The external laryngeal nerve in thyroid surgery: The 'no more neglected' nerve

Aims : To describe a novel surgical technique of 'lateralization' of superior pole to identify and save external branch of superior laryngeal nerve (EBSLN) during thyroidectomy.
Settings and design: Prospective, nonrandomized at a tertiary care hospital in a specialized unit.
Material and methods: Over 30 months, 46 patients underwent thyroidectomy using technique of 1) 'Lateralization' of upper pole and dissection of avascular cricothyroid space 2) identification of EBSLN 3) skeletonization and individual ligation of superior thyroid vessels. Identified nerves were classified according to Cernea's classification. Outcomes were number of nerves identified, number of 'at risk' nerves' bilateral asymmetry and incidence of injury assessed by subjective interview and indirect laryngoscopy.
Results: Of the 78 dissected superior poles, nerves could be identified in 72 (92.31%). There were 22 (28.2%) type I, 42 (53.54%) IIa and 8 (10.25%) IIb 'at risk' nerves. In 32 patients with bilateral dissections, asymmetry of nerve was noted in 15%. Injury to nerve was not recorded in any of the patients. Average weight of glands was 69.59 g. Thyroidectomy was performed for benign disease in 28, malignancy in 4 and thyrotoxicosis in 14 patients.
Conclusions: With technique of 'lateralization' and 'skeletonization and individual ligation of the superior vessels,' EBSLN identification increases and injury can be prevented. These results relate to the utilization of specific surgical technique and it is reasonable to expect that most surgeons, once familiar with the technique, should be able to achieve similar outcomes.