Categorization of ureteroscopy complications and investigation of associated factors by using the modified Clavien classification system

Background/aim: The purpose of the present study was to review the complications of ureteroscopy (URS) by using the modified Clavien classification system (MCCS) and to investigate the factors associated with complications. Materials and methods: Data regarding 811 patients who underwent URS for ureteral calculus were analyzed. Peroperative and postoperative complications were recorded. The patients were divided into seven groups depending on the severity of the complications. The association of sex, stone size, number, and localization with each MCCS grade was also evaluated. Results: The average age was 45 years. The success of the procedure after one session was 93.5%. Complications were recorded in 57.9% of the patients. According to the MCCS, grade I, II, IIIa, IIIb, IVa, IVb, and V complications were documented in 29.8%, 7.1%, 8.6%, 11%, 0%, 1.2%, and 0% of the patients, respectively. The factors associated with the complications graded by MCCS were sex, stone size, number of stones, and localization. In addition, in multivariate analysis, history of previous surgeries for urolithiasis, orifice dilatation, and instrument size were associated with complications. Conclusion: According to MCCS, sex, history of previous surgeries for urolithiasis, orifice dilatation, size of the instrument, stone size, number of stones, and localization are associated with different grades of complications in URS.