Parathyroid Surgery

Introduction:

The parathyroid glands are generally four small, lentil-sized, glands of the endocrine system located in very close proximity (usually attached to) the thyroid gland in the lower midline part of the neck. A normal parathyroid gland weighs only 40-60 milligrams. Due to migration of tissues during the embryonic phase of life, these glands may vary a great deal as to their final expected position in the neck relative to the thyroid gland. The purpose of the parathyroid glands is to produce parathyroid hormone (PTH) which enters the blood circulation and maintains calcium and phosphorus levels in the blood. The most common primary disease associated with the parathyroid glands is overproduction of PTH, known as hyperparathyroidism.

Hyperparathyroidism:

When the parathyroid glands secrete too much parathyroid hormone, the blood calcium level rises. This condition is called hypercalcemia. A benign (noncancerous) but overactive tumor originating in one of the glands, called a parathyroid adenoma, is responsible in approximately 80% of cases. In approximately 2-4% of cases, multiple parathyroid adenomas may be responsible for the disease. In yet another 15% of patients with hyperparathyroidism, all four glands are enlarged, resulting in parathyroid hyperplasia. Fortunately, only 0.5% of all cases of hyperparathyroidism are caused by parathyroid carcinoma (cancer of the parathyroid gland). As such, more than 99% of cases of overactive parathyroid glands are noncancerous. Recognition of the exact cause and type of the disease leading to hypercalcemia is extremely important since the surgeon, based on that knowledge, outlines the appropriate treatment plan to achieve a successful result in curing the patient. Excessive production of PTH triggers the release and loss of excessive amounts of calcium from the bones, resulting in osteoporosis (brittle bones). In addition, it results in an excessive absorption of calcium from food, causing a further and unnecessary increase in blood calcium levels. The amount of excreted calcium in the kidneys and urine increases, resulting in troublesome kidney stones.

In the majority of cases, the cause of hyperparathyroidism is not known. Only in 5% of cases it is genetically linked. Although it is not known to be caused by any social habits or lifestyles, it is known to be twice more prevalent in women than in men. Its incidence increases with age in both men and women. The symptoms are often subtle, to the extent that the condition may go unrecognized for several years before its manifestations become clearly abnormal. The symptoms include formation of kidney stones, osteoporosis and unusual bone fractures, high blood pressure, generalized fatigue and weakness, depression, impaired thinking and memory loss. In addition, a variety of gastrointestinal symptoms such as heartburn, stomach ulcers, nausea, vomiting, constipation and abdominal pain may be associated with hyperparathyroidism.

Parathyroid Surgery:

Surgery is the most common treatment for hyperparathyroidism, and has a 95 percent success rate in curing the disease when performed by an experienced doctor. Surgical removal of one or more abnormally enlarged parathyroid glands is called parathyroidectomy. Not all individuals with hypercalcemia or hyperparathyroidism require parathyroid surgery. In fact, approximately 50% of patients with known hyperparathyroidism do not meet the criteria for becoming candidates for surgery. These are patients who have been diagnosed to have mildly elevated calcium with mild elevations in parathyroid hormone (PTH) by blood testing, but do not have any overt manifestation of hyperparathyroidism. These patients can be followed regularly and closely by their primary care physician or endocrinologist for evidence of progression of the disease to more severe levels. They need to have their blood calcium levels and bone density measured periodically and should be examined by their doctor to detect early signs of the disease. There are also medications available to treat hyperparathyroidism. However, over 50% of patients are candidates for surgery, and fortunately 95% of them can be cured by one surgical procedure. The only definitive cure is achieved through surgery. During the operation, the patient is given either general or local anesthesia. Your surgeon will make a small incision in the neck just under the Adam's apple and remove the abnormal gland(s) through that incision. The particular type of the disease, and whether or not one or more glands are affected, will determine how many glands need to be removed. Some healthy parathyroid tissue needs to be left in place to prevent hypoparathyroidism (decreased parathyroid hormone level). To identify the abnormal gland(s) prior to surgery, a high resolution ultrasound and a radionuclide parathyroid scans are quite helpful in most cases and give the necessary anatomic information that the surgeon needs. With accurate localization of the abnormal gland(s), a surgeon familiar with the minimally invasive parathyroid surgery can perform that surgical technique with distinct advantages to the patient.

Parathyroid Surgery Continued »

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