Change of Hydronephrosis after Pyeloplasty in Children with Unilateral Ureteropelvic Junction Obstruction

Park, Sungchan; Ji, Young Hwan; Park, Young Seo; Kim, Kun Suk

Abstract

PURPOSE: In this prospective study, the immediate postoperative changes of hydronephrosis, following pyeloplasty in children with a unilateral ureteropelvic junction obstruction, were evaluated.
MATERIALS AND METHODS
The study population consisted of 30 patients with a unilateral ureteropelvic junction obstruction, who underwent open pyeloplasty between September 1997 and December 2003. The serial changes of hydronephrosis in children with consecutive ultrasonography were evaluated at 1, 4 and 10 months after the pyeloplasty. Diuretic renograms were performed before and 4 months after the surgery.
RESULTS
Of the thirty patients in whom ultrasonography was serially performed at 1, 4 and 10 months following pyeloplasty, improvements of the hydronephrosis were shown in 20, 66 and 80%, respectively. Of the 24 patients who showed no improvement of the hydronephrosis at 1 month after the pyeloplasty, 18 had improved at 10 months. Two patients underwent a reoperation at 4 and 5 months after the pyeloplasty, respectively. One had persistent severe hydronephrosis and a urinary tract infection, and the other persistent hydronephrosis and a decreased differential renal function on follow-up studies. There was no significant difference between the patients with and without improvements of the hydronephrosis at 4 months after the pyeloplasty in terms of the preoperative factors.
CONCLUSIONS
Hydronephrosis can persist following pyeloplasty, but improve with time. Patients with persistent or aggravated hydronephrosis following pyeloplasty can be observed, as long as there is no deterioration in the renal function or a urinary tract infection. No conclusion, with regard to a reoperation, can be drawn from isolated persistent hydronephrosis found during ultrasonography.