A New Modification of Dismembered Pyeloplasty for Primary Ureteropelvic Junction Obstruction

AIM: To present the results of a new modification of dismembered pyeloplasty performed to prevent the occurrence of secondary obstruction. METHODS: Modified dismembered pyeloplasty was performed in 35 children (age range 3 months to 16 years) who had unilateral ureteropelvic junction obstruction. In postoperative follow-up, presence of hydronephrosis on ultrasonography, differential renal function (DRF) and renal drainage half-time on technetium-99m diethylenetriaminepentaacetic acid (DTPA) renography were recorded and compared with preoperative data. RESULTS: Mean anteroposterior renal pelvic diameter, mean preoperative DRF and radioisotope clearance half-time on DTPA renography of the affected kidneys were 61.4 mm, 38.6% and 34.3 min in children with prenatal hydronephrosis, and 67.5 mm, 37.6% and 39.4 min in children that presented with symptoms, respectively. After surgery, mean anteroposterior renal pelvic diameter, mean DRF and radioisotope clearance half-time on DTPA renography of the affected kidneys were 10.9 mm, 45.9% and 11.9 min in children with prenatal hydronephrosis, and 20 mm, 41.9% and 15.2 min in children that presented with symptoms, respectively. No failure was observed in any patient at an average follow-up of 26 months (range 1-5 years). CONCLUSIONS: Open dismembered pyeloplasty is the treatment of choice for intrinsic ureteropelvic junction obstruction. The modification of dismembered pyeloplasty that we performed is an alternative for the prevention of secondary obstruction.