Thyroidectomy is removal of thyroid tissue. Total thyroidectomy implies removal of the entire gland. Thyroid lobectomy means removal of a half of the thyroid. If the thyroid were compared to a butterfly, lobectomy removes one wing. Almost never are nodules removed individually from the thyroid gland. They are within the gland itself, not sitting on top of it. Total thyroidectomy is ideal for patients with thyroid cancers, large goiter, bilateral thyroid nodules, or in patients who require thyroid surgery who are already taking thyroid supplementation.
Thyroid lobectomy is reserved for patients with benign thyroid disease affecting only one half of the thyroid. With thyroid lobectomy operations, a biopsy is performed during surgery to ensure that the tissue is benign. In the event that cancer is detected, the correct operation is a total thyroidectomy. It is much easier to accomplish this with one operation rather than to have the patient return for another. Incisions for thyroidectomy are typically 3-4 cm and operating time averages an hour. Of course, for larger or more complex thyroids or for larger patients, this may vary. Lobectomy is a shorter operation but time is allowed for biopsy during the operation. Incision placement will be demonstrated at the consultation. Drains are not typically used except in extreme cases. Operations are almost always done as an outpatient. The exceptions are for patients with complex medical issues or for patients traveling from a distance.
Reoperative thyroidectomy is typically performed on patients with recurrent thyroid cancer or recurrent thyroid goiters. When thyroid cancer recurs in lymph nodes, surgery is essential to remove new disease. Scar tissue is a normal response from surgery, which can increase the risks of additional surgeries. This can increase potential for bleeding, hypocalcemia, or voice changes. It is particularly essential to have an experienced endocrine surgeon for reoperative surgery. Most patients with reoperative surgery are still able to be managed as an outpatient.
Most patients with thyroid cancer are concerned about the potential for metastatic spread. Thyroid cancer rarely spreads outside the neck. Most times cancer spreads to the central neck (the area between the voice box extending down along the trachea to the chest), or the area surround the jugular veins and carotid arteries. Even with metastatic spread, prognosis for thyroid cancer remains very good. Patients will coordinate with surgeons, endocrinologists, and sometimes radiation oncologists to provide multidisciplinary care following surgery for metastatic cancer.
Central Neck Dissection
The central neck dissection involves removing lymph nodes closest to the thyroid gland. It is the removal of lymph nodes in the region of the voice box and the windpipe down to the upper part of the chest cavity. This surgery is also called a level VI (six) lymph node dissection. Once the pathologist examines the lymph nodes for cancer, we use this information to help in deciding if a patient needs radioactive iodine treatment.
Lateral Neck Dissection
A lateral neck dissection is removal of lymph nodes on the side of the neck. The lymph nodes of the neck are divided into levels and named by roman numerals (Levels I-VI). This surgery is removal of levels II, III, IV, and V. There are many nerves in the neck that are at risk for injury during this type of surgery and this type of surgery is only recommended if thyroid cancer has been proven to be in these lymph nodes. Proof of lymph node involvement is confirmed with a biopsy using neck ultrasound.
As with any surgery, there are risks involved with the lateral neck dissection. In the hands of an experienced surgeon, these risks are low. The nerves that are at risk for a lateral neck dissection include the recurrent laryngeal nerve, the phrenic nerve, the spinal accessory nerve and cervical nerves. The recurrent laryngeal nerve, a branch of the vagus nerve, innervates the vocal cord and injury can affect the voice. The phrenic nerve controls breathing by innervating the diaphragm and injury can to it can cause breathing problems. The spinal accessory nerve controls the trapezius muscle and helps with shoulder movement. Injury to it can cause shoulder weakness. The cutaneous cervical nerves that innervate the skin in this region are at risk and if injured cause numbness. Large blood vessels that are also at risk include the carotid artery and the internal jugular vein. The thoracic duct that drains lymphatics is also at risk during this type of surgery and injury can require drainage.
Parathyroidectomy is removal of one or more parathyroid glands to correct hyperparathyroidism. Hyperparathyroidism is a condition in which excess parathyroid hormone is made by the gland or glands that moves calcium from the bones to the bloodstream. This result is having a calcium level that is too high in the blood, to the detriment of low calcium in the bones. Preoperative testing including ultrasound and sometimes Sestamibi nuclear scanning which is used to identify which of the four parathyroid glands is abnormal. This helps to direct the surgeon where to look in the neck to find the abnormal gland. Intraoperative blood testing to use to document cure and intraoperative pathology is used to exclude the potential of cancer (which is very rare). In cases of localized parathyroid disease (the surgeon knows which gland is affected), the operation is usually very fast. In the event that the disease is not localized, the surgeon will examine all four glands to see which or all might be affected. In the case that all four glands are abnormal, 3.5 glands will be removed. The body can function perfectly normally on 0.5 parathyroid gland. Patients recover quickly and are able to be outpatient. Specific care is given to education regarding the signs of low blood calcium post operatively. After cure, the calcium moves from the blood back to the bones. Sometimes this happens too quickly and the patient must supplement with oral calcium vitamins in the short term.
Reoperative parathyroidectomy is when a second surgery is needed in patients who have had a parathyroid surgery in the past. This is done in the case when the first surgery did not yield a cure because of failure to find the abnormal parathyroid or failure to recognize that more than one parathyroid gland was contributing to the problem. These patients are carefully prepared with preoperative imaging to ensure success. This can be a challenging operation and should only be attempted by a highly trained endocrine surgeon.