The objective of aneurysm surgery is to exclude the aneurysm from the circulation while preserving blood flow distal to the lesion. A subset of complex large, giant, or fusiform intracranial aneurysms, however, may be unamenable to clipping or clip reconstruction of the parent vessel. In such cases, occlusion of the parent vessel, first described by Hunter, is a treatment option. In many patients, however, sacrifice of the parent artery has an associated risk of ischemic stroke. Therefore, sacrifice of the parent vessel can be supplemented with distal revascularization to provide the necessary distal blood flow while allowing the aneurysm to be trapped. The indications, options, and operative techniques for microvascular bypass are described, and the surgical approaches for revascularization of aneurysms of both the anterior and posterior circulation are detailed.