A ruptured internal carotid artery blood blister-like aneurysm with rebleeding after single-layer neck-bridging stenting and complete obliteration after double-layer stenting: A case report

Background: Blood blister-like aneurysms (BBAs) are difficult to treat surgically, and an established treatment strategy is yet to be determined. Treatment options are limited in cases where direct surgery is difficult, and endosaccular embolization is considered infeasible. Case Description: A 31-year-old man presented with subarachnoid hemorrhage due to rupture of an internal carotid artery BBA. Treatment in the acute phase was considered; however, because both direct surgery and endosaccular embolization were difficult, a single low-profile visualized intraluminal support (LVIS) device was deployed while the patient was receiving dual antiplatelet therapy. Approximately 2 weeks later, the aneurysmal component enlarged, rebleeding occurred, and a second stent was deployed. Disappearance of the aneurysm was confirmed 7 months later. Conclusion: For a ruptured internal carotid artery BBA, a single-layer LVIS stent was placed as initial treatment, followed by placement of a second layer during the subacute phase. Although no ischemic complications occurred, rebleeding developed. Since a single-layer placement may not prevent rebleeding, close follow-up is necessary after treatment, and prompt intervention is required if any changes occur in the aneurysmal segment.