Background
The external branch of the superior laryngeal nerve (EBSLN) injury is an important and not uncommon, though frequently overlooked, complication of thyroid surgery. The rate of EBSLN injury has been reported to vary from 0 to 58%, depending on different postoperative assessment methods. Injury to the EBSLN during thyroid operation can paralyze ipsilateral cricothyroid muscle, and the clinical symptoms mainly include vocal fatigue and diminished vocal frequency range, especially with respect to raising pitch, which may result in decreased quality of life, particularly for voice professionals.
Patients and methods
This prospective study included 22 patients with goiter. They were divided into two groups: group 1 (G1) included all cases in whom nerve stimulator was used and group 2 (G2) included all cases in whom trial of visual identification of the EBSLN was done.
Results
It was found that patients with short obese neck, large gland size, large gland weight, and retrosternal extension showed difficulty in EBSLN identification and had high risk of nerve injury (<0.042, 0.04, 0.03, and 0.041, respectively). Nerve stimulator has improved identification of EBSLN (<0.036) with less voice affection postoperatively (<0.04), with no statistical difference between both groups regarding operative time.
Conclusion
It was concluded that routine use of nerve stimulator in surgical interventions on the thyroid gland will be beneficial for more secure identification and prevention of EBSLN injury and preservation of voice quality postoperatively.