Vocal quality impact of thyroidectomized patients underwent inferior laryngeal nerves monitoring.

OBJECTIVE: The present study's goal was to estimate the inferior laryngeal nerves monitoring impact on patient's vocal quality after thyroidectomy in head and neck surgery training program. METHODS: Eighty-five patients were evaluated, mean age 48,19 yrs., with no thyroid hormone dysfunctions. They were randomly distributed into two groups. Forty patients were operated on without nerve monitor (Group A) and other 45 with nerve monitor (Group B). The groups were controlled by gender, age, tobacco use, thyroid volume, surgery extent, post-op hypoparathyroidism, malignancy and laryngeal trauma. The patients went through perceptive evaluation and acoustic vocal analysis, before and after surgery (1st and 4th week). The same group of head and neck resident surgeons operated on all patients. RESULTS: In perceptive evaluation, only breathiness (4th week), showed significant difference between the groups (25% in Group A vs. 6.7% in Group B, p = 0.041). However, when the patients were compared with themselves, evaluating the status before versus after surgery, none of the parameters, not even breathiness, showed any significant difference. In vocal acoustic analysis, no significant difference was observed. Fundamental frequency (Hz) in women was 202.62 (before surgery), 198.19 (1st-week) and 191.90 (4th-week) in Group A, and 193.48 (before surgery), 190.63 (1st week) and 186.81 (4th week) in Group B. CONCLUSION: At the present study, there was no impact, neither improvement nor worsening, in vocal quality of patients submitted to thyroidectomies with inferior laryngeal nerves monitoring. LEVEL OF EVIDENCE: Level 1.