Persistent proatlantal artery with carotid-vertebral anastomosis. Case report.

The authors describe the occurrence of proatlantal artery as an incidental angiographic observation in a young Indian soldier. This primitive anastomotic channel is seen extending from near the origin of the external carotid artery to the suboccipital region, traversing the foramen magnum and coursing beyond like a vertebral artery. The developmental and roentgenological aspects of carotid-basilar and carotid-vertebral anastomosis are discussed, along with a review of four similar cases reported previously.