Management of recurrent hyperthyroidism in patients with Graves’ disease treated by subtotal thyroidectomy

Abstract

If the aim of surgical treatment for Graves' disease is not permanent hypothyroidism, it is difficult to avoid recurrent hyperthyroidism completely. The management of recurrent hyperthyroidism, however, is neither easy nor obvious. Improvement in the sensitivity of TSH assay has allowed the diagnosis of latent hyperthyroidism. Little is known about the clinical course of latent hyperthyroidism. We studied the management and outcome of recurrent hyperthyroidism in patients with Graves' disease treated by subtotal thyroidectomy. Between January 1988 and August 1991, 1115 patients with Graves' disease were treated by surgery. Postoperative thyroid function was evaluated by free T3, free T4 and TSH measurements. One hundred seventy-five patients with suppressed TSH secretion for at least 6 months were categorized as having recurrent hyperthyroidism. Eighty patients (45.1%) also had elevated thyroid hormone levels, (group 1). The remaining 95 patients (54.9%) had normal thyroid hormone levels with suppressed TSH values (group 2). In group 1, 58 patients were treated with antithyroid drug (ATD), 12 with iodine and 10 with radioiodine (RI). Remission of Graves' disease was obtained in 22 patients (11 by ATD, 1 by iodine and 10 by Ri). On the other hand, patients in group 2 were followed up without medication, and spontaneous remission was observed in 21 of theln (22.1%). It was difficult to induce remission of overt recurrent Graves' disease by ATD or iodine. In contrast spontaneous remission could be obtained in some patients with postoperative latent hyperthyroidism.