Abstract
High positioned basilar top aneurysms (BTAs) present especial technical problems when approached by the conventional pterional or subtemporal approach. Particularly when the aneurysm is posteriorly projected, visualization of the perforating branches is extremely difficult even by the use of newly devised zygomatic approaches. We recently had a 60-year-old female patient with such a BTA, which was discovered in the course of a checkup for sudden headache.
While the the patient wanted surgery after having been well informed, the use of conventional approaches requiring overt brain retraction was considered extremely dangerous because a small infarct in the right basal ganglia was found in the preoperative MRI scan. Therefore, we decided to use the anterior transcallosal approach (ATA), which makes it possible to view the aneurysm and the perforating branches from above, namely through the floor of the IIIrd ventricle. The aneurysm was successfully and easily clipped by this approach. The postoperative course was uneventful except for a transient disturbance of recent memory. We describe the technical features of this approach and discuss its feasibility for the treatment of high positioned BTAs.