Thromboembolic complications after combined internal carotid ligation and extra- to-intracranial bypass

Twelve cases of probable embolic complication occurring during or after therapeutic occlusion of the internal carotid artery are summarized briefly. In each case, an extracranial-to-intracranial bypass procedure had been performed. These cases were collected from an informal survey of 30 neurosurgeons. In most instances, the middle cerebral artery became occluded as a result of an embolus, probably formed in the occluded internal carotid artery or possibly in the giant aneurysm being treated. The literature on surgical carotid occlusion is reviewed, with particular emphasis on the frequency and pathogenesis of ischemic complications.