Comparison of percutaneous nephrolithotomy and retrograde flexible nephrolithotripsy for the management of 2-4 cm stones: a matched-pair analysis

OBJECTIVE Currently, the indications for retrograde intrarenal surgery (RIRS) have been extended due to recent improvements in endoscopic technology. In this study, we compare the outcomes of percutaneous nephrolithotomy (PCNL) and RIRS in the treatment of 2-4 cm kidney stones. MATERIALS AND METHODS Between September 2008 and January 2011, 34 patients who had renal stones ranging from 2 to 4 cm in diameter were treated with RIRS. The outcomes of these patients were compared with patients who underwent PCNL using matched-pair analysis (1:1 scenario). The matching parameters were the size, number and location of the stones as well as age, gender, body mass index, solitary kidney, degree of hydronephrosis, presence of previous shock wave lithotripsy and open surgery. Data were analysed using Fisher's exact test, Student's t test and the Mann Whitney U test. RESULTS Stone-free rates after one session were 73.5% and 91.2% for RIRS and PCNL respectively (P = 0.05). Stone-free rate in the RIRS group improved to 88.2% after the second procedure. Mean operation duration was 58.2 (+/-) 13.4 min in the RIRS group but 38.7 (+/-) 11.6 min in the PCNL group (P < 0.0001). Blood transfusions were required in two patients in the PCNL group. Overall complication rates in the PCNL group were higher, but the differences were not statistically significant. Hospitalization time was significantly shorter in the RIRS group (30.0 + 37.4 vs 61.4 + 34.0 h, respectively; P < 0.001). CONCLUSION Satisfactory outcomes can be achieved with multi-session RIRS in the treatment of 2-4 cm renal stones. RIRS can be used as an alternative treatment to PCNL in selected cases with larger renal stones.