Blood Supply of the Spinal Cord

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- Discussion:
    - blood is supplied to vertebral column by way of segmental arteries
          that arise near it from the aorta, or from adjacent arteries in
          areas beyond the extent of the aorta;
    - costocervical & intercostal arteries in thorax; lumbar and iliolumbar
          arteries in lumbar region; and lateral sacral arteries in pelvis;
    - dependence on 3 vessels: anterior median logituninal arterial trunk &
          pair of posterolateral trunks near the posterior nerve rootlets;
    - relative demands of gray matter and white matter;
          - longitudinal arterial trunks are largest in cervical and lumbar regions
                  near the ganglionic enlargements and are much smaller in thoracic region;
          - metabolic demands of gray matter are > those of white matter,
                  which contains fewer capillary networks;

- Anterior Spinal Artery:
      - single artery runs in the ventral midline from foramen magnum to the filum terminale;
      - artery is supplied by series of 5-10 unpaired radicular arteries that
            originate from vertebral arteries & aorta and its branches;
      - blood supply of anterior portion of cord is much more vulnerable than
            that of posterior portion and can be decompensated by occlusion of
            large radicular branch or lesions of the aorta;
      - two longitudinal pathways include the anterior spinal artery (ASA) &
            posterolateral arteries;
            - 75% of the blood supply to spinal cord is derived from ASA;
            - ASA arises from the vertebral artery caudal to the basilar artery;
            - two arteries from either side, one from each vertebral artery, join each other between
                  C1 & C6 & form single arterial channel;

- Posterior spinal arteries:
      - posteriorly, there are paired posterior spinal arteries, which are fed
            by smaller radicular arteries at nearly every spinal level;

- Segmental Arteries of the vertebral column supply radicular arteries;
    - in thoracic and lumbar regions segmental arteries are known as intercostal
          and lumbar arteries which arise from posterior aspect of aorta;
          - these segmental arteries proceed to intervertebral foramina appropriate
                  to their level, where they divide into terminal branches;
          - one of the largest radicular arteries is the ARM (or Artery of Adamkiewicz);
    - Artery of Adamkiewicz;
          - largest of the segmental arteries w/ a characteristic hairpin bend is referred to as the
                  arteria radicularis magna (ARM) and is also known as artery of Adamkiewicz;
          - although in early embryonic development every segment of spinal cord receives
                  paired radicular arteries, these disappear, leaving one or two cervical,
                  two or three throacic, and one or two lumbar arteries;
          - most commonly arises at T10 on left side, however, position may vary from
                  T7 to L4, with it being on right side in 17% of pts;
                  - usually the artery enters a single intervetebral foramen between the levels of T9-T11;

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The blood supply of the spinal cord.
      GF domissee. JBJS 56-B. 1974. p 225-235.