Most patients with mitral-valve abnormalities are candidates for surgical repair. In about 85 percent of cases, the valve can be repaired instead of replaced. The surgeon can repair the valve tissue and also modify blood vessels to increase blood supply to the valve. In cases where the valve is too damaged to be repaired, patients have two options for replacement. In one type of replacement, the surgeon implants a mechanical valve, usually made from carbon fiber or titanium. This valve is very durable, but the patient must take blood-thinning medication for the rest of his life. (Those who cannot take the medication reliably should avoid this option.) The second replacement option is a bio-prosthetic valve. It is usually constructed from the sac lining of a cow’s heart (bovine pericardium) or is an actual mitral valve from a pig (porcine valve). Unless the patient has a heart-rhythm disturbance, this valve requires no blood-thinning medications. However, it will wear out and must be surgically replaced every 10-20 years. No surgical option is right for everyone; a patient should discuss his case with his doctor.

Both repair and replacement require an open-heart surgery that takes place under general anesthesia. As with all open-heart procedures, the surgeon enters the chest cavity by cutting the breastbone. He stops the patient’s heart after the patient is placed on a heart-lung machine. He then makes an incision in the left atrium to access the mitral valve. The operation takes three to four hours, not counting anesthesia and surgical prep. After surgery, the patient remains in intensive care for one to two days and is usually discharged after six to eight days. The breastbone takes six weeks to heal, and the patient can usually return to work after four to eight weeks.

Anesthetics are used to put the patient to sleep. Usually the patient is given a blood thinner, such as heparin, during the operation. This helps prevent the blood from clotting in the heart-lung machine. After surgery, the patient receives medicines, such as protamine, that help stop bleeding. Once the risk of bleeding has passed, a patient who has received a mechanical valve will be put on blood thinners (often a drug called Coumadin).

In some patients, mitral-valve disease is not severe enough to warrant surgery. For them, regular physical exams and electrocardiograms may be enough if symptoms are stable. For those who are old or in poor health, surgery may be too risky. Some of these patients (those with mitral-valve stenosis) may be appropriate for a procedure in which a catheter is inserted into a vein and a small balloon is inflated in the narrow mitral valve, widening the opening. This procedure is safer than surgery, although the benefits do not last as long.

A malformed mitral valve can almost always be successfully repaired or replaced. In the hands of an experienced heart surgeon, surgical repair and replacement has a low mortality rate and relatively few complications.

Because surgery on a heart valve is an extremely invasive procedure, it carries risks, most of which can be predicted. For a relatively healthy patient, the risk of dying from repair or replacement is less than 2 percent. There is a less than 5 percent risk of complications, such as re-bleeding from interior surgical incisions, infection at the wound site, and inadvertent surgical damage to the heart’s coronary arteries or pacemaker function. When they happen, these complications can generally be corrected with follow-up procedures. There are also small but finite risks of complications from general anesthesia.

The most common risk of no treatment is the development of congestive heart failure, a condition in which a weakened heart cannot pump enough blood to all regions of the body. A patient who develops congestive heart failure is at risk of early death.

Occasionally a patient’s condition is so dire that an emergency valve surgery is necessary. Most of the time, however, the patient and doctor can plan the surgery well in advance.