Inception of novel equations for estimation of differential renal function changes after successful pyeloplasty in children.

Introduction: Ureteropelvic junction obstruction is the most common cause of pediatric hydronephrosis. Anderson Hynes dismembered pyeloplasty as the standard surgical treatment in such cases.

Purpose: To evaluate and detect factors that affect renal function changes (improvement) after successful pyeloplasty using Tc-99 m Diethylenetriaminepentaacetic (DTPA) renography in children and to predict renal scan changes after successful pyeloplasty.

Methods: This retrospective study was conducted on children ≤ 18 years of age who underwent successful pyeloplasty from May 2018 to May 2022. Pelvic-abdominal ultrasonography and radioisotope scan Tc-99 m DTPA were performed in all patients.

Results: Postoperative group showed a significant increase in renal parenchyma thickness, split renal function, and glomerular filtration rate with a decreased renal pelvis anteroposterior diameter (p < 0.05). There was a significant correlation between each postoperative decrease in the anteroposterior diameter of the renal pelvis and the postoperative increase in parenchyma thickness with the postoperative increase in split renal function. The equation used to detect postoperative split renal function and glomerular filtration rate had a high detection rate.

Conclusions: Pyeloplasty resulted in significant improvements in hydronephrosis, and renal parenchymal changes in association with renal pelvis diameter can predict Postoperative increase in split renal function and glomerular filtration rate.