AU727097B2

AU727097B2 - Endoprosthesis

Info

Publication number: AU727097B2
Application number: AU34211/97A
Authority: AU
Inventors: Marc Gianotti
Original assignee: Schneider Europe GmbH
Current assignee: Schneider Europe GmbH
Priority date: 1996-08-16
Filing date: 1997-08-15
Publication date: 2000-11-30
Anticipated expiration: 2017-08-15
Also published as: JP3203212B2; DE59610404D1; EP0824899B1; ATE238738T1; AU3421197A; JPH10165512A; EP0824899A1; CA2209883C; CA2209883A1

Abstract

The flexible tubular mesh structure (2) has ends (4) and an elastic tubular sheath (6). The mesh structure consists of rows of peripherally extending mesh made of juxtaposed cavities (12) bounded by the mesh material (10). The part of the sheath near one end consists of an embedding part (14). This at least partly encloses the mesh structure and consists of a projecting end (16) protruding beyond the end and next to the embedding part.

Description

S F Ref: 383850

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

S

.5* Name and Address of Applicant: Schneider (Europe) *A Cqb" Ackerstrasse 6 CH-8180 Bulach

SWITZERLAND

Marc Gianotti

S.

*5*S

S.

S

Actual Inventor(s): Address for Service: Invention Title: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Endoprosthesis The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845 1 Endoprosthesis The invention relates to an endoprosthesis for the internal support of hollow organs in living creatures, comprising a flexible tubular mesh structure with open ends and an elastic tubular covering, whereby the mesh structure is composed of circumferentially extending mesh rows, consisting of lined up spaces enclosed with mesh material.

Open ends of endoprostheses as described in the introduction often bear a risk of injury of the hollow organ into which such an endoprosthesis has to be implanted. Depending on the design they comprise for example pointed wire ends when the mesh structure is braided from wires or sharp edges when the mesh structure is punched or etched out of a sheet metal tube. For this reason the tissue of the stented hollow organ can be traumatically injured due to movements of the endoprosthesis, eg. when repositioning or removing the endoprosthesis, or due to movements of the hollow organ, eg. by the peristaltic for instance of the foodpipe.

From EP 0621 015 Al an endoprosthesis is known which has a cylindrical wall formed of a wire-netting and a covering layer of elastic material extending over oa part of the length of the endoprosthesis. Since the covering layer terminates with the open end of the endoprosthesis it does not provide sufficient protection from pointed or sharp edged terminating parts of an open end of the cylindrical wall. The covering layer can be penetrated or slitted as the endoprosthesis is radially condensed for introduction into a hollow organ to be stented or as the implanted endoprosthesis is axially compressed due to peristaltic movements of the hollow organ, so that injuring end parts are set free. In this state an atraumatic displacement of the endoprosthesis within the hollow organ can not longer be achieved.

The problem of the invention is to develop an endoprosthesis as described in the introduction in such a way that a hollow organ which is internally supported by it is protected from injuries by pointed or sharp-edged terminating parts at a front end of the mesh structure. Moreover, a possibility shall be provided to reposition an endoprosthesis of the kind named at the beginning within a hollow organ or to remove it completely out of the hollow organ without causing damage to the hollow organ.

According to the invention the problem is solved by an endoprosthesis for the internal support of hollow organs in living creatures, comprising a flexible tubular mesh structure with open ends and an elastic tubular covering, whereby the mesh structure is composed of circumferentially extending mesh rows, consisting of lined Libc/02386 2 up spaces enclosed with mesh material, characterised in that in the region of an open end of the mesh structure the covering comprises an embedding portion, enclosing at least partially the mesh structure, and a projecting portion, following next to the embedding portion and projecting over the open end. When in the region of an open end of a mesh structure the elastic tubular covering comprises an embedding portion, enclosing at least partially the mesh structure, and a projecting portion, following next to the embedding portion and projecting over the front end, injuring pointed wire ends and sharp edges at the front end of an endoprosthesis are covered by a sufficiently long projecting material buffer, which is secured against loss by the embedding portion being connected with the mesh structure. Specifically when implanting an endoprosthesis according to the invention into a hollow organ which performs peristaltic movements in form of axial pushes against an open end of the endoprosthesis, eg. the foodpipe, the partly turned back projecting portion serves as an additional protective layer. Besides that 15 the covering comprising the embedding and projecting portion reduces the foreign body feeling of a patient into hers or his foodpipe such an endoprosthesis has been o introduced, said feeling being enforced by uncovered wire ends touching the inside wall of the foodpipe. As an particular advantage it turns out that the projecting portion of the covering is a target which can relatively well be caught by gripping devices in order to be able to adjust the position of the endoprosthesis for example *.oin proximal direction. At the same time a possibility is created for a complete S"removal of the endoprosthesis out of the hollow organ.

