Thursday, July 2, 2009
By David Goldenberg
Nearly 10,000 Americans every year experience hyperparathyroidism, a chronic condition that causes high blood-calcium levels. The disease is caused if one or more of the four tiny parathyroid glands located behind the thyroid in the neck become enlarged and produce too much parathyroid hormone (PTH). This is usually caused by a benign tumor called a parathyroid adenoma. It sometimes causes osteoporosis, kidney stones, abdominal problems, depression and fatigue, among other illnesses.
Hyperparathyroidism can be successfully treated by surgically removing the abnormal parathyroid gland, or in some cases, multiple glands. Minimally invasive radioguided parathyroidectomy, or MIRP, is a surgical procedure used to treat patients diagnosed with primary hyperparathyroidism. A safer and less invasive approach to a traditional parathyroidectomy, MIRP can usually be performed through a one to 1.5 inch incision in the neck. Before MIRP, surgeons searched for and removed the faulty parathyroid gland through a large incision. This approach often required surgical exploration of both sides of the neck.
Before surgery, patients are injected with a radioactive material that washes out quickly from the thyroid. It remains only in the diseased parathyroid gland (adenoma) and is not absorbed readily by healthy parathyroid glands. Two hours later, the parathyroid is viewed on a radioisotope scan to help locate the abnormal parathyroid gland and is found through the incision using a hand-held radiation detector. While the patient is still asleep, a rapid blood test is taken to look for a drop in PTH levels. Within 10 minutes of removing the offending adenoma, the levels will have dropped 50 percent compared to the pre-op test. The procedure takes less than one hour, and in some instances, is performed in as little as 15 minutes.
Because the procedure is minimally invasive, most patients go home the same day of the procedure -- usually just a few hours later. Most patients experience rapid relief with little scarring or side effects.
As with any surgery, there are risks. There is a low risk of nerve damage to the vocal cord and a small risk of developing chronically low calcium levels.
MIRP is not for everybody with hyperparathyroidism. Less common types of hyperparathyoridism are managed either medically (with medicine) or with other various types of surgical procedures.
To learn more about hyperparathyroidism, please visit Penn State Milton S. Hershey Medical Center Health Information Library.
Dr. David Goldenberg is an associate professor of head and neck surgery at Penn State Hershey Otolaryngology-Head and Neck Surgery.