Transseptal approach for extended endoscopic resections of the maxilla and infratemporal fossa.

BACKGROUND: Larger and more extensive lesions of the maxilla and infratemporal fossa are being successfully managed by entirely endoscopic approaches. There are still limitations in access, especially the anterolateral maxilla. The suitability of various surgical approaches was assessed in relation to surgical access achieved.
METHODS: Surgical access was compared in 10 cadaver heads. Five zones were defined: zone 1, nasal cavity; zone 2, medial to infraorbital nerve (ION); zone 3, lateral to ION; zone 4, anterior maxilla; and zone 5, premaxillary tissue. Endoscopic maxillary surgery consisted of standard antrostomy, modified medial maxillectomy, or complete medial maxillectomy with lacrimal duct resection. Transseptal and ipsilateral approaches were compared in each surgical state. The degree of angulations and resection zone accessed were recorded from image-guided surgery. The limits of both straight and curved instrumentation were also compared.
RESULTS: Transseptal access improved surgical access by 14.7 +/- 2.5 degrees when compared with ipsilateral approaches (p < 0.001) across all situations. The access to zone 3 across all specimens was significantly improved by 63.3-97.6% (chi2 = 20.83; p < 0.001) after all three surgical states. After complete medial maxillectomy, access to zone 4 increased from 25.0 to 85.0% (chi2 = 14.54; p < 0.001) with a transseptal approach.
CONCLUSION: Extended endoscopic maxillary surgery combined with a transseptal option enables additional access to previously considered challenging locations. Preoperative assessment of skull base tumor, papilloma and angiofibroma extent, and resection margin will dictate surgical approach.