Abstract

Objective: To compare computed tomography (CT) stone volume and Guy’s Stone Score (GSS) as pre operative predictors of stone free rate (SFR) and early (≤30 day) complications after single tract percutaneous nephrolithotomy (PCNL).
Methods: This prospective, analytic observational study was conducted at Dr Soetomo General Hospital, Surabaya, Indonesia, between 1 March 2024 and 30 June 2025. It included 82 adult patients who underwent single tract PCNL. Stone volume was calculated by ellipsoid formula on Synapse 3D®, anatomical complexity was assessed by GSS I-IV, while the primary outcome was stone-free rate (SFR) and secondary outcome was early complications (PCNL-specific Clavien-Dindo). Mann-Whitney U, χ², and Spearman correlation were used for data analysis.
Results: Sixty one patients achieved SFR (74 %). Median stone volume was 4.91 cm³ (IQR 4.19–5.68) in stone free versus 12.03 cm³ (10.00–13.33) in non stone free cases (p < 0.001). Stone volume correlated strongly and inversely with SFR (ρ= –0.75, p

Key words: percutaneous nephrolithotomy; Guy’s Stone Score; stone volume; stone free rate; Clavien–Dindo complications.