Visual Field Preservation in the Treatment of the Brain Arteriovenous Malformation Located near the Lateral Ventricle

Abstract

When treating brain arteriovenous malformations (AVM), it is crucial to carefully consider treatment strategies, including preoperative embolization and surgical approaches, based on the nidus, feeder, and drainer locations. The treatment of AVM near the lateral ventricle poses the risk of visual field defects and language dysfunction. Among the 41 patients with AVM treated at our hospital between January 2010 and September 2022, three presented with lesions near the lateral ventricles. We compiled imaging findings, treatment strategies, and functional prognoses, focusing primarily on visual field defects. All patients experienced bleeding, but the symptoms were limited to headaches and vomiting, with no neurological deficits. Preoperative embolization using Onyx was performed in all patients. Case 1: A lesion was identified in the lateral aspect of the left ventricular trigone. The main feeder entering the base of the nidus was embolized for use as the deepest reference point during surgery. The nidus was removed using ViewSite through a high parietal approach. Although right homonymous hemianopsia was noted postoperatively, considerable improvement was observed after two weeks. Case 2: The lesion was located in the left ventricular trigone. Following embolization, it was removed using ViewSite through an occipital transcortical approach. Postoperative homonymous hemianopsia occurred but generally improved over six months. Case 3: The lesion was in the left medial temporal lobe. After embolization, the mass was removed via a subtemporal approach. Cerebral infarction occurred in the lateral part of the thalamus, resulting in right homonymous hemianopia, kanji agraphia, and sensory impairment. Careful consideration is required to avoid visual field defects when treating AVMs near the lateral ventricle. The use of ViewSites holds promise for reducing the risk of visual radiation.