Introduction Blister-type cerebral aneurysms are rare, making up a combined 6.6% of ruptured intracranial aneurysms. Because of their shallow, broad-based morphology, these aneurysms can be challenging to treat. More recently, the role of endovascular treatment with flow-diverting stents has gained favor. It is believed that the utilization of flow-diverting stents may better address the underlying pathology through arterial wall remodeling and subsequent aneurysm occlusion over time. One major advantage with flow-diverting stents is the avoidance of direct aneurysm wall interaction. The major disadvantage, however, is the requirement of dual antiplatelet therapy (DAPT) both prior to and following stent placement, given that many patients present in the setting of hemorrhage. To date, no definitive antiplatelet regimen guidelines have been established in the setting of flow-diversion for acutely ruptured intracranial aneurysms.

Cangrelor is an intravenous P2Y12 platelet receptor antagonist which has shown promise as an antiplatelet agent of choice due to its reversible binding as well as its rapid onset and offset capabilities. In this paper, we present a series of patients with ruptured blister-type aneurysms who were treated with flow-diverting stents and placed on cangrelor during the periprocedural period.

Methods A single-center retrospective analysis of ruptured intracranial aneurysms was performed. Five patients with ruptured blister-type aneurysms that were treated with flow-diverting stents from September 2019 to February 2023 were included in the study. The patient charts, imaging data, and procedural reports were reviewed and evaluated for presence of rebleeding, antiplatelet agents used, complications, and 90-day mRS throughout the hospitalization and post-discharge follow up.

Results Five patients were evaluated, all of which presented with spontaneous rupture of aneurysms located at the supraclinoid internal carotid artery. Each patient received an initial loading dose of aspirin in addition to cangrelor 15 μg/kg loading dose and a 2 μg/kg/minute maintenance dose prior to stent placement. Following stent placement and immediate post procedure head CT, the patients were subsequently transitioned to aspirin 81 mg daily and either prasugrel 5 mg or clopidogrel 75 mg daily. In one patient, an additional flow diverting stent was placed due to persistent residual aneurysm five months after initial treatment. None of the patients experienced recurrent hemorrhage or ischemic complications. Of the four patients who have survived to 90 days, the mean mRS score was 0.5, with one patient currently still within the 90-day window.

Conclusion Blister-type aneurysms are rare and complex lesions which present many treatment dilemmas, particularly in the setting of hemorrhage. While flow-diversion continues to gain favor in treating these lesions, the use of dual-antiplatelet therapy remains a concern due to risk of rebleeding. Because of its onset and rapid offset capabilities, cangrelor may serve as a safe and effective adjunctive antiplatelet medication in the setting of flow-diversion for acutely ruptured aneurysms. However, the need for more large comprehensive studies, including randomized controlled trials, remains.

Disclosures K. Cicilioni: None. X. Guo: None. J. Dye: None.