An Easy Risk Stratification to Recommend the Optimal Patients with 2-3 cm Kidney Stones to Receive Retrograde Intrarenal Surgery or Mini-percutaneous Nephrolithotomy

To create an easy risk stratification to recommend the optimal subset of patients with 2-3 cm kidney stones to receive retrograde intrarenal surgery (RIRS) or mini-percutaneous nephrolithotomy (MPCNL). A retrospective patient cohort was reviewed and compared (RIRS, n = 147 and MPCNL, n = 129). Overall, RIRS group obtained a lower SFR (66% vs. 93.3%, p < 0.001) compared to MPCNL group. The RIRS group had more overall complication (12.2% vs. 8.5%) and more urosepsis (2.7% vs. 1.6%) than the MPCNL group, although there was no statistical significance. However, two patients in MPCNL group underwent embolization to treat perioperative bleeding. On multivariate analysis for RIRS group, lower calyx involved [OR 2.67], multiple calyces [OR 4.49], severe hydronephrosis [OR 2.38] were three significant predictors of SFR, which decreased from 88.8%, 70.3%, 52.1% to 25% corresponding to patients with 0, 1, 2, 3 risk predictors, respectively (p = 0.008), with a good predictive accuracy (AUC = 0.657; p = 0.002). When patients with no risk factor and patients undergoing RIRS had a similar high SFR and no possibility of bleeding, compared to matched patients undergoing MPCNL. Although generally RIRS showed a lower SFR for 2-3 cm stones compared to MPCNL, our easy risk stratification can recommend the optimal subset of patients with 2-3 cm kidney stones to receive RIRS or MPCNL. When these patients with no above-mentioned risk factors, RIRS can be first considered as an alternative to PCNL because it might be potentially less invasive and achieve a similar very high stone-free rate.