Propensity Score-Matched Analysis Comparing Retrograde Intrarenal Surgery with Percutaneous Nephrolithotomy for Large Stones in Patients with a Solitary Kidney

Purpose: To evaluate the clinical efficacy, safety, and cost of retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) in the treatment for large renal stones in patients with a solitary kidney. Patients and Methods: In this study, 117 patients with a solitary kidney who had undergone PCNL or RIRS for renal stones larger than 2 cm between January 2010 and December 2016 were retrospectively evaluated. The patients' demographic data, clinical characteristics, and perioperative outcomes were collected through a review of their medical records. Forty-three patients treated with PCNL were compared to 43 patients treated with RIRS by propensity score-matched analysis. The stone-free rate, retreatment rate, complication rate, and efficacy quotient (EQ) were assessed in both groups. Results: Initial stone-free rate of the PCNL group after a single procedure was significantly higher compared with the RIRS group (74.42% vs 34.88%, p < 0.001), whereas there was no significant difference in the final stone-free rate after repeated procedures (90.70% vs 88.37%, p = 0.713). PCNL had a significantly lower retreatment rate than RIRS (16.28% vs 63.79%, p < 0.001), and the PCNL group underwent fewer procedures than the RIRS group (p < 0.001). Thus, PCNL group had a higher EQ (78.00% vs 53.52%). Although cost per procedure of PCNL was significantly higher compared with RIRS (p < 0.001), the total costs were comparable. Complication rate of RIRS was lower compared with PCNL with no statistical significance (p = 0.193), and acute kidney injury rates were also comparable (PCNL vs RIRS: 13.95% vs 6.98%, p = 0.533). Conclusions: With fewer repeated surgical procedures, higher EQ, and comparable total costs, PCNL is recommended as the first choice for the treatment of large renal calculi in patients with a solitary kidney. As for specific indications such as anticoagulant drugs, RIRS is a safer choice with fewer complications and acceptable final stone-free rate.