THE INFRA-AORTIC ARTERIES OF THE SPINE - THEIR VARIABILITY AND CLINICAL-SIGNIFICANCE

The infra-aortic spinal arteries caudal to the aortic bifurcation were studied in 20 perinatal and adult cadavers to determine their import relative to extraforaminal approaches to the lower lumbar discs as wel l as their probable involvement in certain cases of radiculomedullary ischemia. Analysis of these specimens indicated that, despite consider able variation, the arteries to the L4-L6 and L5-S1 intervertebral for amens generally were not related to the disc dorsolateral zones where lateral surgical approaches are best accomplished. Also, the frequency in which the fourth as well as the fifth lumber and all sacral segmen tal vessels were dependent on the posterior division of the hypogastri c artery may help explain how spinal cord ischemia could occur in indi viduals with vulnerable cord vascular patterns and/or spinal arteriopa thy after interruption of hypogastric artery blood flow during pelvic operations.