Mitral Valve Stenosis

The mitral valve is made up of two leaflets that open and close to allow the forward flow of blood coming from the lungs to the left-sided upper and lower pumping chambers.

What is Mitral Valve Stenosis?

Mitral Valve Stenosis
Normal vs. stenotic mitral valve

Mitral valve stenosis occurs when your mitral valve (the valve between the upper and lower left-sided pumping chambers of the heart) opening becomes narrowed. The mitral valve’s two leaflets become calcified, thickened or scarred and no longer open properly. This subsequent narrowing blocks the flow of blood into the lower pumping chamber or left ventricle.

Stenosis happens most often in the aortic valve but can also occur in your mitral valve. In many cases, mitral valve stenosis is caused by rheumatic fever, occurring in childhood, from a Streptococcal throat infection that seeds onto the mitral valve.  Occasionally it may occur through the natural wear and tear caused by aging.  As you get older, calcium can form on the valve’s leaflets. As this deposit builds up, the opening can become narrower and blood will not flow as easily through the mitral valve.

When mitral valve stenosis becomes severe, the valve must almost always be replaced. There are alternative repair techniques that can be performed but will depend on the extent of damage of the mitral valve. If left untreated, mitral valve stenosis can lead to fluid buildup in the lungs since the blood is not effectively crossing the valve and entering the lower chamber of the heart. In addition, this back up of blood can cause the upper chamber or left atrium to enlarge and an abnormal heart rhythm can develop called atrial fibrillation. This irregular heart rhythm can lead to stroke if left untreated. As this condition progresses failure of the RIGHT-sided heart chambers can occur. The blood backs up into the lungs and subsequently backs up even further into the right atrium.

Surgical Procedure for Mitral Valve Stenosis

Mitral Aortic Valve Surgery
Minimally invasive valve surgical incisions vs. traditional open sternotomy incision

Traditional open heart surgery for severe mitral valve stenosis usually requires cutting open your chest through the sternum (breast bone), but at Baylor St. Luke’s Medical Center we offer a minimally invasive technique by specially-trained surgeons. Minimally invasive cardiac surgery for mitral valve stenosis can be done through small incisions between the ribs (sometimes called “keyhole” or “port access” surgery). Compared to a standard open procedure, this minimally invasive keyhole surgery is typically associated with less pain, fewer blood transfusions, shorter intensive care unit and hospital stays, less scarring, fewer wound infections, smaller incisions and faster recovery – and increased patient satisfaction.

Heart Valve Replacement Options

Annuloplasty Ring Replacement
Annuloplasty Ring Placement

While narrowing of the mitral valve typically requires valve replacement with a mechanical valve or a biological valve, our surgeons can occasionally correct the disease by repairing the patient’s own native valve. Repair of the stenotic mitral valve typically involves dividing the scarred valve tissue to make it open more widely and enlarge one of the leaflets to improve the coaptation or closing mechanism.

If you require a mitral valve replacement, this can often be performed utilizing a biological tissue valve or a mechanical valve. A tissue valve may reduce the risk of clotting and not require the use of anticoagulant medications after the early post-operative period. Current tissue valves last between 10 to 20 years depending on the age of the patient at the time of the implantation. Mechanical valves are highly durable and will typically not need replacement. These valves are associated with a higher risk of clotting, requiring patients with mechanical values to take blood thinning medication (Coumadin) for the rest of their lives. Monitoring of the blood levels of this medication is required on a four to six week interval for life. Patients who are in chronic atrial fibrillation will require life-long Coumadin regardless of the valve implanted.

During most heart surgeries, including minimally invasive heart valve surgery, it is necessary to put you on the heart/ lung bypass machine. The heart and lung bypass machine will take over the circulation of blood throughout your body. Your heart will begin beating again once it starts to receive its own blood at the end of the procedure.

Outcomes after Heart Valve Stenosis Surgery

After your surgery at Baylor St. Luke’s Medical Center in Houston, Texas you will be taken to the recovery room. You will be connected to some monitors and IV lines. You may also have a special IV in your neck to measure the pressures in your heart as well as your heart function. You typically may have several other tubes and catheters that will remain in place for one or two days after surgery to help monitor your condition.

After one ortwo days in the recovery room, you will be transferred to a hospital room for further monitoring and care. You will be able to walk in your room and the hallways on the day after your surgery with a nurse or rehabilitation staff assisting you.  The average hospital length of stay is three to five days, although this will depend on your general condition and coexisting conditions. Patients receiving Coumadin may need to stay in the hospital until an adequate or therapeutic blood level is achieved. You will be discharged home or to a skilled nursing or rehabilitation facility, depending on your level of support at home. Before you leave Baylor St. Luke’s Medical Center, the cardiac surgical team will discuss your recovery program and schedule your follow-up visits.