The FRED Flow-Diverter Stent for Intracranial Aneurysms: Clinical Study to Assess Safety and Efficacy

Patient 1 with a 4.4-mm residual aneurysm of the initial posterior inferior cerebellar artery segment close to its origin from the V4 segment of the left vertebral artery (solid white arrow, A). After recoiling, we implanted a FRED 3.5 × 13 mm to cover the orifice of the posterior inferior cerebellar artery origin (B). The flow-diverting working zone (inner stent) is centrally positioned over the posterior inferior cerebellar artery origin (solid white bracket marked with 1 asterisk, C). The outer stent, which provides stable vessel anchorage symmetrically, overlaps the proximal and distal edge of the inner flow-diverting stent. Its distal flared ends are marked with solid white brackets and 2 asterisks (C). At 3-month follow-up, complete occlusion of the residual aneurysm was observed, with no residual inflow (D), which was also verified on different projections and 3D DSA. At the base of the coil basket, the overprojection of a proximal posterior inferior cerebellar artery loop (dashed white arrow, D) simulates residual aneurysm filling, but contrast washes out rapidly at this position after the arterial phase (not shown). Complete occlusion was also confirmed by unenhanced and enhanced TOF-MRA at 3 and 6 months.