Transoral endoscopic anatomy of the parapharyngeal space: a step-by-step logical approach with surgical considerations

Background Surgical approaches to the parapharyngeal spaces are challenging. Little is known about the transoral perspective of the anatomy of the parapharyngeal space. Thus, transoral approaches are seldom performed, and only for small-sized tumors. Methods Six freshly injected cadaver heads were dissected to illustrate the transoral surgical anatomy of the parapharyngeal space. Results The transoral window dominates the parapharyngeal space from the medial pterygoid muscle laterally to the superior constrictor muscle medially. The stylopharyngeus and styloglossus muscles seem to be critical landmarks in this approach. Posterior to these muscles and laterally to the superior constrictor muscle, the internal carotid artery, internal jugular vein, and lower cranial nerves are identifiable. Conclusion This anatomic study emphasizes the critical role of the superior constrictor, styloglossus, and stylopharyngeus muscles and highlights the concept of a logical step by step technique that allows the identification of important structures and the creation of safe surgical corridors.