Background Flow diverters (FDs) result in high occlusion rates of aneurysms located distally to the carotid artery. However, the complications reported are not negligible. New modified surface FDs have low thrombogenic properties that may reduce ischemic complications related to the treatment. In addition, a modified surface FD may allow for the use of a single antiplatelet medication to reduce hemorrhagic risk during the procedure. The aim of this study was to assess the safety and efficacy of the p48 MW HPC (phenox, Bochum, Germany) to treat distal intracranial aneurysms under the use of aspirin monotherapy.

Methods The primary endpoint was the incidence of any neurologic deficit after treatment after 6 months of follow-up. The secondary endpoint was the rate of the complete occlusion of the aneurysms at the 6-month follow-up. Enrollment of 20 patients was planned, but after inclusion of seven patients the study was stopped due to safety issues.

Results Seven patients with eight aneurysms were included. Among the seven patients, three (42.8%) had ischemic complications on the second day after FD deployment. Two patients experienced complete recovery at discharge (National Institutes of Health Stroke Scale (NIHSS) score=0), while one patient maintained mild dysarthria at discharge (NIHSS score=1) which improved after 6 months (NIHSS score=0). All three patients had no new symptoms during the 6-month follow-up. Complete aneurysm occlusion occurred in six (75%) of the eight aneurysms at the 6-month follow-up.

Conclusions Antiplatelet monotherapy with aspirin for the treatment of distal intracranial aneurysms with this modified surface FD resulted in a significant incidence of ischemic complications after treatment.