Thyroid and Parathyroid Dysfunction after Total Laryngectomy

Background: The proximity of the thyroid and parathyroid glands to the larynx puts them at risk in treatment of squamous cell carcinoma of this region. Hypothyroidism and hypoparathyroidism are of the complications that follow treatment of various head and neck cancers. Aim of Work: To assess the incidence of hypothyroidism and hypoparathyroidism after total laryngectomy. Patients and Methods: Parathyroid and thyroid gland functions were evaluated in 40 patients who were diagnosed as T3, T4 cancer larynx who were treated with total laryngectomy with thyroidectomy with or without postoperative radiotherapy. It is a prospective analytic study. Serum T3, T4 TSH and total calcium levels were performed in those patients before and after total laryngectomy and were repeated one month later. The association of hypothyroidism and hypoparathyroidism were analyzed against several patient parameters including tumor and treatment characteristics. Results: Study included 40 patients who were treated with total laryngectomy with thyroidectomy with or without postoperative radiotherapy. Twenty five patients (62.5%) had hypoparathyroiism proved by hypocalcemia 1 week postoperative. While 4 patients (10%) had hypothyroidism 1 week postoperative and 3 patients (7.5%) had only high TSH. After 1 month 6 patients (15%) continued to have hypoparathyroidism, and 8 patients (20%) had hypothyroidism. Conclusion: Thyroid and parathyroid dysfunction are common complications after total laryngectomy specially if combined with radiotherapy. They should be anticipated and treated promptly.