Assessment of Survival and Function of Heterotopic Auto-transplanted Thyroid Tissue after Total Thyroidectomy for Non-toxic Multinodular Goiters

Background/Objective:Limited animal and human studies have shown function, albeit inadequate, of implanted thyroid tissue in muscles. This work aimed to ascertain results in a larger number of patients, finding practical method for implantation, studying the effect of changing weight of implant and effect of passage of time on its function. Method: Forty patients had total thyroidectomy for simple multinodular goiters. A piece of the excised gland was finely minced, mixed with saline as emulsion, and injected in thigh muscles. Twelve patients had 5-g implants, while 28 patients had 10-g implants. Four parameters were studied at 2 months, 6 months, and 12 months: technetium isotope uptake by the implant; thyroid stimulating hormone (TSH); free T3 (FT3); and free T4 (FT4). Results: All auto transplanted thyroid tissue survived and functioned. After 12 months, mean values (_ standard deviation) of isotope uptake, TSH, FT3, and FT4 of the 5-g implants were 0.44 _ 0.16%, 27.74 _ 30.4 UI/mL, 3.07 _ 1.10 pg/mL, and 1.01 _ 0.3 ng/dL, respectively. Those for the 10 g implants were 0.71 _ 0.20%, 22.78 _ 19.7 UI/mL, 3.92 _ 1.2 pg/mL, and 1.05 _ 0.3 ng/dL, respectively. Ten-gram implants showed significantly higher isotope uptake than 5-g. TSH, FT3, and FT4 significantly improved over the period of 1 year.

Conclusion: Injection of thyroid tissue suspension is a simple method for thyroid auto transplantation. TSH was elevated in the majority to maintain normal or near normal thyroid hormones. Ten-gram implants showed higher isotope uptake than 5-g, although this difference was not reflected by thyroid hormone profile. The implant seemed to function better with the passage of time from 2 months to 12 months.