Surgical anatomy of the parapharyngeal space: Multiperspective, quantification-based study

Background: Several surgical approaches to the parapharyngeal space (PPS) have been proposed. An objective description of advantages and limitations of the surgical routes is lacking. Methods: Ten cadaver heads were dissected using the transnasal (medial, lateral), sublabial, transoral (transpharyngeal, transvestibular, transmandibular), transcervical (transcervical, transparotid, transmandibular, transmastoid), and type C and D infratemporal approaches. Neurovascular and musculoskeletal structures encountered were analyzed. A navigation-based quantification of working volume and exposure of PPS compartments was accomplished. Results: Transnasal approaches exposed the upper PPS, though with limited working volume. Transoral approaches exposed the middle PPS, minimizing neurovascular structures crossed. Only transcervical and skull base approaches exposed the entire PPS, crossing several neurovascular structures. Conclusion: A tentative systematization of the surgical approach(es) to PPS in relation to different targets is provided: unicompartmental resection can be performed with a single, conservative access, whereas multicompartmental dissections frequently require a wider or multiportal approach.