ABSTRACT
The CA and SMA arise from the ventral surface of the upper abdominal aorta and may be compromised by atherosclerotic disease of the ventral aspect of the aortic wall extending into the vessel origins. Typically these orifice lesions do not extend more than 1-2 cm into the visceral branches. This proximal distribution of disease spares the primary branches of the visceral trunks and allows the development of extensive collateral blood flow, using the previously described normal anastomotic pathways. Infrarenal aortic atherosclerotic disease is very common; it frequently occludes the IMA origin and also compromises iliac flow. The multiple vessels supplying the gastrointestinal tract and the many collateral pathways imply that visceral branch occlusive disease is predictably extensive before symptoms result.
