A Novel Dissection Method Using a Flexible Neuroendoscope for Resection of Tumors Around the Aqueduct of Sylvius

Background Flexible endoscopes have both a wide range of movement and a wide field of view and are therefore widely used for endoscopic third ventriculostomy and biopsy. However, tumor resection around the aqueduct of Sylvius using flexible endoscopes has scarcely been reported. Case Description We report 2 cases of tumor resection around the aqueduct of Sylvius. The first case is a 38-year-old man presenting with progressive headache, nausea, and diplopia. Magnetic resonance imaging (MRI) revealed a 1.4 cm nonenhancing mass at the entry of the aqueduct of Sylvius and occlusive hydrocephalus. We performed tumor resection and endoscopic third ventriculostomy (ETV) simultaneously. His symptoms disappeared after the operation. Final pathologic diagnosis was ancient schwannoma. The second case is a 78-year-old woman presenting with progressive disturbance of consciousness (coma). MRI showed 0.7 cm nonenhancing mass at the entry of the aqueduct of Sylvius and occlusive hydrocephalus. We performed tumor resection and ETV similarly. Her consciousness improved after the operation. Final tumor diagnosis was cavernous malformation. In both cases there was no additional neurologic deficit after the surgery. Conclusions By using a flexible endoscope for tumor dissection, resection of a tumor without a neck, which cannot be removed through aspiration alone, becomes possible. To our knowledge, the presented cases are the first to describe the effectiveness of complete resection of a tumor in the third ventricle using flexible endoscopy.