BACKGROUND: Nonvestibular schwannomas of the skull base often represent a challenge owing to their anatomic location. With improved techniques in endoscopic endonasal skull base surgery, resection of various ventral skull base tumors, including schwannomas, has become possible.
OBJECTIVE: To assess the outcomes of using endoscopic endonasal approach (EEA) for nonvestibular schwannomas of the skull base.
METHODS: Seventeen patients operated on for skull base schwannomas by EEA at the University of Pittsburgh Medical Center from 2003 to 2009 were reviewed.
RESULTS: Three patients underwent combined approaches with retromastoid craniectomy (n = 2) and orbitopterional craniotomy (n = 1). Three patients underwent multistage EEA. The rest received a single EEA operation. Data on degree of resection were found for 15 patients. Gross total resection (n = 9) and near-total (>90%) resection (n = 3) were achieved in 12 patients (80%). There were no tumor recurrences or postoperative cerebrospinal fluid leaks. In 3 of 7 patients with preoperative sensory deficits of trigeminal nerve distribution, there were partial improvements. Patients with preoperative reduced vision (n = 1) and cranial nerve VI or III palsies (n = 3) also showed improvement. Five patients had new postoperative trigeminal nerve deficits: 2 had sensory deficits only, 1 had motor deficit only, and 2 had both motor and sensory deficits. Three of these patients had partial improvement, but 3 developed corneal neurotrophic keratopathy.
CONCLUSION: An EEA provides adequate access for nonvestibular schwannomas invading the skull base, allowing a high degree of resection with a low rate of complications.
ABBREVIATIONS: CN: cranial nerve
EEA: endoscopic endonasal approach
ICA: internal carotid artery
RMC: retromastoid craniectomy