What effect do different 200 μm laser fibres have on deflection and irrigation flow rates in a flexible ureterorenoscope?

The objective of the study is to evaluate the reduction in flow and scope deflection of four leading 200-μm marketed laser fibres (Boston Scientific Flexiva™ 200, Boston Scientific Flexiva™ Trac Tip 200, Lumenis SlimLine™ EZ200 and Optical Integrity ScopeSafe™) via a flexible ureterorenoscope. A laboratory-based bench test was performed using a Flex X2™ flexible ureterorenoscope. Mean upward/downward deflection angles and flow rates (ml/min) for each fibre were calculated and compared to a control. The Optical Integrity ScopeSafe™ fibre has the least loss of deflection, losing only 8 % upward and 6 % downward deflection. Deflection loss was significantly less with this fibre compared to all other fibres (p < 0.0001). Mean flow rates were significantly greater with the Optical Integrity ScopeSafe™ laser fibre at 23 ml/min (p < 0.0001). Despite all fibres marketed as 200 μm, the deflection and flow properties show marked variations. The Optical Integrity ScopeSafe™ 200-μm laser fibre offers the best overall performance with significantly improved flow rates and the least loss of scope deflection.