Expanded Endoscopic Multiaxial Access to the Midline Cranial Base and Infratemporal Fossa Through the Maxillary Osteoplastic Window

Objective: The medial and posterolateral walls of the maxillary sinus form a bony barrier to the posterior nasal and pterygomaxillary space. A portal through these spaces provides an endoscopic corridor to the midline cranial base and infratemporal fossa. In this study, we present our experience with the maxillary osteoplastic window as an endoscopic portal to the midline cranial base and infratemporal fossa.

Method: A maxillary osteoplastic window approach was performed, removing the entire anterior maxillary wall as a single bone flap. The osteoplastic flap was replaced at the end of the case. Selective removal of the medial and posterolateral maxillary wall provided endoscopic access to the posterior nasal cavity, sphenoid sinus, clivus, and infratemporal fossa. All cases were performed with image-guided navigation.

Results: The osteoplastic flap provided an average of 6 cm² endoscopic widow. Craniocaudal access from the sella to the inferior extent of the midline clivus was achieved. An expanded transclival dissection into the posterior cranial fossa was performed in one patient for removal of a chordoma. Lateral access into the infratemporal fossa allowed removal of extensive vascular tumors. There was no sensory loss in the V2 distribution attributed to the approach.

Conclusion: The maxillary osteoplastic flap provides an expanded window that extends the endoscopic access to the midline cranial base and infratemporal fossa.