Recapping bypass surgery – Medical Update
Coronary bypass grafting is used to circumnavigate blocked coronary arteries and “revascularize” the heart, restoring its bloodflow and overcoming the oxygen shortage that causes symptoms such as angina (chest pain). Bypass surgery is a safe, effective and now routine operation, with few procedure-related deaths and low rates of complications (such as stroke). Although a coronary bypass operation is cardiac surgery, surgeons don’t actually operate inside the heart but rather work on the coronary arteries which lie on the heart’s surface.
Before the surgery, an angiogram test with dye injection and X-rays shows which coronary arteries are most badly obstructed, where the blockages are and the general condition of the arteries. Depending on which and how many of the coronary artery branches are blocked, more or less bypass grafts will be done. The surgeons construct a detour, bypassing the blocked or narrowed parts of the coronary arteries with pieces of saphenous vein (from the patient’s leg), or with parts of the thoracic or mammary artery (inside the rib cage). These segments or “grafts” are used to re-route the coronary blood supply bypassing the worst obstructions. The new grafts take over the function of the blocked vessel(s). So far there is no artificial substitute that can be used for grafting.
A bypass operation usually takes three to four hours. While one surgical team opens up the chest and connects the patient to the heart-lung machine, another works on the leg, removing a piece of vein. The heart-lung machine takes over the function of heart and lung, circulating and oxygenating the blood while the surgeons work. The body is sometimes cooled during surgery so that the tissues need less oxygen. The heart is stopped while the surgeons operate on tiny vessels only a few millimetres in diameter. A person may need three, four or more bypass grafts. Whether surgeons use all saphenous vein grafts or include thoracic artery grafts depends on the individual case. Following the grafting operation there is an immediate resurgence of the blood supply (revascularization) to the heart muscle. Once the operation is completed, the heart is restarted, the heart-lung machine disconnected and the patient taken to the intensive care unit (ICU).
The stay in the ICU is usually one day, maybe slightly longer in some Gases. The removal of leg vein rarely presents any long-term problems because other veins take over its function. There may be some postoperative swelling and discomfort, which soon fade. By the end of the first day after surgery improvement is usually substantial. Many tubes and lines are out, the patient can talk, sit up, move around and drink fluids. By the second to fourth day, patients are taking walks along the corridor. During the rest of the hospital stay the staff try to start bypass patients on an exercise program. By the time most go home — usually 5 to 6 days after the operation — they can take a shower, shampoo their hair, answer mail and climb a few stairs.
About 6 to 10 weeks after surgery most patients get a checkup with their cardiologist, perhaps an exercise stress test, before starting a rehabilitation program. Many post-bypass patients find that cardiac rehabilitation programs aid adjustment and help to diminish post-surgical depression, lift flagging spirits and teach people how to strengthen the heart by exercising within safe limits.
Large scale trials have shown bypass grafting to be very successful in relieving angina and improving survival in people with extensive coronary artery disease. However, its overall efficacy declines somewhat after 8-10 years, as the grafts may deteriorate or atherosclerosis can develop in other parts of the coronary arteries. While women undergoing bypass operations have usually had more surgical complications than men, recent studies at one University of Toronto hospital find the procedure equally successful in both sexes.
Angioplasty — insertion of a thin catheter with an inflatable balloon at the end to stretch the artery wall and squash the plaque that causes arterial blockage — is a safe method of revascularizing the heart, provided there aren’t too many blockages and the arteries are suitable for this procedure. Success rates compare well with bypass surgery and the procedure has similarly low risks of death and complications. The advantages of angioplasty are that it does not require anesthesia or surgery, and it is less traumatic with a shorter hospital stay. However, angioplasty is less effective than bypass surgery in keeping people angina-free, and up to one third get recurrent chest pain that requires further treatment. In one study, those who underwent bypass surgery subsequently had less angina, required less heart medications and were less likely to need repeat treatments than those who had angioplasty. Bypass grafting continues to be the preferred method for many people with coronary heart trouble.
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