Presentation, Management and Long-Term Outcome of Ureteropelvic Junction Obstruction in Duplex Kidneys.

PURPOSE: Ureteropelvic junction obstruction in association with a duplex collecting system is a rare but challenging upper urinary tract pathology. We report our 21-year experience with this anomaly in terms of presentation, diagnostic evaluation and management.

MATERIALS AND METHODS: We retrospectively identified all patients with ureteropelvic junction obstruction in a duplex collecting system between 1991 and 2012. We reviewed each case for presenting symptoms, anatomy and management. Median followup was 10.8 years (range 2 to 22).

RESULTS: Ureteropelvic junction obstruction in duplex kidneys was diagnosed in 21 patients. Ten patients presented with clinical symptoms such as flank pain and urinary tract infection but 11 were asymptomatic. Six patients were diagnosed by prenatal ultrasound. The lower pole and the upper pole were affected in 22 and 3 renal units, respectively. Bilateral ureteropelvic junction obstruction was found in 4 cases. Duplication was complete in 5 patients, incomplete in 11 and undetermined in 5. Surgery was performed in 14 patients, including pyelopyelostomy or ureteropyelostomy in 7, dismembered pyeloplasty in 6 and heminephrectomy in 1. Reintervention was required in 1 case. Conservative treatment was adopted in 7 patients with clinically insignificant obstruction and unimpaired renal function. In all of these patients upper urinary tract dilatation gradually improved during 3 years.

CONCLUSIONS: Ureteropelvic junction obstruction in a duplex kidney is a rare but challenging anomaly that requires careful evaluation. Treatment should be individualized according to clinical presentation (symptomatic/asymptomatic), anatomy (lower/upper pole), duplication type (complete/incomplete) and obstruction with time (severity/development) on dynamic renogram.