Mitral Valve Replacement

You have a disease of one of the valves of your heart. In you or your child's case, it is the Mitral valve which needs replacing. Mitral valve replacement is open heart surgery done by a heart surgeon. This operation will treat problems with the mitral valve. The mitral valve is the "inflow valve" for the left side of the heart. Blood flows from the lungs, where it picks up oxygen, and enters the heart through the mitral valve. When it opens, the mitral valve allows blood to flow into the heart's main pumping chamber. This is called the left ventricle. The valve then closes when the ventricle contracts for pumping. This keeps blood from leaking back into the lungs when the ventricle contracts (squeezes). This pumping then pushes blood out to the rest of the body. This surgery is usually done when your heart no longer is able to handle the daily chores of your body.

Surgery may be necessary when the valve does not open or close completely. A stenotic (narrow) valve does not let the blood into the heart normally. This causes blood to back up in the lungs. This makes it hard for the heart to increase the amount of blood that it pumps. This may produce shortness of breath and fatigue. Problems are worse with activity.

If the valve leaflets do not meet correctly when closing, blood may leak backward into the lungs each time the heart pumps. This is called mitral insufficiency. When some of the blood leaks backwards, the heart has to work even harder. The heart can compensate for this over-work for a long time if the leakage came on slowly. Eventually, the heart fails.

Mitral valve problems are uncommonly caused by a birth defect. This is called congenital. More often, simple "wear and tear" may cause the valve to fail. This is called "degenerative disease". This may be related to aging although many young people will have this condition as well. Rheumatic fever may damage the mitral valve. Occasionally, the mitral valve may be damaged by infection. This also causes the mitral valve to leak.

DESCRIPTION OF SURGERY

Many mitral valves can be repaired, especially if they leak from wearing out. When the valve is too damaged to repair, the valve must be replaced. A prosthetic (artificial) valve is used to do this. Valves damaged by rheumatic disease often must be replaced.

Two types of artificial valves are available:

  • Mechanical valves made entirely from man-made materials.

  • Biological valves which are made from animal tissues.

Each has advantages and disadvantages. The choice of which type to use should be made by you and your surgeon taking the following into consideration:

  • Your age.

  • Your lifestyle.

  • Other medical conditions.

  • Your preferences with regard to medications and the risk of another operation.

There are a number of good mechanical prostheses available. All work well. The main advantage of mechanical valves is that they do not wear out. Their main disadvantage is that blood has a tendency to clot on mechanical valves. If this happens the valve will not work normally. Because of this, patients with mechanical valves must take anticoagulants (blood thinners) for life. There is also a small but definite risk of blood clots causing stroke, even when taking anticoagulants.

There are a number of biological choices for mitral valve replacement. Most are made from pig aortic valves. Their main advantage is that they have a reduced risk of blood clots forming on the valve. This lessens the chance of the valve not working or causing a stroke. The key disadvantage of biological or tissue valves is that they have less of a user life as compared with mechanical valves. Over time they will wear out. The rate at which they wear out, however, depends on the patient's age. A young boy might wear out such a valve in only a few years. The same valve might last 10 years in a middle aged person, and even longer in a patient over the age of 70. A tissue valve used in a person over 70 years old will probably not need to be replaced.

RISKS AND COMPLICATIONS

Your cardiologist and cardiothoracic surgeon can best determine your individual risk. It will depend on your age, general condition, medical conditions, and your heart function. In general, the risks include:

  • Effects from the operation itself such as bleeding, infection, and risks of anesthesia are low.

  • Blood clotting caused by the new valve. Replacement with a mechanical valve requires lifelong treatment with medication to prevent blood clots.

  • Infection in the new valve. Infection is more common with valve replacement than with valve repair.

  • Valve failure. Valve failure is more common with valve replacement than with valve repair. Pig valves tend to fail after about 8 to 10 years.

PROCEDURE

Valve repair or replacement is open-heart surgery. You are given general anesthesia (medications to help you sleep). You are then placed on a heart-lung machine. This machine provides oxygen to your blood while the heart is not working. The surgery generally lasts from 3 to 5 hours. During surgery, the surgeon makes a large incision (cut) in the chest. Sometimes the heart is cooled to slow or stop the heartbeat. The damaged mitral valve is either repaired or removed and replaced with an artificial heart valve.

AFTER THE PROCEDURE

  • Recovery from heart valve surgery usually involves a few days in an intensive care unit (ICU) of a hospital. Full recovery from heart valve surgery can take several months.

  • Anticoagulation (blood thinning) treatment with warfarin is often prescribed for 6 weeks to 3 months after surgery for those with biological valves. It is prescribed for life for those with mechanical valves.

  • Recovery includes healing of the surgical incision, gradual building of physical endurance, and exercise. An exercise program under the direction of a physical therapist is usually recommended.

  • Once you have an artificial valve, your heart function and your life will return to normal. You usually feel better than before surgery if you were having problems before the surgery. You should no longer experience shortness of breath and fatigue. However, if your heart was already severely damaged before your surgery, you may continue to have complications of heart disease.

  • You should be able to resume most of your normal activities, although you will have to continue to monitor your condition. You need to watch out for blood clots and infections.

  • Artificial valves need to be replaced after a period of time, so it is important that you see your caregiver regularly.

  • Some individuals with a mitral valve replacement need to take antibiotics before having dental work or other surgical procedures. This is called prophylactic antibiotic treatment. These drugs help to prevent infective endocarditis. Antibiotics are only recommended for individuals with the highest risk for developing infective endocarditis. Let your dentist and your caregiver know if you have a history of any of the following so that the necessary precautions can be taken:

  • A VSD.

  • A repaired VSD.

  • Endocarditis in the past.

  • An artificial (prosthetic) heart valve.

HOME CARE INSTRUCTIONS

  • Use all medications as prescribed.

  • Take your temperature every morning for the first week after surgery. Record these.

  • Weigh yourself every morning for at least the first week after surgery and record your weight.

  • Do not lift more than 10 pounds (4.5. kg) until your sternum (breastbone) has healed. Avoid all activities which would place strain on your incision.

  • You may shower but do not take baths until instructed by your caregivers.

  • Avoid driving for 4 to 6 weeks following surgery or as instructed.

  • Use your elastic stockings during the day. You should wear the stockings for at least 2 weeks after discharge or longer if your ankles are swollen. The stockings help blood flow and help reduce swelling in the legs. It is easiest to put the stockings on before you get out of bed in the morning. They should fit snugly.

SEEK IMMEDIATE MEDICAL CARE IF:

  • You develop chest pain which is not coming from your incision (surgical cut).

  • You develop shortness of breath.

  • You develop a temperature over 102° F (38.9° C).

  • You have a sudden weight gain. Let your caregiver know what the weight gain is.