The functional impact on voice of sternothyroid muscle division during thyroidectomy.

Background: Post-thyroidectomy voice dysfunction may occur in the absence of laryngeal nerve injury. Strap muscle division has been hypothesized as one potential contributor to dysphonia.

Methods: Vocal-function data, prospectively recorded before and after thyroidectomy from two high-volume referral institutions, were utilized. Patient-reported symptoms, laryngoscopic, acoustic, and aerodynamic parameters were recorded at 2 weeks and 3 months postoperatively. Patients with and without sternothyroid muscle division during surgery were compared for voice changes. Patients with laryngeal nerve injury, sternohyoid muscle division, arytenoid subluxation or no early postoperative follow-up evaluation were excluded. Differences between study groups and outcomes were compared using t-tests and rank-sum tests as appropriate.

Results: Of 84 patients included, 45 had sternothyroid division. Distribution of age, gender, extent of thyroidectomy, specimen size, and laryngeal nerve identification rates did not differ significantly between groups. There was a significant predilection for or against sternothyroid muscle division according to medical center. No significant difference in reported voice symptoms was observed between groups 2 weeks or 3 months after thyroidectomy. Likewise, acoustic and aerodynamic parameters did not differ significantly between groups at these postoperative study time points.

Conclusion: Sternothyroid muscle division is occasionally employed during thyroidectomy to gain superior pedicle exposure. Division of this muscle does not appear to be associated with adverse functional voice outcome, and should be utilized at surgeon discretion during thyroidectomy.