Effectiveness of Injection Laryngoplasty for Aspiration in Acute Iatrogenic Vocal Fold Paralysis: A Systematic Review.

Objective/hypothesis: To review current evidence on effectiveness of injection laryngoplasty on aspiration outcomes in acute unilateral vocal fold paralysis.

Study Design: Systematic review.

Methods: A literature search was performed on MEDLINE, Embase, Scopus, and the Cochrane Library from inception of each database to May 2019. Inclusion criteria included case series, case-control studies, prospective cohort studies, and randomized controlled trials assessing the outcomes of early injection laryngoplasty on aspiration in unilateral vocal fold paralysis, in the acute setting. Only English articles with adult study populations were included. Two independent investigators screened all abstracts and manuscripts. Data on study design, patient demographics, interventions, and outcome measures were systematically extracted by both authors for included studies.

Results: Fourteen case series studies comprising 582 patients were included. Results were not quantitatively synthesized due to the heterogeneity of outcome measures. Eleven studies reported that a majority (ranging 50%-100%) of patients in each respective study showed improvement in diet intake (progression from nil per os to oral) or Penetration-Aspiration Scale (PAS) scores after injection laryngoplasty. However, none of the investigations used a control group, and therefore, did not account for the possibility of improvement of function related to placebo or Hawthorne effects rather than attributed to intervention.

Conclusions: No robust evidence was found to support injection laryngoplasty as an effective measure to improve aspiration outcomes in acute iatrogenic vocal fold paralysis. Current practices rely on empirical observations and scarce expert opinions. Further prospective investigations with controlled objective measures are necessary to definitively demonstrate the effectiveness of IL for aspiration management. Laryngoscope, 132:813-821, 2022.