Off-Pump Bypass Surgery
What is off-pump bypass surgery?
Off-pump coronary artery bypass surgery, also known as “beating heart” surgery, differs from traditional coronary artery bypass surgery, because a heart-lung machine (on-pump) is not used. Rather than stopping the heart, advances in medical technology and operating equipment now allow the surgeon to stabilize portions of the heart during surgery. With a specific area of the heart stabilized, the surgeon can go ahead and bypass the blocked artery in a highly controlled operative environment. Meanwhile, the rest of the heart keeps pumping and circulating blood to the body.
What are the benefits?
The aim of off-pump bypass surgery is to decrease the morbidity of coronary artery bypass surgery, such as stroke, renal failure and the need for blood transfusions. The off-pump approach may also lessen the risk of what are called cognitive changes that have been seen in many patients who underwent CABG with cardiopulmonary bypass (heart-lung machine). These short-term changes include memory loss, difficulty thinking clearly and problems concentrating for lengthy periods. They usually improve over the months following surgery. But a study in the February 8, 2001 New England Journal of Medicine raised the question of whether these short-term changes may affect long-term cognitive function. Although the reason for these cognitive changes is not yet definitely known, many physicians believe the changes are related to the fact that emboli (tiny particles, most commonly atherosclerotic plaque) are dislodged into the bloodstream when the heart-lung bypass machine is used. As they travel throughout the circulation, the emboli may affect the brain, resulting in cognitive dysfunction.
What are the risks?
Researchers found that the results of both on- and off-pump surgeries were excellent. The risk of stroke, heart attack during surgery, and death were similar and low in patients undergoing both on- and off-pump CABG. There were fewer cognitive side effects in the off-pump patients, less renal (kidney) failure requiring dialysis, less red blood cell usage, and fewer infections of chest incisions in the off-pump patients. One concern is that off-pump patients had more incomplete revascularization, meaning that fewer patients had blood flow fully restored than on-pump patients. Off-pump bypass may be inappropriate, counterproductive or unsafe, depending on many factors. It's always best to discuss your individual case with your physician.
