The parathyroid glands, which are behind the thyroid gland in the neck, regulate levels of blood calcium through the production of parathyroid hormone. Sometimes a parathyroid gland has to be removed because it produces too much parathyroid hormone, causing symptoms such as bone loss and kidney stones. Minimally invasive parathyroid surgery is the name given to an operation which involves removing one or more of the parathyroid glands through a small incision. The procedure takes less than half an hour, and the patient may be sedated and semi-awake, or unconscious if preferred. It is usually possible to return home a couple of hours after the operation, and other benefits of the minimally invasive technique include reduced pain, rapid wound healing and a low risk of complications.
Minimally invasive parathyroid surgery is most often carried out due to the growth of a tumor in one of the parathyroid glands. Almost always, this is not a cancerous growth but is something known as an adenoma. The adenoma produces excessive amounts of parathyroid hormone, leading to hypercalcemia, or high calcium levels in the blood, and loss of bone calcium. There are usually four parathyroid glands, and, normally, only one of them contains an adenoma. The excess parathyroid hormone secreted by one gland reduces the activity of the other glands until they become inactive.
Surgeons can detect the abnormal gland by measuring the relative activity of all the glands using a technique known as a sestamibi scan. In a sestamibi scan, an injection is given of a small amount of a radioactive substance that collects inside the overactive parathyroid gland. An image taken by what is called a gamma camera picks up the radioactivity, revealing the position of the abnormal gland.
Using one of these scans before minimally invasive parathyroid surgery identifies an adenoma and avoids the requirement of making a large cut to inspect all of the parathyroid glands by eye. During the operation, a special probe, known as a gamma probe, may also be used to measure the activity in each of the parathyroid glands. This means that the location of the adenoma can be confirmed during surgery.
Levels of parathyroid hormone in the blood are sometimes measured while surgeons are carrying out minimally invasive parathyroid surgery. Parathyroid hormone levels at the start of the procedure are compared with the levels following removal of the gland containing the adenoma. A fall in the amount of parathyroid hormone indicates that the problem gland has been removed.
Different combinations of techniques may be used by surgeons during minimally invasive parathyroid surgery, but almost all patients are cured and complications rarely occur. It may be necessary to take calcium tablets after the operation. Patients can usually return to light, everyday activities the same day and heavier work after around five days.