What are the major pathways of collateral circulation to supply the lower extremities in a patient with known aortic occlusion?
A simple way to help remember the collateral supply is to divide it into anterior, middle, and posterior pathways.
- • Anterior pathway: Subclavian artery through the internal mammary artery to the superior epigastric artery, to the inferior epigastric artery, and then to the external iliac artery. This is known as the pathway of Winslow.
- • Middle pathway: Superior mesenteric artery to the inferior mesenteric artery, via the arc of Riolan and the marginal artery of Drummond, to the superior and inferior hemorrhoidal arteries, to the internal iliac arteries, and then to the external iliac arteries.
- • Posterior pathway: Lumbar arteries to the internal iliac arteries via retroperitoneal collaterals and then to the external iliac arteries by way of the iliolumbar and circumflex iliac arteries.