Prognosis of Laryngeal Paralysis Following Thyroidectomy

Abstract

Injury to one or both recurrent laryngeal nerves during operation on the thyroid gland occurs frequently and usually results in paralysis of the vocal cord. When a patient who has sustained such an injury is examined in consultation, questions arise as to whether or not the voice will return to normal, when improvement should begin to become evident and what will be the future status of the laryngeal mechanism.In an effort to answer some of these questions, histories of 504 patients who underwent partial thyroidectomy at the Johns Hopkins Hospital during the past five years were reviewed. In most, but not all, of the cases the larynx was examined by an otolaryngologist both before and after operation. In 32 patients the recurrent laryngeal nerves were injured at operation\p=m-\a minimal incidence of 6.3 per cent. The histories of several other patients whose larynxes had not been examined, recorded a persistent hoarseness following thyroidectomy. These patients were not included in this study. Additional information about the voice and the appearance of the larynx was obtained by reexamination of as many of these 32 patients as could be induced to return to the clinic.Thirty of the 32 patients with injury to the recurrent nerve had partial lobectomy on both sides; from each of the other 2 an adenoma was removed. Local anesthesia (procaine) was used for 5 of these patients ; general anesthesia, for the others. Seventeen had hyperthyroidism; 14, nontoxic goiter, and 1, carcinoma. In 24 the paralysis was unilateral-on the right side in 14 and on the left in 10. In 11 of these 24 patients the nerve was injured on the side on which the lesser amount of thyroid gland was removed. In 8 both vocal cords were paralyzed, either partially or completely. In a patient whose right vocal cord was paralyzed at a previous operation, injury to the left recurrent laryngeal nerve at a second operation resulted in bilateral palsy of the abductor muscles.Respiratory stridor during the operation was noted in only 1 patient, and an examination of the larynx made some days later showed paralysis of only one vocal cord. According to the operative notes, the recurrent laryngeal nerves were seen in only 2 of the 32 patients in whom the nerves were injured. In each case it was the left nerve which was From the