Background
External branch of superior laryngeal nerve (EBSLN), which is the motor supply of the cricothyroid muscle, is closely related to superior thyroid vessels with multiple anatomical variations. Thyroidectomy may be complicated with EBSLN injury with postoperative voice changes. This study aimed to compare between identification and nonidentification of EBSLN on post-thyroidectomy voice changes.
Patients and methods
A prospective comparative study was conducted at Ain Shams University Hospitals between March 2018 and March 2021. It included 150 cases of total thyroidectomy who were divided sequentially into two groups, group A (cases with nonidentification of EBSLN) and group B (cases with identification of EBSLN). We excluded from group B the cases of failed identification of the nerve (even unilateral) after trial of dissection and identification. Preoperative demographics, operative and postoperative data were collected and compared between two groups. EBSLN affection as the main outcome was assessed by a combination of postoperative voice changes and laryngoscopic finding.
Results
Group A included 75 cases and group B included 66 cases after exclusion of nine (12%) cases due to failure of intraoperative identification. There was a nonsignificant difference between both groups as regards preoperative demographics and operative data (blood loss, operative time, and complications). As regards postoperative EBSLN affection, we did not find any significant difference between both groups (6.7% in group A vs. 4.5% in group B).
Conclusions
Visual identification of EBSLN in thyroidectomy is feasible by an experienced surgeon with no significant benefits over individual ligation of superior thyroid vessels close to the thyroid capsule without identification of the nerve.