Sequential defunctionalization followed by thyroxine supplementation as preoperative preparation of hyperthyroid patients undergoing thyroidectomy.

BACKGROUND: Preparing hyperthyroid patients for thyroid surgery with a combination of antithyroid drugs and thyroxine has long been controversial because this combination usually results in only partial inhibition of thyroid function. We therefore used large doses of antithyroid drugs to completely inhibit the synthesis of thyroxine and render the thyroid gland defunctionalized. We then administered physiologic doses of thyroxine to inhibit thyroid-stimulating hormone secretion. We have named this treatment "sequential thyroid defunctionalization followed by thyroxine supplementation." METHODS: Four hundred and seventy-one hyperthyroid patients seen at our hospital were divided into experimental and control groups. The control group was treated preoperatively with antithyroid drugs and iodine preparation. The experimental group was further divided into four subgroups and treated with "sequential thyroid defunctionalization followed by thyroxine supplementation". Each of the four subgroups received different doses of antithyroid drugs and thyroxine for differing time periods. Thyroid function was assessed at each stage of treatment, as were operative blood loss volumes and postoperative complications. RESULTS: Compared to the control group, the four experimental groups showed less thyroid congestion and surface varices at surgery. Patients in subgroup A also had thyroid glands that were almost histologically normal. The mean operative blood loss volume of the experimental group was less than that of the control group (326 +/- 163) ml in the control group; (196 +/- 57) ml in subgroup A; (230 +/- 71) ml in subgroup B; (240 +/- 80) ml in subgroup C; and (312 +/- 97) ml in subgroup D). The postoperative complication rate of the experimental group was 8.64% (21/243) whereas that of the control group was 17.54% (40/228). CONCLUSIONS: Sequential thyroid defunctionalization followed by thyroxine supplementation is effective in reducing the bleeding volume and postoperative complication rate in selected hyperthyroid patients undergoing thyroidectomy.