Definition of Thyroidectomy

Thyroidectomy: The surgical removal of part or all of the thyroid gland.

Subtotal thyroidectomy, the more commonly performed operation, involves removal of only a part of the gland. This procedure may be done to:

• Remove a tumor from the thyroid,
• Reduce the mass of a goitrous (enlarged) thyroid gland, or
• Treat hyperthyroidism (excess production of thyroid hormone).

The goal in the case of hyperthyroidism is to leave just enough thyroid tissue to make a normal amount of thyroid hormone. If too much thyroid is removed, the patient will produce too little thyroid hormone (hypothyroidism) and need treatment to return the thyroid status to normal (euthyroid) status. The possible complications of thyroid surgery include vocal cord paralysis and accidental removal of the parathyroid glands (located behind the thyroid gland), resulting in low calcium levels (the parathyroid glands regulate calcium).

Subtotal thyroidectomy is appropriate in some people with hyperthyroidism, especially those with a large goiter, and it may also be indicated in cases with a coexistent thyroid nodule whose nature is unclear. The patient is treated with an antithyroid drug until euthyroidism has been achieved and inorganic iodide is also usually administered for seven days before surgery to "cool down" the overactive thyroid gland. In surgical centers with the most experience, hyperthyroidism is cured in more than 98% of cases with low rates of complications. Surgery is more costly than nonsurgical therapy of hyperthyroidism (with an antithyroid drug or radioactive iodine).

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=5783
Last Editorial Review: 11/26/2000