Identification of the External Branch of the Superior Laryngeal Nerve during Thyroid Surgery

To compare the level of intra-operative identification of external branch of the superior laryngeal nerve (EBSLN) through classical conventional clinical methods of prevention against those applying intraoperative neuromonitoring (IONM).

The study included 102 patients with interventions on the thyroid gland performed in the surgical clinics of St George University Hospital and the Department of Special Surgery of Plovdiv Medical University. All operative procedures were performed by the standard technique of capsular dissection and IONM.

Of all 102 thyroid procedures 87 (85.3%) patients underwent total thyroidectomy and 15 (14.7%) had unilateral thyroid lobectomy. One hundred fifty-five (82.01%) out of 189 expected EBSLN were identified and investigated intraoperatively when trying to identify visually EBSLN by the so called classical (conventional) methods of prevention. With the use of IONM, 181 (96.76%) EBSLN were correctly identified. Compared to the preliminary results of visual identification - 155/189 (82.01%) EBSLN, the degree of identification of EBSLN through IONM reached 96.76% which is a statistically significant difference (P <0.05) Conclusion: The use of IONM during thyroid resection significantly improves the degree of identification of EBSLN compared to conventional means of prevention. Routine use of IONM in surgical interventions on the thyroid gland will be beneficial for more secure identification and prevention of EBSLN.