The Survival of Flexible Ureterorenoscopes in Terms of the Total Stone Area and Total Usage Time

We investigated the survival of a flexible ureterorenoscope (FURS) in regard to the total stone area (TSA) and total usage time (TUT) to determine the cutoff values for its survival. Data were obtained from 1326 patients who underwent flexible ureterorenoscopy. The stone area and the usage time of the FURS were obtained in each case. The data from each FURS were considered as a group. The TSA was calculated as the sum of the stones for which only one FURS broke, and the TUT was calculated as the sum of the time of use within the body in all cases during the tool's survival. Data from 13 groups of 1258 patients were analyzed in regard to the TSA and TUT. We found a positive correlation of the case number with the TSA and TUT. The Pearson correlation coefficients were 0.983 and 0.937 for the TSA and TUT, respectively (