Patch aortotomy for aortic valve replacement after previous coronary artery bypass grafting. Exposure for aortic valve operations after previous coronary artery bypass grafting may be technically difficult owing to the presence of patent vein grafts on the proximal aorta. A patch or "island" aortotomy technique that allows excellent exposure of the aortic valve is presented here. In select patients this approach may facilitate cardioplegia administration. 