Famous Tobagotwo Writings On Valve Selection

[Ross]

Some thoughts on Mech vs Xenograft

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It's a terrible coin flip.

The survival rate is about the same for either path over time.

Some people go through their surgeries with surprising ease. Some have a hard time of it. Some people do just fine with Coumadin management. Others have difficulties, perhaps because their body chemistries are not as stable.

The problem is, you don't get to see which one of these you are until afterwards.

The general bleeding issue attributed to Coumadin is not as great in younger patients, and then is primarily in head injuries that would also cause internal bleeding in a non-ACT-treated person. Until you pass traditional retirement age, it isn't very likely that you'll bleed to death from a "normal" injury or cut, or general rough-and-tumble. (Although the slap-shot hockey puck in the head might do it.)

The risk of valve-related stroke or embolism is similar in a properly anticoagulated mechanical valve recipient and one with a biological valve who is not taking antiplatelet drugs (e.g., aspirin or Plavix). However, the risk of intracranial hemorrhage on Coumadin is increased 7- to 10-fold. Hold it - not as bad as it sounds. The result is only a .3% to 1% risk. [Management of intracranial bleeding associated with anticoagulation: balancing the risk of further bleeding against thromboembolism from prosthetic heart valves Francesca Crawley, David Bevan, Damian Wren http://jnnp.bmjjournals.com/cgi/content/full/69/3/396 ]

Well, you say, then just give me the tissue valve and pass me the baby aspirin. Then I'll sweeten the odds in two ways. Ahh, not so simple. The tissue valve has the disadvantage of requiring resurgery over time, which only happens occasionally with mechanical valves. That's where the risk for xenograft valves catches up with mechanicals: in the reoperations.

The risks balance over age. A younger patient risks more from multiple surgeries with biological valves. An older patient with more fragile veins risks more with warfarin and the risk of intracranial or gastrointestinal bleeding from hemorrhage.

Again, the survival rate is about the same for either path over time.

For people in their forties, I think it's the hardest call of all.

At 52, I realized that I would have one more surgery in my lifetime with a tissue valve. It was the decision I made. The surgery and recovery went very smoothly for me, and I am content with it. The result for me is an independent existence, with my sole compromise being that I take preventative antibiotics before dental cleanings and intrusive medical procedures. But it doesn't go that smoothly for everyone.

And at 45, it would have been a muddier decision. The first valve might last a shorter time, due to a more active, younger chemistry. I might wind up needing a third valve in my seventies. That's a bad time to go get a new one, although a catheter-delivered valve will likely be a viable option at that point.

Also, it is to be remembered that the year or so before the bovine or porcine tissue valve needs replacement, it isn't operating up to capacity, much as your current, natural valve isn't now.

However, managing Coumadin for 35 years isn't "nothing," either, even for those who do it well. There are issues with standard medical tests (many threads on colonoscopy, for instance). There are cretinous doctors, nurses, and ER personnel who don't understand ACT and make poor medical care decisions. There are issues with many ignorant dentists regarding dental work while on ACT. There are blood draws and visits to the clinic (even with home machines), and the medication is critical, as the embolism/stroke risk rises from one percent to four percent without anticoagulation. There is also added concern when undergoing any other type of surgery, in balancing the risk of bleeding with the risk of the mechanical valve throwing a clot. It makes sense to consider the possibility of other physical problems developing over time. Many people take these things right in stride. Some find them depressing or frightening.

Then there are the crossover issues. Having a tissue valve doesn't mean you might not wind up on Coumadin eventually for atrial fibrillation or a stroke or heart attack episode. And mechanical valves aren't always forever, as there are a few things your body may do that can cause them to have to be replaced (usually not due to their failure, but due to an expanding aortic root, a change in your heart circumstances, or growth of tissue on the valve).

If you've got a bicuspid valve, I would strongly suggest you discuss with your surgeon the possibility of stabilizing your aortic root, regardless of the type of valve you choose. This appears to be a primary cause for failures of Ross Procedures as well as some valve replacements.

There are many good threads about the choice of valve types (and then of brands and models within those types) on the site. Use the advanced search to locate some of them. You will notice some heat in most of the discussions, as it is a matter of passion to many who've made the choice. Please try to ignore the unavoidably human histrionics and glean the thoughts and information from these threads.

My only real advice is to find the arguments that ring truest to you personally, and go with your gut feel. As I said, the odds are basically interchangeable, so the only right decision is the one that feels best to you, that suits your personality and your mental and emotional makeup. And once you've made your decision, never look back.

Best wishes, gentlemen.
__________________
Bob H

"No Eternal Reward will forgive us now for wasting the dawn..." Jim Morrison

I am not a Medical Professional. Aortic Stenosis w/severe calcification. Aortic valve replaced by Medtronics Mosaic porcine tissue valve on 4/6/04. The procedure was performed by Dr. Tyrone Krause, Chief of Thoracic Surgery, Robert Wood Johnson University Hospital, New Brunswick, NJ. Dr. Krause is a true Zen Master Mechanic in the world of valve replacement surgery.

