[Congenital ureteral valves: report of 2 cases].

Congenital ureteral valves have not been a well recognized condition for the cause of ureteral obstruction. In our first case a 21-year-old male presented with left flank pain. Intravenous urography showed left mild hydronephrosis due to upper ureteral obstruction. Partial ureteral resection and re-anastomosis was performed. Histology demonstrated mucosal folds with smooth muscle. In our second case a 12-year-old boy presented with left flank pain. Retrograde pyelogram showed a fold-like filing defect which suggested ureteral valve. Endoscopical valve resection through nephrostomy was performed. Optimal management and diagnostic difficulties were discussed.