[2 cases of exception to the law of Weigert and Meyer]

The authors report two cases of uropathy with duplicated ureters where Weigert Meyer law was not respected: one reflux to the upper pole segment and one megauretere with reflux to the lower pole segment. These exceptions must be absolutely recognized before endoscopic subureteral injection of polytetrafluoroethylen. Only retrograde pyelography can clarify anatomic situation and pathologic ureteral orifice. Retrograde pyelography must be used if the slightest doubt hangs over pathologic duplex system.