Abstract
The study included two patients under carotid ligation associated with STA-MCA double anastomosis for intracavernous giant aneurysm and six patients with occlusion of the internal carotid artery. All cases underwent rCBF measurement using single photon emission tomography within three hours after cerebral attack or ligation. Cases of internal carotid artery occlusion were classified two types under rCBF study. One was a marked global ischemic flow pattern, more than 50% reduction, in the affected side with hemispheric flow reduction in the healthy side. This type did not demonstrate any cross-circulation from the healthy side by angiography. The other was a focal ischemic flow pattern in the affected side, especially the watershed region, with a slightly hemispheric flow reduction in the healthy side. This type demonstrated good cross-circulation from the other side. Surgical adaptation of carotid ligation for giant carotid aneurysm was the existence of crosscirculation. It was possible to have a focal ischemic lesion under only carotid ligation as well as ICA occlusion, even if the patients had good cross-circulation. In order to associate with STA-MCA double anastomosis, it was assumed that the focal ischemic lesion and slightly global reduction of the healthy side (diaschisis) could be prevented.
