How does a saphenous vein graft work?

• A. Harvested from the leg; distal end anastomosed to the coronary artery distal to occlusion.
• B. Harvested from the leg; proximal end anastomosed to the ascending aorta.
• C. Harvested from the leg; distal end distal to occlusion and proximal end to the ascending aorta.
• D. Harvested from the leg; is used to bypass veins only.

Answer: (C)

A saphenous vein graft creates a new route for blood to bypass a narrowed coronary artery by connecting a leg vein between the aorta and the coronary artery beyond the blockage. The proximal end is attached to the ascending aorta to receive high-pressure arterial blood, while the distal end is connected to the coronary artery downstream of the occlusion to perfuse the myocardial territory that would otherwise be starved. This setup—proximal to the aorta and distal to the occlusion—is what allows blood to flow from the aorta into the graft and into the coronary circulation beyond the blockage. The other ideas either omit the aortic connection, misplace the graft ends, or incorrectly state that grafts are used only for veins.