CABG Off-pump is a coronary artery bypass graft (CABG) done without putting the patient on a heart-lung machine. Off-pump CABG permits surgery on multiple vessels within the heart by mechanically stabilizing it. Off-pump surgery is minimally invasive, as compared to surgery on the heart-lung machine. The potential benefits include shorter hospital stay, less bleeding, less chance for infection, less risk of irregular heartbeats (arrhythmia), less trauma, shorter recovery time, and greater cost effectiveness. Off-pump CABG was initially created to avoid brain injuries attributed to the pump. However, no differences have been found in the rate or extent of mental decline in people who had traditional on-pump surgery as compared to those who had off-pump CABG. The rate of grafts that are still patent (open) 3 months after surgery was found to be lower with off-pump surgery than with on-pump surgery (88% vs. 98%), according to a 2004 study. The lower graft-patency rate with off-pump surgery is a risk of off-pump CABG. All of this ignores, of course, that studies which show no difference in mortality between matched groups of patients given CABG and conservative medical management.