COMPARATIVE EFFECTIVENESS OF MINI-PCNL VERSUS ESWL IN PAEDIATRIC RENAL STONES OF 1–2 CM: A PROSPECTIVE RANDOMIZED COMPARATIVE STUDY

Abstract

Background: The incidence of paediatric urolithiasis has approximately doubled over the past 20 years, with a current global prevalence near 50 per 100,000 children. Extracorporeal shock wave lithotripsy (ESWL) is noninvasive but shows reduced efficacy for stones >1 cm and for stones in dependent calyces. Mini-percutaneous nephrolithotomy (mini-PCNL) achieves high stone-free rates (SFR) using 11–20 Fr tracts. Comparative data for 1–2 cm stones in children remain limited.

Objective: To compare the efficacy and safety of mini-PCNL versus ESWL in children with 1–2 cm renal stones.

Methods: We conducted a prospective randomized comparative trial at the Institute of Kidney Diseases, Peshawar, Pakistan (January–December 2024). After institutional review board approval (IKD-2024-01), 120 children aged 3–14 years with a single renal stone of 1–2 cm on non-contrast CT were randomized to mini-PCNL (n = 60) or ESWL (n = 60). The primary outcome was stone-free rate at 3 months, defined by CT as no residual fragment >3 mm. Secondary outcomes included hospital stay, operative time, need for auxiliary procedures, complications (Clavien–Dindo classification), quality-adjusted life years (QALYs), and cost-effectiveness. Analysis was by intention-to-treat; multivariable logistic regression adjusted for age, sex, stone density, and location.

Results: Follow-up was completed for 117 patients (mini-PCNL 60; ESWL 57). Baseline characteristics and imaging were balanced between groups. At 3 months, SFR was higher after mini-PCNL than ESWL (88.3% [53/60] vs 71.9% [41/57]; risk difference 16.4%, 95% CI 2.1 to 30.7; p = 0.021). The advantage of mini-PCNL was most pronounced for lower-pole stones (SFR 94.4% vs 63.5%; p = 0.012). Median hospital stay was longer for mini-PCNL (2.4 ± 0.8 days vs 0.3 ± 0.2 days; p < 0.001). Two or more ESWL sessions were required in 68.4% of ESWL patients. Overall complication rates were similar between groups (mini-PCNL 13.3% vs ESWL 15.8%; p = 0.695). In cost-effectiveness analysis, mini-PCNL was dominant or cost-effective for stones ≥1.2 cm, with an incremental cost-effectiveness ratio of approximately US$1,280 per QALY gained.

Conclusion: In children with 1–2 cm renal stones, mini-PCNL achieved higher stone-free rates than ESWL, particularly for lower-pole and higher-density stones, with comparable morbidity and favorable cost-effectiveness for stones ≥1.2 cm. ESWL remains a reasonable alternative for smaller, nondependent stones in compliant patients.