Impact of laser enucleation equipment on irrigant flow rate: an in vitro study

Fluid irrigation is critical for adequate visualization during transurethral endoscopic surgery. There is a paucity of data comparing irrigation by resectoscope, working tools, or fluid system. This study aims to measure flow rate through four different resectoscopes with varying working channel configurations and irrigation systems to compare different configurations of clinical equipment used during laser endoscopic enucleation of the prostate (LEEP).

We measured irrigation flow rates through four different sized resectoscopes with three different working channel configurations using five different irrigation systems in a benchtop model. Irrigation was run through each equipment configuration for 30 s in duplicate, and flow rate was calculated.

One hundred measurements were performed in 50 different equipment configurations. From fastest to slowest, resectoscope flow rates were as follows: 28Fr Storz, 26Fr Storz, 26Fr Wolf, and 24.5Fr Wolf (p < 0.0001) with no statistically significant difference seen among the three working channel configurations. From fastest to slowest, irrigation system flow rates were as follows: 150 cm Y-tubing, 150 cm Level-1, 100 cm Y-tubing, 100 cm Level-1, and Thermedx 60 mm Hg (p < 0.0001). Comparing irrigation systems, within group standard deviations were low except in the 100 cm and 150 cm Level-1 systems (SD 53.7 and 56.6mL/min respectively).

Resectoscope irrigation followed the principles of fluid dynamics, with larger caliber scopes providing greater flow independently of working equipment selections. Despite the inconsistencies seen with the Level-1, higher pressure irrigation resulted in faster flow across all equipment configurations. Future studies with larger sample sizes are necessary to understand if these findings are reproducible and clinically impactful.