Percutaneous nephrolithotomy vs. robotic pyelolithotomy for large renal stones: an inverse probability treatment weighting analysis

The American Urologic Association (AUA) and the European Association of Urology (EAU) guidelines endorse percutaneous nephrolithotomy (PCNL) for symptomatic stones larger than 20 mm despite significant risks such as bleeding and urosepsis. Robotic pyelolithotomy (RPL) is emerging as an appealing alternative to PCNL, particularly for patients with anatomical variations like pelvic or horseshoe kidneys, malrotation, previous unsuccessful PCNL, and congenital renal anomalies such as ureteropelvic junction obstruction (UPJO). A retrospective observational study was conducted involving patients from Miulli Hospital and A. Gemelli University Hospital between February 2016 and December 2023. Adults with large renal stones, including both pelvic and caliceal stones, who underwent either RPL or PCNL were included. The primary outcome was the Stone-Free Rate (SFR) at 12 months. Secondary outcomes included operative time, estimated blood loss, delta hemoglobin, delta creatinine, hospital stay length, and complications. This study compares the effectiveness and outcomes of PCNL and RPL using Propensity Score-Inverse Probability Treatment Weighting (PS-IPTW) analysis. No statistically significant differences were found in the 12-month SFR between RPL and PCNL, both in the calyceal-pelvic (73.6% vs. 70.6%; P=0.722) and pelvic groups (91% vs. 91.7%; P=1). Complication rates were also similar between RPL and PCNL in both the calyceal-pelvic (15.4% vs. 14.3%; P=0.856) and renal pelvic groups (27.3% vs. 10.8%; P=0.225, with Clavien-Dindo Grade ≥3 complications in 9% vs. 8.9% and 4.4% vs. 0%, respectively. RPL showed significant advantages in operation time in the pyelocaliceal (P<0.001) and pelvic groups (P=0.006), delta creatinine (P=0.018) in the pyelocaliceal group, and hospital stay length in the pelvic group (P=0.011). RPL demonstrated similar success and complication rates compared to PCNL, with significantly lower intraoperative time, delta creatinine rate, and hospital stay length. RPL is a safe, effective, and minimally invasive treatment option, particularly valuable for large renal stones in patients with complex anatomy and those requiring concomitant renal reconstructive procedures.