Endoscopic anatomy of the pterygopalatine fossa.

BACKGROUND: The pterygopalatine fossa can be involved with a variety of infectious and neoplastic processes. This region can be entered endoscopically, but endoscopic landmarks to localize the neurovascular structures in the pterygopalatine fossa have not yet been reported.

OBJECTIVES: The purpose of this study is to describe the location of the neurovascular structures in the pterygopalatine fossa in relation to consistent intranasal landmarks.

METHODS: Endoscopic dissections of cadaveric heads were performed. The locations of neurovascular structures in the region were defined.

RESULTS: The sphenopalatine foramen (SPF) served as the primary intranasal landmark to the pterygopalatine fossa (PPF). Mean distances from the SPF were measured with the following results: SPF to sphenopalatine ganglion (SPG), 4 mm medially and 6 mm laterally; SPF to foramen rotundum (FR), 7 mm; and SPF to vidian canal (VC), 2 mm. The internal maxillary artery followed an irregular and inconsistent course, making it difficult to define a reliable landmark for its location in the fossa.

CONCLUSION: Entering the PPF inferior to the horizontal plane of the SPF along a vertical line drawn inferiorly from the infraorbital canal will avoid injury to the major neural structures in the fossa. Because of the inconsistent course and location of the internal maxillary artery, this structure may be at risk no matter where the fossa is entered. These landmarks will allow the surgeon to enter the PPF with more accuracy and less patient morbidity.