Thyroid Surgery

The operation is named for how much gland is removed. A hemithyroidectomy, or lobectomy, takes one half and leaves the other to produce hormone. A total thyroidectomy removes the whole gland, and a near-total leaves only a small rim of tissue. When cancer is present, the surgeon may also clear lymph nodes from the central compartment of the neck or from the side, a neck dissection. Parathyroidectomy removes one or more of the small parathyroid glands that sit behind the thyroid when they overproduce parathyroid hormone and raise blood calcium. Access is usually through a short transverse incision placed in a natural crease low in the neck. Some centres offer remote-access approaches that hide the incision entirely, working through the armpit, behind the ear or through the mouth, often with a surgical robot or endoscope.

Surgery is recommended when a nodule biopsy shows cancer or is suspicious or indeterminate, when a nodule or goitre is large and causes a pressure sensation, breathing difficulty when lying flat, a change in the voice or difficulty swallowing, and when a goitre extends behind the breastbone. It is also recommended for an overactive thyroid from Graves disease or a toxic nodular goitre when antithyroid medicine has not worked or is not tolerated and radioiodine is unsuitable, for example during planned pregnancy or with significant eye involvement. Parathyroid surgery is recommended for primary hyperparathyroidism causing high calcium with kidney stones, bone thinning or symptoms, and in younger patients even without symptoms. Small, benign, symptomless nodules are usually watched rather than removed.

The assessment before surgery includes an ultrasound map of the gland and the neck nodes, a needle biopsy where indicated, blood tests of thyroid and, for parathyroid disease, calcium and parathyroid hormone, and often an examination of the vocal cords. Under general anaesthesia the surgeon opens a short transverse incision, separates the strap muscles in the midline and exposes the gland. The two recurrent laryngeal nerves, which move the vocal cords, and the external branch of the superior laryngeal nerve, which controls pitch, are identified and protected, and their function is checked with intraoperative nerve monitoring. The parathyroid glands are identified and preserved with their blood supply where the operation allows; a gland that loses its supply can be transplanted into a neck muscle. Small vessels are sealed with energy devices, the specimen is removed and, in cancer surgery, the relevant nodes are cleared. The wound is closed with a fine subcuticular stitch or tissue glue, sometimes over a small drain. The operation usually takes about 1 to 3 hours.

Preparation depends on the reason for surgery. An overactive thyroid is brought under control with medicine before the operation to avoid a surge of hormone during anaesthesia. Imaging is reviewed to plan the extent of the operation, and for parathyroid disease a localisation scan such as sestamibi with single photon emission computed tomography, or a four-dimensional computed tomography, is used to find the abnormal gland. Vitamin D deficiency is corrected beforehand, because it makes low calcium after surgery more likely. Routine blood tests and, in older patients, an electrocardiogram confirm fitness for anaesthesia. Blood-thinning medicines are adjusted on medical advice. For international patients, ultrasound images, biopsy results and blood tests can be reviewed remotely, with a repeat ultrasound and vocal cord check on arrival.

Most people spend one night in hospital. The throat feels sore and the neck stiff for a few days, and the voice is often a little tired or husky at first. Calcium is measured after a total thyroidectomy, since the parathyroid glands can be temporarily stunned, and calcium and vitamin D supplements are given if the level falls, usually for a few weeks. Thyroid hormone replacement is started before discharge when the whole gland has been removed. The wound is checked at about one week and the dressing removed. Most people return to light work in 1 to 2 weeks and to full activity by about 3 to 4 weeks, avoiding heavy lifting for a fortnight. For treatment abroad, plan about 7 to 10 days so the wound is checked, the pathology result is discussed and calcium and hormone levels are seen to be stable before flying. Thyroid blood tests are then repeated near home at about 6 to 8 weeks so the dose can be adjusted.

In experienced hands thyroid surgery is safe and the serious risks are uncommon. Temporary hoarseness or voice fatigue affects a minority and usually resolves within weeks to months; permanent voice change from injury to the recurrent laryngeal nerve is rare, and nerve monitoring is used to reduce it further. Temporary low calcium after removal of the whole gland is relatively common and causes tingling in the fingers and around the mouth, treated with supplements; permanent low calcium requiring lifelong treatment is uncommon. Other risks include bleeding into the neck, which is rare but needs immediate attention and is the reason for an overnight stay, wound infection, and a scar that thickens in people prone to it. Lifelong thyroid hormone is needed after total thyroidectomy, and roughly one in five people are also placed on hormone after removal of one lobe. Where surgery was done for pressure symptoms or an overactive gland, relief is reliable, and outcomes for differentiated thyroid cancer treated surgically are generally favourable.