Early vs Delayed Extracorporeal Shock Wave Lithotripsy for Residual Stones After Percutaneous Nephrolithotomy

Residual renal stone fragments remain a common clinical issue following percutaneous nephrolithotomy (PCNL), with reported incidence ranging from 10% to 30%. These fragments may act as a nidus for recurrent stone formation, infection, or obstruction, necessitating further intervention. Extracorporeal shock wave lithotripsy (ESWL) is widely used as a non-invasive treatment option for such residual stones; however, the optimal timing of ESWL after PCNL remains unclear. Early application of ESWL may enhance stone clearance before fragment embedding or encrustation occurs, but it could be associated with increased risk of bleeding or infection due to incomplete renal healing. Conversely, delayed ESWL allows for better tissue recovery but may permit stone growth or persistence of symptoms. This prospective randomized comparative study aims to evaluate the optimal timing of ESWL after PCNL in patients with residual renal stones ≤15 mm. Eligible patients will be randomized into two groups: early ESWL (within 7-14 days after PCNL) and delayed ESWL (after 3-4 weeks). The primary outcome is the stone-free rate at 3 months, while secondary outcomes include complication rates, pain scores, renal function changes, and the need for additional interventions. The results of this study are expected to provide evidence-based guidance on the ideal timing of ESWL following PCNL to maximize efficacy and minimize complications.