Postoperative endocrine function in patients with surgically treated thyrotoxicosis.

Abstract

Endocrine function after surgery for thyrotoxicosis is difficult to predict. The operative morbidity and long-term thyroid function of patients surgically treated for thyrotoxicosis is presented, and factors postulated to affect long-term function are correlated with outcome. The clinical records of 289 consecutive patients who underwent surgery for thyrotoxicosis were reviewed. Indications for surgery, intraoperative findings, postoperative complications, and endocrine status 1, 2, and 5 years after surgery were analyzed. Sex, age, duration of medical treatment, weight of thyroid removed and preserved, and antimicrosomal/antithyroglobulin antibody status were correlated with outcome 5 years after surgery. The incidence of permanent recurrent laryngeal nerve injury and hypocalcemia were 0.7% and 1.7%. The cumulative hypothyroid and hyperthyroid rates for the first, second, and fifth postoperative years were 13.8% and 3.5%, 14.5% and 4.8%, and 15.6% and 8.0%. All the prognostic variables analyzed did not achieve a significant correlation with outcome at 5 years by univariate and multivariate age- and sex-adjusted relative risk. Failure from hypothyroidism develops early; recurrent hyperthyroidism increases with the number of years of follow-up. Patients undergoing subtotal thyroidectomy warrant long-term follow-up because of the inability to accurately predict postoperative function with consistently reliable prognostic factors.