Retroperitoneoscopic pyelotomy combined with the transposition of crossing vessels for ureteropelvic junction obstruction

Purpose: We developed a new approach of retroperitoneoscopic pyelotomy combined with the transposition of crossing vessels for ureteropelvic junction obstruction as an alternative to conventional antegrade or retrograde endopyelotomy. Materials and Methods: From February 1997 to August 1999 we treated 5 cases of ureteropelvic junction obstruction due to crossing vessels that were diagnosed by helical computerized tomography. Ureterovascular hydronephrosis characterized by a malrotated renal pelvis with anterior crossing vessels was observed in 4 cases and ureteropelvic junction obstruction with a posterior crossing artery was present in 1. After endoureterotomy stent insertion under cystoscopic guidance we performed retroperitoneoscopic endopyelotomy with the kidney in standard position. Crossing vessels were transposed to a higher position to remove obstruction and fixed with peripelvic tissue via retroperitoneoscopy. In all eases a longitudinal incision approximately 1.5 cm. long was made with a potassium titanyl phosphate laser. Results: Convalescence was uneventful in all patients and the endoureterotomy stent was removed 4 to 8 weeks after surgery. Postoperatively helical computerized tomography showed the successful transposition of crossing vessels and significant hydronephrosis resolution in all cases. All patients were asymptomatic during followup of 17 to 28 months. Conclusions: Despite our small number of patients our results are sufficient to conclude that retroperitoneoscopic pyelotomy combined with the transposition of crossing vessels is a simple and reliable method for treating ureterovascular hydronephrosis and associated conditions.