 

[Ross]

Ross Procedure Considerations

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Chilihead has pointed out an obvious flaw in this thread, inthat we haven't discussed the Ross Procedure. This is a procedure that replaces your faulty aortic valve with your nearly identical pulmonary valve, and usually places a homograft (from a human donor) in the less-demanding pulmonary valve position.

When it is successful, the Ross Procedure is the gold standard for aortic valve replacement, offering the only possibility of one-time valve surgery that produces lifelong, living-tissue repair without drugs.

A Ross-type procedure has also been tried in very limited numbers on the mitral valve, with mixed results.

One difficulty with the Ross Procedure is developing a feel for when it is appropriate. From postings during the last year, it appears that some of the surgeons who perform them are also unsure when it is a good risk. This is a poignant reason to seek out a highly experienced surgeon for the Ross procedure, who has years of successful patients in his wake. If you want to do it, look for a Stelzer.

There are some things that can make a Ross Procedure fail over the short term (less than ten years). I believe these are not due to poor surgery or a failure of the procedure itself, but of the diagnosis instead. This is important, because a failed Ross Procedure leaves the heart more damaged than more traditional surgeries do.

I believe that the cardiologist and the surgeon must fully understand the cause of the surgery candidate's valve disease, and whether it is a static or progressive problem. My personal observations and assumptions from posts and articles are that the cardiologist and surgeon must have a high degree of certainty that there is not a tendency toward aneurism; that other valves are not deteriorating as well, which may require later replacement or repair; and that the patient is not developing myxomatous (spongy) tissue as part of a bicuspid aortic syndrome, as the valve tissue itself will fail.

They must also stabilize the aortic root, if there is any chance that it will grow or deform.

These types of issues were evident in most of the failed Ross procedures.

I don't know the current, long-term success rate for Ross procedures, but it is certainly better than 50%, and I will edit the number here into this posting, if someone will provide it from a good source. I offer this because I note that I have discussed reasons for failure, but not much about the positive side of successes. It really is a beautiful thing when it is well done.

The aortic valve, being your own tissue, roots itself and continues to thrive as your own, living tissue. However, in many cases, there is a fairly strong reaction to the pulmonary homograft in the short term, and just as it starts to look quite bad, the response fizzles out and the valve settles down to long-term normalcy. This is common enough that it is considered a normal course of events, and some surgeons even feel it is a good sign for long-term success of the pulmonary homograft.

The homograft pulmonary valve can fail due to autoimmune reactions to it, or it can slowly close up over time, if the person lives a very long life. But slow failure of the pulmonary valve is not as severe an issue as an aortic or mitral valve, and its surgery is considered less difficult and less dangerous (although it certainly wouldn't seem that way to someone who is having it). It's also under trials for replacement via catheter. As it's under far less pressure than the aortic valve, it's a far better candidate for catheter-placed valves in their current state of development.

Best wishes,
__________________
Bob H

"No Eternal Reward will forgive us now for wasting the dawn..." Jim Morrison

I am not a Medical Professional. Aortic Stenosis w/severe calcification. Aortic valve replaced by Medtronics Mosaic porcine tissue valve on 4/6/04. The procedure was performed by Dr. Tyrone Krause, Chief of Thoracic Surgery, Robert Wood Johnson University Hospital, New Brunswick, NJ. Dr. Krause is a true Zen Master Mechanic in the world of valve replacement surgery.

 

[Ross]

Mechanical and Tissue Valve Considerations

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The fact is that at your age, it is a real crapshoot.

You would likely require two more surgeries to continue with tissue through your life. That is no small thing, although a growing number of people have decided that way as tissue valves have improved. There are are issues that go with more surgeries, largely around scar tissue, that affect your odds and affect your likelihood of having atrial fibrillation, the most common reason for people to take Coumadin (warfarin) other than having a mechanical valve.

However, warfarin is not a negligible addition to your life, either. Each person's response to anticoagulation therapy (ACT) is unique, so another person's experiences may not mirror your own. Many people do very well with it; others fare poorly. For some, there is not much difference in bruising levels or even bleeding. For others, it can exacerbate nosebleeds, menstrual issues, or ease of bruising. A look through the last year's worth of the Coumadin/anticoagulation forum's files will give you a better understanding of some of the concerns that can accompany ACT for those who are not as fortunate in their experiences.

It is to be remembered that warfarin is not an evil thing: it's what makes it possible to put mechanical valves into people's hearts without causing clots and strokes.

The fatality statistics are similar for mechanical and tissue. They are slightly more favorable for mechanical valve recipients in younger patients, and a little better for tissue owners in older patients. However, the data for those studies comes from prior-generation tissue valves, so it is an open question what those statistics will look like later on.

A lot of making the choice has to do with your perception of risks and your tolerance for daily regimen.

Mechanical valves have a fairly constant, low-level risk of stroke and its alter-ego, bleeding problems. While this risk is enhanced when some medical procedures are required, it is generally just a background noise most of the time. You may find that you can ignore that risk over time, or that you feel empowered by controlling your warfarin intake and INR.

