[Endoureteropyelotomy in impassable stenosis of the pyeloureteral junction: instrumental conversion of the stenosis into an intrapelvic ureterocele].

: The authors describe a new endourological procedure for resolving cases of stenosis of the impassable ureteropyelic union. The procedure consists in raising the pyeloureteral union by means of a Chevassu's catheter equipped with its wire guide, introduced backwards into the ureter and which, when pushed externally, situates the ureteropyelic union by way of intrapyelic ureterocele. We then proceed to the lengthwise cutting of this ureterocele under nephroscopic view until the ureteral catheter is exposed. With this procedure a successful solution is provided for those cases that were debarred from endourological surgery because the tutor catheter was unable to pass.