Thyroid resection

Thyroid resection, also called thyroidectomy, can involve removing one thyroid lobe or the whole gland. Removing one lobe is called lobectomy; removing the whole gland is called total thyroidectomy. Completion thyroidectomy removes the remaining thyroid after an earlier lobectomy. The amount removed and the route used to reach the thyroid are separate choices. Conventional surgery uses an incision in the neck. Remote-access surgery reaches the thyroid from another location, such as through the mouth, with the aim of improving the cosmetic result. Eligibility depends on the disease and the surgeon’s training and experience with that approach.

The cancer type and its extent matter when comparing removal of one lobe with removal of the whole thyroid. For papillary thyroid cancer confined to one side but involving lymph nodes along the side of the neck, lobectomy has been studied as an alternative to total thyroidectomy in selected patients without obvious growth beyond the thyroid or aggressive cancer subtypes. This comparison does not establish the best operation for every thyroid cancer. Medullary thyroid cancer is a different setting: total thyroidectomy remains the established surgical standard, while lobectomy is being investigated for selected one-sided, non-hereditary tumours. Choosing an approach through the mouth instead of a neck incision is also a trade-off: cosmetic benefits may come with a longer operation, a longer hospital stay and more early pain.

For one-sided papillary thyroid cancer with spread to lymph nodes along the side of the neck, a comparison covering six studies and 1,894 patients found no clear difference between lobectomy and total thyroidectomy in remaining free of cancer recurrence at five years. Average follow-up was 76.9 months. The five-year comparison had a hazard ratio of 1.03, where a value of 1 means no difference; its uncertainty range was 0.68 to 1.56. This is a comparison between groups, not an individual’s chance of cure. A broader analysis of differentiated thyroid cancer, covering 46 retrospective studies and 98,604 patients, found more recurrence after removal of half the thyroid than after total thyroidectomy. The narrower and broader findings therefore do not support a single conclusion for all patients; the cancer population and the extent of surgery need to be considered together.

Thyroid surgery can injure the recurrent laryngeal nerve, a nerve involved in voice function, and may cause voice impairment. It can also lead to low blood calcium and reduced parathyroid hormone production, called hypoparathyroidism. These problems can be temporary or permanent. Risk varies with the extent of surgery and any lymph node removal. In particular, thyroid cancer surgery involving the whole gland and lymph nodes along the side of the neck is associated with greater risk of hypoparathyroidism around the operation. Completion surgery after an earlier lobectomy is a separate treatment decision: comparisons in selected patients with differentiated thyroid cancer found lower odds of temporary low calcium than with total thyroidectomy performed upfront, but no clear differences in permanent low calcium, nerve injury or a collection of blood after surgery. These comparisons do not measure the combined risk of both operations for an individual patient.

Pain, nausea and vomiting can affect early recovery after thyroid surgery. In 11 randomised trials involving 943 adults undergoing thyroidectomy, intravenous lidocaine given around surgery reduced pain scores at several measured times during the first 48 hours compared with placebo. This concerns a treatment delivered by the clinical team, not a medicine to start independently. Further cancer treatment is a separate decision from recovery after the operation. Among 5,260 patients with low-risk differentiated thyroid cancer in ten studies, adding radioactive iodine after thyroidectomy did not show a clear improvement in five-year survival without recurrence compared with no radioactive iodine. This finding applies to low-risk disease, not to every thyroid cancer.