Effect of Endoscopic Glottoplasty on Acoustic Measures and Quality of Voice: A Systematic Review and Meta-Analysis.

INTRODUCTION

The voice is an important marker of the transition process to the new gender identity of the transgender person. For 20% of patients seeking voice feminization, voice therapy is not completely satisfactory, and surgery should be considered, with endoscopic glottoplasty being the current practice. While the increase in fundamental frequency (F0) after glottoplasty has been well described, no systematic review of the literature or meta-analysis regarding other acoustic parameters and quality of voice has been performed yet.

OBJECTIVE

To define the effect of endoscopic glottoplasty on acoustic measures and quality of voice by assessing F0, maximum phonation time (MPT), frequency range, and grade of dysphonia.

METHODS

A literature review was performed in Medline/PubMed, Cochrane, Science Direct, LILACS, and Google Scholar, following PRISMA guidelines, with no constraints on publication date. We included studies in English, Portuguese or Spanish that assessed transgender women who underwent endoscopic glottoplasty. All the included articles were measured in terms of their methodological quality.

RESULTS

The PRISMA approach yielded 14 studies, totaling 566 patients. There was significant heterogeneity between studies regarding follow-up time, surgical technique and perioperative care. Thirteen studies were submitted to meta-analysis. The results showed significant changes in pre- to postglottoplasty mean differences of F0 = 78.49 Hz (95%CI: 75.69-81.30), MPT = -1.11 seconds (95%CI -1.67 to -0.54), frequency range = -3.55 semitones (95%CI -5.74 to -1.36) and grade of dysphonia on the GRBAS scale = 0.44 (95%CI 0.27-0.61).

CONCLUSION

Glottoplasty is effective in significantly increasing fundamental frequency, but slightly decreases MPT, frequency range and vocal quality measured by the grade of dysphonia on the GRBAS scale.