Nerve-locating technique results in fewer cases of hypoparathyroidism, vocal paralysis
A small percentage of patients who receive thyroidectomies experience hoarseness, hypoparathyroidism or even vocal paralysis due to a damaged nerve. Now, a team of Turkish researchers has determined which of two nerve-locating techniques has a lower complication rate.
Scientists at Bezmialem Vakif University in Istanbul recently reported that finding the recurrent laryngeal nerve (RLN) where it enters the top of the thyroid is preferable to looking for where it exits the bottom of the gland.
The former direction is called the superior-inferior, or top-down RLN-locating, method, which scientists determined results in fewer side effects on average, compared to the inferior-superior, or bottom-up, technique.
In a recent edition of the journal Archives of Otolaryngology: Head and Neck Surgery
, the team published the results of a study that followed the tracheal, vocal and thyroidal health of 195 patients who underwent partial or complete thyroidectomies.
The authors found that when doctors located the RLN in the inferior-superior fashion, about 1.5 percent of patients ended up with permanent vocal paralysis. By contrast, none of the superior-inferior cases resulted in this irreversible side effect.
Likewise, more than 3 percent of inferior-superior RLN locations led to permanent hypoparathyroidism, while none of the superior-inferior cases did.
Scientists concluded that finding the RLN where it enters the top of the thyroid gland appears to be safer and result in fewer instances of temporary or permanent nerve damage.
In general, how often do such side effects occur after thyroidectomies? The Columbia University Department of Surgery estimates that one in every 100 thyroid removal procedures involves some damage to the RLN and other nerves adjacent to the gland.
Of these cases, most involve temporary hoarseness or an inability to control the volume of the voice, an effect that typically recedes in a matter of weeks.
Permanent vocal paralysis is rare, the department notes, adding that damage to the nerves that control the parathyroid glands occurs in roughly one in every 300 thyroidectomies.