Efficacy of Injectable Laryngoplasty With Hyaluronic Acid and/or Calcium Hydroxyapatite in the Treatment of Glottic Incompetence. Systematic Review and Meta-analysis

Background: Injectable laryngoplasty with hydroxyapatite and hyaluronic acid is frequently used for the treatment of glottic incompetence. The effectiveness of these substances is controversial due to the heterogeneity of studies.

Objectives: To evaluate the effectiveness of the treatment for glottic incompetence using hydroxyapatite and hyaluronic acid.

Study design: Systematic review and meta-analysis.

Data sources: MEDLINE, PUBMED, LILACS, SCOPUS, EMBASE, Cochrane, clinicaltrials.gov, published and unpublished trials, Web of Science.

Eligibility criteria: Studies that evaluated vocal fold function before and after 4-6 weeks and 6 months of hydroxyapatite and hyaluronic acid injection in adults with glottic incompetence.

Exclusion criteria: studies with outcome, follow-up time or type of intervention outside the predetermined pattern or systematic review and meta-analysis.

Synthesis of methods: Primary outcome - Maximum Phonation Time. Secondary outcomes - Voice Handicap Index (VHI)-30, Parameters G and B of GRBAS Scale. Outcomes were analyzed for mean differences with the corresponding 95% CI.

Results: Six hundred forty-four studies identified, 12 included (5 CaHA; 6 HA; 1 HA and CaHA). After 4-6 weeks the mean difference were: MPT (+5.86), IDV (-39.32), G (-1.14), and B (-1.46). After 6 months: MPT (+5.97), IDV (-30.13), G (-1.33), and B (-1.33).

Limitations: Studies comparing injectable drugs are small, as well as the number of patients in each one, making the isolated comparison of substances difficult.

Conclusions and implications: There is an evidence that the injectable substances HA and CaHA are effective in the treatment of glottic incompetence, however, it is important that more studies are carried out comparing the two substances.