[Endopyelotomy for ureteropelvic junction obstruction: results and complications].

We treated eleven cases of primary ureteropelvic junction obstruction with percutaneous endopyeltomy. Endopyelotomy was successful in nine of the eleven cases. Complications during and after endopyelotomy occurred in three cases, two of which had pyelonephritis and the other severe postoperative hemorrhage requiring blood transfusion due to incision of a posterior crossing vessel. In this last case, the kidney was supplied by three arteries. The lower segmental artery passed behind the ureter. We emphasized that angiography should be performed to rule out the presence of a posterior crossing vessel before endopyelotomy, when it is doubtful if an extrinsic cause of ureteropelvic junction obstruction is present.