Skull base approaches to basilar artery aneurysms

We studied the relative merits and advantages of approaches to basilar artery (BA) aneurysms. In the last 5 years, 30 BA aneurysms have been operated on at our institution. Twenty-three of them received Hunt and Hess Grades of 0 to 3, and most of these were operated on early. A combination of approaches, including the transsylvian, subtemporal, orbitozygomatic, presigmoid, and extreme lateral were used in various cases. The far lateral approach was used for lower BA aneurysms and vertebrobasilar junction aneurysms. Midbasilar and basilar apex aneurysms were operated on using the orbitozygomatic and pterional approaches and two patients were operated on using the presigmoid approach. Cadaveric studies were performed to see if the orbitozygomatic approach increases the cone of visibility as compared to the traditional pterional approach. Intraoperative angiography was performed on the last 20 patients and made a difference in the operative course in four patients. Twenty-three patients achieved good results, four patients did poorly, and three patients died. There was one infection and one cerebrospinal fluid leak. Although anatomical approaches indicated there is an increased cone of visibility with the orbitozygomatic approach, we only used this increase in exposure for giant basilar tip aneurysms and those with a high neck. The far lateral approach worked very well in lower BA aneurysms and vertebrobasilar junction aneurysms, achieving low morbidity rates. Based on this clinical series, the anatomical approaches and technical refinements for operative approaches to BA aneurysms will be presented.