Also , the flexible ureteroscope utilization as well as the operative time was significantly decreased in tURSL stone migration subgroup ( 25.5 vs. 72.3 % , P = 0.000 ) , ( 44.96 11.0 min vs. 59.17 9.2 min , P = 0.000 ) with higher SFR after retrograde intrarenal surgery ( RIRS ) ( 96.2 vs. 74.5 % , P = 0.000 ) .