Seoul National University Bundang Hospital validates light-guided vocal fold injection

A research team led by Professor Cha Won-jae at Seoul National University Bundang Hospital has provided large-scale clinical evidence supporting the safety and efficacy of ‘light-guided vocal fold injection’. The study, which included data from 378 procedures performed on 257 patients with unilateral vocal fold paralysis between October 2020 and February 2024, was published in the journal ‘Otolaryngology–Head and Neck Surgery’.

Unlike traditional methods where it is difficult to observe the needle tip beneath the vocal fold mucosa, the light-guided technique uses a light source and optical fibers to transmit light to the needle tip. This allows clinicians to monitor the needle's position in real-time via an endoscopic screen. The analysis showed that in all 378 cases, the needle tip reached the target accurately without piercing the mucosa or causing misinjection.

Clinical outcomes showed significant improvement in vocal function. Among 180 cases with pre- and post-operative voice metrics, the Voice Handicap Index (VHI-10) score decreased from 34.3 to 25.4 after four weeks, and the maximum phonation time increased from 3.6 to 6.9 seconds. The procedure was also noted for its efficiency, with an average initial injection time of approximately 114 seconds.