Advances help protect parathyroid during thyroid surgery
But inadvertent removal remains common, UK study finds
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Accidental removal of the parathyroid glands during thyroid surgery has become less common — decreasing by about 35% from 2021 to 2023 — likely reflecting better surgical awareness and imaging tools such as near-infrared autofluorescence, according to a study in the U.K.
But inadvertent removal is still common, occurring in nearly one out of five surgeries, and can lead to hypoparathyroidism.
The study, “Inadvertent parathyroidectomy in thyroid surgery with and without near-infrared autofluorescence: a two-centre retrospective observational study,” was published in the European Archives of Oto-Rhino-Laryngology.
Thyroid surgery can cause damage to or the accidental removal of the nearby parathyroid glands (inadvertent parathyroidectomy) and lead to acquired hypoparathyroidism. Hypoparathyroidism is marked by low levels of the parathyroid hormone (PTH), which controls how much calcium and phosphorus circulate in the body. Normally, PTH is produced in the parathyroid glands.
Because of this, surgeons try to preserve the parathyroid glands during thyroid surgery. One tool that may help is near-infrared autofluorescence, which makes parathyroid glands glow during surgery, helping surgeons see them more clearly. However, there is limited evidence on the effectiveness of fluorescence-guided thyroid surgery.
Reviewing cases
The researchers reviewed past cases of adults who underwent thyroid surgery at two U.K. hospitals from 2021 to 2023. Their analyses covered three types of thyroid surgery: hemithyroidectomy (removal of half the thyroid), total thyroidectomy (removal of the whole thyroid), and completion thyroidectomy (removal of remaining thyroid tissue after a previous surgery).
Out of 1,037 thyroid surgeries performed, 829 were included in the study. Most patients were women (77.2%), and the median age was 50. The most common reason for surgery was suspected or confirmed thyroid cancer, followed by thyroid nodules (lumps) and Graves’ disease, an autoimmune disease that causes an overactive thyroid.
Nearly half of the patients (49.5%) underwent hemithyroidectomy, while the rest had either total thyroidectomy (34.7%) or completion thyroidectomy (15.8%). Some patients also had central neck dissection (10.9%), a procedure in which lymph nodes in the central neck are removed, often when cancer is present.
Inadvertent parathyroidectomy occurred in 153 thyroid surgeries (18.5%). Rates were significantly higher when central neck dissection was performed (41.1%, compared with 15.7% without the procedure).
In 243 of the thyroid surgeries, doctors used near-infrared autofluorescence for guidance, and this helped reduce the rate of inadvertent parathyroidectomy (14% vs. 20.3%). The difference was even larger in thyroid surgeries without central neck dissection (10.7% vs. 17.7%), while no significant differences were observed in more complex cases.
The rate of inadvertent parathyroidectomy dropped from 21.6% in 2021 to 13.9% in 2023. This improvement likely reflects better awareness by surgeons and pathologists (specialists in diagnosing diseases by examining tissues, cells, and fluids in a laboratory), more careful examination of removed tissues, and more consistent reporting, the researchers said.
Patients whose parathyroid glands were accidentally removed were more likely to have low PTH and to develop early hypocalcemia (low calcium levels). These patients were also more likely to need alfacalcidol, the active form of vitamin D, which helps increase levels of calcium, after thyroid surgery.
After six months, permanent hypoparathyroidism was more common in patients who had inadvertent parathyroidectomy (10.5% vs. 3.9%).
“Inadvertent parathyroidectomy remains common, particularly when central neck dissection is performed,” the researchers wrote. “Near-infrared autofluorescence may offer modest benefit, while temporal improvements likely reflect increased surgical and pathological awareness, routine specimen examination, and more consistent reporting practices.”
