抄録
Large but non-giant cerebral aneurysms are usually treated with neck clipping, which carries larger risk compared with clipping for smaller aneurysms.
To maximize the benefit of clipping over the risk, the authors have been cautious about the following points. 1) Preoperative evaluation of not only the aneurysm morphology but also collateral blood flow during temporary occlusion of the parent artery proximal to the aneurysm. 2) Positioning and craniotomy to minimize brain retraction. 3) Monitoring of motor evoked potential to tailor the temporary occlusion time. 4) Utilization of the retrocarotid space by dissecting vessels from the temporal lobe facing the Sylvian fissure and retracting the temporal lobe posteriorly. This is especially important for internal carotid-posterior communicating (IC-Pcom)/anterior choroidal (ACh) and basilar terminal aneurysms in terms of visualization of ACh, perforators of Pcom, and the aneurysm neck behind the IC, as well as to obtain a wide working space even after temporary clipping of the proximal basilar artery. 5) Bypass surgery can be used to prolong permissible temporary occlusion time or to provide permanent blood flow in conjunction with parent artery occlusion, when clipping is considered too risky. 6) Intraoperative reassessment of the surgical strategy by an endovascular surgeon is sometimes valuable to decide whether the clipping should be accomplished or abandoned, with a change to endovascular therapy.
