破裂脳動脈瘤の natural history: 救命救急センターにおけるクモ膜下出血の overall outcome

Abstract

To study the natural history of ruptured cerebral aneurysms, the overall management result of subarachnoid hemorrhage obtained in the Emergency Medical Center (EMC) of Kyorin University was analyzed. During the calendar year 1994, 65 cases were managed in the EMC and another 31 cases in a neurosurgical ward. Among 290 consecutive cases directly admitted to EMC since 1989, about half the patients were hospitalized within one hour from onset and 95% within 6 hours. Their neurological condition on admission was categorized according to the Hunt and Kosnik grading. Eighteen percent were in Grade IV and 63 percent were in Grade V. About 40% of the patients showed abnormal pupillary findings and also had ataxic or apneic respiratory pattern on admission. Among the studied patient-population, 23% were dead on arrival. Ruptured aneurysm was verified in 46% of all and obliteration of the aneurysm was completed in 35% of all the patients. Overall management mortality rate was 72% and favorable outcome was obtained only in 14% of cases. These figures were similar to or worse than those from reported epidemiological studies on the natural history of ruptured aneurysms. The major causes of poor outcome of the present cases were the primary brain damage due to aneurysm rupture, rebleeding of the aneurysm and acute respiratory failure. We concluded that the conventional management strategy yields a limited outcome and only the prophylactic treatment of unruptured asymptomatic aneurysm can improve the natural history of the whole spectrum of patients with cerebral aneurysms.