くも膜下出血再発症例におけるｄｅ ｎｏｖｏならびにｇｒｏｗｉｎｇ ｕｐ ａｎｅｕｒｙｓｍの検討

Abstract

From July 1971 to December 1998, 1001 patients with subarachnoid hemorrhage (SAH) were admitted to our hospital. Among them, 706 patients received treatment surgically, including 684 neck clippings for intracranial aneurysms. But 17 of these patients (2.5%) suffered recurrent SAH between a 5-to 23-year period (average 14 years) from their previous surgery. To determine the etiology of the recurrent SAH we reviewed all these cases and reevaluated the angiograms taken just after the initial surgery and at the time of the recurrent SAH. Bleeding was found to be from a de novo aneurysm in 8 cases (47%) and from an enlarged aneurysm that had been too small to operate on earlier (less than 4 mm) in 5 cases (29%). The average period of recurrence was 15.9 and 12.6 years, respectively. The incidence of the recurrent SAH caused by a ruptured de novo aneurysm was 1.3%. The characteristics of patients with de novo aneurysm are: 1) 75% are female, 2) the average time before a recurring SAH is as long as 15.9 years, 3) all are cases of multiple aneurysms, 4) 75% have hypertension. There were close similarities between the cases of multiple aneurysms and de novo aneurysms. The rupturing of enlarged aneurysm that had been small and unruptured was identified in 5 patients. The time from the previous surgery ranged 7 to 23 years (average 12.6 years). Among them, 4 have hypertension and all are cases of multiple aneurysms. We can conclude that the cerebral artery of the SAH patients has the potential to develop into a recurring SAH caused by the rupturing of a de novo or growing aneurysms over a long period. And it was suspected that de novo aneurysms are one of multiple aneurysms but develop at a different time. Planned postoperative follow-up angiography to detect newly formed or growing aneurysms should be performed.