A New Stent for Direct Treatment of Intracranial Aneurysms

The intracranial aneurysm is a weak region in the wall of an artery in the brain, where dilation of the artery wall may occur. Because the wall of the aneurysm is very thin, lacking the normal layer structure found in healthy arteries, it is easy to rupture and leads to subarachnoid hemorrhages [1, 2]. Current methods for treating the intracranial aneurysms are surgical clipping and endovascular coiling [3]. In the surgical clipping method, a surgical clip is placed across the neck of the aneurysm through open surgery. The risk of this method is high, especially for elderly or medically complicated patients. In endovascular coiling, one or more coils are delivered into the aneurysm from a remote incision on the artery to trigger a thrombus inside the aneurysm sac. This method is less invasive and therefore safer compared to surgical clipping. However, it is less suitable for treating wide-necked aneurysms because the coils can not stay permanently inside the aneurysm sac. To solve this problem, stents have been used in association with coils [4]. In this procedure, a stent is first placed across the neck of the aneurysm, serving as a scaffold inside the artery lumen. Then, the coils are delivered into the aneurysm through the interstices of the stent. Although stent-assisted coiling is superior to using coils alone for the treatment of the wide-necked aneurysms, it is more complicated and requires longer operation time. Besides, neither of the coiling embolization methods can be used for treating the aneurysms which lack a defined saccular component.