1998 Volume 7 Issue 7 Pages 463-465
A case of subarachnoid hemorrhage (SAH) resulting from a dissecting aneurysm of the internal carotid artery is reported. A 51-year-old woman suffering from a sudden loss of consciousness was admitted to our hospital in a stuporous state. Computed tomography revealed a diffuse SAH at the basal cistern. Cerebral angiography detected no aneurysm other than a small protuberance at the orgin of the A2 segment of the left anterior cerebral artery. However, on left frontotemporal carniotomy, the arterial wall of the origin of the A2 segment appeared normal and, unexpectedly, a fusiform enlargement with a subadventitial hematoma was observed at the C1-C2 segment of the right internal carotid artery. On the basis of the angiogram and operative view, a dissecting internal carotid artery aneurysm was suggested as the cause of the SAH. The enlarged portion of the carotid artery was wrapped with cotton sheet and the postperative course was uneventful until the patient developed a comaproducing SAH 16 days after surgery. Cerebral angiography at this time revealed aneuysmal dilation, suggesting the formation of a pseudolumen, at the C1-C2 segment of the right internal carotid artery. After conservative therapy for the subsequent 16 days, the dissecting aneurysm was successfully terated by proximal occlusion of the right internal carotid artery with a detachable balloon. Although dissection of the internal carotid artery resulting in arterial stenosis or occlusion has been regarded as a cause of inchemic stroke in youth, only four cases of a dissecting internal carotid aneurysm producing SAH have been previously described.
