Login to Access Video or Poster Abstract: MP50-05
Sources of Funding: None

Introduction

Holmium:YAG laser is the most used laser for urolithiasis treatment. As recommended in the literature, we use metallic scissors to cut the fiber tip in order to restore its effectiveness._x000D_ Many cleaving methods have been described to avoid the fiber damage and to restore its greatest power such as metallic surgical scissors, scalpel, ceramic scissors or strippers. The aim of this study was to compare different methods of cleavage in order to improve the use of the laser in endo-urology.

Methods

New single use 272µm fibers (Rocamed®) were used with the MH01-ROCA FTS30W (Rocamed®) lithotripter. Five different kinds of fiber tip were compared: a new intact fiber, cleaved with ceramic scissors, cleaved with metallic scissors, first cleaved with ceramic scissors then stripped and first stripped then cut with ceramic scissors (Figure 1A-1B). The fibers were used against synthetic stones, with fragmentation and dusting settings. We measured power output at 0, 1, 5, 10 and 15 minutes and evaluated the laser beam after 1 minute (Figure 1C).

Results

At t0, all the fibers had less than 7.5W. For fragmentation parameters (Figure 2A), there was a statistical difference between the 5 groups at 0 minutes (p=0.042) and 1 minute of laser use (p=0.042). After 1 minute of laser use, there was no statistical differences between the 5 groups. For dusting parameters (Figure 2B), there was a statistical difference at 0 minutes (p=0.022). At the 1-minute analysis and after, all the results were not statistically different. _x000D_ Laser fibers are made with two layers of silica with different refractive indices, which allow the light to travel along the fiber until the fiber tip. When the interaction of the two layers of silica is damaged, as in lithotripsy, or after cleaving the fiber, the energy leaks through the fissures and the power output is decreased.

Conclusions

Cleaving the fiber tip may restore its effectiveness to the fiber but, as we demonstrated, only for a limited time. Though, cleaving the fiber tip may preserve the scopes from damages._x000D_

Funding

None