Evaluation of the Patients with Antenatal Hydronephrosis Diagnosed Ureteropelvic Junction Obstruction with the Hydronephrosis Severity Score

Objective: Ureteropelvic junction obstruction is the main cause of obstructive antenatal hydronephrosis. Although surgery is the traditional treatment modality, there is still no consensus on surgical indications. We aimed to analyse the patients referred as antenatal hydronephrosis and diagnosed with ureteropelvic junction obstruction with Hydronehprosis Severity Score that has been developed by Babu at al. Method: The patients who were admitted with antenatal hydronephrosis in 2013-2018 and diagnosed as ureteropelvic junction obstruction and followed up in our clinic for at least one year were evaluated. The cases with unilateral hydronephrosis were included. Those with vesicoureteral reflux, horseshoe kidney, hydroureter, ureterovesical junction obstruction were excluded. Renal ultrasonography and nuclear scintigraphy results were re-evaluated. They were grouped as mild (0-4), moderate (5-8) and severe (9-12) based on scoring of three parameters; differantial renal function, drainage curve pattern and US grade. Clinical outcomes were also classified in three groups; resolution (grade 1-no hydronephrosis), persistance (grade 2-3 hydronephrosis) and surgical intervention. The relation between the scores and clinical outcomes were analysed. Results: A total of 57 patients were evaluated. 2 with horseshoe kidney, 4 with vesicoureteralreflux, 7 with bilateral hydronephrosis, 4 with ureteric outlet obstruction, 12 with incomplete records were excluded. Finally, 28 patients were included. Hydronephrosis was resolved in 4 (14.2%), persisted in 5 (17.8%) and surgical intervention was required in 19 (67.8%) patients. 1/5 patients with mild, 15/20 patients with moderate and 3/3 patients with severe HSS underwent surgery. 77.2% of the patients with a total score of ≥6 initially required surgical intervention at their follow-up. Conclusion: HSS may provide a significant predictive value for surgical intervention for the patients classified as “mild” or “severe” at the initial evaluation. In the “moderate” group, the risk increases in the patients with HSS≥6. Existing data should be evaluated with larger case series.