Researchers assess risk of nerve damage in thyroid cancer surgeries

While it has become more uncommon in recent decades, nerve damage incurred during surgery for thyroid cancer is still a possibility for people undergoing an operation to remove some or all of the gland. Recently, researchers tried to quantify the incidence of and risk factors for recurrent laryngeal nerve damage.

The recurrent laryngeal nerve (RLN) supplies electrical impulses that make the larynx move, according to Gray's Anatomy. Damage to this nerve can cause hoarseness or even impair a person's ability to speak.

In a recent study published in the Oman Medical Journal, a group of surgeons from Dammam University, Saudi Arabia, found that major thyroid surgeries appear to increase the risk of RLN damage, particularly if a patient undergoes a follow-up surgery.

The team began by stating that RLN damage is quite rare today, noting that injuries to the nerve occur in approximately 1 to 2 percent of all thyroid surgeries. In the study itself, slightly more than 4 percent of participants suffered some form of nerve damage related to the removal of thyroid carcinomas.

Researchers followed 340 patients admitted for thyroid cancer, hyperthyroidism, goiter and other diseases of the thyroid gland. They found that over the course of all observed surgeries, 13 cases of RLN damage occurred.

Most of them involved unilateral damage, or injury to to the RLN affecting just one side of the larynx. This sort of damage can result in a hoarse voice once patients have recovered. Of the 11 patients who had unilateral RLN damage, just one patient suffered a permanently hoarse voice.

Just two participants experienced bilateral RLN injuries, which affect the entire larynx and can more seriously impede the ability to speak. Neither case was permanent.

The study's authors analyzed data on the risk factors associated with these injuries and came to the conclusion that what increases risk of RLN damage the most is secondary surgery. While fewer than 3 percent of primary surgeries ended in RLN injury, more than 21 percent of secondary, or follow-up, surgeries did.

Likewise, total thyroidectomies and a failure to identify RLN damage during the procedure each increased the risk of hindered nerve function.

Surgery is still one of the most effective treatments for thyroid cancer, a disease that takes the lives of nearly 1,700 Americans each year, according to the National Cancer Institute.