SVG (saphenous vein graft) to obtuse marginal (OM) branch
Coronary angiogram in a post coronary artery bypass (CABG) person. Sternal wires indicate the post CABG status. Catheter tip can be seen engaged in the ostium of the saphenous vein graft (SVG – medical abbreviation) in the ascending aorta. Part of the catheter in the descending aorta is also visible as it is a transfemoral coronary angiogram. SVG is nicely visualized throughout its whole length up to its anastomosis on to the obtuse marginal (OM) branch of left circumflex coronary artery. Faint retrograde filling into the proximal part of OM is visible as well as good filling into the distal branches.
The grafts are also called aortocoronary saphenous vein grafts as the proximal ends are anastomosed to the aorta and distal end to the coronary artery. For the same reason, coronary artery bypass surgery was called aortocoronary bypass in an era where arterial grafts like left internal mammary (LIMA) grafts were not being used commonly .
Even though LIMA graft has better long term patency, SVG remains the most common conduit for CABG because of limited length of the former . Often LIMA is used for anastomosis to a single vessel (left anterior descending coronary artery or its diagonal branch). Sometimes skip grafts of LIMA are used to connect multiple coronary branches.
Cox JL, Chiasson DA, Gotlieb AI. Stranger in a strange land: the pathogenesis of saphenous vein graft stenosis with emphasis on structural and functional differences between veins and arteries. Prog Cardiovasc Dis. 1991 Jul-Aug;34(1):45-68.