Mesenteric arterial disease: the present position.

An organ lives on its blood supply, and the gastrointestinal tract is no exception. It is nonetheless true that until recently more interest has been shown in the function of the alimentary system as an absorptive or excretory organ than in the physiology of its own nutrition which makes these functions possible. There is at present no method of measuring blood flow to the intestine of an intact human being, because its arterial supply, unlike that of the heart or kidney, arrives through three separate vessels with a very variable pattern of internal anastomosis, and its venous return is via an internal, portal, system which cannot be catheterized. A measurement of total intestinal blood flow might not, in fact, be very useful, because without knowing how this was shared between the absorptive, the motile, and the supporting tissues of the gut, it would be difficult to correlate clinical abnormalities with any quantitated deficit in arterial input'. Also, we have come to realize that the symptoms and signs of bowel ischaemia are very difficult to interpret at the bedside, and there is as yet no system of laboratory tests which will reliably distinguish them from any other cause of major illness. However, with the advent of more refined biochemical tests and of selective visceral angiography, our understanding of these conditions is growing and it seems appropriate to review, very briefly, the present position.