Cardiac Surgery

Cardiac Surgery

Dr. Kennedy
Cardiac Surgery is surgery of the heart and/or great vessels and is performed by a cardiac surgeon. Frequently it is done to treat complications of ischemic heart disease, correct congenital heart disease, or treat valvular heart disease created by various causes including endocarditis and it also includes heart transplantation.

The earliest operations on the pericardium (the sac that surrounds the heart) took place in the 19th century. Surgery on the great vessels such as aortic coarctation repair, Blalock-Taussig shunt creation, and closure of patent ductus arteriosus became common after the turn of the century and falls in the domain of cardiac surgery, but technically is not heart surgery. Surgery on the great vessels was followed by the development of closed-chest heart surgery. A small incision was made, but the chest cavity is not opened, and the surgeon blindly worked on the beating heart. Palliation of severe mitral valve stenosis, which was common in the past due to rheumatic fever, could be accomplished by poking a finger into the (mitral) valve through an incision in the left atrium. If a finger didn’t do, a knife was passed through the incision to incise tissue. Later a special incision for aortic valve stenosis was developed which was made through an incision in the left atrium producing results similar to that accomplished by surgeon’s finger in a stenosed mitral valve.

Repair of intracardiac pathologies require a bloodless and motionless environment and that means the heart must be stopped and drained of blood. The first successful intracardiac correction of a congenital heart defect using hypothermia, in which the patient’s body temperature is lowered to reduce the need for oxygen, was performed by Dr. C. Walton Lillehei and Dr. F. John Lewis at the University of Minnesota in 1952.

In open heart surgery the patient’s chest is opened and surgery is performed on the heart. (The term “open” refers to the chest, not to the heart itself.) The heart may or may not be opened depending on what is needed. The patient needs the function of the heart and lungs replaced by an artificial method, hence the term cardiopulmonary bypass. Dr. John Heysham Gibbon at Jefferson Medical School in Philadelphia reported the first successful use of extracorporeal circulation by means of an oxygenator in 1953, but he abandoned the method, disappointed by subsequent failures. In 1954 Dr. Lillehei realized a successful series of operations with the controlled cross-circulation technique in which the patient’s mother or father was used as a “heart-lung machine.” Dr. John W. Kirklin at the Mayo Clinic in Rochester, Minnesota started using a pump-oxygenator in a series of successful operations, which was soon followed by other surgeons.

Since the 1990s, surgeons have begun to perform off-pump bypass surgery – coronary artery bypass surgery without the cardiopulmonary bypass described above. In these operations, the heart is beating during surgery, but is stabilized to provide an almost stationary work area. It is believed that this approach results in fewer post-operative complications (such as postperfusion syndrome) and better overall results.

A new form of heart surgery that has grown in popularity is robotic heart surgery in which a machine is used to perform surgery while being controlled by the heart surgeon. The advantage to this is that the size of the incision made in the patient does not have to be bigger than 3 small holes for the robot’s much smaller hands to get through. Also, a major advantage is the recovery time of a patient. Instead of 6 months of recovery time, some patients have recovered and resumed playing athletics in a matter of weeks.

The development of cardiac surgery and cardiopulmonary bypass techniques has reduced the mortality rates of these surgeries to relatively low levels. For instance, repairs of congenital heart defects are currently estimated to have 4-6% mortality rates. Nevertheless, this is a significant level of mortality and therefore surgery on the heart is never elective. It is done to save lives. A concern with cardiac surgery is the incidence of neurological damage. Stroke occurs in 2-3% of all people undergoing cardiac surgery. A more subtle re sults is known as postperfusion syndrome (aka pumphead). The symptoms of postperfusion syndrome were initially felt to be permanent, but have been shown to be transient with no permanent neurological impairment.

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