. This, for example, applies for a percutaneous implant located in the shinbone of a guinea pig. However, in most cases a skin penetration in the area of the shinbone will not be desirable.

Several examinations were done to stabilise an implant which penetrates the skin and enters into a soft tissue to achieve a better wound healing.

In the references Y. C. G. J. Paquay, J. E. de Ruijter, J. P. C. M. van der

Waerden and J. A. Jansen: Tissue reaction to Dacron® ve- lour and titanium fibre mesh used for anchorage of percutaneous devices", Biomaterials 1996, Vol. 17(12), 1251-1256; M. Gerritsen, Y. C. G. J. Paquay and J.A. Jansen:

"Evaluation of the tissue reaction to a percutaneous access device using titanium fibre mesh anchorage in goats", J. Mater. Sci . : Materials in Medicine 1998 Vol. 9, 523-528;

J.A. Jansen and X. F. Walboomers: "A new titanium fibre mesh-cuffed peritoneal dialysis catheter: An Experimen- tal animal study", J. Mater. Sci: Materials in Medicine 2001 Vol. 12, 1033-1037; is mentioned that it is an advantage to fix the implant in a porous material which is arranged under the skin. This fixing gives fewer movements between the skin and the part of the implant penetrating the skin, which makes it easier for the skin to grow close to the surface of the implant.

X. F. Walboomers and J. A. Jansen: "Bone tissue induc- tion, using a COLLOSS®-filled titanium fibre mesh scaffolding material", accepted for publication in Biomate- rials, discloses, that by means of a bone regeneration material, like for example Colloss, an ectopic bone can grow where bones do not naturally exist. By this ex- periment the bone regeneration material was surrounded by a mesh of titanium fibre.

It is an object of this invention to provide a percutaneous implant which decreases the risk of infections.

Based on this object, a percutaneous implant corresponding to the preamble of claim 1, has been invented whereby the first end is fixed to an ectopic biological material .

The advantage of fixing the implant to an ectopic biological material is that this will make the implant independent of the location of natural material like bones, wherein the implant could be fixed. This will improve the ingrowth of skin cells to the part of the implant penetrating the skin. The use of biological material prevents the rejection of the implant by the body. The implant can be used for several years.

Advantageously, the ectopic biological material is an ectopic bone tissue. Bone is a stable material with high stiffness. Thus it is possible to fix the implant properly.

Preferably, the ectopic bone tissue has been grown by means of a bone graft material. A bone graft material could be a bone regeneration material such as Colloss. Therefore, it is possible to grow bone tissue somewhere in the body for fixing the percutaneous implant where it is needed, without being dependent on the locations of the natural skeletal bone. The optimum dose of Colloss has not yet been systematically investigated, but for the initial studies 20 mg Colloss were used for a 0,7 m³ hollow.

Preferably, the ectopic bone tissue has been grown in a mesh. Thus, the forming of the ectopic bone is simpli- fied. The mesh is formed to a small bag. In this bag the bone growth material is placed. Then the mesh can be implanted at the desired spot.

Preferably, the mesh is a titanium or tantalum mesh. These materials are not rejected by the body. Thereby, the risk is low that the mesh generates an inflammatory response . Advantageously, the distance between the mesh and the skin is small. Small means that the mesh is implanted as near as possible at the surface of the body. Par- ticularly, the distance is smaller than 10 mm. It has been shown, that the wound healing is improved when the implant is stabilised at a location as near at the skin as possible.

Preferably, the part of the implant being fixed in the ectopic bone tissue has a surface made of tantalum or titanium. This part of the implant is in direct contact with body fluids. In order that fibrous tissue does not occur it is important that the material of the implant is osteointegrative . Such a material is tantalum or titanium.

In the preferred embodiment the implant is mechanically fixed to the mesh. Thus, the forces which act upon the implant are transmitted to a large area of the ectopic material, so that the load of the ectopic material is small .

Preferably, the implant has a first opening in the first end and a second opening in the second end, creating a passage from the inside of the body to the outer surroundings. Thus it is possible to use the implant as an access to provide the body with drugs for example. Likewise the implant can be used for dialysis or sampling.

Preferably, the first opening is at the side of the implant. The implant does not have to break through the ectopic material in order to form an access to the inner body. Thus the implant can comprise a shorter length.

