What are the parathyroid glands?
The parathyroid glands are located in the neck, behind the thyroid gland . There are usually four parathyroid glands (two on each side), and they are very small - each usually about the size of a sesame seed. The function of the parathyroid glands is to control the level of calcium in the bloodstream by producing Parathyroid Hormone (PTH). They produce more hormone if the calcium level is low, and stop producing hormone when the level is too high. To raise the calcium level in the bloodstream, the effect of the PTH is to take calcium out of the bones.
About a high calcium level
If a patient's calcium is consistently too high he or she might develop the following symptoms:
Fractures of bones with minor trauma
If we find that a patient has a consistently elevated calcium level, and that the PTH level is elevated, surgical treatment of the problem is usually needed. Usually, we will get a Parathyroid Scan before surgery, which may help us determine which of the four glands is producing the excess hormone.
What we usually find is a parathyroid adenoma, which is a benign enlargement of one of the glands. The adenoma produces extra amounts of PTH and the adenoma does not respond to the body's normal feedback mechanisms that tell it to stop producing hormone.
Various x-ray studies of the neck can be done to try to find the adenoma. Examples are CT scan, ultrasound, MRI and parathyroid Scan. Sometimes these are helpful - sometimes not. Even if these x-ray studies do not show an adenoma, exploration of the neck to try to find an adenoma is indicated.
About the operation
The operation can take anywhere from one to three hours. The incision for a parathyroid exploration is crosswise, just beneath the "Adam's apple". The operation consists of an attempt to find the abnormal gland. If the parathyroid scan has already showed us which gland is the problem, we will just look for that gland, and if it is enlarged, that is all we will remove. However, if the scan is inconclusive, or the operative findings don't agree with the scan, we will attempt to find all four parathyroid glands, and remove the one that appears to be enlarged. Unfortunately, the adenoma is not always easy to find. It can be in various places in the neck, and can even be in the upper chest. If it is found, it is removed.
Potential problems with the operation
Sometimes we are unable to find the adenoma, and in that case the problem is not solved and the calcium level will remain high. Possibly additional x-rays may be needed, and another operation may be necessary in the future if that is the case.
The other problem that can occur after surgery is that the calcium level now drops too low. This can be because the remaining parathyroid glands are making too little hormone, and the body's bones are taking in all the available calcium. If the calcium level is too low, a patient needs to take supplemental calcium and Vitamin D to correct this. Usually this is a temporary problem as the body gets used to a normal PTH level.
The nerves to the vocal cords (recurrent laryngeal nerves) are located behind the thyroid gland. These nerves must be visualized and avoided during our search for the parathyroid glands. These nerves are very small and fragile. There is one on each side. If one of these nerves is damaged a patient would have temporary or permanent loss of function of that vocal cord. This would result in hoarseness if it happened to one nerve. If the very unusual circumstance occurred where both nerves were permanently injured, a person would not be able to talk, and would require a tracheotomy to breathe. This is a very rare circumstance that usually happens in situations involved with removal of very large glands or tumors in the neck, not parathyroid surgery.