Intravascular surgery for basilar artery aneurysm is a remarkably recent method of therapy. A very important point in this procedure is continuous determination of the patient's neurological state through electroencephalographic monitoring using a compressed spectral array (EEG CSA) and through auditory brainstem evoked respones (ABR) and high quality intraoperative angiograms obtained with a digital subtraction unit (DSA).
Case: A 64-year-old female suffered subarachnoid hemorrhage from a basilar tip aneurysm (4×5×9mm). Her neurological state at admission was Hunt & Kosnik grade V. Conservative therapy was applied and a ventriculo-peritoneal shunt was performed. Her neurological state had improved to grade IV six months later. One year after onset intravascular surgery was indicated, as complications had arisen.
[Operative procedure]: The DSA consists of a portable C-arm fluoroscope, low-noise camera, two video monitors, an image-processing system, and a hard disk storage system. EEG CSA and ABR were useful neurophysical monitoring methods. The aneurysm was occluded with a Hieshima detachable balloon catheter through the femoral approach. The balloon also occluded the posterior cerebral artery and there was a immediate change in EEG CSA and ABR. The DSA soon verified this and the balloon was deflated and repositioned. The balloon was again inflated for 40 minutes and then detached. It again moved slightly and DSA showed the left posterior cerebral artery to be stenosed. Three months after the operation, the patient's neurological state had improved to Hunt & Kosnik grade III. It was concluded that DSA and double monitoring (EEG CSA, ABR) during intravascular surgery are useful in the treatment of basilar aneurysms.
