抄録
A 73-year-old female, who had been followed up for a right anterior cerebral artery aneurysm and a left middle cerebral artery aneurysm, presented with sudden onset of headache and loss of consciousness. CT showed subarachnoid hemorrhage (SAH) and subsequent three dimensional-CT angiography (CTA) revealed an enlargement of the anterior cerebral artery aneurysm, which was highly suspected to be the ruptured one. The aneurysmal neck was successfully clipped. After the 15th day, the follow-up CTA revealed a de novo aneurysm of the anterior communicating artery that had not been recognized either on the onset day or six months earlier. Because the de novo aneurysm was thought to be the cause of SAH, the aneurysmal neck clipping was then performed. The postoperative course was uneventful.
There are several reasons why the ruptured aneurysm was not identified during the first radiological study. In that case, intraluminal thrombosis could be the cause. We should keep in mind that rupture of de novo aneurysms can be associated with multiple unruptured aneurysms and should comprehensively identify ruptured aneurysms.
