Thyroid Surgery (Thyroidectomy)

Thyroidectomy is the removal of part or all of the thyroid gland, under general anaesthesia.

When surgery is needed

1. Thyroid cancer, or suspicion of it. This is an absolute reason to operate.
2. Large nodules. A large nodule can press on the neck and can look disfiguring, even when it carries no cancer risk. A needle biopsy can also miss a small cancer inside a large nodule. For these reasons a nodule over 4 cm can be operated on.
3. An overactive thyroid. The whole gland, or one active nodule, works too hard. If medicine and radioactive treatment do not answer, surgery can be done.

The types of operation

1. Total thyroidectomy. The surgeon removes the whole gland: the right and left lobes, the isthmus in the middle, and the pyramidal lobe that runs upwards.
2. Near total thyroidectomy. The surgeon deliberately leaves 1 to 2 grams of tissue in the thyroid bed. This is done when the voice nerve runs tightly through the thyroid tissue, so that the nerve is not harmed. That amount of tissue cannot work as a gland, so the aim is only to protect the nerve.
3. Subtotal thyroidectomy. More than 1 to 2 grams of tissue is left behind. This is not an accepted technique today, and less experienced surgeons choose it. The remaining tissue is more than in the second method but still cannot produce enough hormone. It must never be used for thyroid cancer, and it should not be chosen for benign disease either.
4. Total lobectomy. The surgeon removes one whole lobe and does not touch the other. This is used when a single nodule is suspicious for cancer. The lobe holding the nodule comes out and the patient is woken. The pathology examination afterwards settles whether it is cancer. If there is no cancer, no further treatment is needed, and the other lobe almost always produces enough hormone, so the patient needs no tablets.
5. Completion thyroidectomy. The rest of the gland is removed in a second operation, when the pathology shows cancer.

The structures the surgeon protects

The nerves. Two nerves from the same root control the vocal cords: the superior and the inferior laryngeal nerve. They govern the movement of the cords for voice and for breathing, and the main one is the inferior laryngeal nerve. There is a pair on each side, four in total. The superior laryngeal nerve controls the quality of the voice and its pitch. These nerves almost always run very close to the thyroid, so the surgeon finds them during the operation and protects them carefully.

The parathyroid glands. These glands release parathyroid hormone, which controls the calcium metabolism of the body. There are three, four or five of them, each about 1 by 1 cm, and they sit close against the thyroid. One surviving gland is enough to keep calcium metabolism going. If all of them are lost, the calcium level in the blood falls severely, and the patient has to take calcium and sometimes synthetic parathyroid hormone.

Frozen section

During the operation the removed lobe, or a suspicious lymph node, can be examined by a rapid pathology method. It tells the surgeon whether the tissue is cancer and helps the surgeon decide how to continue. It is highly accurate but not absolutely certain, so the final answer comes from the full pathology examination.