抄録
Although temporary clipping is used in aneurysmal surgery, its value has not been determined. In this study, we have assessed the influence of temporary clipping upon higher brain function and a cerebral infarct occurring in the territory of the Heubner's artery in patients with ruptured anterior communicating artery aneurysms. The subjects consisted of 89 patients operated on in the acute stage through the pterional approach (ranging in age from 35 to 70 years). Temporary clipping was used only when neck clipping was hard to perform because the aneurysm adhered strongly to the surrounding tissue, or because intraoperative bleeding occurred. Temporary clipping was performed on 22 patients, but not on the remaining 67. Temporary clips were placed at the dominant or bilateral Al segments. We observed cerebral infarction in the head of caudate nucleus on CT scans obtained within 48 hours after operation. These two groups showed no significant differences in age, preoperative neurological grade, or the amount of blood clots on CT scans.
The development of the cerebral infarction significantly related to the following factors: the use of a temporary clip, intraoperative bleeding, and dissecting time (the time interval between the beginning of exposure of the internal carotid artery and the termination of aneurysmal clipping). As this dissecting time became longer, it was more difficult to perform aneurysmal clipping. If temporary clipping was used for the same period, the perforator territory infarction occurred more frequently in cases with intraoperative bleeding, longer dissecting time, or both.
Approximately 80% of the patients showed an excellent or a good outcome, regardless of the cerebral infarction in the territory of the Heubner's artery. However, higher brain functions were affected in patients with the perforator infarction. We performed neuropsychological tests such as WAIS, colored matrices test, and Benton retention test. Higher brain functions were kept intact both in 6 patients with no abnormality on CT scans and in 3 with small perforator infarctions. (<2cm). In 2 patients with large infarctions (<2cm), attention and memory were slightly impaired, although they showed normal daily activities. In 2 patients with bilateral perforator infarctions, however, memory and thinking faculties were markedly disturbed. They developed Korsakoff's syndrome and their outcome became poor. These neuropsychological impairments could be attributed to the infarction in the territory of the perforator, including the limbic system.
In order to obtain a better outcome and maintain mental functions in patients with ruptured anterior communicating artery aneurysms, perforator injury must be avoided and temporary clipping should be used with the greatest care.
