THE FRONT DOOR TO MECKEL'S CAVE: AN ANTEROMEDIAL CORRIDOR VIA EXPANDED ENDOSCOPIC ENDONASAL APPROACH-TECHNICAL CONSIDERATIONS AND CLINICAL SERIES

OBJECTIVE: Tumors within Meckel's cave are challenging and often require complex approaches. in this report, an expanded endoscopic endonasal approach is reported as a substitute for or complement to other surgical options for the treatment of various tumors within this region. METHODS: A database of more than 900 patients Who underwent the expanded endoscopic endonasal approach at the University of Pittsburgh Medical Center from 1998 to March of 2008 were reviewed. From these, only patients who had an endoscopic endonasal approach to Meckel's cave were considered. The technique uses the maxillary sinus and the pterygopalatine fossa as part of the working corridor. Infraorbital/V-2 and the vidian neurovascular bundles are used as surgical landmarks. The quadrangular space is opened, which is bound by the internal carotid artery medially and inferiorly, V-2 laterally, and the abducens nerve superiorly. This offers direct access to the anteroinferomedial segment of Meckel's cave, which can be extended through the petrous bone to reach the cerebellopontine angle. RESULTS: Forty patients underwent an endoscopic endonasal approach to Meckel's cave. The most frequent abnormalities encountered were adenoid cystic carcinoma, meningioma, and schwannomas, Meckel's cave and surrounding structures were accessed adequately in all patients. Five patients developed a new facial numbness in at least I segment of the trigeminal nerve, but the deficit was permanent in only 2. Two patients had a transient VIth cranial nerve palsy. Nine patients (30%) showed improvement of preoperative deficits on Cranial Nerves III to VI. CONCLUSION: In selected pati ents, the expanded endoscopic endonasal approach to the quadrangular space provides adequate exposure of Meckel's cave and its vicinity, with low morbidity.