The Postoperative Prognosis of Ureteropelvic Junction Obstruction according to the Appearance of the Ureter of Preoperative Retrograde Pyelography

Kim, Jae Wook; Han, Sang Won; Choi, Seung Kang

Abstract

PURPOSE: Controversy still exists about the necessity for a preoperative RGP (retrograde pyelography) in UPJO (ureteropelvic junction obstruction), but no standard has been established. Therefore, to define the role of preoperative RGP in UPJO, the postoperative prognosis, using the appearance of the ureter in preoperative RGP, was studied.
MATERIALS AND METHODS
Between Jan. 1996 and Oct. 2001, the radiological studies of 38 children (mean age: 10.66 months), out of 77 diagnosed with UPJO followed by pyeloplasty, were available for a retrospective review. The subjects were divided into three groups: -group A; UPJ (ureteropelvic junction) narrowing only, group B; multiple narrowing, and group C; a hypoplastic ureter, based on the findings of the preoperative RGP. The improvements in the hydronephrosis, according to the comparison between the preoperative and postoperative U/S (ultrasonography), performed at 6 and 12 months after the operation, were retrospectively analyzed.
RESULTS
The number of patients in the groups A, B and C were 15 (16 renal units, one bilateral UPJO), 11 and 12 (13 renal units, one bilateral UPJO), respectively. There were no statistically significant differences in the degree of preoperative hydronephrosis (mean+/-S.D., p>0.5). The degree of hydronephrosis (mean+/-S.D.) found at the U/S 6 and 12 month follow ups were 2.00+/-0.63 and 1.63+/-0.50, 1.91+/-0.70, and 1.45+/-0.52 and 2.92+/-0.76 and 2.62+/-0.77 in groups A, B and C, respectively, with all showing improvements. There were statistically significant differences in the degree of improvement in group C compared to groups A and B (p<0.05).
CONCLUSIONS
The current study has shown that hydronephrosis, with a hypoplastic ureter, has a tendency to improve more slowly than other types of ureteral narrowing. Therefore, if the long-term follow-up data show the same results, a preoperative RGP may play an important role in evaluating the postoperative prognosis of UPJO.