Flow Diversion in Patients With Concurrent Anticoagulation: Multicenter Experience and Systematic Review of Literature.

Background and objectives: Dual antiplatelet therapy is used to minimize thromboembolic complications after flow diversion (FD). Oral anticoagulation (AC) has been associated with increased risk of hemorrhagic complications. Our multicenter study and systematic review of literature describes the safety and efficacy of FD in patients on concurrent AC.

Methods: This was a retrospective study of patients on concurrent AC before FD for an intracranial aneurysm at 3 participating institutions between January 2018 and January 2024. Outcomes of interest were angiographic occlusion (assessed using the O'Kelly-Marotta (OKM) Grade), postoperative complications, in-stent stenosis, and functional outcome (measured using the modified Rankin Scale). PubMed was searched to identify articles that reported outcomes of interest in patients undergoing FD on AC.

Results: Nineteen patients with 20 aneurysms underwent FD while on AC. The median age of the cohort was 71%, and 89.4% were female (n = 17). Forty percentage (n = 8) of aneurysms were completely occluded (OKM grade D) and 20% (n = 4) developed clinically asymptomatic in-stent stenosis at their last follow-up. Overall, 84.2% of patients (n = 16) were functionally independent, 1 patient was lost to follow-up and 2 patients experienced mortality. Our systematic review of literature identified 2 articles describing rates of occlusion ranging from 25% to 71.4%, with increased rates of delayed rupture and retreatment among patients on AC.

Conclusion: We report low rates of complete aneurysm obliteration after FD in patients on concurrent AC. Future research could help identify the appropriate antithrombotic regimen in this cohort.