Sequential rupture of multiple intracranial aneurysms with rapid de novo bleb formation: A case report

Background: Managing multiple intracranial aneurysms (MIAs) in subarachnoid hemorrhages (SAHs) can be challenging, especially when rapid morphological changes such as de novo bleb formation can increase the risk of sequential rupture. In addition, identifying the rupture source is often difficult in the case of symmetrical hematoma distribution. Case Description: This study investigated a 66-year-old woman with an SAH and three aneurysms: Right and left internal carotid-posterior communicating (IC-PC) aneurysms and an anterior communicating artery (Acom) aneurysm. Magnetic resonance imaging was contraindicated owing to an intraocular foreign body. Based on size, shape, and intraoperative hematoma, the right IC-PC aneurysm was identified as the rupture source and surgically clipped. On post-operative day 4, a de novo bleb appeared on the untreated left IC-PC aneurysm. Despite the stable diameter, it ruptured on post-operative day 13, causing a second SAH. The left IC-PC aneurysm and Acom aneurysm were clipped. The patient recovered with a Modified Rankin Scale score of 2 at 8 months. Conclusion: This case study highlighted the rapid development of a de novo bleb and subsequent sequential rupture in MIAs. Even aneurysms initially deemed low risk can become unstable within a few days, especially during the vasospasm period. In addition, short-term imaging follow-up is necessary for the early detection of morphological changes. A comprehensive management of MIAs in the acute phase, including the consideration of early treatment for seemingly stable aneurysms, may prevent catastrophic rebleeding.