46 Endoscopic Endonasal Transmaxillary Approach to the Vidian Canal and Meckel’s Cave • Tumors isolated to the Meckel’s cave. • Tumors with middle fossa–extracranial extension. • Tumors with pure extracranial involvement along the second (V2) and third (V3) branch of the trigeminal nerve. • Position: Supine with the head fixed with a Mayfield head holder. • Body: The body is placed horizontal or in slight reverse Trendelenburg position (15-30°). • Head: The head is slightly extended and rotated to the right. • Abdomen and contralateral thigh are prepped and draped in a sterile fashion in case a fat graft or fascia lata are needed. • Start with a rigid 0° endoscope. • 1% lidocaine with 1:100,000 epinephrine is used to vasoconstrict the sphenopalatine artery (SPA) at the sphenopalatine foramen, in addition to infiltrating the uncinate process and vertical lamella of the ipsilateral middle turbinate. • Resection of the posterior third of the septum allows for a binostril, 4-handed surgical technique and greater maneuverability of surgical instruments. • Middle turbinate • Uncinate process Fig. 46.1 Endoscopic view of the middle turbinate and uncinate process. • A contralateral nasoseptal flap must be harvested (see Chapters 38 and 39). • Complete a septectomy by resecting the posterior nasal septum. • Introduce the endoscope from contralateral nostril. • Sphenoidectomy is performed. • Uncinectomy is carried out. • Middle turbinate is resected. • Maxillary sinus ostium is identified. • Ethmoidectomy is performed: the ethmoidal bulla and supra-bulla cells are both removed. • Removing the ethmoidal bulla does facilitate the removal of the posterior wall of the medial junction of maxillary sinus. • Middle turbinate. • Uncinate process. • Ethmoidal bulla. • Maxillary sinus ostium. • A wide maxillary antrostomy is carried out. • The infraorbital neurovascular bundle is identified. • Sphenopalatine artery is cauterized and divided. Fig. 46.2 Probe in the maxillary sinus.
46.1 Indications
46.2 Patient Positioning
46.3 Surgical Approach (Fig. 46.1)
46.3.1 Critical Structures
Abbreviations: NS = nasal septum; RMT = right middle turbinate; TMT = tail of the middle turbinate; UP = uncinate process.
46.4 Nasal Stage (Figs. 46.2, 46.3)
46.4.1 Critical Structures
46.5 Maxillary Sinus Stage (Fig. 46.4)
Abbreviations: MO = maxillary ostium; NS = nasal septum; P = probe; RMT = right middle turbinate; TMT = tail of the middle turbinate; UP = uncinate process.
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