Exp Clin Endocrinol Diabetes 2006; 114 - P13_169
DOI: 10.1055/s-2006-933054

Transient voice changes following thyroid surgery and surgical efforts to minimize postoperative dysphonia

TJ Musholt 1, PB Musholt 2, C Fottner 3, J Garm 1, U Napiontek 4, A Keilmann 4
  • 1Gutenberg University Medical School, Endocrine Surgery, Mainz, Germany
  • 2Gutenberg University Medical School, Endocrine Surgery & Endocrinology, Mainz, Germany
  • 3Gutenberg University Medical School, Endocrinology, Mainz, Germany
  • 4Gutenberg University Medical School, ENT and Communication Disorders, Mainz, Germany

While vocal cord paralysis or permanent dysphonia are rare postoperative complications of thyroid resections, transient or subclinical voice changes seem to be more frequent than commonly known.

In a prospective study on 83 patients undergoing thyroid resections (Tx), the pre- and postoperative vocal performance (phonetogram data of speaking and singing voice etc.) was assessed in addition to laryngoscopic vocal cord examination. 27 patients with cervical interventions for primary hyperparathyroidism served as control group (PTx). The personal surgical experience to prevent or minimize postoperative dysphonia is described.

Transient postoperative changes of the mean speaking fundamental frequency were observed in women following Tx only: the pitch dropped from mean 225 to 212Hz (p=0.01).

The singing voice was almost undisturbed following PTx, but was significantly altered in both genders following Tx: in women, the mean highest pitch dropped from e2 to cis2 (657 to 558Hz, p=0.001) accompanied by marked reduction of the maximal sound pressure level (95 to 90 dB, p=0.0002). In male patients, both mean highest and lowest pitch of the singing voice decreased, but to a lesser extent (high 441 to 399Hz, p=0.028; low 85 to 80Hz, p=0.029). The severity of voice alterations did not seem to be related to the extent of the thyroid surgical procedure. In all patients, the observed voice changes resolved within 6–10 weeks after surgery.

Surgical efforts to minimize postoperative dysphonia include: careful dissection of the recurrent laryngeal nerve (RLN); subcapsular ligation of the superior thyroid artery to prevent injury to the superior laryngeal nerve, elaborate hemostasis during surgery; application of a fleece-bound fibrin hemostat covering the RLN to prevent postoperative hematomas. Although damage to the laryngeal muscles is not definitively proven to evoke dysphonia, the surgeon refrains from cutting through the sternothyroid, sternohyoid, and omohyoid muscles.

Following thyroid surgery, subclinical voice changes are commonly observed even in cases of intact RLN neuromonitoring and laryngoscopically intact vocal cord function. Voice professionals may experience temporary voice changes for up to 6–10 weeks.