Results
A total of 949 who underwent f-URS and laser lithotripsy between March 2015 and June 2020 were included in the study. Of 949 patients 603 were male and 346 were female with a mean age of 47.2±14.3 (range 2-84 years). Mean stone burden was 102.6±42.2 (48-270 mm2). In Table 1, the comparison of characteristics of stone-free and non stone-free patients was shown. There were significant differences between two groups according to age, previous URS or precutaneous nephrolithotomy (PCNL) history, number of stone, stone density, maximum stone diameter, stone burden, lower calyx localization, preoperative hydronephrosis, preoperative J stent placement, operation time, hospitalization time and complications. All nomograms (RUSS, modified S-ReSC, Ito’s nomogram, R.I.R.S.) were predicted stone-free status (AUCs were 0.689, 0.657, 0.303 and 0.690, respectively) (Table 2). Only the Ito’s nomogram’s ROC curve was below reference line, because the higher score indicates residual stone presence in this nomogram however higher score was predictive of stone-free in others (Fig 1). All scoring systems were predicted complications with AUC values of 0.689, 0.646, 0.286 and 0.664 for RUSS, modified S-ReSC, Ito’s nomogram, R.I.R.S., respectively (Table 3).Although all scoring systems were able to predict complications only Ito’s nomogram was able to predict Clavien ≥2 complications (p=0.016).