Vascular injection of eleven perinates revealed that each lumbosacral
spinal-nerve root received its intrinsic blood supply from both distal and
proximal radicular arteries through which the blood flowed toward a mutual
anastomosis in the proximal one-third of the root. Segmental arteries
supplied the distal vessels while their proximal equivalents received blood
from their respective anterior or dorsolateral spinal arteries, which
derived their flow from the large, irregularly located medullary arteries.
CLINICAL RELEVANCE: The region of relative hypovascularity formed below the
conus by the combined areas of anastomoses in the cauda equina may provide
an anatomical rationale for the suspected neuroischemic manifestations
concurrent with degenerative changes in the lumbar spine.