Percutaneous retropelvic endopyelotomy for treatment of ureteropelvic junction obstruction

PURPOSE: A new minimally invasive approach for endopyelotomy for the treatment of ureteropelvic junction obstruction (UPJO) is described. The results are compared with those of other lines of treatment. MATERIALS AND METHODS: A total of 39 patients with UPJO underwent percutaneous retropelvic endopyelotomy. Retrograde percutaneous renal access, using the Lawson catheter and deflecting guidewire, was done for creation of the nephrostomy tract. Using holmium laser through a 28-Fr nephroscope, a small window was made in the posterolateral surface of the renal pelvis. The nephroscope was advanced from the renal pelvis to the retropelvic space through that window. Crossing vessels were easily detected and were either coagulated or avoided. The window incision was extended distally, and the narrow ureteropelvic junction (UPJ) was incised using holmium laser. RESULTS: The entire procedure was done in the supine position within 1 h. The presence of secondary stones, hugely dilated renal pelvis, high insertion of the UPJ, and whether UPJO was primary or secondary, did not alter the results. The only factor that affected the results was split function of the obstructed renal unit. The success rate was 100% when the split function exceeded 35%. When the split function was <35%, the success rate dropped to 56%. CONCLUSION: Percutaneous retropelvic endopyelotomy is a promising approach for the treatment of UPJO that gave favorable results. The use of the nephroscope provided a wide visual field. The wide-field facilitated detection of crossing blood vessels with no incident of vascular injury. It also facilitated endopyelotomy with high precision. Ureteral injury was not a risk factor.