A case of coil-embolized unruptured saccular aneurysm associated with fenestration of the intracranial vertebral artery

Abstract

Purpose: Association of cerebral aneurysm with vertebral artery (VA) fenestration is extremely rare. The frequency of VA fenestration is reported as 1-2% and aneurysm formation in conjunction with fenestration other than VA fenestration has been well described. Furthermore, association of aneurysm with "true" VA fenestration excluding VA duplications has been reported in only 1 case. We report a case of unruptured aneurysm associated with "true" VA fenestration treated with coil embolization.
Case presentation: A 70-year-old female was referred to our department with an unruptured cerebral aneurysm of the left VA. The aneurysm enlarged over the 3-year follow-up period. Three-dimensional digital subtraction angiography revealed a fenestration of the left VA associated with the aneurysm at its proximal bifurcation. We treated the aneurysm with coil embolization using balloon-assisted technique with sufficient packing density (23.8%).
Conclusion: High-resolution imaging modalities are required to detect the fenestration of the intracranial VA when associated with aneurysm. Endovascular treatment appears to be effective for aneurysms at this location owing to its complex anatomy, though deliberate consideration of treatment indications is inevitable as the natural history of this condition is not well known.