Risk factors for surgery in children with ureteropelvic junction obstruction due to antenatally detected ınfantil hydronephrosis.

Background: Although the majority of cases with antenatally detected hydronephrosis (ANH) resolve during postnatal period; patients should be monitored for the risk of developing ureteropelvic junction obstruction (UPJO) which requires surgical intervention. We aimed to define independent risk factors for operation in whom diagnosis of UPJO was precisely proven with histopathological evidence.

Methods: Medical files of 155 children (186 renal units) with anteroposterior pelvic diameter (APPD) ≥ 7 mm or ≥ 1SFU (Society of Fetal Urology) grade of pelvicalyceal dilatation were retrospectively investigated. Patients who underwent pyeloplasty and whose pathological examinations of resected ureteral samples confirmed obstruction, were compared to non-interventional group in terms of demographics, serum creatinine, APPD, SFU grade, cortical thickness and diuretic renogram. Multiple regression models were used to predict independent risk factors for pyeloplasty.

Results: 155 patients (186 renal units) were recruited for the study. Pyeloplasty was performed in 50(32.2%) patients. Increased APPD, T1/2 and Tmax values with low parenchymal thickness and DRF were demonstrated in operated patients compared to those who did not. Significant decrease in APPD and T1/2 values and also significant improvement in parenchymal thickness were observed in conservatively managed group. Multivariate analysis revealed high APPD measurements and time activity curve patterns to be associated with significantly increased likelihood of surgical intervention.

Conclusions: There is still an ongoing debate on which screening method should be used for the accurate diagnosis of UPJO or the indications for surgical intervention. Baseline APPD and diuretic renogram curve were found to be significant in predicting surgery for UPJO.