Rupture of a giant aneurysm of the inferior wall of the internal carotid artery after saphenous vein interposition graft to the middle cerebral artery.

A patient with a giant aneurysm of the inferior wall of internal carotid artery presented with progressive vision failure with optic nerve atrophy on the left eye. She underwent exploration of the aneurysm, which was found impossible to clip. Clamping of the common carotid artery was not tolerated there being inadequate collateral circulation. A saphenous vein graft was interposed between the occipital artery and a branch of the middle cerebral artery. The previously unruptured aneurysm bled fatally 4 hours after surgery, just before intended clipping of the aneurysm or ligation of the internal carotid artery.