In several neurovascular interventions, direct oral anticoagulants (DOACs) are required in addition to antiplatelet therapy. Antiplatelet therapy can be reliably assessed by platelet function tests. However, anticoagulant monitoring is not part of clinical routine, and DOAC efficacy is often assumed. In selected clinical situations, it may be essential to measure the anticoagulant effect of DOACs to make more informed treatment decisions. We present two cases involving flow diverter treatment of basilar artery aneurysms, highlighting the clinical importance of detecting poor or absent DOAC response using a point-of-care pharmacodynamic assay.