Alex J. Chiluisa

This paper describes the design, development, and experimental evaluation of a novel steerable optical fiber for endoscopic laser surgery. The proposed device consists of an off-the shelf optical fiber installed into a flexible sheath (outer diameter: 1.6 mm) equipped with a custom distal steering mechanism. Thanks to its compact size, the proposed device can be easily deployed through the instrument channel of most commercially available clinical endoscopes. Among the procedures where we believe the new device could be beneficial, in this paper we focus on laser surgery of the larynx, i.e., the voice box. We report experimental findings, collected in in vitro models (additively-manufactured phantoms), demonstrating that the steerable fiber significantly expands surgical access, thus enabling physicians to address disease in locations that would normally be beyond reach.

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