STRECKER STENT AS URETERAL STENT - EXPERIMENTAL-STUDY

Urothelial lining of the metallic stents could result in an ideal prosthesis, included in the wall of the urinary tract, and therefore avoiding the risk of migration and incrustation. This principle has already been successfully applied to urethral prostheses. To evaluate this principle in endoureteral implantation, six balloon-expandable metal stents, composed of tantalum wire (Strecker(R) stent), 4 mm in diameter, were implanted in the ureter of three large female pigs via cystostomy and retrograde ureteral intubation. The animals were sacrificed 3 months later for anatomic and radiologic assessment. At this time, a single stent was still in its original place, as three had migrated, and two had been expelled. All of the stents present at the end of the study were obstructed by marked urothelial hyperplasia. Intestinal metaplasia, related in part to this particular experimental model, was observed constantly within the papillary hyperplasia. These results suggest that the principle of endourethral implantation of metal stents cannot be applied directly to endoureteral implantation.