Trial of autotransplantation of cryopreserved thyroid tissue for postoperative hypothyroidism in patients with Graves' disease

Abstract

Background: Some patients with Graves' disease who select surgical therapy so they can discontinue antithyroid medication require lifelong levo-thyroxin (l-T4) replacement therapy because of irreversible postoperative hypothyroidism. The aim of this study was to enable the replacement of absent thyroid hormone through autotransplanted thyroid tissue that had been cryopreserved since the initial thyroid operation, and to release these patients from lifelong l-T4 administration.

Study design: At the time of subtotal thyroidectomy for Graves' disease, the surgical specimen was partially cryopreserved at -196 degrees C until it was used for autotransplantation. After obtaining sufficient informed consent, four patients with postoperative hypothyroidism underwent autotransplantation of cryopreserved thyroid tissues. These patients required 50 to 150 microg/day of l-T4 at 1.8, 3.4, 3.5, and 2.8 years after operation. For the transplantation, 2.5 to 3.5 g of cryopreserved thyroid tissue was autotransplanted into the forearm muscle of each patient.

Results: In three of the patients, l-T4 administration could be discontinued and the clinical symptoms of hypothyroidism disappeared because of an improved serum thyroid-stimulating hormone level. Pathologic and immunohistochemical examinations of the thawed cryopreserved tissue demonstrated well-preserved thyroid structure and thyroglobulin-positive follicular cells and colloids, suggesting that the transplanted material was functional. In addition, 123I scintiscanning in patients 1 and 2 indicated an accumulation of radioactive iodine at the transplantation sites. One patient, who was able to discontinue l-T4 administration for 6 months, subsequently required l-T4 again because of recurrent hypothyroidism.

Background: Despite a few remaining uncertainties that must be resolved before this procedure is optimized, autotransplantation of cryopreserved thyroid tissue promises to be a useful therapeutic procedure for treating permanent postoperative hypothyroidism in patients with Graves' disease.