Parathyroid surgery is extremely safe, and complications are unusual. There is, furthermore, evidence to suggest that complications are less likely to occur in operations performed by specialist surgeons who perform such surgery frequently.
The most important potential complications specific to surgery on the parathyroid glands are voice change and hypocalcaemia (low blood calcium levels). In addition to this in around 2 people out of every 100 the operation does not cure the parathyroid problem.
Voice change. Minor voice changes after parathyroid operations very occasionally occur, and usually consist of a ‘tiring’ of the voice towards the end of the day, and an inability to project the voice, for example in shouting or singing. These changes almost always disappear after a few weeks, and often are not even noticeable except to people who use their voice professionally (eg. singers, telephonists).
More significant alterations in the voice, consisting of a more noticeable hoarseness, should occur in less than 1 in 100 people after parathyroid surgery. This occurs due to an injury to the recurrent laryngeal nerve (RLN) during the operation. The RLN is a nerve that runs very close to the parathyroid glands, and controls the voicebox (larynx). Most RLN injuries recover spontaneously over time (often taking 12-18 months), but may occasionally need further minor surgical procedures to improve the voice.
Hypocalcaemia (low blood calcium levels) occurs only rarely after removal of parathyroid glands. Unless several parathyroid glands have had to be removed this problem usually occurs because the remaining parathyroid glands can take a few weeks to work normally again once the abnormal, overactive gland is removed.
Most people with hypocalcaemia need no specific treatment, and the problem resolves spontaneously over a few days. A small number of people will, however, develop symptoms of hypocalcaemia (most commonly, tingling or numbness in the lips and fingertips) and need calcium tablets for a few weeks after surgery. Some people may even have symptoms of hypocalcaemia if their calcium level is normal post-operatively. This is because the body’s cells have become adapted to high calcium levels, and take a few weeks to ‘reset’ to become used to normal calcium levels again.
Failure of the surgeon to find the abnormal parathyroid gland. In this situation, the calcium level remains high after operation. There are two main reasons for this:
The abnormal parathyroid gland is hidden in an unusual place in the neck and cannot be found at operation. This is more likely to occur if the surgeon performing the operation is not adequately experienced in parathyroid surgery, or performs this type of surgery infrequently. In this, more than any other type of endocrine surgery, surgeon experience is extremely important.
The abnormal parathyroid gland is not in the neck. This occurs in 1-2% of people, and happens because of the way the parathyroids develop when you are in your mother’s womb. The commonest place that glands such as these occur in is the chest. Specialised tests are needed to find these glands, and surgery can then be performed in most cases.