Abstract

Tarek Ahmed Mahmoud*, Esam El din Salem Morsy, Hany Abd Elraoof Ali Morsy, AbdelmoneimMohammed Abouzeid, Ahmed Mamdouh Abd Elhamed, Elnisr Rashed Mohamed and Hazem Mohamed Elmoghazy

Objective: We aimed to define the best timing for surgical intervention in infants born with antenatal hydronephrosis due to ureteropelvic junction obstruction to minimize the associated renal damage.

Material and methods: We prospectively followed infants born with antenatally diagnosed UPJO presented at our outpatient clinics for evidence of obstructive injury with a standard protocol with ultrasonography and renal scintigraphy. Indications for surgery included progression of hydronephrosis on serial ultrasonographic follow up, initial Differential Renal Function (DFR) ≤35% or >5% loss in subsequent studies, and recurrent Urinary Tract Infections (UTI). Univariate and multivariate analyses were utilized to define the predictors for surgical intervention, while the appropriate cut-off value of the initial APD was determined using the ROC analysis.

Results: Univariate analysis revealed a significant association between surgery, the initial anteroposterior diameter, cortical thickness, society for fetal urology grade, UTD risk group, initial DRF, and recurrent UTI (P-value<0.05). No significant association between surgery and sex or side of the affected kidney (P-value 0.91 and 0.38, respectively). On multivariate analysis, the initial APD, initial DRF, obstructed renographic curve, and recurrent UTI during follow up (P-value <0.05) were the only independent predictors for surgical intervention. An initial APD of 23 mm can predict surgical requirement, with a specificity of 95% and sensitivity of 70%.

Conclusion: For antenatally diagnosed UPJO, the APD value (at the age of 1 week), DFR value (at the age of 6-8 weeks), and occurrence of recurrent UTI during follow-up are significant and independent predictors of the need for surgical intervention. APD, when used with a cut off value of 23 mm, is associated with high specificity and sensitivity for predicting surgical need. Therefore, even bilateral cases can be safely followed using a strict protocol.