Resident Harvard Medical School / Mass Eye and Ear Otolaryngology–Head and Neck Surgery Boston, Massachusetts
Objective: To understand the benefits of side-firing optical fibers in the endoscopic laser treatment of benign lesions of the larynx. We hypothesize that side-firing optical fibers provide better access to traditionally hard-to-reach locations, e.g., the face of the arytenoid mucosa or the inferomedial aspect of the vocal folds.
Method: We performed a comparative study of four different fiber designs: a traditional forward-looking fiber, and three side-firing fibers that emit light at an angle of 45, 70, and 90 degrees, respectively. The study was conducted in simulation, using eight different 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: The side-firing laser fiber angles of 45, 70, and 90 degrees were found to increase total tissue coverage by [32.18-112.65]%, [58.72-196.68]%, and [67.39-244.44]%, respectively, compared to traditional forward-looking fibers. The variability of ranges can be attributed to the unique larynx anatomies as well as their configuration at the time of imaging.
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.