Total thyroidectomy - the procedure and the risks
Total thyroidectomy involves removal of the entire thyroid gland and is usually performed for the treatment of thyroid cancer, nodular goitre affecting both sides of the gland, or thyrotoxicosis causing overactivity of the gland. Total thyroidectomy is a straightforward procedure performed under general anaesthesia, with a supplemental local anaesthetic cervical plexus block to reduce post-operative pain and discomfort. An incision is required and this is best placed in a skin crease high in the neck in order to provide an optimal cosmetic outcome. A hospital stay of either one or two nights is standard. After total thyroidectomy, all patients require thyroxine replacement for life. This simply replaces the natural hormone previously produced by the gland and has no side effects or complications (see FAQ on thyroxine)
Any operation carries with it the risk of a complication or unanticipated outcome. General risks of any operation include the possibility of an anaesthetic reaction, bleeding, infection, or thrombosis. There are also clearly a significant number of exceedingly uncommon potential complications which cannot be detailed. The specific risks of total thyroidectomy include:
DAMAGE TO THE RECURRENT LARYNGEAL NERVES: The recurrent laryngeal nerves supply the muscles of the larynx which are responsible for the voice as well as for protecting the airway. These nerves run directly through the operative site and lie against the back of the thyroid gland. They are often stretched during removal of the thyroid and may be damaged, or may temporarily lose their function after surgery. Loss of function of one nerve leads to a croaky voice. The risk of this occurring in expert hands is 1% (1 in 100 operations) but may be higher with less experienced surgeons. Loss of function of both nerves is a major issue and may lead to a tracheostomy or a tube in the airway, although the risk of this is exceedingly small at less than 1 in 10,000 cases. Some surgeons use nerve monitoring although there is absolutely no evidence that this reduces the risk of nerve damage (see FAQ on IONM).
DAMAGE TO THE PARATHYROID GLANDS: The parathyroid glands are tiny glands about the size of a grain of rice which sit on or near the back of the thyroid gland and are responsible for calcium metabolism. They are often damaged or have their blood supply disrupted during removal of the thyroid, although any damaged ones will be transplanted into the nearby muscle. However in 1% of cases, in experienced hands, they still do not survive leading to a low calcium level which needs to be replaced. As a precaution, all patients having total thyroidectomy go home on calcium supplements for a couple of weeks and can then stop them but 1% will need to continue with both calcium and Vitamin D for life.
PERSISTENT DISEASE: At surgery every attempt is made to remove all of the thyroid tissue, however sometimes small embryological remnants may be left behind and these can slowly grow to cause a recurrent goitre. The risk of this happening is around 2%.