ABSTRACT
We expierenced two cases of intradural verteral artery dissecting aneurysms. The presenting symptom was subarachnoid hemorrhage in one case and ischemic symptom in the other. The preoperative angiographic finding typically showed fusiform dilatation and proximal and/or distal narrowing of the affected artery. In one case, the vertebral artery was clipped distal to the PICA and in the other case trapping was performed through the extreme lateral transcondylar approaches. This approach permits a control of the aneurysm through the direct view of whole length of the vertebral artery, lower cranial nerves and ventral brain stem. In order to obtain ample view and to save the lower cranial nerves and perforating vessels, jugular tubercle should be sufficiently drilled out. Postoperitive neurological outcomes were favorable except mild hoarseness for some period in trapping case.