There are four parathyroid glands in the neck, but most people with parathyroid disease (hyperparathyroidism) have only one enlarged gland.
A parathyroid gland is approximately the size of a grain of rice. One gland can grow to the size of an olive or larger if a tumor (adenoma) develops inside of it.
The Surgical ProceduresMIRP
Minimally invasive radio-guided parathyroidectomy (MIRP) requires approximately a one inch incision. The cure rate is as high as or higher than a conventional parathyroidectomy.
MIRP uses a small, radio-guided probe to locate the diseased parathyroid gland. MIRP has a lower complication rate than the standard surgical procedure. Most types of parathyroid disease can use the MIRP surgery.
The MIRP Procedure
- The patient receives an IV injection of Technetium 99, a safe radioactive agent, a few hours before the operation.
- The parathyroid adenoma absorbs Technetium 99, but the healthy parathyroid glands do not. The Technetium emits radioactive signals that helps the surgeon locate the abnormal gland.
- A pencil-sized probe is inserted through the incision in the neck. The probe detects the radioactive signals (similar to a Geiger counter), which directs the surgeon to the diseased gland.
- The diseased gland is removed through the same incision.
The procedure takes about an hour, less time than a conventional parathyroidectomy. Only one side of the neck is probed, so there is no risk to the laryngeal (voice box) nerve on the opposite side of the neck.
Patients rarely need pain medication after the surgery. Calcium supplements are usually taken for several days, until the remaining parathyroid glands regain normal function.
Conventional parathyroidectomy requires a six to eight inch incision in the neck, to locate the enlarged parathyroid gland.
The patient is given a general anesthesia. An incision is made. The parathyroid glands reside behind the thyroid gland, so the muscles of the neck and the thyroid are moved to the side.
The enlarged parathyroid gland is located and removed. While the patient is still asleep, a technician tests the level of calcium in the patient's blood. If the amount of calcium has decreased to a normal level, the surgeon is assured the diseased gland was removed.
During this procedure, the surgeon needs to expose the structures on both sides of the neck. The incision usually heals well, but the scar is large.