For centuries, the heart, like the brain, was considered to be territory forbidden to surgeons, and it was not until after World War II that cardiovascular surgery emerged as a valuable method of treating heart disease. Prior to World War II there were only a few cases in which surgical procedures succeeded in curing or partially correcting diseased hearts. In 1925, Henry S. Souttar in England successfully split a mitral valve in a patient with" mitral valve stenosis (narrowing), but this operation was not repeated or successfully duplicated by other surgeons. In 1928, Edward D. Churchill in Boston cured a serious case of chronic constrictive pericarditis, and in 1938, Robert E. Gross, also in Boston, performed the first successful operation in which a patent (open) ductus arteriosus was ligated (tied off).
It was the experience of American surgeons working with thousands of chest wounds during World War II that provided the evidence that heart surgery was feasible. One of the first heart operations performed after the war was the opening of a narrowed mitral valve. In this operation, which was pioneered by Dwight Harkin and Charles Bailey in the late 1940's, the surgeon's finger was inserted into the valve through the left atrium. This relatively simple procedure was more or less successful in treating pulmonary edema and congestion in thousands of patients throughout the world during the next decade. Other valve deformities, however, were then still unapproachable.
Also during the 1940's and through the 1950's, congenital defects of the heart and blood vessels became subject to surgical treatment. Gross' method of closing off a patent ductus arteriosus became an almost routine and safe operation, and it is still widely used today. This operation is performed for two basic reasons: it spares the patient's overworked heart, and it prevents a bacterial infection of the ductus arteriosus, which is always a threat in untreated patients.
Perhaps the most severe congenital defect that has been in the limelight since the 1940's is the tetralogy of Fallot, a combination of four heart defects that is responsible for most blue babies. In 1945, Alfred Blalock of Baltimore, with the advice and help of Helen Taussig, introduced the first operation to enable blue babies to survive. The following year, Willis J. Potts of Chicago introduced a different surgical technique to achieve the same end, but it was not until the advent of open-heart surgery in the 1950's that it was possible for this complicated anomaly to be completely corrected.
During the time that heart surgery was being developed and perfected, there was also considerable progress in the correction of abnormalities of the arteries and veins. Various techniques were developed to treat varicose veins, and sometimes even the large veins leading to the heart—the inferior and superior venae cavae—were objects of surgical attention. Operations on the larger arteries, however, constituted a more dramatic chapter in the history of cardiovascular surgery. Aneurysms (bulging enlargements) of the aorta excited much interest, and efforts, sometimes successful, were made to prevent aneurysms from bursting. The technique used in the early 1900's involved the insertion of many feet of fine wire into the artery to produce a blood clot in the bulging sac so that the aneurysm could not burst. In the 1940's, Clarence Crafoord of Stockholm and Robert Gross independendy pioneered the operation that has now become routine for curing congenital coarctation (narrowing) of the aorta, generally by removing a greatly narrowed portion and inserting a piece of artificial tubing or a piece of a large artery or vein from a blood vessel bank. During the 1960's, often witii the help of a pump oxygenator, or heart-lung machine, many operations were performed to repair or replace large sections of the aorta and its major branches.
The introduction of the pump oxygenator in 1953 by John H. Gibbon of Philadelphia was the next dramatic step in the development of cardiovascular surgery. Pump oxygenators have slowly improved since then, and today they are used widely in open-heart surgery and other extensive cardiovascular operations. In a pump oxygenator, venous blood from the body is oxygenated and then pumped into the patient's arterial system so that the body cells, including the cells of the heart muscle, are not deprived of oxygen even though the heart has stopped beating. Within this instrument, the heart valves, especially the aortic valve, can be repaired or replaced while the heart is standing still. Following an operation, which may take as long as Uiree hours, the heart is revived with electric shock.
Probably the greatest achievement in heart surgery during the 1960's was the introduction of surgical techniques to transplant the human heart. The first operation of this type was performed by Christiaan Barnard of South Africa in 1967, and this operation was quickly followed by a score of similar operations in the United States and elsewhere. Many of the recipients died within hours, days, weeks, or mondis following the operation, but others survived.
The procedure of heart transplantation is still in its experimental stage, but it is certain to have a definite place in the future after several problems, including the rejection phenomenon and the establishment of heart banks, have been overcome. It is to be hoped, however, that extreme measures such as heart transplants will not be necessary if medical science achieves its ultimate goal—the prevention of heart disease in people under the age of 80.
No comments yet.