Impact of hydronephrosis grade on surgical parameters and stone-free rates in prone percutaneous nephrolithotomy: a...

To assess the effect of hydronephrosis (HN) grade on operative parameters, complication rates, and stone-free rates (SFR) in patients undergoing prone percutaneous nephrolithotomy (PCNL) performed under a standardized surgical protocol.

This retrospective study included patients who underwent prone PCNL between January 2021 and June 2024. Patients with bilateral stones or anatomically abnormal kidneys were excluded. HN grade was determined by ultrasonography and confirmed with non-contrast computed tomography. Operative parameters, including operative time, number of accesses, hemoglobin drop, transfusion requirement, hospital stay, and complications, were compared among mild, moderate and severe HN groups.

A total of 327 patients were retrospectively screened. After applying the exclusion criteria, 242 patients who underwent prone PCNL between January 2021 and June 2024 were included in the final analysis. The mean age was 51.4 ± 13.9 years. HN was mild in 40.5 %, moderate in 37.6 %, and severe in 21.9 % of patients. Operation time increased significantly with HN grade (p=0.001), while other parameters including SFR (p=0.521) and complication rate (p=0.760) showed no significant differences. Operation time was the only independent predictor of stone-free status (p<0.001). Subgroup analysis according to median stone burden demonstrated that the association between HN grade and operative time persisted only in patients with lower stone burden (≤5.69 cm³, p=0.010), whereas this relationship was not significant in patients with higher stone burden (>5.69 cm³, p=0.052).

HN grade does not significantly affect surgical success or complication rates after prone PCNL, although higher grades were associated with longer operative times. HN grade alone should not be considered a limiting factor for achieving complete stone clearance. However, stone burden may be a more important determinant of operative complexity in patients with higher stone burden.