[Congenital segmental duplication of the lumbar ureter (author's transl)].

In a 23-year-old man attacks of nephritic colic led to the discovery of an obstruction on the left lumbar ureter. Segmental resection of the ureter was performed, removing 10 mm of malformed, obstructed ureter. This was an incomplete duplication, the two ureteral segments lying side-by-side, each with its own musculature, for a distance of 7mm. Above and below the anomaly, the ureter was normal. This exceptional malformation is compared with other internal obstructions of the ureter.