It is another object of the invention to provide a method of fixing a percutaneous implant according to claim 1.

This object is solved by a method comprising the fea- tures of claim 11.

By using this method, the operation time is short, because the step of forming the mesh bag and fixing the implant at the mesh bag can be done before the opera- tion starts.

Preferably, the mesh is implanted first, and when the ectopic bone tissue has been formed in the mesh, the implant is inserted by a new operation.

While the implantation is made in two separated operations, infections can be avoided. The time between the two operations is long enough for the ectopic bone tissue to grow inside of the mesh. This is required for a good stabilisation of the implant and takes some weeks. In this time, the operation wound is healed. The implant is inserted and fixed by means of a second operation. Thereby, infringement of the skin is less than at the insertion of the mesh, by what the critical time for infections decreases.

An embodiment of the invention will be described with reference to the attached drawings . Fig. 1 is a view of a percutaneous implant with the inner opening at the side of the implant.

Fig. 2 is a view of a percutaneous implant with the inner opening at the bottom of the implant.

Fig. 1 shows a percutaneous implant 1 that could be for example a catheter. The implant 1 has one end 2 outside the skin 3 and the other end 4 under the skin 3 inside the body, the implant 1 having an inner opening 5 inside the body in the side of the implant 1, and an outer opening 6 outside the body. An ectopic bone 7 is enclosed in a titanium mesh 8 and the implant 1 is lo- cated in body tissue 9.

The implant 1 is fixed to the ectopic bone 7, which is grown by means of a bone graft material. Indeed, the implant 1 could be mechanically fixed to the mesh 8. The inner opening 5 stays in contact with the outer opening 6 through the hollow implant thereby connecting the body tissue 9 with outer surroundings. This connection can be used such as for drug administration or dialysis. Because the inner opening 5 stays at the side of the implant 1, it is possible to arrange the end 4 inside the ectopic bone.

Fig. 2 shows the same as Fig. 1, only the implant 1 penetrates the ectopic bone 7 and the inner opening 5 is in the bottom of the implant 1.

This embodiment is provided for application when a deeper intrusion is needed. Nevertheless it is possible to arrange the ectopic bone 7 near by the skin 3, because the implant 1 penetrates the ectopic bone 7 and the inner opening 5 is in contact with body tissue 9 under the mesh 8.

Claims

1. Percutaneous implant (1) comprising a first end (4) and a second end (2), having the first end (4) under the skin (3) and the second end (2) outside the skin (3), characterised in that the first end (4) is fixed to an ectopic biological material.

2. Percutaneous implant according to claim 1, characterised in that the ectopic biological material is an ectopic bone tissue (7).

3. Percutaneous implant according to claim 1 or 2, characterised in that the ectopic bone tissue (7) has been grown by means of a bone graft material.

4. Percutaneous implant according to one of the claims 1 to 3, characterised in that the ectopic bone tissue (7) has been grown in a mesh (8) .

5. Percutaneous implant according to one of the claims 1 to 4, characterised in that the mesh (8) is a titanium or tantalum mesh.

6. Percutaneous implant according to one of the claims 1 to 5, characterised in that the distance between the mesh (8) and the skin (3) is small.

7. Percutaneous implant according to one of the claims 1 to 6, characterised in that the part of the implant (1) being fixed in the ectopic bone tissue (7) has a surface made of tantalum or titanium.

8. Percutaneous implant according to one of the claims 1 to 7, characterised in that the implant (1) is mechanically fixed to the mesh (8).

9. Percutaneous implant according to one of the claims 1 to 8, characterised in that the implant (1) has a first opening (5) in the first end (4) and a second opening (6) in the second end (2), creating a passage from the inside of the body to the outer surroundings .

10. Percutaneous implant according to one of the claims 1 to 9, characterised in that the first opening (5) is at the side of the implant (1) .

11. Method of fixing a percutaneous implant to an ectopic bone tissue, the implant comprises a first end under the skin and a second end outside the skin, characterised in that a mesh bag is formed by an osteointegrative material, then the first end of the implant is fixed at the mesh bag and after filling the mesh bag with bone graft material the implant is implanted at the desired spot by means of surgical invention.

12. Method of fixing a percutaneous implant according to claim 11, characterised in that the mesh is implanted first, and when the ectopic bone tissue has been formed in the mesh, the implant is inserted by a new operation.