Mitral Valve Repair

Anatomy of the Mitral Valve: The heart is a biological pump with four chambers and four valves directing the flow of blood. The right side of the heart collects the blood from the body and pumps it into the lungs.

The left side of the heart collects the blood from the lungs and, in turn, pumps it into the body. Between the two chambers on the right side lies the tricuspid valve. The other valve – the pulmonary valve -- is on the right side is between the bottom chamber and the main feeding artery to the lungs.

On the left side lies the mitral valve between the top chamber and the bottom chamber. The aortic valve lies between the bottom chamber on the left side and the main feeding vessel of the body -- the aorta. The pulmonary valve and the aortic valve have three leaflets, and are relatively simple valves. Their function resembles that of valves of an engine, except these valves allow blood to flow in one direction only.

The mitral valve is a complex apparatus whose function is intimately related to the left ventricle -- the bottom chamber on the left side. This valve has four basic components; the annulus, or ring of the valve; two leaflets; the chords that attach to the free edge of the leaflets at one point, and to the papillary muscles at the other end. All are attached to the base of the left ventricle. All these components work in harmony to maintain an effective and efficient function of the left ventricle.

Disorders of the Mitral Valve: Any disruption of the mitral valve components could lead to a leaking of the valve. This is commonly known as mitral regurgitation.

A narrowing of the valve -- mitral stenosis -- could also occur--and is much more common in third-world countries. Typically it is linked to the disease -- rheumatic fever. This condition is rare in the United States.

A much more common condition is mitral valve prolapse, which causes poor operation of the mitral valve leaflets, and may result in leakage or a backward flow of blood into the left atrium from the left ventricle.

However, not all patients with mitral valve prolapse have symptoms or leakage, and do not require treatment. They need to be followed carefully to detect progression of this disorder.

As mitral regurgitation progresses, fluid builds up in the lungs and increases the workload of the left ventricle. The body compensates for this by retaining more fluid, and by increasing muscle mass of the left ventricle. At some point, the compensation fails. Patients become progressively more symptomatic, and this can result in congestive heart failure and dilation of the left ventricle.

Symptoms of Mitral Valve Disorders: Not all patients with mitral valve prolapse need surgery, unless there is significant regurgitation of blood, resulting in symptoms, such as:

• Shortness of breath with exertion or exercise and/or when lying down flat in bed;
• Swelling of ankles and feet;
• Awakening in the middle of the night with shortness of breath;
• Fatigue, feeling tired with a lack of energy.

The fluid the body retains to compensate for the leaky valve tends to gravitate toward the feet during the day, causing ankle swelling, and manifests itself as tightness of shoes in the evening. In a prone position at night, the fluid that has gravitated to the feet moves back into the bloodstream, causing increased lung congestion. This requires patients to wake up and sit up, preferably near an open window, in order to obtain relief.

Treatment of Mitral Valve Disorders: Treatment with medications, including diuretics, has remained the mainstay of managing these patients.

With technological advances in heart surgery over the last 50 years, doctors have been able to replace any defective valve. The replacement of the aortic valve was very successful and significantly improved long-term survival of patients.

However, the same did not hold true for mitral valve replacement. Why? Because, replacement of the mitral valve results in a discontinuity of the valve components in relationship to the left ventricle. The outcome is dysfunction of the left ventricle in the long term, and a poor long-term prognosis for mitral valve replacement. For many years, doctors were rightly reluctant to subject patients to mitral valve surgery until absolutely necessary.

In the 1970s, Dr. Alain Carpentier, a famous cardiothoracic surgeon in France, developed various techniques to reconstruct the mitral valve, using the same tissues, and yet maintaining the intimate continuity between the valve and the left ventricle. This preserved the efficiency of the left ventricle and significantly improved long-term patient survival.

With further refinements, many techniques have been developed to repair the mitral valve -- now the standard of care for patients with mitral valve disorders. Mitral valve repair has been so successful in the short- and long-term that doctors recommend the procedure be done in very early phases of mitral regurgitation, before there is damage to the left ventricle.

Not all patients with mitral valve disorders can have successful mitral valve repairs, particularly if their tissue is significantly damaged, and may require valve replacement as a last resort.

After mitral valve repair, all patients are kept on Coumadin (a blood thinner) for two to three months to allow for healing to occur within the heart. These blood thinners are usually stopped, unless the patient has an irregular heartbeat. Patients who have had a mitral valve replacement, particularly mechanical, are required to continue taking Coumadin for life.

With a successful mitral valve repair, the patient breathes better, sleeps throughout the night, and has the energy to enjoy a much better quality and quantity of life!

Before referring a patient to a heart surgeon, the doctor should carefully evaluate the experience and expertise of that surgeon. Personally, I have extensive experience and expertise in repairing the mitral valve, with a full success rate in over 80% of my patients.

For more information, call (517) 487-2273.