With internal thoracic artery graft you wouldn't need to make proximal anastomosis. With radial artery graft backward flow will flush the air away. With vein graft do the proximal anastomosis first, then sequential, and last distal, and flush by tightening the anastomotic suture line only after clamp release. Remaining visible bubbles in the graft removed by thin needle puncture. Use soft bulldog clamps to avoid graft damage and later stenosis.