Zhang Y, et al. - In cases having a solitary kidney, experts compared percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for the treatment of lower calyceal calculi with a diameter of 2 to 3 cm. A higher one-session stone-free rate was achieved by the PCNL than retrograde intrarenal surgery (RIRS) in the treatment of lower calyceal calculi within 2-3cm in diameter. Nonetheless, RIRS with less bleeding and shorter postoperative hospital stay could present as an alternative.