Extradural extranasal combined transmaxillary transsphenoidal approach to the cavernous sinus: A minimally invasive microsurgical model

The authors have previously described an extradural transmaxillary approach to the anterior compartment of the cavernous sinus. In an effort to expand the surgical access to that area without necessitating a craniotomy or wid e transfacial dissection, they present a modification of the transmaxillary approach to the sellar region and cavernous sinus. Methods: The approach w as developed on 12 fresh and 12 embalmed cadaveric specimen, and 2 dry skul ls. The initial sublabial incision is followed by a maxillotomy to expose t he course of the infraorbital nerve (terminal branch of maxillary branch of the trigeminal nerve) on the roof of the maxillary sinus. The route of the infraorbital nerve is traced to the pterygopalatine fossa as a guide to th e foramen rotundum, Superomedial drilling of the foramen rotundum is then p erformed to reveal the contents of the superior orbital fissure. After the nerves are safely identified in the superior orbital fissure, medial enlarg ement of the window into the cavernous sinus is made possible by drilling t he lateral and posterior wall and septum of the sphenoid sinus. Results: Th e combined transmaxillary transsphenoidal approach offers an excellent expo sure of the sellar and infrasellar region. The approach offers clear visual ization of the ipsilateral loop of the carotid artery, the pituitary fossa, and the cranial nerves of the ipsilateral cavernous sinus. Mean operative reach is 38 mm from the posterior wall of the maxillary sinus to the ipsila teral carotid loop and 56 mm to the contralateral loop. The width of the op erative window is 26 mm at the base within the cavernous sinus. Conclusion: The model offers a minimally invasive approach that avoids the need for cr aniotomy or violating the nasal cavity. It may be safely employed to access vascular as web as invasive lesions of the sellar and infrasellar region, The approach offers excellent visualization of the ipsilateral intracaverno us carotid artery with both proximal and distal control, as well as cranial nerves III, IV, VI, V2, the hypophyseal region, and the medial aspect of t he contralateral cavernous sinus.