Duplication of the renal pelvis and ureter: associated anomalies and pathological conditions.

Thirty-one patients with anomalous and/or pathological conditions in the duplication of the renal pelvis and ureter were studied in order to analyze the urographic findings. A segmental defect evident in the visualization was caused by the abscess of one of the poles in the kidney. In patients with hypoplasia of one of the poles, the other normal pelvis extended to the neighboring segment, and consequently showed the same pattern as a simple pelvis and ureter on urography. The renal hypoplasia was apt to be combined with simple or ectopic ureterocele and ectopic ureteral opening. In patients with non-visualization of two pelves, hydronephrosis or renal hypoplasia was proved by other radiological modalities including computed tomography. Incidence of vesicoureteral reflux was more frequent in the ureter of the lower pelvis. Reflux was also found between the two ureters of the bifid ureter. It was concluded that these urographical findings correlated closely with pathological conditions.