The Pipeline embolization device (PED, ev3 Endovascular, Plymouth, MN, USA) and Silk flow-diverting stent (Balt Extrusion, Montmorency, France) is a widely utilized flow diverter in the treatment of intracranial aneurysms, particularly those with unfavorable configurations.
Flow modification has caused a paradigm shift in the management of intracranial aneurysms. Since the FDA approval of the Pipeline Embolization Device (Medtronic, Dublin, Ireland) in 2011, it has grown to become the modality of choice for a range of carefully selected lesions, previously not amenable to conventional endovascular techniques. While the vast majority of flow diverter stents operate from within the parent artery (ie, endoluminal stents), providing a scaffold for endothelial cells growth at the aneurysmal neck while inducing intra-aneurysmal thrombosis, a smaller subset of endosaccular flow disruptors acts from within the lesions themselves 1).
It is a braided, platinum and nickel-cobalt chromium alloy, wire mesh cylindrical implanted device.
An aneurysm treated with a flow diverter is expected to involute over time, contrary to the immediate obliteration expected by surgical clipping or coiling. Yet, which aneurysms will respond to PED therapy and the time frame to expect full obliteration remains unclear 2).
It works by causing progressive flow redirection leading to thrombosis within the aneurysm.
Close to one-fifth of aneurysms, however, fail to occlude after PED placement.