Super multiple-tract minimally invasive percutaneous nephrolithotomy in one stage for treating complex renal stones: an initial experience.

Background: Complex kidney stones usually require multi-tract percutaneous nephrolithotomy (PCNL) to remove the stone completely. The aim of this study was to evaluate the clinical feasibility and safety of super multiple-tract (≥ 5 tracts) minimally invasive percutaneous nephrolithotomy (Mini-PCNL) in one stage for treating complex renal stones.

Methods: From March 2019 to August 2023, the perioperative clinical data of 35 patients who underwent super multiple-tract Mini-PCNL for complex kidney stones in our institution were collected and analyzed, retrospectively.

Results: A total of 35 patients were included in this study. The mean stone size and volume were 78.9 ± 22.8 mm and 13792.4 ± 5509.3 mm³, respectively. The mean S.T.O.N.E. score was 10.8, including 21 patients (60.0%) with scores ≥ 11. The average Guy's stone score was 3.5. The mean number of percutaneous tracts was 6.3 (range, 5-13). The average surgery time and length of hospital stay were 149.8 min and 3.4 days, respectively. The mean serum creatinine level declined by 6.5 mol/L (P = 0.518) and the mean hemoglobin drop was 24.9 g/L (P < 0.001). The postoperative complication rate was 25.7%, including one case of severe complication (Clavien grade IV). The mean follow-up time was 3.5 months, and the average glomerular filtration rate declined by 1.1 ± 8.7 ml/min (P = 0.463). The stone free rate was 82.9% after one- stage super multiple-tract Mini-PCNL.

Conclusion: When performed by experienced urologists, super multiple-tract Mini-PCNL for treating some complex renal stones in one stage is feasible and safe in enhancing the stone-free rate.