Benefits of Side-Firing Optical Fibers in Endoscopic Laser Treatment of the Larynx.

Objective: To elucidate potential tissue coverage of side-firing optical fibers in office-based endoscopic laser treatment of larynx, as well as to demonstrate their enhanced ability to address challenging anatomic areas.

Method: We performed a comparative study of four different fiber designs: a traditional forward-facing fiber, and three side-firing fibers that emit light at an angle of 45°, 70°, and 90°, respectively. The study was conducted in simulation, using eight three-dimensional models of the human larynx generated from microtomography x-ray scans. A computer program simulated the insertion of the endoscope into the larynx, and the Möller-Trumbore algorithm was used to simulate the application of laser light.

Results: Side-firing laser fibers increased potential tissue coverage by a mean of 50.2 (standard deviation [SD] 25.8), 73.8 (SD 41.3), and 84.0 (SD 47.6) percent for angles of 45°, 70°, and 90°, respectively, compared to forward-facing fibers. Angled fibers provided access to areas of the larynx considered difficult to address by traditional methods, including the infraglottis, laryngeal ventricle, and right vocal fold.

Conclusion: Simulation results suggest that side-firing optical fibers have the potential to enhance anatomical access during in-office endoscopic laser procedures in the larynx. Further research is needed to better understand the benefits and any potential risks or contraindications of side-firing optical fibers.

Level Of Evidence: NA Laryngoscope, 133:1205-1210, 2023.