Hj Majid, Raza N, Shafi M, Mjk Niazi, As Khan, Mehboob Alam, Ali I, Hm Dar, Javed A, Ali R Mirza, Khan E, Tufail M.
Identification and Preservation of the External Laryngeal Nerve during Thyroid surgery: Surgical and Anatomic Considerations.
Proceeding Shaikh Zayed Postgrad Med Comp Jan ;22(1):7-13.

Iatrogenic injuries of external branch of superior laryngeal nerve (EBSLN) during thyroid surgery are not uncommon due to the possibility of anatomic variations in the relationship of this nerve with superior thyroid vessels and the result may be devastating to those patients who rely on their voices professionally. The study included 2 groups. Group A was a prospective nonrandomized analytical series of all consecutive patients undergoing thyroidectomies for various conditions in Surgical Unit II, Shaikh Zayed Postgraduate Medical Complex, Lahore, Pakistan during a three years period (November 2004 - November 2007). This group consisted of 133 patients. Male to female ratio was 1:3. Mean age was 35.22 years (range: 17-71 years). Ninety one (68.42%) patients had bilateral dissection (total, sub-total or neartotal thyroidectomies) and 42 (31.57%) had unilateral dissection (hemithyroidectomy I lobectomy and isthumusectomy). Thus, a total of 224 superior polar dissections were carried out. Three (3 .296 %) patients out of the 91 patients in the bilateral dissection group had asymmetrical nerves. Eighty one (60.9%) patients had benign disease, 32 (24.06%) had malignancy and 20 (15.03%) had toxic goiter. Nerve could not be identified in 42 (18.75%) polar dissections {positive identification in 182 (81.25%) polar dissections} . Three (2.25 %) patients in this study had clearly documented EBSLN injury as determined by voice changes, patient interview and IDL. In Group B, the anterior neck triangles of 19 embalmed human cadavers (i.e. 38 neck half preparations) of both sexes and variable ages with neither enlarged · thyroid glands nor any other signs of abnormality in this region were dissected in the dissection halls of two medical colleges in Lahore. The course and topographical relations (especially in relation to the superior thyroid vessels, superior pole of the thyroid and the cricothyroid muscle) of the EBSLN as well as bilateral asymmetry were noted as for Group A. Nerves were classified according to classification of Cernea et al. Good knowledge of the anatomy and relations of the EBSLN with meticulous dissection and ske letonisation and individual ligation of the superior polar vessels is the key to success.

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