The influence of remnant size, antithyroid antibodies, thyroid morphology, and lymphocyte infiltration on thyroid function after subtotal resection for hyperthyroidism.

Abstract

AbstractThe influence of thyroid remnant size, antithyroid antibody titre, thyroid morphology, and lymphocyte infiltration on postoperative thyroid function was studied in 179 patients undergoing subtotal thyroidectomy because of hyperthyroidism. The surgical procedure was strictly standardized and included determination of the thyroid remnant size. The preoperative medication used was beta‐adrenoceptor blocking agents in 101 patients and antithyroid drugs and thyroxine in 78. With remnant size adjusted to 6–10 g (or, in goiters less than 20 g, to 25–30% of initial gland weight), the overall recurrence rate after 2–8 years (mean 5.3±2.0) of follow‐up was 1.7% and the incidence of thyroid hypofunction was 29.6%.In toxic nodular goiter (TNG; n=63), a significant negative correlation was found between TSH and remnant size after 12 months as well as a significantly lower remnant weight in patients developing postoperative hypothyroidism. In toxic diffuse goiter (TDG; n=116), there was no difference in remnant size between euthyroid and hypothyroid patients. For patients with TDG treated preoperatively with beta‐blockers, the incidence of autoantibodies against thyroid cytoplasm was increased in patients who postoperatively developed thyroid dysfunction. Within the group of TDG developing hypofunction, we found increased titre of autoantibodies and “presence of lymphoid tissue” more often in patients treated preoperatively with beta‐blockers compared to thyrostatics. In toxic nodular goiter, the remnant size was considered the parameter most helpful to the surgeon in predicting postoperative thyroid function.