Injection laryngoplasty outcomes in irradiated and nonirradiated unilateral vocal fold paralysis

Objectives/hypothesis: To evaluate the effect of radiation therapy on voice outcome and duration of effect of calcium hydroxylapatite (CaHA) injection laryngoplasty in unilateral vocal fold paralysis (UVFP) patients.

Study design: Retrospective case series.

Methods: UVFP patients treated with CaHA injection laryngoplasty at the University of California San Francisco Voice and Swallowing Center were identified. Demographic information, history of irradiation to the larynx, and time to additional medialization procedures were obtained. Examinations at presentation and follow-up were analyzed for laryngostroboscopic parameters and CAPE-V scores.

Results: Four nonirradiated and five irradiated patients underwent a total of six and nine injection laryngoplasties, respectively. Time to additional procedures was longer in irradiated patients (P = 0.02). Prior to injection, nonirradiated patients had more severe glottic insufficiency (P = 0.007, 0.002) than did irradiated patients. Postinjection, irradiated patients demonstrated improvement in overall voice quality, breathiness, and loudness, while nonirradiated patients demonstrated improved overall quality, breathiness, pitch, and loudness. Voice quality was not statistically different between patient groups.

Conclusion: CaHA injection laryngoplasty improved voice quality in both irradiated and nonirradiated patients. Nonirradiated patients experience greater vocal improvement compared to irradiated patients. Vocal cord stiffness due to radiation-induced changes may be responsible for the lack of improvement in pitch. Time to additional procedures was longer in irradiated patients and may be secondary to effects of prior radiation on graft resorption. Vocal fold medialization with CaHA injection remains a safe and efficacious treatment for UVFP in both irradiated and nonirradiated patients.