[Functional relevance of the type I arteria proatlantica in carotid disobliteration].

Primitive embryonic anastomotic vessels between the carotid and vertebrobasilar arterial systems occasionally persist into adult live. Coincidence with cerebrovascular disease may be of functional relevance. We report a case of segmental internal carotid occlusion and aplasia of both vertebral arteries in combination with persistence of proatlantal artery type I. Recurrent cerebral ischemia required revascularization of the segmental occluded internal carotid artery. Disobliteration was successfully performed with an uneventful postoperative course. The patient recovered well from his neurological deficits. Clinically, the combination of persistent proatlantal artery with occlusive disease of the carotid arteries may lead to atypical neurological deficits. In cerebrovascular surgery, a persisting proatlantal artery, as a main supply vessel of the vertebrobasilar system, is of great importance if the carotid artery is clamped.