Neurovascular Sparing Transposition of Pterygopalatine Fossa: Anatomical Principles and Techniques

Objective: Sacrifice of pterygopalatine fossa (PPF) neurovascular structures during endoscopic endonasal transpterygoid approach (EETPA) may impact a patient's comorbidity. We present anatomical and surgical techniques for maximizing PPF transposition while preserving its neurovascular structures through orbito-pterygo-sphenoidal (OPS) ligament release and descending palatine canal (DPC) decompression. Methods: The EETPA was performed on six specimens. Two measurements were obtained to assess PPF transposition: (1) Inferior transposition (distance between the superior margins of the base of the pterygoid process and PPF); (2) lateral transposition (distance from Eustachian tube lateral margin to PPF medial margin). Results: After incising the OPS ligament, a mean gain of PPF inferior transposition of 7 mm (4–11 mm, p = 0.03) was observed, with a total inferior transposition of 12 mm (6–15 mm). Subsequently, the posterior half of the inferior turbinate was removed and the DPC was decompressed, with a mean gain of PPF lateral transposition of 12 mm (range 8–15 mm, p = 0.01). Conclusion: The OPS ligament release offers a significant advantage for the PPF inferior transposition, allowing access to the inferolateral recess of the sphenoid sinus, cavernous sinus, and paramedian middle cranial fossa, while the DPC decompression provides a significant advantage for the PPF lateral transposition, granting access to the Eustachian tube and ITF. Level of Evidence: N/A.