Mechanical vs.
Tissue Valves

By Dr. Tonya Henderson-Meyer

It’s very hard to put into words the experience of being told you have a life-threatening medical problem. Many of you reading this know that first hand. There is a flood of different feelings all at the same time. If you are like me, and didn’t even feel sick, the shock of it seems all the more difficult. One day I’m running a half marathon and two months later I’m diagnosed with severe aortic stenosis. Thus began the process of figuring out what to do and when to have it done. Initially I was told I would have several years before I would require valve replacement. Over the next few months it became clear that was not the case. My aortic aneurysm was large, my bicuspid aortic valve was stenosed and I wanted to remain active. The surgeons I spoke with said 3-6 months without exception.

When I first started researching the treatment options of valvular heart disease, I don’t think I had quite accepted my fate. Basically I wanted a solution that would allow me to go on just as I had before I knew the condition of my valve. Unfortunately, that solution doesn’t exist. Don’t get me wrong, I was very happy there was a fix for my bicuspid aortic valve and aortic aneurysm but the fix was open heart surgery. That was scary.

I found out there are currently three different options for treating bicuspid aortic valve in adults 1) mechanical heart valve, 2) tissue valve, 3) Ross procedure. I was initially interested in the Ross procedure, a surgery in which the patient’s existing pulmonary valve is used as the replacement for the diseased aortic valve. A tissue valve (usually human cadaver valve) is then used to replace the pulmonary valve. I thought this could be the ideal solution for me because I could avoid medication and in theory, have a life-long solution that would not require re-operation in the future. After meeting with a surgeon who recommended the Ross procedure and doing a more thorough literature search, I met with surgeons here in San Diego and in Los Angeles. Armed with a more thorough understanding of the Ross procedure, I decided I was not a good candidate for that procedure. There remained too many questions about the need for further operations on one or both valves in the future. If I had followed the first surgeon’s recommendations without researching the details more carefully, I would have undergone the Ross Procedure based upon my desire for the “ideal solution.” After ruling out the Ross procedure, I then moved on to the decision between the more traditional treatments with a mechanical heart valve or tissue valve.

It was an interesting process, deciding between a tissue and mechanical heart valve. Initially, in my quest to get my same life back, I thought tissue would be the way to go but after speaking to several surgeons my mind began to open up to the possibility of a mechanical heart valve. There are some general guidelines for surgeons as to which type of valve should be used for replacement of the aortic valve.

1. In healthy patients under 65 years old a mechanical heart valve is recommended because tissue valves wear out in 8-12 years and need to be replaced. A mechanical heart valve should and usually does last the rest of the patient’s life thus eliminating the need for redo or replacement surgery. All patients who receive a mechanical heart valve must take warfarin (brand names include Coumadin and Jantoven), a blood thinner, to prevent clots from forming on the valve.
2. In patients over 65 years of age usually a tissue valve is recommended because the lifespan of the tissue valve in this age group is slightly longer (10-15 years) and replacement will usually not be necessary in the patients lifetime. Some patients who receive tissue valves will have to take warfarin as well.

Even with that information I still wasn’t sure I wanted to take warfarin all my life. There is so much negative information on warfarin that I really wanted to educate myself on the risks of warfarin vs. another operation in 8-12 years. These conclusions are what helped me decide:

1. I was fairly certain I was going to need an aortic root replacement to replace both the bicuspid aortic valve and the aortic aneurysm. The mortality risk of a repeat root replacement is 10%. This meant that if I chose a tissue root replacement, I would have a 1 in 10 chance of dying when I needed that root replaced, a surgery that would be inevitable. For me, this risk was unacceptable and the inconvenience of warfarin was a better alternative.
2. I’m a very active person who likes to run. I knew if I got a tissue valve I wouldn’t necessarily have to take warfarin but I wondered what my life would be like as I got closer to needing another valve replacement. Tissue valves eventually calcify and gradually lose function, most commonly becoming stenotic. In younger, more active patients, this process occurs more rapidly. As the valve began to deteriorate, I would feel compelled to slow down and become less active in an effort to slow the process down. Thus I would have to give up sports and running for a period of months or more likely years before my next valve replacement.

Now having gone through open heart surgery I’m amazed at how good I feel but I would not want to plan on doing it again. In the end there are many things to consider in making this decision. I am glad I talked with several doctors who urged me to look at all the possibilities because initially I really couldn’t picture myself taking warfarin for the rest of my life. I am very happy with my valve and I know this is the best choice for me. You may decide a tissue valve is a better choice for your life. But whatever you decide, I hope you find this information useful.

* Please note: The mortality risk of redo aortic valve replacement is somewhat lower than the risk of a redo aortic root replacement. The exact number varies significantly with the hospital, surgeon, and other factors, including the patient's underlying health problems.

Links for Additional Information on Cardiac Valve Disease & Treatment

• ACC/AHA guidelines for the management of patients with valvular heart disease. A report of the American College of Cardiology/American Heart Association. Task Force on Practice Guidelines
  "This is a comprehensive resource which covers guidelines re: all aspects of valvular heart disease and it's treatment. Unfortunately these guidelines are from 1998, so the information is slightly dated. Remember that these are only guidelines and not every cardiologist and cardiothoracic surgeon follow them precisely. Nevertheless, it is an excellent resource and gives great detail and an extensive list of references."
• Searching for the Truth: A Mechanical or a Tissue Valve
  This article is a review article published in the Journal of Heart Valve Disease from 2004. It gives recommendations on what type of valve (mechanical vs. tissue) should be used in patients requiring aortic or mitral valve replacement. These recommendations are based upon a review of reported rates of complications related to valve replacement. These potential complications include: Incidence of thromboembolism, Bleeding due to anticoagulation medication, Structural valve deterioration, and Mortality from re-operation for structural valve deterioration.
• CarboMedics.com
  This is the official site for CarboMedics, the company that manufactures the mechanical valve conduit that was used in Tonya's open heart surgery to repair her aortic aneurysm and bicuspid aortic valve.
• ValveReplacement.com
  This is a site where you can find patient stories and discussion forums which give information on valvular heart disease from the patient's point of view.
• "Life After Open Heart Surgery"
  This page gives some useful information for what patient's should expect during their recovery from open heart surgery.