During the past three years from 1971 to 1973, 413 cases of cerebral aneurysms have been experienced in our clinic, in which direct intracranial operation was carried out mainly by the ligation and/or clipping of the aneurysm neck in 393 cases. Post-operative statistics showed that the cases which were operated on within the first week after the last subarachnoid hemorrhage, had the highest mortality and morbidity rate. A closer analysis of the 64 cases with surgery within the first week revealed that the highest and second highest mortality and morbidity rates were in cases with operations on the 3 rd and 4 th days following the last hemorrhage, respectively. However, only one of 17 cases operated on within 48 hours died. And furthermore follow-up studies, taken 6 months to 3 years after discharge, showed that the remaining 16 cases were working and leading a useful life.
In the study of 31 cases operated on within the first 4 days after the aneurysm rupture, the most remarkable fact is that the post operative results were good in cases with surgery on the 1st or 2 nd day, even if the pre operative conditions were severe, such as Grade III or IV by Hunt and Hess' classification. On the contrary, in cases operated on in the 3 rd or 4 th-some of them Grade I or II, so-called “good risk patients”-deteriorated and cases graded III and IV all worsen or died.
The important factors affecting the patient's condition after an aneurysm rupture seem to be the degree of the increased intracranial pressure caused by the hematoma and circulatory disturbance of the cerebrospinal fluid and the degree of brain destruction caused by the intensity of the arterial blood from the rupture. Therefore it is reasonable that an early aneurysm surgery, within 48 hours, including the removal of the hematoma and the reduction of the high intracranial pressure by ventricle drainage is effective not only to prevent a possible fatal re-rupture, but also to improve the patient's poor pre-operative condition. In addition an operation within 24 hours greatly lessens the possibility of the occurrence of post-operative vaso-spasms by the removal of the subarachnoid clot existing around the brain artery, which may play a major role in producing vasospasms. The surgical results closely correlated with the incidence of vasospasms which were: 14.3%, 60%, 83.3%and 75% for the 1st, 2nd, 3 rd and 4 th days respectively.
Although in cases operated on, in 3 rd and 4 th days continuous high intracranial pressure aggravates the conditions, the most detrimental factor affecting the poor surgical results may be attributable to cerebral infractions due to vasospasm, especially those which appear in the postoperative stage.