Staged resection of large hypervascular vestibular schwannomas in young adults.

Two young adults underwent resection of large hypervascular vestibular schwannomas (acoustic neuromas) via two-stage surgery. The first patient, a 27-year-old woman with hydrocephalus, had a large hypervascular vestibular tumor in the left cerebellopontine angle (CPA) supplied by the left anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA). The second patient, a 34-year-old woman, had a large AICA-supplied hypervascular vestibular tumor in the left CPA that displaced the brain stem significantly. At the initial stage, only the lateral aspect of the tumor was debulked due to excessive bleeding from the tumor bed. Angiography 1 or 2 months after the initial operation showed that the tumor was hypovascular. At the second stage, the remnant medial aspect of the tumor was relatively avascular and nonadherent to the brain stem. Without blood transfusion during the second stage, the tumor was removed totally in the first patient and subtotally in the second patient. Pathological examination revealed that dilatated blood vessels were prominently increased at the first surgery; however, at the second surgery, the number of blood vessels had decreased, showing necrosis and degeneration. Although there are no absolute indications for the staged resection of vestibular schwannomas, this procedure may represent one of the safest options for these difficult lesions in young adults.