[Self-expanding permanent endoluminal stents in the ureter. 5 years results and critical evaluation].

The use of self-expanding permanent endoluminal stents (SPES) in the upper urinary tract proved to be a useful alternative to double-J splints and percutaneous nephrostomy in malignant extrinsic ureteral obstruction. Between April 1990 and August 1995, 65 ureteral obstructions (58 malignant and 7 benign strictures) were treated by implantation of a SPES. The devices used were the Wallstent (Schneider, Zürich, Switzerland; 62 times) with diameter of 7 mm and length of 3-10 cm and the Memotherm stent (Angiomed, Karlsruhe, Germany; 3 times), diameter 8 mm, length 5 cm. To obtain optimal results, a newly developed implantation technique was necessary. Primary patency was 55%, assisted patency 45%. Causes of reocclusion were incrustation (3 times), tumor ingrowth into the SPES (17 times) and tumor overgrowth beyond the ends of the SPES (11 times). We did not observe any of the following complications: infection, compression of the SPES by the tumor, erosion of other surrounding structures such as blood vessels, allergic reactions, peristaltic problems.