Transoral Endoscopic Anatomy of the Parapharyngeal Internal Carotid Artery: A Cadaveric Study with Novel Modular Classification

Objective: The parapharyngeal internal carotid artery (ppICA) lacks a solid and uniform classification, and the absence of consistent terminology hinders anatomical reporting and surgical planning. To address this gap, we introduce a novel modular classification of the ppICA into three surgical segments, aligned with the topographic subdivision of the parapharyngeal space (PPS): infrapetrous or upper ppICA (UppICA), extending from its entry into the carotid canal to the stylo-muscular complex; stylo-muscular or middle ppICA (MppICA), located at the level of the styloid tip in relation to the stylopharyngeal diaphragm and ligamentous complex; and infra-styloid or lower ppICA (LppICA), extending from this intersection to the most caudal point accessible through a transoral route ([ Fig. 1 ]). This framework was then applied to quantitatively assess angle of exposure and surgical freedom for each segment during a transoral endoscopic approach. Methods: Ten sides from five latex-injected cadaveric heads were dissected using a rigid endoscopic-assisted transoral corridor via a retromolar trigone incision. Image-guided neuronavigation (accuracy