The thyroid gland principally produces a hormone called thyroxine. This hormone circulates around the body in the blood and controls the speed at which the body’s chemical processes work. The normal thyroid has considerable spare capacity for making thyroxine and so normally removal of as much as half of the gland can be undertaken without any need to give thyroxine replacement in the form of daily tablets after the operation. If, however, the whole thyroid has been removed you will need to take thyroxine for the rest of your life. Very close to the thyroid gland are four tiny glands called parathyroid glands, each not much bigger than a grain of rice. These produce a hormone which controls the level of calcium in your body. The parathyroid glands are normally left in place during thyroid surgery, but their function may be affected by the operation on the thyroid (see below).
Thyroid surgery requires a general anaesthetic and a stay in hospital, which is normally just overnight. Access to the neck obviously requires that the surgeon make an incision in the neck. This is made in a natural skin crease of the neck. The incision is symmetrical even if the thyroid abnormality is only on one side. Most thyroidectomy incisions heal to produce a very satisfactory scar. The skin is usually closed with a resorbable suture which does not need to be removed.
Lymph node surgery for Thyroid Disease
For some types and stages of thyroid cancer, the removal of affected lymph nodes is recommended. This surgery often requires a larger incision and carries with it additional complications and issues relating to stay in hospital and post operative care. This will always be discussed prior to surgery. The details of lymph node removal can be found on the Neck Dissection page.
Most thyroid operations are straightforward and associated with few problems. All operations carry risks which include postoperative infections (e.g., in the wound or a chest infection), bleeding in the wound and problems due to anaesthesia but these are very rare. Some specific complications of thyroid surgery are discussed below.
Scar: The scar may become relatively thick and red for a few months after the operation before fading to a thin white line. Very rarely some patients develop a thick exaggerated scar but this is uncommon. Most people who develop a problem scar have a personal or family history. Various strategies are employed to help address wound problems should they occur.
Voice change: Voice abnormalities immediately post op can be due to either endotracheal intubation or an effect of surgery. A specific problem related to thyroid surgery is injury to one or both recurrent laryngeal nerves. These nerves pass very close to the thyroid gland and control movement of the vocal cords. Injury to these nerves causes hoarseness and weakness of the voice. The external laryngeal nerve may also be injured and this results in a weakness in the voice although the timbre of the voice is unchanged.
Difficulty may be found with the high notes when singing, the voice may tire more easily and the power of the shout is reduced. Less than 5% of people should have a demonstrable vocal cord palsy following thyroidectomy. Careful surgery reduces the risk of permanent accidental damage to a very low level (<1%) but cannot absolutely eliminate it. Injury to both nerves is extremely rare but is a serious problem and may require a tracheostomy (tube placed through the neck into the windpipe).
Low blood calcium levels: Patients undergoing surgery to the thyroid gland are at risk of developing a low calcium level if the four tiny parathyroid glands (see image below), which control the level of calcium in the blood, stop working after the operation. It is normally possible to identify some if not all of these glands and so avoid a long-term problem. Unfortunately even when the glands have been found and kept they may not function normally. This occurs in about 20% of patients. If this happens then you will need to take extra calcium and/or vitamin D tablets for a few weeks. The risk of you needing longterm medication because of a low calcium level is very small indeed (less than 1%).
Thyroid function: If it has been decided to remove all the thyroid gland then you will require lifelong replacement of thyroxine. Fortunately this is a straightforward once a day regimen with little requirement for adjusting the dosage. If half the gland is removed (hemithyroidectomy) then the remaining gland should produce sufficient hormone – this will be monitored with blood tests. Only 15% of patients following hemithyroidectomy will require supplemental thyroxine.
Bleeding: Any surgical wound may bleed following the operation. Bleeding in the neck from thyroid surgery is rare (about 1 in 100) but does occur and occasionally results in the need to remove the blood clot requiring a second brief operation usually a few hours after the main surgery.