Introduction Post-operative dual anti-platelet therapy (DAPT) after flow diversion treatment of intracranial aneurysms varies but generally involves Aspirin and a PDY12 antagonist such as clopidogrel or ticagrelor. Cessation of DAPT typically occurs after 6-month follow-up to minimize thromboembolic complications. However, there is evidence that cessation of DAPT as soon as 3 months post-operatively can be safe, especially in patients that have increased risk of bleeding or require surgery.

Objective To examine incidence of thromboembolic and hemorrhagic events after 3 months versus after 6 months follow-up after flow diversion of cerebral aneurysm while on DAPT.

Methods This is a retrospective observational study of patients prospectively enrolled in the Stroke Thrombectomy and Aneurysm Registry (STAR) database at a single large academic medical center between January 2014 and December 2022. Patients with unruptured intracranial aneurysms of the anterior circulation treated by endoluminal flow diversion were included. The primary outcome was the occurrence of hemorrhagic or thromboembolic complications after the immediate post-operative period. All patients had baseline platelet aggregation testing performed. Patients were divided into 3- and 6-month cohorts, and complications were identified on clinical and radiographic follow up.

Results During the study period, of the 155 patients that were included, 54% (n=84) underwent DAPT for a 3-month duration, while 46% (n=71) were treated for 6 months. 4 (4.8%) patients in the 3-month DAPT cohort had complications, with 3/4 patients having events before the 3-month follow-up visit. Thromboembolic and hemorrhagic complications were equal in number (n=2 each). There were 0 complications in the 6-month cohort. Any differences in complication rate between both cohorts was not statistically significant (RRR: 7.62 [.42, 139.23], p=95% CI).

Conclusions Only 0.6% (n=1) of patients exhibited complications after 3 month follow-up. We conclude that DAPT duration of 3 months after endoluminal flow diversion of unruptured cerebral aneurysms of the anterior circulation is not associated with increased rates of hemorrhagic or thromboembolic complications compared to a traditional 6-month regimen.

Disclosures S. Srinivasan: None. A. White: None. M. Al-Abdulkareem: None. J. Barr: None. L. Pride: None. J. White: None. R. Novakovic-White: None. R. Sillero: None. B. Welch: None.