Causes of damage of single use ureteroscope: a single center 2-year experience

Background Since the evolution of flexible ureteroscopy from being reusable to disposable then reused disposable scopes aimed basically to reduce the cost, this study was conducted to evaluate the causes of reused disposable flexible ureteroscope damage in order to extend its longevity and increase the number of procedures per scope. Patients and Methods: This retrospective study was conducted in a single center between September 2022 and September 2024. Sixty-two reused disposable flexible ureteroscopes after resterilization were used for 202 patients over 235.7 hours. Potential causes of scope damage were observed, recorded and analyzed. Results The observed causes of reused disposable flexible ureteroscope damage were as follows: 32.3% of scopes were damaged by laser fiber related damage (either by sudden withdrawal of fiber during firing or transmitted energy), 27.4% by sustained excessive deflection, 19.4% by scope backloading technique, 9.6% by traumatic ureteral access sheath usage (such as scope withdrawal while deflected over the access sheath and stone fragment lodgment between the sheath and scope) and 11.3% by instrumental working channel damage. On comparing different related causes of damage, fine deflection proved to be superior to excessive deflection (p < 0.001) and access sheath usage proved to be significantly superior to backloading (p = 0.005) while there were no significant difference on comparing laser settings. Conclusion Longevity of su-FURS can be extended through the avoidance of possible causes of damage. The best cost effective practice can be achieved by performing flexible ureteroscopy with avoidance of scope backloading in tight ureter and using of ureteral access sheath, avoidance of excessive deflection by lower calyceal stone relocation and avoidance of in-situ disintegration and insertion of laser fiber in a straight scope before deflection with careful holding of the fiber to avoid its sudden withdrawal while firing inside the scope.