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| The butterfly-shaped thyroid gland, shown in pink here, sits atop the trachea (windpipe). |
Anatomy and physiology The thyroid gland sits in the middle of the neck atop the windpipe. The butterfly shaped gland has two lobes: a left
lobe and a right lobe. The thyroid gland makes and secretes thyroid hormone. Thyroid hormone is involved in maintaining the
body's metabolism. The most common reason patients are
referred for thyroid surgery is after evaluation for a thyroid nodule. Thyroid nodules are fairly common particularly in women.
Because nodules are so common, further evaluation is warranted only after the nodule reaches a certain size, 1cm. A fine needle
aspiration, which is performed in the office under local anesthesia, is the first step in diagnosis. A needle and syringe
is inserted through the skin into the nodule to extract some cells for analysis. If the biopsy results come back as cancer
or possible cancer, then thyroid surgery will be recommended. Surgery
may also be recommended for a goiter, which is essentially an enlarged thyroid. A goiter is benign but, if large enough, can
cause symptoms such as difficulty swallowing or pain and pressure in the neck. Finally, in rare cases, your physician may recommend surgery for hyperthyroidism (overactive thyroid) that cannot
be well controlled by medication.
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| The thyroid nodule is visualized here in purple. |
Who is at Risk?Risk factors for thyroid cancer include - Age
- most patients who develop thyroid cancer are over 40 years old
- Women
- women are three times as likely as men to develop thyroid cancer
- Race- Caucasians are more likely to get thyroid cancer than African-Americans
- Family history of thyroid cancer
- History of radiation
exposure to the neck
- Iodine deficiency in the diet
How is it diagnosed? The diagnosis of cancer or possible cancer is made with a thyroid biopsy. Thyroid biopsies can be done in the office.
A small needle and syringe is inserted into the nodule and a few cells are aspirated. Those cells are examined under a microscope
to make the diagnosis. If the results return as cancer or possible cancer, then surgery is scheduled. How do I prepare for surgery? If you are over 45 years old, you will need some additional preoperative testing to aid the anesthesiologist in taking
care of you. Those tests include blood work, a chest X-ray, and an EKG. How is the surgery performed? A horizontal
incision is made along the base of your neck usually along a skin crease. The thyroid gland is identified, carefully detached
from the windpipe, and removed, with care taken not to destroy adjacent structures. For a diagnosis of cancer, a total thyroidectomy, removal of the entire gland, is performed to
remove any cancer cells that my have spread within the thyroid gland. Complete treatment of thyroid cancer includes administration
of one dose of radioactive iodine to kill any remaining thyroid cells that may have spread beyond the thyroid. For a diagnosis of possible cancer, only the lobe where the cancer is suspected
is removed. This is a called a thyroid lobectomy. If after removal of the one lobe, the diagnosis of cancer is confirmed,
then a second surgery is needed to remove the remaining thyroid. For
patients with hyperthyroidism, many surgeons recommend a subtotal thyroidectomy. This involves removing one lobe
in its entirety and then a subtotal or near total resection of the opposite lobe. The small tuft of thyroid remaining may
prevent the need for lifelong thyroid hormone supplementation.
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| A thyroid lobectomy, removal of one lobe of the thyroid, is shown here. |
Complications of Surgery
The most serious risks of thyroid surgery include bleeding underneath the skin resulting in a blood clot that puts
pressures on other structures such as the windpipe. Pressure on the windpipe can cause difficulty breathing.
Two key structures exist in the neck close to the thyroid and can be
damaged during surgery. The recurrent laryngeal nerve lies along the back of the thyroid. This nerve is responsible for movement
of the vocal cords. Injury to the nerve can cause voice hoarseness which is most often temporary but can be permanent. The
other structures are the parathyroid glands which control calcium levels in the body. They often get bruised during surgery,
causing low calcium levels in your blood and requiring you to take calcium supplements temporarily. If they are permanently
damaged, you will need to take calcium supplements for life.
The
last two complications mentioned are rare in the hands of experienced surgeons. Patients at higher risk for these complications
are those with large goiters extending below the collar bone or in those undergoing their second operation on the thyroid.
What to expect after surgery?
The surgery usually takes approximately 2 hours. There may be a surgical drain
placed next to the incision in your neck. This will be removed the morning after surgery. Your throat may be sore because
of the breathing tube placed during the operation. You will be able to drink liquids immediately after surgery and eat once
you are fully awake. You will be discharged the day after surgery. Those who have had a thyroidectomy will be hypothyroid
(exhibiting underactive thyroid function) after surgery and will need to take a daily thyroid hormone pill. If you had a diagnosis
of cancer, you will need to see an endocrinologist to schedule the administration of the radioactive iodine. Those who have
a thyroid lobectomy will not need any supplemental medication.
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