In conventional bypass surgery, the heart is stopped and the functions of the heart and lungs are taken over by a machine which removes carbon dioxide from venous blood, adds oxygen to the blood, and pumps it to organs throughout the body. In off-pump surgery, by contrast, the heart continues to beat while the surgeon bypasses blocked coronary arteries, as with conventional surgery, with veins removed from the legs and/or a mammary artery.
Introduced 25 years ago, off-pump surgery has become more popular in the 10 years or so since a technical advance.
Which procedure is better? An expert panel, which reviewed the results of a number of studies, concluded that "patients may achieve an excellent outcome with either type of surgery." The panel also indicated that the outcome depended more on other factors than on the type of surgery. Some of the probable advantages of off-pump surgery are a slightly lower risk of short-term memory loss and other cognitive abnormalities, less blood loss and the subsequent need for transfusion, and less damage to heart muscle and kidneys.
One of the disadvantages of off-pump surgery is a trend toward fewer open vein grafts one year after the surgery. In addition, it is difficult to bypass certain obstructed arteries with an off-pump procedure.
If bypass surgery is recommended for you, you should discuss which type of procedure your surgeon plans to use. Because off-pump surgery is technically more difficult and requires more time and experience to master, you should be careful to obtain details of your surgeon's experience, especially if he or she plans to use off-pump bypass surgery.