Comparison of Holmium:YAG and Thulium Fiber Lasers on the Risk of Laser Fiber Fracture.

ABSTRACT

OBJECTIVES: To compare the risk of laser fiber fracture between HoYAG laser and Thulium Fiber Laser (TFL) with different laser fiber diameters, laser settings, and fiber bending radii. METHODS: Lengths of 200, 272, and 365 µm single use fibers were used with a 30 W HoYAG laser and a 50 W Super Pulsed TFL. Laser fibers of 150 µm length were also tested with the TFL only. Five different increasingly smaller bend radii were tested 1, 0.9, 0.75, 0.6, and 0.45 cm. A total of 13 different laser settings were tested for the HoYAG laser six fragmentation settings with a short pulse duration, and seven dusting settings with a long pulse duration. A total of 33 different laser settings were tested for the TFL. Three laser settings were common two both lasers 0.5 J × 12 Hz, 0.8 J × 8 Hz, 2 J × 3 Hz. The laser was activated for 5 min or until fiber fracture. Each measurement was performed ten times. RESULTS: While fiber failures occurred with all fiber diameters with HoYAG laser, none were reported with TFL. Identified risk factors of fiber fracture with the HoYAG laser were short pulse and high energy for the 365 µm fibers (p = 0.041), but not for the 200 and 272 µm fibers (p = 1 and p = 0.43, respectively). High frequency was not a risk factor of fiber fracture. Fiber diameter also seemed to be a risk factor of fracture. The 200 µm fibers broke more frequently than the 272 and 365 µm ones (p = 0.039). There was a trend for a higher number of fractures with the 365 µm fibers compared to the 272 µm ones, these occurring at a larger bend radius, but this difference was not significant. CONCLUSION: TFL appears to be a safer laser regarding the risk of fiber fracture than HoYAG when used with fibers in a deflected position.