Dural-cortical arterial anastomosis as a collateral channel in carotid occlusive disease

The authors report four cases of occlusive disease of the internal carotid artery, which showed unique angiographic features of collateral circulation. Direct extracranial-cerebral arterial anastomoses have been observed between the middle meningeal artery, superficial temporal artery, occipital artery, and particularly the anterior falx artery and the recurrent meningeal branch of the ophthalmic artery and the cortical leptomeningeal arteries. ‘Retia mirabilia’ circulation in its original and strict sense has not been observed.