Metallic Wallstents: a new therapy for extrinsic ureteral obstruction.

Self-expanding metallic stents, frequently used in interventional radiology, were implanted into 15 obstructed ureters in 12 patients. The cause of obstruction was lymph node metastases of different malignant tumors or direct tumor compression of the ureter. Followup in 12 patients was 3 to 31 weeks. Immediately after implantation all stents drained well. During the initial 4 weeks slight obstruction occurred due to hyperplasia of regenerating urothelium. The stents were fully incorporated into the ureteral wall 8 weeks after implantation, they were covered by smooth epithelium and the hyperplasia had disappeared. Complications were hemorrhagia in 1 patient and incrustation in 2. No infection was observed. Complications due to the tumor were obstruction distal to the stent in the presence of a widely open catheter in 3 patients. Early results are presented. Late results are not yet available. The method seems to be minimally invasive and easy to perform.