Abstract
The extent of thyroidectomy in Graves' disease is still controversial. At our institution, we have aimed to achieve long-term euthyroidism without thyroxine replacement therapy, thus, subtotal thyroidectomy has been employed. We prospectively studied whether the surgical outcome was improved by a strategy of leaving smaller thyroid remnants. Between 1989 and 1998, 1897 patients with Graves' disease were treated by subtotal thyroidectomy and their thyroid function was determined 2 to 3 years later. The 10-year trial was divided into three periods: 1989-1991 (Period 1, n=690), 1992-1994 (Period 2, n=587) and 1995-1998 (Period 3, n=620). Different maximum thyroid remnant sizes were prospectively established for each period: up to 7 g left in Period 1, up to 6 g in Period 2 and up to 5 g in Period 3. Thyroid function at 2 to 3 years after thyroidectomy and the occurrence of surgical complications were compared among the three groups. The relapse rate for Period 1, Period 2, and Period 3 was 14.1%, 12.6%, and 10.9%, respectively, and the rate of euthyroidism decreased and rate of hypothyroidism increased from period to period. Surgical complications increased in Periods 2 and 3. For preventing relapse, the strategy of reducing the thyroid remnant is effective. Subtotal thyroidectomy leaving 3 to 4 g remnant tissue is a suitable surgical option for Graves' disease.
