Classification System for Lateral Pharyngotomy

Abstract

Objective: 1) Propose a classification system of lateral pharyngotomy (LP) used in exposing various sites of the oropharynx, supraglottis, and hypopharynx. 2) Describe the structures visible with each category of lateral pharyngotomy. Method: An anatomic study on 5 fresh-frozen human cadavers was carried out at the Medical Education and Research Institute. After exposure of the anterior compartment of the neck and laryngeal framework, progressively more extensive pharyngotomy was performed. The pharyngeal structures exposed with each extension were recorded by video and still photography. Results: Entry into the pharynx between the hypoglossal nerve cephalically and the superior laryngeal nerve caudally (Type I LP) provided exposure of the epiglottis and ipsilateral tongue. Exposure toward the pyriform apex was facilitated by dividing the superior laryngeal artery (Type II LP). This provided exposure to the postcricoid area, arytenoids, and cervical esophageal inlet. The digastric and stylohyoid muscles were transected (Type III LP) to provide exposure of the entire base of tongue, uvula, and soft palate. Division of the hyoglossus and mylohyoid muscles was classified as Type IV LP, adding visualization of the vallecula and contralateral tonsil. Conclusion: An appropriate class of pharyngotomy may be chosen depending on the structures requiring exposure. This cadaver-based anatomic study delineated the anatomic structures to be divided to facilitate exposure of pharyngeal subsets. A classification system is proposed that defines the steps in gaining access to the pharynx.