Superior rectal artery origin from the median sacral artery--angiographic appearance, developmental anatomy, and clinical implications.

Two angiographic observations of significant rectal vascularization by branches originating from the median sacral artery (MSA) are reported. In the first case, the MSA provided a complete superior rectal trunk, with left and right branches, while in the second, the MSA only contributed superior rectal branches to the right side of the rectum, the left side being supplied by left internal iliac branches. The angiographic appearance, developmental anatomy, and clinical significance of these variants are discussed.