Comparison of Complications of Injection Laryngoplasty via Direct Versus Flexible Laryngoscopy.

Objectives: Injection laryngoplasty (IL) is commonly performed for glottic insufficiency and has historically been performed under general anesthesia via direct laryngoscopy (DL), with an increasing number of procedures being performed in the office setting via flexible laryngoscopy (FL). Existing literature regarding complications of IL primarily addresses immediate peri-procedural complications and adverse reactions to the injection material. This is the first study utilizing a large multi-institutional database comparing complications of IL performed via DL versus FL.

Study design: Retrospective database study.

Methods: Patients who underwent IL were queried on the TriNetX Research platform from 2017 to 2024. Patients were stratified by injection approach (DL or FL). The two cohorts were balanced via propensity score matching for age at time of procedure, sex, race, and ethnicity. Diagnoses of dyspnea, stridor, dysphagia, odynophagia, persistent dysphonia, and laryngeal edema were compared between the two groups from the day of the procedure to three months postprocedure.

Results: A total of 6921 and 6832 patients underwent IL via DL and FL, respectively. Patients undergoing IL via DL had higher odds of experiencing dyspnea (OR = 1.375, P = 0.0014), stridor (OR = 4.443, P < 0.0001), and laryngeal edema (OR = 1.782, P < 0.0001), but had improved voice outcomes with lower odds of persistent dysphonia (OR = 0.568, P < 0.0001). Odds of developing dysphagia or odynophagia were comparable between the two cohorts.

Conclusion: IL procedures performed via DL were more likely to be associated with airway-related complications but had better voice outcomes up to three months after the procedure. Future study is needed to better determine the etiology of these complications to improve safety and efficacy.