Role of Ultrasonography and Dynamic Renal Scintigraphy Parameters in Decision Making Regarding Performance of Pyeloplasty in Children with Ureteropelvic Junction Obstruction

Abstract

Objective: There are conflicting results regarding the time of surgical treatment in patients with ureteropelvic junction obstruction (UPJO). Therefore, we aimed to compare the predictive power of ultrasonography (USG) and dynamic renal scintigraphy parameters in the diagnosis and treatment of UPJO. Material and Methods: Patients diagnosed with UPJO between 2015 and 2020 were evaluated retrospectively, other congenital urinary anomalies were excluded. Renal pelvis anteroposterior diameter (APD) was evaluated by USG and staged according to the Society for Fetal Urology grading system. In dynamic renal scintigraphy, time to reach maximum renal activity (Tmax), time to clear half of the maximum activity (T1/2), differential renal function, and diuretic response were recorded. Results: A total of 59 patients were included. Thirteen of 59 (22.0%) patients underwent pyeloplasty. The frequency of high-grade hydronephrosis and renal pelvis APD was higher in the pyeloplasty group than in the non-pyeloplasty group. In addition, Tmax and T1/2 were significantly longer in the pyeloplasty group than in the non-pyeloplasty group (p<0.010). Binary logistic regression analysis revealed that only increased renal pelvis APD was independently associated with pyeloplasty (p = 0.030; odds ratio = 1.2). An APD of 21.5 mm was the best cutoff value to identify patients requiring pyeloplasty. The sensitivity and specificity were 84.0% and 87.0%, respectively Conclusion: Our findings suggest that USG and dynamic renal scintigraphy are useful tools for determining whether to perform pyeloplasty in patients with UPJO. Furthermore, APD can be a reliable, easy, and inexpensive method for follow-up and treatment.