[Aneurysm of the anterior communicating artery as a possible late complication of internal carotid artery ligation].

A case of a 55-year-old woman with anterior communicating artery aneurysm has been described. The aneurysm led to subarachnoid haemorrhage 8 years after ligation of the right internal carotid artery in order to turn off an aneurysm of this artery. Angiography showed the existence of collateral circulation through the arterial circle of the brain with haemodynamic disturbances, confirmed by Doppler ultrasonography. According to the views found in the literature these disturbances are considered the probable factor of initiation of the described aneurysm.