Anatomical observations on the arterial supply to the lumbosacral spinal cord of the cat

The pattern of arterial supply to the cat's lumbosacral spinal cord was examined in a dozen latex‐injected specimens with a view to determining what precautions might be taken in the procedure of rhizotomy to minimize embarrassment of the cord's circulation. The single ventral spinal artery was found to receive on an average 4.1 significant radicular contributions, of which one or two arteries at the fourth or third lumbar levels on the left were invariably of especially large size. Equal numbers, about six to eight, of contributions to the two dorsolateral arterial trunks were present. Anastomotic channels greater than 50 m̈ in diameter were rather poorly developed between dorsolateral and ventral arterial channels, especially across the middorsum. The dorsal radicular artery in 82 of 97 roots examined was seen to pierce the ventral root in order to reach a position along the ventral aspect of the dorsal root. In most cases this penetration occurred central to the ganglion. The bearing of this feature on reported differences in behavioral effects from rhizotomy by intradural section and by ganglionectomy is discussed, as well as other aspects of the effect of rhizotomy on cord criculation.