Arteriovenous Malformations of the Spinal Cord

Abstract

The arterial blood supply of the spinal cord has been well and extensively described (Kadyi 1889, Clemens et al. 1957, Adamkiewicz 1881). The dorsal rami of the segmental intercostal and lumbar arteries give rise to a spinal ramus which amongst its other branches sends a neural branch to supply roots, spinal ganglia and, in a number of instances, to go on as either an anterior or posterior radicular artery to the cord. The number of neural branches that actually reach the spinal cord on average is twenty-four. The dominant blood supply to the cord is by a series of usually no more than six to eight anterior radicular arteries which together with descending branches from the vertebral arteries, contribute blood supply to the anterior spinal artery. The dominant contributors to the blood supply of the spinal cord are the vertebral vessels in the upper cervical cord, branches from the vertebral vessels in the lower cervical cord, and the artery of Adamkiewicz or arteria radicularis magna found on the left side accompanying any anterior root from D6 to L4 (Adamkiewicz 1881). Most frequently, however, it occurs on roots between D 8 and D 12. The general surgical experience is that the division of no single radicular artery is likely to impair the blood supply of the spinal cord with the exception of the arteria radicularis magna, but that extensive disruption of intercostal arteries of supply as, for example, by dissecting thoracic aneurysm, are likely to affect the cord as high as the critical watershed between the relatively poorly arterialized thoracic cord and the cervical enlargement.