Flow diverters for treatment of intracranial aneurysms: Current status and ongoing clinical trials

The ultimate treatment goal for intracranial aneurysms is to reconstruct the vessel wall and correct the hemodynamic disturbance. A flow diverter is a stent placed in the parent artery to reduce blood flow in the aneurysm sac to the point of stagnation, gradual thrombosis, and neointimal remodeling to maintain outflow in the side branches and perforators. Here, we review the two commercially available flow diverters, the Pipeline Embolization Device (PED) and the SILK flow diverter (SFD). The rates of severe hemorrhagic complications have been reported to be 2% for the PED and 0.8% for the SFD. The results of studies completed thus far show that endovascular reconstruction with flow diverters is an effective treatment of wide-necked, fusiform, large, and giant unruptured intracranial aneurysms, with 5% to 10% of patients experiencing permanent major morbidity and mortality. The results of ongoing studies may resolve whether flow diverters can replace coil embolization for the treatment of all, or selected, intracranial aneurysms.