Flow diverter treatment for internal carotid artery aneurysm following management of distal cerebral aneurysms: Technical note

In recent years, the effectiveness of flow diverters (FDs) for the treatment of intracranial aneurysms has been reported. While FDs are effective, their deployment involves advancing a delivery wire distally, which may pose a risk if a distal aneurysm exists within the same artery. In such cases, the delivery wire could potentially perforate the distal aneurysm. Here, we present two cases of tandem aneurysms in which an internal carotid artery (ICA) aneurysm was treated with an FD following the treatment of a distal cerebral aneurysm. A 44-year-old woman and a 67-year-old woman underwent magnetic resonance imaging for headache or abducens nerve palsy. In both cases, two aneurysms were revealed: one at the ICA and the other either at the middle cerebral artery or the top of the ICA. Due to the risk of perforation by the delivery wire during FD deployment, the distal aneurysms were treated first—either with surgical neck clipping or stent-assisted coil embolization. One month after the initial treatment, FD placement for the ICA aneurysm was performed as planned without complications in either case. This is the first report where tandem aneurysms were successfully treated with treatment for distal cerebral aneurysms, followed by FDs for proximal ICA aneurysms. We emphasize the potential risk of perforation of the distal aneurysm by the delivery wire during FD placement. Treatment of distal cerebral aneurysms beforehand can help ensure the safe and effective use of FDs in patients with tandem aneurysms.