Introduction: Minimally invasive transoral surgery for oropharyngeal cancer is a challenge for head and neck surgeons because of the inside-out anatomic presentation and the confined workspace. This study was performed to describe the main neurovascular and muscular landmarks in a transoral approach. The authors propose an anatomic stratification for this surgery.
Materials and methods: Lateral wall of the oropharynx and base of the tongue of 15 formalin-fixed heads (30 sides) and 5 fresh cadaveric heads (10 sides) sagittal sectioned were dissected from the inside outwards. Dissection of 7 fresh cadaveric heads via an endoscopic transoral approach was also performed.
Results: The lateral oropharyngeal wall was divided into 3 layers from medial to lateral, based in the styloid muscle diaphragm. The first layer, medial to styloid muscles, includes the tonsillar vascularization and the lingual branch of the glossopharyngeal nerve. The second layer, lateral to constrictor muscles, includes the pharyngeal venous plexus, the glossopharyngeal nerve, and the lingual artery. The third layer, lateral to styloid diaphragm, includes the parapharyngeal and submandibular spaces, the carotid vessels and lingual, vagus, glossopharyngeal and hypoglossal nerves. The base of the tongue was divided into central and lateral parts, which contain the lingual artery and lingual branches of the glossopharyngeal nerve. The main landmarks to find the neurovascular structures in each layer are described.
Conclusion: The authors propose an anatomic division, which helps to plan oropharynx and base of the tongue surgery. This anatomic stratification is useful to surgeons when performing a reconstruction of the oropharynx with a transoral approach.