The Effect of Laser Fiber Cleave Technique and Lithotripsy Time on Power Output

Various cleave techniques have recently been shown to significantly impact initial laser fiber power output during holmium laser lithotripsy. The impact of cleave technique on long-term power output has not been well characterized. The purpose of this study was to determine the effect of laser cleave technique on power output over time.

In this randomized single-blinded study, five cleave techniques were tested on two holmium laser fiber diameters (200, 365 μm) over 15 minutes of laser lithotripsy with calcium oxalate monohydrate stones. Comparisons between cleave techniques and fiber diameters were performed using independent samples Mann-Whitney U, Kruskal-Wallis, and homogeneity of variance tests with a significance of p < 0.05.

The 365-μm fiber was more durable and less affected by burnback degradation than the 200-μm fiber (p < 0.05). While initial power output varied between cleave techniques, all significance disappeared by 3 minutes. Power output decreased rapidly by a mean of 0.62 W over 4 minutes (p < 0.05), following which there was no significant change.

These findings confirm that initial laser fiber power output is significantly influenced by cleave technique, and the ceramic scissor is the optimal tool for cleaving between procedures. However, because of rapid fiber tip degradation and power loss, this study argues against routine cleaving to improve procedural efficiency in lengthy ureteroscopy cases.