You are not proof from further OHS because you have a mechanical valve. If you have a bicuspid valve syndrome, you may have aneurisms that occur over time that require surgical intervention. If you have deterioration of the heart due to endocarditis or radiation treatments, your problem may be progressive, affecting other valves, which may then require surgery themselves.

Warfarin does require regular testing, sometimes from labs, and most people do have to balance their eating (and drinking) habits to keep their INRs in range. Coumadin and its effects are interactive with many other drugs and some common herb supplements. This reduces the number of pharmaceutical remedies that may be available to you, including over-the-counter pain relievers, like aspirin, ibuprofen (Advil, Medipren), and Aleve, as well as prescription NSAIDs.

There seems to be little accuracy to the doomsaying doctors who would deny Coumadin users so many activites out of fear of bleeding events. Those which bear some concern are activities which may result in head injuries, as it may be more difficult to halt intercranial bleeding. However, when Sonny Bono died after skiing into a tree, he wasn't on warfarin to my knowledge, so the risk may be somewhat elevated, but remains relative.

There is still a fair amount of ignorance among doctors about the proper treatment of people on Coumadin ACT, and you will need to become your own advocate to ensure that one bad doctor or nurse doesn't do you more harm than good. Doctors may improperly order you to go off of your ACT for procedures that don't require it. Some dentists may also demand you go off of warfarin for extractions or similar procedures. Your primary risk from these unlearned professionals is stroke, due to being off of your Coumadin. When you do have bridging therapy with heparin or lovenox, such as for Colonoscopy and some other intrusive medical procedures, it may include self-delivered injections.

So, it would be hard to accept a blanket statement that the use of Coumadin or the risk of stroke is nothing. That said, a mechanical valve itself is highly reliable, runs trouble-free, and rarely deteriorates. It can be an answer for life for some, with no further surgeries.

Tissue valves have peak risks at operation time, and lower risk in between. They have periods when they are in decline, much as your current, original valve is having, before they are replaced. That means a year or more of valve function problems in the future for this new valve, when it hits its useful life limit. And it will happen again in your case, with a second valve, before you are likely to keep your third valve for the rest of your life.

Second or third surgeries tend to be more difficult and run longer, although in non-complicated cases, the risk factor is only mildly elevated. Scar tissue and adhesions tend to cause the most difficulty for the surgeon. However, other health issues, even unrelated to the heart, that come up as you age may make that surgery more difficult for you, or raise your risk level for it substantially.

With multiple surgeries, you also run the risk of restrictions to heart movement due to scar tissue in the heart or in the pericardium which surrounds the heart. Your likelihood of arrhythmias increases as well, as some electrical conductivity and contractility in the heart muscle is diminished in scarred areas.

Having a tissue valve does keep you free from the requirements of valve-related daily medication and testing. You are essentially normal between valve deterioration cycles, with no short-term restrictions on your activities or diet (getting fat is still not a good idea, as it causes overall stress on the heart).

However, having a tissue valve does not always make you free from having to take Coumadin. If you develop atrial fibrillation, or if you are felt to be susceptible to stroke, you doctor may prescribe it for you anyway. Paradoxically, having multiple surgeries is a causitive factor for atrial fibrillation, as is advancing age.

It is to be noted that, with a normal heart structure, you can switch from or to either valve type at any time a surgery is already required on the valve. For example, if you were to have a tissue valve now, and wind up on Coumadin anyway, you could change over to a mechanical valve when replacement of the current valve comes due.

Despite your surgeon's bent toward the stentless valve, the tissue valve with the best track record for longevity is the bovine valve, which has consistently averaged five years' longer useful life than any of the porcine valves to this point, stented or stentless. I would not consider going the tissue route without at least discussing that with your surgeon. His perception is currently based on marketing, not actual patient use study data. Although new anticalcification treatments and perservative techniques have recently been introduced for both types, the structures of the valves have not been changed from their predecessors, so the historical data is likely to still follow through.

Future advancements may change the scenery, but don't hold your breath - or your surgery. The On-X mechanical valve is undergoing trials to see if aspirin ACT provides enough anti-clot safety to allow patients to use it in place of warfarin. However, the results will be unknown for some time.

On the tissue side, if you are older and have other problems, your tissue valve might be replaceable with a catheter-introduced valve, in a more complicated angiogram-like procedure, rather than through more OHS. Some of this type of valve are undergoing trials at this time. However, catheter-placed valves are currently inferior with regard to valve opening size and longevity, and are only being used in compassionate cases.

Each choice is has its appeal and downsides. It is best to look within yourself for the choice that most works with your personal bent, your tolerance for different types of risk, and your ability to faithfully follow some elements of a required routine in life.

Best wishes,
__________________
Bob H

"No Eternal Reward will forgive us now for wasting the dawn..." Jim Morrison

I am not a Medical Professional. Aortic Stenosis w/severe calcification. Aortic valve replaced by Medtronics Mosaic porcine tissue valve on 4/6/04. The procedure was performed by Dr. Tyrone Krause, Chief of Thoracic Surgery, Robert Wood Johnson University Hospital, New Brunswick, NJ. Dr. Krause is a true Zen Master Mechanic in the world of valve replacement surgery.