Expanded Endoscopic Endonasal Approach for Non-Vestibular Schwannomas
Endoscopic Endonasal Approach for Non-Vestibular Schwannomas
BACKGROUND: Non-vestibular schwannomas of the skull base often represent a challenge due 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 expanded endoscopic endonasal approach (EEA) for non-vestibular schwannomas of the skull base.
METHODS: Seventeen patients operated 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 multi-stage EEA. The rest received single EEA operation. Data for degree of resection were found for 15 patients. A 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: EEA provides adequate access for non-vestibular schwannomas invading the skull base, allowing a high degree of resection with a low rate of complications.