Most people have four parathyroid glands that lie adjacent to the thyroid. Each gland is approximately the size and shape of a grain of rice. Other than their close proximity to the thyroid gland, there is no other relationship between the thyroid and parathyroid glands.
The parathyroid glands produce parathyroid hormone (PTH) that controls the body’s calcium levels. The most common disease of the parathyroid glands is primary hyperparathyroidism and is due to overproduction of PTH. This increases the body’s calcium levels. The symptoms of primary hyperparathyroidism can include:
- Kidney stones
- Abdominal pain
- Muscular aches and pains
Approximately 85% of patients with primary hyperparathyroidism are suitable for minimally invasive parathyroidectomy. The remaining 15% of patients will require open parathyroidectomy. Dr O’Neill will discuss the appropriate operation for you at your pre-operative visit.
Most patients who undergo parathyroid surgery stay in hospital only one night post-operatively. The PTH and calcium levels are checked post-operatively to ensure that primary hyperparathyroidism is cured.
Minimally Invasive Parathyroidectomy
In more than 85% of patients with primary hyperparathyroidism only one of the four parathyroid glands is overactive. Scans (Parathyroid sestamibi, ultrasound scans and sometimes parathyroid CT scans) can help to identify which of the four glands is abnormal. If scans do identify only one abnormal gland, this parathyroid gland can be targeted for removal via a minimally invasive parathyroidectomy. This procedure involves a 2 to 2.5cm incision directly over the parathyroid gland and removal of only this gland. Primary hyperparathyroidism is cured in 95% of patients after minimally invasive parathyroidectomy.
In some patients the overproduction of PTH is produced by more than one parathyroid gland or imaging does not localise the disease to only one gland. Minimally invasive parathyroidectomy is not suitable in these patients and open parathryoidectomy is undertaken. This involves a slightly larger incision (4 to 5cm), the inspection of all four parathyroid glands and removal of any abnormal glands. In some cases of minimally invasive parathyroidectomy the abnormal parathyroid gland cannot be found during the operation and the surgeon will convert to open parathyroidectomy.
Risks of Parathyroid Surgery
Although uncommon, there are risks associated with parathyroid surgery. These can include:
- Voice changes
The nerves that supply the voice run closely adjacent to the parathyroid glands. Great care is taken during surgery to ensure that these nerves are not damaged. Long-term voice changes are uncommon and occur in less than 1% of patients who undergo parathyroid surgery. The movement of your vocal cords will usually be checked both before and after your surgery with a flexible telescope inserted through the nose (nasendoscopy). In most cases Dr O’Neill will perform this procedure when you see her before the surgery and again at your post-operative visit.
- Low or persistently high calcium levels
Even in the hands of an expert endocrine surgeon, up to 5% of patients may not be cured with parathyroid surgery and calcium levels may remain persistently raised after surgery. In some patients further surgery will still cure primary hyperparathyroidism. Occassionally patients calcium levels may become too low after parathyroid surgery. This is usually due to “stunning” of the remaining parathyroid glands and will almost always recover. If this is the case then tablets can be given to boost the calcium levels. Patients are almost always weaned off these over the weeks following parathyroid surgery.
The parathyroid gland has a very rich blood supply. Bleeding after parathyroid surgery is very uncommon (occurs in fewer than 1% of patients). Occasionally patients may require a second operation if bleeding is significant.
- Wound healing problems (scarring, infection)
It is necessary to make an incision in the neck to remove the thyroid. In most patients the scar will heal to a thin line over a period of months after thyroid surgery. Everyone heals slightly differently and some people are prone to red and raised scars (hypertrophic or keloid scars). Many scars will continue to improve over the six to eighteen months after surgery.
In addition to these risks that are specific to parathyroid surgery any operation with a general anaesthetic is associated with risks to your health. Serious complications in healthy patients are extremely rare. Potential problems can include:
- Heart problems (heart attack, stroke, death)
- Lung problems (pneumonia)
- Blood clots (clots in the legs or lungs)
- Drug reactions
It is important that you tell Dr O’Neill and your anaesthetist if you have any other medical conditions or take any regular medications prior to your surgery.
Other helpful websites
- Australian and New Zealand Endocrine Surgeons
- American Association of Endocrine Surgeons Patient Information Site