The four valves of the heart--the mitral, aortic, tricuspid and pulmonic--separate the four chambers of the heart. These valves are critical for maintaining the direction of blood flow through the heart, and when working properly, allow the heart to move blood into the circulatory system. When these valves become diseased, the heart cannot provide the body with an adequate supply of blood. To repair these valves, surgery is needed. The success rate of valve surgery is high and the risk of death is two to five percent, according to the National Institute of Health. The valves that become damaged due to infection or aging most commonly, are the aortic and mitral valves.
The Surgery
Replacing a valve requires that the surgeon have access to the heart. In order to do this, the patient is taken to the operating room where after proper anesthesia, the surgeon makes an incision from the top of the sternum to the xiphoid, or bottom of the sternum. After tissue has been dissected away, the sternum is then opened with a jig saw to expose the beating heart. Prior to stopping the heart, tubes will be placed in the right atrium and the aorta, which connect the patient to the heart-lung machine, also known as the cardiopulmonary bypass machine (CPM). This machine takes all the blood from the patient and oxygenates it while the heart is stopped. The blood is then returned to the patient. In order to prevent blood from going to the heart, the aorta is clamped off. This allows the surgeon to remove any remaining blood from the heart and stop the heart in order to work on the valves.
Replacement
Aortic or mitral valve replacement requires a highly skilled surgeon with years of training. A valve is replaced when it becomes stiff or the opening of the orifice becomes small, and the heart has to work hard to force the blood through the system. When a valve "leaks" it allows back flow to occur and the heart is overwhelmed with excess volume. The surgeon literally cuts open the atrium in order to access the valve, takes out the old valve, and replaces it with either a mechanical or biological valve. Mechanical valves are made from metal. Natural valves are harvested from cadavers or made from bovine or porcine valves, according to the National Institutes of Health. Mechanical valves require the patient to remain on life-long anticoagulation, usually Coumadin. Once the surgery is done, the patient spends a few days in the intensive care unit, and then moves to a surgical floor, from which the patient is finally be sent home.
Minimally Invasive Surgery
Minimally invasive surgery requires further levels of expertise. This type of surgery uses small incisions in the chest wall and a robot to replace the valve. According to the Texas Heart Institute, people who are obese, have severely damaged valves, or have blocked arteries, are not eligible for minimally invasive surgery. When using a robot, the surgeon sits at a special console and manipulates a hand-set. These movements are sent to the instruments that have been placed inside the patient through the small incisions. The robot's actions are actually more delicate than the surgeon's and very precise. Robotic, or minimally invasive, surgery can decrease the length of stay in the hospital and the recovery time for the patient.
