[Obstructive uropathy after kidney transplantation. Experiences with endourologic incision of ureteral stenoses]

Between 1985 und March 1991 we have managed 8 upper urinary tract obstructions in kidney transplants using an endourological approach. After a graft rejection was excluded an obstruction was initially diagnosed by nephrosonography and further confirmed by IVP or antegrade pyelography. To investigate the urodynamic relevance of the stenosis, all patients underwent preoperative diuretic isotope renography. In all cases a percutaneous pyelostomy was done to preserve renal function. 7 of these 8 patients demonstrated a stenosis of the ureter, while in one case, the obstruction was caused by a coagulum in the renal pelvis. Incision of the stricture then was performed with a flexible knife antegrade or retrograde and stented for 4-6 weeks. In 6 out of 7 cases with a proven stenosis of the ureter, the cold knife incision lead to a successful outcome, while in one patient, the kidney had to be removed due to uncontrolled bleeding 12 days after successful percutaneous incision. Our results indicate, that the cold-knife-technique for the management of upper urinary tract obstructions in kidney transplants is a promising, fast and in most of the cases effective method. Due to its minimalinvasive character and excellent results, this approach is able to replace open reintervention in most cases.