Prosthesis for ductus choledochus containing a tumor

The invention relates to a bile duct endoprosthesis made of a tube.

Tumors in the area of ​​the Leberhilus, which can emanate from the bile ducts or from the liver, generally lead to a displacement of the bile ducts and to the accumulation of bile by the accumulation of the bile liquid it leads to a progressive jaundice with heavy damage of the liver and subsequent heavy changes on the whole organism. Tumors in the area of ​​the hepatic portal and also in the bile ducts cause a direct constriction of the lumen and, due to the pressure exerted on the bile duct by au-ben, indirectly a transfer of the draining bile ducts. In order to divert the accumulated bile fluid, surgical procedures are used in which the bile ducts in the region of the liver, which have been widened in such a state, are diverted into a loop of intestine sutured to the liver. With this method, however, a sufficient drain can often not be achieved and, secondly, particularly weakened patients are heavily burdened by the procedure.

It is also known to bridge the closed bile portion by a tubular endoprosthesis. Tubes made of thermoplastics and silicone compounds are only partially suitable for this purpose, since they crust in a short time and a firm involvement in the surrounding tissue does not materialize.

Endoprostheses and implants made of carbon and graphite are compatible with the body's own tissue. A special, referred to as glassy carbon or glassy carbon form is for example for heart valves (US-PS 35 26 906), middle ear prostheses (DE-PS 19 26 587) and implantable stimulating electrodes (EP 00 09 727) use!:. The requirement profile of a bile duct endoprosthesis differs substantially from the known applications of glassy carbon. The invention is therefore based on the object to change the surface condition such that a tubular bile duct endoprosthesis of glassy carbon does not encrusted and the ingrowth is accelerated into the body tissue surrounding the prosthesis.

This object is achieved in a bile duct endoprosthesis of a tube in that the tube consists of glassy carbon, the outer surface roughened by micropores and provided with grooves and the inner surface has a finely polished surface.

Glassy carbon is obtained by pyrolysis of three-dimensionally crosslinked synthetic resins, such as, for example, phenolformaldehyde or furan resins, at a moderate heating rate. The resulting carbon is very hard and abrasion resistant and has glassy smooth surfaces and fracture surfaces. To produce the bile duct endoprosthesis, which advantageously has the shape of a continuous straight or curved tube, it is expedient to fill a correspondingly formed casting mold with a hardenable resin and crosslink the resin by heating the mold to a temperature of about 120 to 200⁰C. The resin body is then heated to about 800 to 1200 by further heating⁰C carbonized in an inert or reduced atmosphere In another method, tube-like shapes are produced by spinning

Glassy carbon has a smooth surface that does not generally encrust in contact with supersaturated solutions. In the presence of bile fluid, however, encrustations still occur, which significantly affect the function of a glassy carbon bile duct endoprosthesis. According to the invention, these encrustations are avoided by polishing the inner circumferential surface of the pipe. Suitable polishing agents are, for example, diamond powder or chalk powder; the average surface roughness of the polished inner surface should be less than 0.1 μΐη.

On the other hand, the smooth surface of the vitreous carbon precludes anchoring the endoprostheses in the living tissue. This disadvantage of the vitreous carbon is eliminated in the endoprosthesis by roughening its outer circumferential surface. Accordingly, the existing of a glassy carbon tube bile duct endoprosthesis is only functional when the outer surface roughened and the inner surface is finely polished.

The invention will be explained in the following with reference to a drawing by way of example:

The biliary endoprosthesis shown in the figure consists of a slightly curved tube 1 made of glassy carbon, whose outer surface is provided with grooves 2 and roughened by flat micropores 3. The average depth of the grooves is about 1.5 mm and the depth of the micropores about 100 μητι. The inner circumferential surface 4 of the tube is finely polished.

For this 1 sheet drawings