The Role of Direct Surgery in the Treatment of Intracranial Aneurysms

Abstract

  Selection of either direct surgery or endovascular treatment for patients with an intracranial aneurysm depends on individualized factors such as shape and location of the aneurysm in view of an advantage and a disadvantage of each therapeutic modality. Surgical clipping has the advantage of being able to deform an aneurysm into an appropriate shape under direct vision and shows its superiority in a complex-shaped aneurysm or an aneurysm from which a branch or a perforator originates. In order to achieve this purpose, surgeons must visualize all anatomical structures around an aneurysm, dissect an aneurysm circumferentially to provide the aneurysm with mobility and secure a wide operative field for the inspection from various angles. On the other hand, as surgeons cannot directly observe the blood flow in intracranial arteries during surgery, intraoperative monitoring such as doppler ultrasonography, indocyanine green (ICG) videoangiography and motor-evoked potential (MEP) monitoring is mandatory. Recently, large or broad-neck aneurysms have become indicated for endovascular treatment with advances in intracranial stents. However, surgical clipping is still an attractive therapeutic option for large aneurysms as it can completely block the blood flow at the neck. Another advantage of direct surgery is brought about revascularization by bypass surgery. Bypass surgery also plays an important role in combined treatment with endovascular therapy for complex aneurysms. To understand and utilize maximally the advantages of direct surgery will further improve the therapeutic result of patients with intracranial aneurysms.