Voice quality after transoral CO 2 laser microsurgery (TOLMS): systematic review of literature

Purpose: Transoral laser microsurgery (TOLMS) with carbon dioxide is a safe approach for laryngeal carcinoma. In literature there are three main methods for evaluating speech outcomes: acoustic and aerodynamics analysis, perceptual evaluation and patient-reported outcomes (PROs). The aim of this study was to systematically review the literature about the voice quality outcomes of TOLMS according to type of cordectomy. Methods: A systematic literature review was performed and all the results until December 2021 were extrapolated. We evaluated the acoustic and aerodynamics parameters (fundamental frequency, harmonics to noise ratio, jitter, shimmer and maximum phonation time), perceptual data (GRBAS scale) and patient-related outcomes (VHI scale). Results: 24 studies met the inclusion criteria for a total number of 1207 patients enrolled. The number for each type of cordectomy are: 287 type I (23.78%), 311 type II (25.78%), 328 type III (27.14%), 129 type 4 (10.69%) and 152 type V (12.60%). Patients are grouped according to the type of cordectomy in: limited cordectomy (type I and II) and extended cordectomy (types III-IV-V). The difference between two groups is statistically significative in terms of acoustic analysis, perceptual data and patient-related outcomes (p < 0.05). Conclusions: Patients who underwent type I or II cordectomy have significantly better quality of voice in terms of VHI, perceptual voice quality evaluations and acoustic parameters compared to type III, IV and V cordectomies. The effect of TOLMS on the voice should depend from the extent of the resection and in particular from the scar of the vocal muscle.