Vascular reconstruction for cerebral aneurysms in the anterior circulation

Abstract

Vascular reconstruction for complicated cerebral aneurysms is sometimes required in order to prevent ischemic complications during the temporary occlusion of the parent arteries. In this paper, the authors discuss the usefulness and the effectiveness of vascular reconstruction in surgical treatments of cerebral aneurysms. Methods and Materials: (a) An STA–MCA anastomosis is performed in order to monitor the pressure of MCA while the large or giant middle cerebral aneurysms are clipped. The STA–MCA bypass provides a way of checking the patency of both the radial artery graft and the M2 portion. Checking the pressure of the MCA also acts to confirm the functioning of the radial artery graft or temporary radial artery bypass. As a side note, it should be known that the patient's arm must be lifted and held in position in order to perform temporary radial artery bypass. The STA–MCA anastomosis works as a back-up bypass during anastomosis of both the radial artery and the M2 portion of the MCA. (b) The radial artery graft is performed in the cavernous portion of carotid giant aneurysms with a proximal ligation of the cervical internal carotid artery. (c) Temporary radial artery bypass is used when clipping the carotid C1 and C2 portions of giant aneurysms. This prevents ischemic troubles during the temporary occlusion of the internal carotid artery. (d) When clipping anterior communicating aneurysms, A2z-A3 aneurysms, and dissecting aneurysms of ACA, an A3–A3 side-to-side anastomosis is performed in order to preserve blood flow to the distal anterior cerebral artery. Discussion: The STA–MCA bypass is a basic technique in cerebrovascular surgery, and is especially useful when performing cerebral aneurysm surgery. It acts primarily as an insurance, and secondarily as a way of restoring parent arteries after trouble, such as a laceration of the aneurysmal neck or a laceration of the parent artery. Although the temporary radial artery bypass cannot secure the ischemia of perforators, such as anterior choroidal arteries, it is an effective and useful method of preventing ischemic troubles within intracranial main trunk arteries. The A3–A3 bypass secures blood flow to the distal anterior cerebral artery and is therefore applicable in the combined unilateral A2 stenosis or A2 occlusion in the clipping of Acom aneurysms. In addition, an A3–A3 bypass can be used when dealing with large or giant aneurysms around the anterior communicating artery.