The Study of The Secrets of The Flexible Ureterorenoscopy for The Longer Survival of the Flexible Ureterorenoscopes

Abstract Purpose The aim of the study was to investigate whether the durability of the f-URS will be affected due to the volume and location of the stone and some anatomical features of the including infundibulopelvic angle(IPA), and location anomalies. Materials and Methods The collected data from705 patients’ data including their age, sex, stone location, and stone volume,S-ReSC score, Hounsfield unit(HU) as stone density,IPA, BMI, and the usage time off-URS by using 10f-URS were included to study. Exp(B) values and confidence intervals(95%CIs) of parameters were calculated with COX regression and Roc curve analysis was also used to determine the cut-off value. Results Renal malformation, DJ stent use, previousESL application, and UAS use did not affect contrary to expectations stone volume, HU, IPA, and S-ReSC score were among the factors statistically significant affecting the durability of the device. It was observed, Exp(B)values ​​of the affecting factors to be0.984, 0,268, 0.894, and0.607, respectively. we found the most appropriate cutoff value for IPA as41.25 degrees. Conclusion The mean stone volume broken by each of the subsequent f-URS may increase, while the mean operative time may decrease as time progresses. This result shows us the importance of mastery of the device, such as the deflection maneuver, and the correct use distance of the laser, which improves with the increase in user experience, and makes us interpret that the operation time is shortened with this self-confidence. Factors including stone volume,HU,IPA,S-ReSC score affect the durability of thef-URS device and the as well as manufacturing features.