Aortic

Valve Replacement

The most common type of heart valve replacement is replacement of the aortic valve. This is often shortened to "AVR," for Aortic Valve Replacement.

Image from AHA

The aortic valve separates the heart from the aorta. The aorta is the biggest blood vessel in the body and it carries blood from the heart to the body. 

The aortic valve gets a lot of wear & tear through the years because of the high pressures generated in the left ventricle, the high pressures needed to get blood throughout the body.

When diseased, the aortic valve can either become stiff or become leaky.

A stiff aortic valve is called AORTIC STENOSIS

A leaky aortic valve is called AORTIC INSUFFICIENCY

A stiff or leaky valve will often caused abnormal blood flow through it, which creates a murmur.

A murmur is an abnormal sound - but it may or may not represent a disease or a problem that needs to be fixed. 

Listen to NORMAL HEART SOUNDS

Listen to AORTIC STENOSIS MURMUR

Listen to AORTIC INSUFFICIENCY MURMUR

The amount of stiffness or leakage is usually determined using a fancy ultrasound, called an ECHOCARDIOGRAM. 

An ECHOcardiogram is often confused with an ELECTROcardiogram. 

To keep them straight, just remember ECHO uses sound waves to look at the valves and ELECTRO looks at the electricity of the heart rhythm

ECHO

EKG

The ECHO will show how much stiffness aka stenosis, or how much leakage aka insufficiency the valve may have. 

The amount of stenosis or insufficiency may be NONE TRACE MILD MODERATE or SEVERE.

Many people have some leakage of one or more valves. In general, valves only need to be replaced if there is SEVERE stenosis or insufficiency, and especially if the patient is having symptoms, or if the heart is becoming weak.

In general, the aortic valve cannot be repaired but must be replaced; that is, the bad valve must be removed and a new valve put in. In rare cases, the aortic valve may be repaired, where the patient's valve is kept in place and altered so that it works properly. 

If an aortic valve needs to be replaced, there are several options on how it can be done:

STERNOTOMY

MINIMALLY- 

  INVASIVE

TAVI

A sternotomy is the "usual" method for AVR. The breastbone is cut from top to bottom. 

This allows access to all areas of the heart and multiple procedures on the heart can be performed, if needed. 

If a patient requires AVR and bypass grafts, then a sternotomy is usually required and a minimally-invasive method cannot be used. 

Many patients do not like the thought of a sternotomy, but most patients tolerate a sternotomy well. 

It usually takes Dr. Pool 2-3 hours to perform an AVR thru a sternotomy. 

Dr. Pool recommends not driving for 2 weeks after sternotomy. And no lifting over 10 lbs for 2 months. After 2 months, the breastbone will be healed and most patients have no restrictions at that point. 

A minimally-invasive method can often be used for AVR. 

The method Dr. Pool uses involves a small incision at the top of the breastbone. This allows for most of the strength of the bone to remain intact.

If a patient requires AVR and bypass grafts, then a sternotomy is usually required and a minimally-invasive method cannot be used. 

It usually takes Dr. Pool 2-3 hours to perform a minimally-invasive AVR.

Dr. Pool does not usually recommend a minimally-invasive approach for very large patients or for patients who have a very weak heart. 

Dr. Pool recommends not driving for 1 week after a minimally-invasive AVR. And no lifting over 10 lbs for 6 weeks. 

The stiff old valve provides friction with the new valve, which holds it in place. 

The least invasive method for AVR is called TAVI, which stands for Transcatheter Aortic Valve Implantation. 

The stiff old valve provides friction with the new valve, which holds it in place. 

TAVI is also called TAVR. 

With TAVI, no open incision is needed at all. The new valve is put in thru an artery, usually an artery in the groin. It is guided into position in the heart and released. 

There are no sutures holding the new valve in place. 

The FDA has approved TAVI only for certain patients, usually patients who are elderly or frail or have high risk for a traditional AVR. 

Dr. Pool is part of a team of experts at Texas Health Dallas who help determine which patients are eligible for TAVI. 

If an aortic valve needs to be replaced, there are options on what kind of valve to put in:

MECHANICAL VALVE

TISSUE VALVE

TAVI

VALVES

A mechanical valve is made out of metal. Actually, the mechanical valve Dr. Pool usually uses is not made of metal but is made of carbon (called On-X valve). 

A mechanical valve has parts that move in a way that allow for blood clots to sometimes form in the valve. If a blood clot forms, it can go to the brain and cause a stroke. So mechanical valves require a blood thinner to be taken, to avoid blood clots. 

The blood thinner needed for mechanical valves is coumadin, also known as warfarin. Blood levels - known as the INR - must be checked to ensure the correct amount of blood thinning. 

The benefit of a mechanical valve is that it is expected to last "forever," or at least, it is not expected to wear out. In theory, a mechanical valve could last 50 years or more. 

On rare occasion, a mechanical valve can get clogged or break, in which case it will likely need to be replaced. 

Young patients - those in their 20s or 30s - often elect for a mechanical valve. A mechanical valve is not usually placed for older patients. 

A tissue valve is made from tissue - that is, from an animal. There are pig, horse, and cow valves available. The fancy term for this type of valve is xenograft.

A tissue valve has been processed in a way that the patient's body will not reject it. The patient does not usually need to take any special medicines because of a tissue valve, and usually the patient does not require a blood thinner. 

A lot of Dr. Pool's patients choose a tissue valve because of TAVI. If the patient has a tissue valve placed, in 15 years (or whenever the valve wears out), the expectation is that a TAVI valve could then be placed thru the groin, so that the patient does not require another open operation. 

The drawback for a tissue valve is that the valve will eventually wear out. The tissue valve that Dr. Pool usually uses for AVR is expected to last about 15 years (Inspiris valve). 

TAVI valves are a special kind of valve, made of tissue and a metal stent. 

There are currently 2 valves approved for use by the FDA. The Edwards Sapien valve has cow tissue inside a cobalt-chromium stent. The Medtronic Evolut valve has pig tissue inside a Nitinol (metal alloy) stent. 

Dr. Pool is part of a team of experts who can determine if a patient is eligible for TAVI. If a patient is a candidate for TAVI, Dr. Pool and the team will determine which particular TAVI valve is best for that patient. 

A TAVI valve has been processed in a way that the patient's body will not reject it. The patient does not usually need to take any special medicines because of a tissue valve, although it is recommend for the patient to take Plavix for 6-12 months. Coumadin is not needed.

Since it is a relatively new technology, it is not clear how long a TAVI valve will last, though it is expected that TAVI valves will likely last 12-15 years. 

In rare cases, a human valve can be implanted in the aortic position. This is called a homograft. These types of valves are not common and are usually used in cases of life-threatening heart infection (endocarditis) or as part of the Ross Procedure. 

Any type of new heart valve - mechanical, tissue, TAVI, human - can become infected. Fortunately, this does not happen often. But when a replaced valve become infected, it usually requires another operation to replace it again, in order to get rid of all of the infection. 

Dr. Pool can inform a prospective patient of his or her risk during a consultation. If a patient has a low risk for surgery, AVR or a minimally-invasive AVR can be considered, or the patient can be considered for TAVI if his or her risk is high. 

 
 
 

God bless & heal you! 

J. Mark Pool, MD

ABTS Board-certified

214-692-6135

Member of Society of Thoracic Surgeons