Heart valve replacement and repair surgery
Heart valve disease occurs when a valve doesn't work right. A valve may not open all the way. Or, a valve may have problems closing. If this happens, blood doesn't move through the heart's chambers the way it should. If a valve doesn't open all the way, less blood moves through to the next chamber. If a valve doesn't close tightly, blood may leak backward. These problems may mean that the heart must work harder to pump the same amount of blood. Or, blood may back up in the lungs
or body because it's not moving through the heart as it should.
Stenosis occurs when a valve doesn't open fully. The valve may have become hardened or stiff with calcium deposits or scarring. So, it's hard to push open. Blood has to flow through a smaller opening, so less blood gets through the valve into the next chamber. Insufficiency (also called regurgitation) results when the valve doesn't close tightly. The valve's supportive structures may be loose or torn. Or, the valve itself may have stretched or thinned. Blood may then leak back the wrong way through the valve.
Mitral valve stenosis occurs predominantly in women. The reasons for this are unknown but it has been documented in virtually every clinical series about the disease since the turn of the century.
The incidence of rheumatic disease has markedly decreased in the United States due to better prophylaxis treatment of streptococcal infections with the use of antibiotics. Paradoxically, the treatment of mitral valve stenosis may be increasing. The reasons are related to immigration and the incidence of rheumatic heart disease in third-world countries. Immigrants from southeast Asia and South and Central America currently comprise a large number of patients in the United States with rheumatic heart disease
Mitral valve regurgitation (also referred to as mitral valve prolapse or MVP) follows a very different path for a woman versus a man. The condition of mitral valve prolapse is commonly diagnosed in young females yet the incidence in elderly women decreases markedly. Conversely, there is a fairly consistent incidence of mitral prolapse in the male population at both young and old age. Recent studies have indicated that, for men, the incidence of mitral prolapse requiring surgical intervention is higher than for women and it increases with age (Wilcken DEL, HickeyAJ Liftime: Risk for patients with mitral valve prolapse of developing severe valve regurgitation requiring surgery. Circulation 78:10-14, 1988). There is much interest in the etiology of mitral regurgitation. Once the diagnosis of MVP is confirmed, it requires constant vigilance against endocarditis, arrhythmia and mitral regurgitation.
Obtaining medical insurance after being diagnosed with MVP may be difficult for a woman as there is important stigmata associated with the diagnosis, however, there is little evidence that MVP bears a serious prognosis in young women. A research initiative over a 10-year period could provide definitive longitudinal information that may help remove the stigma of the diagnosis for medical insurance purposes.
Valves that are not working properly can sometimes be repaired with surgery. Heart valve surgery is open-heart surgery that is done while the patient is under general anesthesia. An incision is made through the breast bone (sternum). Tubes are used to re-route the blood away from the heart to a heart-lung bypass machine to keep the blood oxygenated and circulating while the heart is being operated on. Operations to replace poorly functioning heart valves are common procedures. They're done to improve the health and vigor of people with heart valve diseases. The surgeon who'll perform the operation is the best person to talk to about specific questions or concerns. He or she can best explain the details of the surgical procedure and recovery period. A replacement valve may be taken from another human heart (cadaver valve) or pig (porcine valve) or it can be a mechanical one.
When the valve disease is serious, medicines may not be enough to control the symptoms. In this case, heart valve surgery may be recommended to prevent permanent damage to the heart. The two types of surgery are valve replacement or valve repair.
Valve replacement involves replacing the faulty heart valve with a prosthetic (artificial) valve. This may be a mechanical or a biological valve (made from human or animal tissue). Mechanical valves have the advantage of lasting a lifetime. However, they require the patient to take blood thinning drugs for the rest of their life, which can increase the risk of bleeding in the body. This can be especially serious if it happens in the brain (this is called a haemorrhagic stroke). Prosthetic valves made of human or animal tissue do not require blood thinners to be taken, but they need to be changed every 10-15 years because they wear out.
Valve repair is usually only recommended for mitral valves which leak, but are not damaged seriously. Heart valve repair is a surgical procedure used to correct a malfunctioning heart valve. Repair usually involves separating the valve leaflets (the one-way "doors" of the heart valve which open and close to pump blood through the heart) or forcing them open with a balloon catheter, a technique known as balloon valvuloplasty.
Both procedures are performed under a general anaesthetic. This means the person is asleep and will feel no pain. The surgeon makes a cut, about 25cm (10") long, down the middle of the breastbone (sternum) and opens the ribcage to reach the heart. Medication is used to stop the heart temporarily. The blood is then rerouted to a heart-lung (bypass) machine. This takes over from the heart and lungs, adding oxygen to the blood and maintaining the circulation.
The damaged valve is replaced or repaired. The surgeon restarts the heart and the blood is allowed to flow back through the heart. The operation lasts around three to five hours.