Endovascular treatment of aneurysm arising from fenestration of the supraclinoid internal carotid artery--two case reports.

We report two cases of aneurysm located in a fenestration of the supraclinoid internal carotid artery, an extremely rare anatomical variant, and describe the feasibility of endovascular treatment using two different strategies applicable for each case. Each presented aneurysm had a particular location on the fenestration, which led to different endovascular approaches. In one case, the aneurysm arose from the proximal junction of fenestration, involving both of its limbs. For this aneurysm, the treatment strategy adopted aimed to achieve a selective exclusion. In the second case, two aneurysms arose from the minor limb of the fenestration, which could be entirely excluded, considering the absence of perforating arteries arising from that carotid segment. To our knowledge, these two cases are the first ICA fenestration aneurysms treated exclusively by endovascular approach, showing two treatment strategies using coils in association to two different endovascular devices (stent/TrisPan(®)).