Impact of laser fiber tip cleavage on power output for ureteroscopy and stone treatment.

Abstract

Holmium:YAG laser is the most used laser for urolithiasis. Generally, we use metallic scissors to cut the fiber tip to restore its effectiveness. Many cleaving methods have been described to avoid fiber damage and to restore its greatest power to the fiber. There is a lack of information regarding which cleaving method should be used and its effect on the fiber. In order to compare these effects, we studied different cleavage methods in terms of power output and its effects on the fiber. New single-use 272-μm fibers were used with a holmium:YAG laser lithotripter. Five kinds of fiber tips were compared: a new intact fiber, cleaved with ceramic scissors, cleaved with metallic scissors, first cleaved then stripped and first stripped then cleaved. The fibers were used against synthetic stones (BegoStone®) similar to calcium oxalate monohydrate, with fragmentation (SP, 5Hz, 1.5J) and dusting (LP, 15Hz, 0.5J) settings. We measured power output at 0, 1, 5, 10 and 15min. For fragmentation parameters, there was a statistical difference between the 5 groups at 0 and 1min of laser use (p<0.05) and none for time period over 1min (p=0.077-0.658). For dusting parameters, there was a statistical difference between the 5 groups at 0min of laser use (p<0.05) and none for time period over 0min (p=0.064-1). Cleaving the fiber tip may restore its effectiveness to the fiber, but only for a limited time, although it may preserve the scopes from damage.