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. Author manuscript; available in PMC: 2015 Apr 8.
Published in final edited form as: Surg Oncol Clin N Am. 2008 Jan;17(1):93–viii. doi: 10.1016/j.soc.2007.10.014

Fig. 4.

Fig. 4

Variations in the anatomic relationship of the main trunk of the ESLN to the inferior constrictor (IC) muscle and superior thyroid pedicle. (A) The ESLN descends superficial to the IC muscle along the superior thyroid vessels so that it is visible in its entire course before innervating the cricothyroid (CT) muscle. (B) The ESLN pierces the IC muscle approximately 1 cm above the cricothyroid membrane (red arrow) so that only its upper portion is at risk for injury. (C) The ESLN runs deep to the IC muscle and, therefore, is protected from unintended injury during dissection in the vicinity of the superior thyroid pole. The cricopharyngeus muscle is marked CP.