Endoscopic endonasal transrotundum middle fossa exposure: Technique of transpterygoid maxillary nerve transposition.

Endoscopic endonasal transrotundum middle fossa exposure: Technique of transpterygoid maxillary nerve transposition.

World Neurosurg. 2018 Feb 01;:

Authors: Wong RH

Abstract
OBJECT: Middle fossa floor access can be challenging. Open skull base approaches have associated morbidity and yield suboptimal working angles around temporal lobe. Endoscopic endonasal approaches to the middle fossa are poorly described, but provide an improved angle. The author hypothesized that the length of the maxillary nerve can be transposed out of foramen rotundum in order to provide a path to expose the full width of the middle fossa floor through the anterolateral and anteromedial triangle.
METHODS: Endoscopic endonasal transpterygoid dissections to expose the middle fossa were performed bilaterally on two silicone-injected cadaveric heads (four sides). Transposition of V2 was then performed on all sides and additional middle fossa exposure was achieved. High resolution CT imaging was obtained to quantify the extent of exposure. A transzygomatic approach was also performed for comparison.
RESULTS: The maxillary nerve was successfully transposed in each dissection. A periosteal fold was identified to assist in the mobilization of the infraorbital nerve. The average middle fossa exposure achieved without transposition was 50% (of the medial to lateral width). Transposition increased that to 95%. Comparison with the open transzygomatic approach demonstrated superior surgical trajectory (inferior to superior) with the endonasal route.
CONCLUSIONS: Endoscopic endonasal transpterygoid approaches with or without transposition of the maxillary nerve provide a reasonable option for sequentially exposing the entire medial to lateral extent of the anterolateral triangle. It provides an advantageous inferior to superior surgical angle and can be considered for the treatment of select middle fossa floor pathology.

PMID: 29410144 [PubMed - as supplied by publisher]

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