Vocal Changes Following Thyroid Surgery: Prospective Study of Objective and Subjective Parameters

Objective. Vocal changes are frequent following a surgical procedure to the thyroid gland. Even though they are a recognized morbidity, their bases are yet to be defined as well as their effect on vocal parameters. This study investigates the objective and subjective changes that occur after the surgery. Study design. This study is a prospective analysis of consecutive cases. Setting. This study was conducted in a single-center tertiary care facility. Subjects and methods. Patients programmed for any thyroid procedure in Hospital Universitario Ramon y Cajal were enrolled consecutively to perform the vocal analysis before and after the surgery from April 2014 to April 2016. Patients were divided according to the vocal fold motility, and their vocal and aerodynamic parameters were obtained by means of electroglottography and phonatory aerodynamic system. Patients filled in the 10-item Voice Handicap Index (VHI-10) questionnaire. Statistical analysis was performed comparing vocal and aerodynamic parameters and quality of life before and after the surgery. Results. 218 patients met inclusion criteria and completed the protocol. A total of 86.6% of the sample showed no vocal motility impairment, whereas the rest of the patients showed a paresis or a paralysis. Maximum phonatory time and VHI-10 questionnaire showed a statistically significant difference (P < 0.05) between groups. No differences were assessed regarding other vocal parameters. Conclusions. Efforts are still needed to understand the groundings and magnitude of the vocal changes after a thyroid surgery.