Objectives: To evaluate the clinical reliability and efficacy of a novel endoscope protection system (EPS) against direct laser energy damage during ureteroscopy.
Methods: We performed an in vivo evaluation of a novel EPS prototype that uses optical feedback from the digital sensor of the Invisio Digital Flexible Ureteroscope (DUR-D) to terminate laser energy on retraction of the fiber. We evaluated 20 consecutive patients undergoing flexible ureteroscopy. In each patient, the laser was retracted into the ureteroscope 4 times during active firing using a fast pull (5 cm/s) and a slow pull (2 cm/s) with the ureteroscope straight and flexed. We documented whether the EPS activated, whether the laser shut down properly, and the length of fiber projecting from the ureteroscope at laser shutdown.
Results: The EPS was 100% effective in shutting down the laser before entry into the ureteroscope in all trials (80/80). The mean length of fiber showing from the tip of the ureteroscope at shutdown was 1.55 mm (range 0-2.5) when the ureteroscope was straight and 1.28 mm (range 0-2.0) when it was flexed. EPS laser shutoff occurred in 50% (10/20) of the cases when the laser fiber was still outside the ureteroscope. One DUR-D ureteroscope was damaged during the trial from mechanical damage.
Conclusions: In this clinical evaluation, the novel EPS was highly effective and reliable. No energy-based ureteroscope damage was noted with slow and rapid retractions of the activated laser into the ureteroscope. The EPS can be used to complement, rather than replace, the standard safe laser technique.