[Operated case of a ruptured aneurysm arising from fenestration of the vertebral artery].

Aneurysm arising from duplication of the vertebral artery (VA) is rare. We report a surgical case of an aneurysm of VA fenestration and provide a literature review. A 42-year-old man suffered from sudden onset of severe headache. CT image revealed subarachnoid hemorrhage predominantly in the posterior fossa. Digital subtraction angiography showed a fenestration of the right VA and the aneurysm arising from the proximal limb of the fenestration. Neck clipping of the aneurysm was performed because embolization was difficult due to the wide neck. The patient was discharged without deficits. Seven cases of an aneurysm of the VA fenestration have been reported. Five cases underwent coil embolization, and 2 underwent craniotomy, trapping, and resection. This is the first case of neck clipping of an aneurysm of the VA fenestration.