Further advantages of an endoprosthesis according to the invention can be seen in preferred embodiments described subsequently with reference to the 25 drawings where in FIG. 1 an open end of an endoprosthesis shown in perspective view of a quarter cut along the longitudinal axis, in FIG. 2 an open end of a first embodiment shown in schematic side elevation, and in FIG. 3 a magnified detail of the open end of a second embodiment is illustrated.

According to FIG. 1 the mesh structure 2 of an endoprosthesis according to the invention comprises at an open end 4 a tubular covering 6, consisting of an embedding portion 14 partially enclosing the mesh structure 2 and of a projecting Libc/02386 4 3 portion 1 6 following next to the embedding portion 14 and projecting over the open end 4.

FIG. 2 schematically shows a portion of a mesh structure 2 which is composed of circumferentially extending mesh rows 8 which consist of lined up spaces 12 enclosed with mesh material 10. For clarification a mesh row 8 is indicated with dotted spaces 12. The embedding portion 14 of the covering 6 which is indicated by a longitudinal hatch encloses the mesh structure 2 starting from the open end 4 completely over the length LE of at least the width B of a mesh row 8.

This guarantees that the covering 6 is interlockingly connected with the mesh lo structure 2 and as a consequence the covering 6 cannot be removed from the mesh structure 2 and got lost by movements of the endoprosthesis in a hollow organ. The length of the projecting portion 16 is in this case of the same order of magnitude as the width B of a mesh row 8. Thus, on one hand the projecting portion 16 provides for a sufficiently strong protection layer between pointed wire 15 ends and the inside wall of the hollow organ and on the other hand enough target area in order to clamp a gripping device to it.

In an advantageous embodiment as shown in FIG. 3 the embedding portion 14 encloses starting from the open end 4 mesh rows squared indicated, consisting of spaces 12' which are not entirely enclosed with mesh material whereby the spaces 12 of the first mesh row 8, consisting of spaces 12 entirely *enclosed with mesh material 10, is no more enclosed by the embedding portion 14.

In addition to the safe anchoring of the covering 6 the freezing effect of the covering 6 to the mesh structure 2 is reduced and therefore flexibility and compressibility of the endoprosthesis in the region of an open end 4 is restricted 25 only slightly.

According to a preferred embodiment of the invention the covering 6 comprises canals, not shown in the figures, tightly enclosing the mesh material and the mesh material 10 being movable along the canals. This enables the covering 6 to follow the deformations of the mesh structure 2 caused by movements of the endoprosthesis as a consequence of axial shortening and bending or radial compression and expansion. By movement of the embedding portion 14 along the mesh material 10 it is possible for the elastic covering 6 to take the state of minimal tension and to reduce therefore the risk of tear or puncture of the covering 6.

Libc/02386

I.

4 In a mesh structure 2 of braided wires 10 the covering 6 comprises an average wall thickness of about half of the diameter of the wires 10. Such a wall thickness has proven effective with respect to the tear strength as well as to the amount of material needed for the covering 6. The covering 6 at the proximal open end 4 of braided mesh structures 2 has turned out to be an advantageous protection against breaking up the braiding which becomes effective for example when hooking with a gripping tool into the braiding distally of the embedding portion 14 and pulling the endoprosthesis in proximal direction.

The covering 6 of an endoprosthesis according to the invention is preferably made of a polyurethane elastomer. Due to its biocompatibility the polyurethane elastomer which is distributed on the trademark ChronoFlexTM by the company PolyMedica Industries can be taken as an example.

a Libc/02386

Claims

1. Endoprosthesis for the internal support of hollow organs in living creatures, comprising a flexible tubular mesh structure with open ends and an elastic tubular covering, whereby the mesh structure is composed of circumferentially extending mesh rows, consisting of lined up spaces enclosed with mesh material, characterised in that in the region of an open end of the mesh structure the covering comprises an embedding portion, enclosing at least partially the mesh structure, and a projecting portion, following next to the embedding portion and projecting over the open end.

2. Endoprosthesis according to claim 1, characterised in that the embedding portion encloses the mesh structure from the open end over a length of at least the width of one mesh row.

3. Endoprosthesis according to claim 1 or claim 2, characterised in that starting from the open end the embedding portion completely encloses mesh rows 15 consisting of spaces which are not entirely enclosed by mesh material, whereby the spaces of the first mesh row consisting of spaces entirely enclosed by mesh material are no more enclosed by the embedding portion.

4. Endoprosthesis according to claim 1, characterised in that the length of Sthe projecting portion is about the width of one mesh row.

5. Endoprosthesis for the internal support of hollow organs in living creatures, substantially as hereinbefore described with reference accompanying drawings. Dated 5 August, 1997 0 SCHNEIDER (EUROPE) AG- m'b Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON Libc/02386