Bioprosthetic valves
Bioprosthetic valves are made primarily from animal tissue [i.e., bovine (cow) pericardium (the tough sac surrounding its heart), a porcine (pig) aortic valve, or human valves taken from cadavers].
Surgical valve replacement
Most heart surgery is performed through an incision across the full length of the breast bone, or sternum. This incision is called a median sternotomy, with the bone requiring about 6 weeks for complete healing.
In selected patients, heart valve surgery can be performed using smaller, or minimally invasive, incisions. Smaller incisions may provide some benefit to patients. Preoperative studies, including a coronary angiography, echocardiography and, in many cases, chest CT (CAT) scan, help to determine which patients are candidates for minimally invasive surgery. These surgical approaches with small incisions also include use of the heart lung machine as do full sternotomy operations.
If the cardiovascular surgeon chooses to replace the patient’s heart valve, the first step is to remove the diseased valve (excise the valve and calcium deposits) and then implant a prosthetic heart valve in its place. Prosthetic valves used to replace diseased natural valves are made from a variety of materials and come in a variety of sizes.
There are two broad categories of prosthetic heart valves that are used to replace diseased valves:
Mechanical valves
Mechanical valves are constructed from synthetic material, primarily carbon.
Tissue valves (bioprosthetic valves)
There are a wide variety of tissue valves:
Heterograft (Xenograft)
Valves or pericardial tissue harvested from medical-grade animals (i.e., bovine (cow) or porcine (pig)).
Homograft (Allograft)
Human valves taken from cadavers.
Autograft/Autologous tissue
A normal valve that has been transferred from one position to another replacing a diseased valve within the same individual.
A heterograft is a biological valve made from animal tissue. For example, pericardial valves traditionally contain leaflets made from bovine (cow) pericardium (the sac surrounding its heart) and are sewn onto a flexible or semi-flexible frame. Another type of tissue valve is a porcine valve. A porcine valve is made from pig’s aortic heart valve and is usually sewn onto a flexible or semiflexible frame to make a “stented” valve; alternatively, the natural porcine aortic root is left intact to function as the frame to make a “stentless” valve.
Each valve is surrounded by a cloth sewing ring. Sutures are placed through this sewing ring to secure the valve to the heart.
Mechanical valves
Mechanical valves include leaflets that are made out of a special type of carbon. These valves usually have two leaflets. The leaflets open and close during the cardiac cycle, ensuring flow of blood in one direction.
Criteria and selection of heart valves
The choice between a mechanical and tissue valve depends upon an individual assessment of the benefits and risks of each valve and the lifestyle, age and medical condition of each patient.
Tissue valves do not require long-term use of blood thinners (anticoagulants). This is an important consideration for those who cannot take blood thinners because of a previous history of major bleeding (e.g., gastrointestinal or genitourinary) or an increased risk of traumatic injury and bleeding related to recreational activity, sports, or advanced age. Tissue valves generally last at least 10 years and, in some people, have lasted longer than 30 years. If a patient under 60 years of age receives a tissue valve, there is a high probability that he or she will require another valve replacement at some point; whereas, most patients who are 70 years and older do not.
Mechanical valves rarely wear out. However, they require daily treatment with blood thinners, and blood thinners can require changes in diet or activity levels.
The decision to choose a tissue or mechanical valve replacement is often related to the patient’s age, with older patients preferentially receiving tissue valves. However, there is no clear agreement on the precise age cutoff where a tissue valve may be preferable to a mechanical valve.
Valve repair
When possible, it is generally preferable to repair a patient’s valve rather than to replace it with a prosthetic device. Valve repair usually involves the surgeon modifying the tissue or underlying structures of the mitral or tricuspid valves.
Nearly all valve repairs include placement of an annuloplasty ring or band. This is a cloth-covered device that is implanted around the circumference, or annulus, of the mitral or tricuspid valve. It provides support to the patient’s own valve and brings the valve leaflets closer together, potentially reducing leaks across the valve. There are a variety of different annuloplasty devices. The surgeon will choose one that best fits your heart valve.
In addition to an annuloplasty, mitral valve repair frequently requires correction of problems with the leaflets or chords, which attach the valve leaflets to the heart. When a mitral valve leaks because of mitral valve prolapse, fixing the leaflets and chords (and adding an annuloplasty ring or band) restores normal valve function.
Care after a heart valve procedure
The normal recovery period from standard heart valve surgery requires four to eight weeks. Recovery may be faster when a smaller incision is employed, for example, with minimally invasive and transcatheter procedures. During this time, patients gradually gain energy and resume normal activities of daily living. Regular check-ups by a heart specialist are essential, and you are encouraged to call or see your doctor whenever you have questions or concerns about your health, especially if you experience any unusual symptoms or changes in your overall health.
Diet and exercise
Two additional important aspects of recovery and general wellness are maintenance of a healthful diet and regular exercise. If your doctor has recommended a special diet, it is important that it be followed. Healthy eating is an important part of a healthy life. During recovery, nutritious food gives your body energy and can help you heal more quickly.
Go to www.heart.org/nutrition for more information about heart-healthy eating, including healthy eating, simple cooking, dining out, heart-smart shopping and heart-healthy recipes.
To improve overall cardiovascular fitness, it is recommended that you combine a balanced diet with your doctor’s recommendations about exercise and weight control. Following a regular exercise program is an important part of maintaining a healthy lifestyle. Under your doctor’s guidance, you should gradually build up your exercise and activity level. Before you begin a new sports activity, check with your doctor.
Anticoagulants
It is important to follow your doctor’s directions for taking medications, especially if an anticoagulant has been prescribed. Anticoagulants, or blood thinners, decrease the blood’s natural ability to clot. If you must take anticoagulant drugs, you will need periodic blood tests to measure the blood’s ability to clot. This test result helps your doctor determine the amount of anticoagulant you need. It may take a while to establish the right dosage of this drug for you, but consistency and working with your doctor are important. Home testing may also be available, so check with your physician about this option. Consult your doctor about interactions with any other drugs you may be taking and dietary restrictions you may have while taking anticoagulants, and also ask about any signs to watch for that might indicate your dosage is too high.
Other health information
Before any dental work, including teeth cleaning, endoscopy or surgery is done, tell your dentist or doctor about your prosthetic heart valve. Patients with a valve implant are more susceptible to infections that could lead to future heart damage. Therefore, it may be necessary to take antibiotics before and after certain medical procedures to reduce the risk of infection.
Furthermore, when traveling for more than a few days, try to maintain diet and exercise level as close to normal as possible. Be sure to discuss all your medicines (including over-the-counter medicines) with your doctor, and don’t change the dosage unless instructed to.
Defects and diagnosis
Valve defects can be deadly if left untreated
A variety of conditions can cause heart valve abnormalities, and there are many ways of determining if you have heart valve disease. Learn what happens with heart valve disease and how it is diagnosed.
Valve defects can be deadly if left untreated
Maintaining a healthy heart is important to living a healthy life
What the heart does
Maintaining a healthy heart is important to living a healthy life
Beating about 2.5 billion times over an average lifetime, the heart provides blood flow to all the cells, tissues, and organs in your body when it's working properly. Clasp your two hands together and that's about the size of a healthy heart. It's important to maintain a healthy heart to live a healthy life.