Background and importance: We present a rare case of fenestration of the left supraclinoid intracranial internal carotid artery with 2 associated aneurysms arising proximally and distally from the fenestration that were successfully treated with endovascular coil embolization. This is the first report of these types of aneurysms treated with coiling alone.
Clinical presentation: A 47-year-old woman underwent a diagnostic workup; magnetic resonance angiography incidentally revealed 2 tandem aneurysms at the supraclinoid and paraclinoid portion of the left internal carotid artery. Angiography revealed fenestration of the left supraclinoid internal carotid artery with 2 aneurysms both proximal and distal to the fenestration. The patient underwent endovascular coil embolization of the aneurysms simultaneously. The smaller trunk was intentionally occluded to achieve complete packing of the proximal aneurysm. Both aneurysms were totally occluded, and no neurological deficits developed in the patient.
Conclusion: Based on previous reports, fenestration has the potential to form an aneurysm, and there seemed to be a relatively high incidence of rupture if accompanied by aneurysm. Coiling is one good option to treat aneurysms and should be considered when multiple aneurysms exist because all aneurysms can be treated simultaneously. Proximal occlusion of the smaller trunk is acceptable because of a retrograde flow from the distal end, even if one exists.