Retrograde Intrarenal Surgery Versus Percutaneous Nephrolithotomy in the Management of Lower-Pole Renal Stones with a Diameter of 15 to 20 mm

Purpose: To compare the outcomes of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for 15 to 20 mm lower-pole (LP) renal calculi by evaluating stone-free rates and associated complications. Patients and Methods: The records of 79 patients who underwent either PCNL (n = 42) or RIRS (n = 37) by standard techniques for 15 to 20 mm LP renal calculi were reviewed retrospectively. Results: In the PCNL group, the stone-free rate was 92.8%(39/42 patients); this rate increased to 97.6% after a second intervention (shockwave lithotripsy in one and RIRS in one). After a single RIRS procedure, 33 of 37 (89.2%) patients were completely stone free. Two patients needed an additional procedure (rigid ureteroscopy in one and RIRS in one), after which they were all completely stone free, resulting in an overall success rate of 94.6%. Two patients had asymptomatic residual fragments <7 mm in the LP of the kidney, and these patients had been followed with ultrasonography of the kidney. For complications, there were minimal differences in both procedures, except for hemorrhage (necessitated transfusion) in three patients who were treated with PCNL. The overall stone-free rates and complication rates for PCNL were higher, but the differences were not statistically significant. Operative time was significantly longer in the RIRS group, and postoperative hospital stay was significantly longer in PCNL group. Conclusion: PCNL and RIRS are safe and effective methods for medium-sized LP calculi. For selected patients, RIRS may represent an alternative therapy to PCNL, with acceptable efficacy and low morbidity.