A multivariate assessment revealed three independent factors influencing success rate (p<0.05): stone size (p=0, 03), stone number (p=0, 001), stone location (p=0, 011) and not influencing (p>0, 05): operation history (p=0, 499), using ureteral access sheath (p=0, 555), stone displacement (p=0, 376), angle between infundibula and renal pelvis (p=0, 533).