Hypoparathyroidism Risk Can Be Lowered by Careful Surgical Gland Dissection, Study Says

Joana Carvalho, PhD avatar

by Joana Carvalho, PhD |

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Central lymph node dissection

Careful identification and dissection of the parathyroid glands during thyroid surgery can reduce the risk of hypoparathyroidism after the procedure, a study suggests.

The study, “Risk Factors of Incidental Parathyroidecomy in Thyroid Surgery,” was published in the journal Cureus.

Hypoparathyroidism is a rare disorder caused by low levels of the parathyroid hormone (PTH) in the body. Normally, PTH is produced when blood levels of calcium fall. One of the consequences of low PTH levels is a marked decrease of calcium in the blood, a medical condition known as hypocalcemia. Hypocalcemia can cause fatigue, muscle spasms, tingling and numbness, and an irregular heartbeat, among other symptoms.

In some cases, hypoparathyroidism and hypocalcemia occur in people who undergo thyroid surgery. The conditions can result from permanent damage to the neighboring parathyroid glands, or their unintentional removal during surgery, called incidental parathyroidectomy, or IP. The parathyroid glands are the structures responsible for producing PTH. Statistics indicate that the incidence of IP ranges between 6.4% and 31.1%.

Despite being one of the most common complications of thyroid surgery, there is still controversy regarding the specific factors that may increase IP risk among those undergoing thyroid surgery.

To address these questions, the researchers reviewed the medical records of 270 patients (218 women and 52 men) who had thyroid surgery between January 2017 and December 2018 in two hospitals in Riyadh, Saudi Arabia.

Factors such as the patients’ gender, the preoperative diagnosis, the type of surgery, and the surgeons’ use of surgical loupes —  small magnifiers mounted within lenses of glasses — during the procedure were evaluated. The goal was to find possible associations between these factors and the incidence of IP.

More than half of the patients (50.7%) had the thyroid surgery, called thyroidectomy, due to the presence of benign nodules. Another 47% had been diagnosed with different subtypes of thyroid cancer. Most of the individuals (86.7%) had a total thyroidectomy, or complete thyroid removal, without neck dissection. In that procedure, surgeons also remove lymph nodes in the neck and surrounding tissue.

Parathyroid tissues were identified in 62 (23%) surgical specimens, indicating that IP occurred in approximately one quarter of the patients undergoing thyroid surgery.

No significant correlations were found between IP and patients’ gender, use of surgical loupes, preoperative diagnosis, or type of surgery.

“Although the risk of incidental parathyroidectomy is inevitable, careful dissection and meticulous intraoperative identification of parathyroid gland during thyroidectomy can reduce the incidence of incidental parathyroidectomy, thereby minimizing the risk of postoperative hypoparathyroidism and hypocalcemia,” the researchers said.