Guidelines for Complications of Cancer Treatment Vol VIII Part B

paramedian position, it will result in a reduced glottic air spacewhich would necessitate a tracheostomy. On the other hand,if both cords are paralysed in abduction, the patient will havesevere aspiration, which may also necessitate a tracheostomy.External branch of the Superior LaryngealNerve:a. Relation to the Joll’s triangle:The EBSLN lies deep to the superior pole of the thyroidgland as it passes to the cricothyroid muscle in thesternothyrolaryngeal (Joll’s) triangle formed laterally bysuperior thyroid pole, superiorly by the attachments ofthe strap muscles and medially by the midline.b. Relation to the superior thyroid pole:Depending on the distance of the EBSLN from thesuperior pole of the thyroid gland, Cernea et al., proposeda classification given below. In their study there was amore than 50% incidence of the EBSLN being less than1 cm from the superior thyroid pole suggesting need formeticulous dissection of the individual superior thyroidartery branches as close to the gland whilst trying toidentify the nerve.EBSLN TypesType I EBSLN crosses the Superior thyroid artery (STA) 1cmcranial to the upper pole of the thyroid gland.Type II EBSLN crosses the STA < 1 cm cranial to the upperpole of the thyroid gland.Type III EBSLN crosses the STA while covered by the Upperpole of the thyroid gland.Type IV EBSLN does not cross the trunk of the STA at all, butruns dorsal to the artery.193