Background The development of ischemic events is relatively common after endovascular interventions, and flow diverters may pose a particular threat owing to their increased technical complexity and high metal content.

Objective To investigate the incidence and potential risk factors for thromboembolic lesions after treatment with a Pipeline embolization device (PED).

Methods This prospective study included a total of 59 patients electively treated with a PED over 12 months. Postprocedural diffusion-weighted imaging sequences of the brain were obtained 24 h after interventions to detect ischemic lesions. Demographic data, aneurysm characteristics, antiplatelet management, and perioperative data were correlated with the rate of ischemic events.

Results The incidence of silent ischemic events after use of a PED was 62.7% (37 patients) and neurological symptoms occurred in 8.1% of affected patients. Development of ischemic events was significantly associated with older patients (≥60 years; p=0.038). Routine use of platelet function assays and newer P2Y12 receptor inhibitors (ticagrelor) were not associated with fewer thromboembolic events.

Conclusions Thromboembolic events are relatively common after treatment with a PED with an incidence comparable to stent-assisted and conventional coiling but the risk of neurological morbidity from ischemic burden is low. Older patients are at particularly increased risk of thromboembolic events.