90% event free survival rates with mechanical valves. 30 years period!

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The Onx must really be good then considering this was a study of SJM valves.

Shiv:
1. My surgeon says on- x is today what st jude was in 1990s. Leaps ahead..
2. On-x is better than other options. US FDA agree with it
 
The Onx must really be good then considering this was a study of SJM valves.

Shiv:
1. My surgeon says on- x is today what st jude was in 1990s. Leaps ahead..
2. On-x is better than other options. US FDA agree with it
On-x is better and new compared to st jude. On'x don't have 35 year history. But here i am talking of mechanical in general. That they stay long...I am sure on-x will have better results than st jude in 35 yrs.. point here was mechanical is better than tissue. For young patient like 30 years old. As they avoid resurgery risk.
 
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Thank you for sharing info-- wonder if this info applies to bileaflet valves made by other companies like Carbomedic?
 
My surgeon who is #2 in the country, says that "today" OnX is the "only" mech valve he would implant DUE to its Design Improvements and the fact that leaves open at 90 degrees, not like the others, and that 90 degrees, is one of the most important facts about it. "For me" at 62 made no sense going through an OPS and PLAN for another one at 75+, makes no sense "for me", IF i was 70+ at the time, sure, tissue no pills, but not at 62-63 range; But We ALL have DIFFERENT perspectives, and there is no rigtht or wrong, BUT when it comes to mechanical valves, TECHNOLOGY is always improving, remember those IBM XT PCs running PC-DOS?.... same thing applies..., "in my perspecitve", we all have different opinions, since we do not live in Totalitariam Racist Communist China with Concentration camps..... , good thing OnX it not made in Com China :)
 

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My surgeon who is #2 in the country, says that "today" OnX is the "only" mech valve he would implant DUE to its Design Improvements and the fact that leaves open at 90 degrees, not like the others, and that 90 degrees, is one of the most important facts about it. "For me" at 62 made no sense going through an OPS and PLAN for another one at 75+, makes no sense "for me", IF i was 70+ at the time, sure, tissue no pills, but not at 62-63 range; But We ALL have DIFFERENT perspectives, and there is no rigtht or wrong, BUT when it comes to mechanical valves, TECHNOLOGY is always improving, remember those IBM XT PCs running PC-DOS?.... same thing applies..., "in my perspecitve", we all have different opinions, since we do not live in Totalitariam Racist Communist China with Concentration camps..... , good thing OnX it not made in Com China :)
Very well said Sire! Kudos to you
 
Well I can quote you my surgeon who said On-X and St.. Jude are equivalent, but he'd prefers St. Jude. Dueling surgeons makes as much sense as dueling banjos :)

I think you do people a disservice by claiming one brand/type is better than another. You are no expert and neither is your surgeon, surgeons implant valves they do not make them.
 
On-x is better and new compared to st jude. On'x don't have 35 year history. But here i am talking of mechanical in general. That they stay long...I am

The Onx leaflet can open to 90 deg but they don't. That has been proven and it is in published literature.
Better is your opinion - there is no scientific literature in print that says the Onx is "better".
 
My surgeon who is #2 in the country
#2 in what? And in what country? Please share ranked list as others may find useful.

says that "today" OnX is the "only" mech valve he would implant DUE to its Design Improvements and the fact that leaves open at 90 degrees,
I'm no expert on this but my understanding is that there are other factors a surgeon uses when determining which type of mechanical heart valve to implant. e.g. what valve the surgeon is most skilled and comfortable implanting, valve size, presence of scar tissue, or other abnormalities/conditions, such as an aneurism that will require compatible grafting or material with the valve, that may need to be addressed.

A good surgeon should give you their best choice for you given your circumstances and condition which may not be same for others.
 
I think every heart valve comes with an instructions for use manual. This is the company's FDA approved labeling detailing the clinical and flow results that the company found in their study for FDA approval. This would be the best way to compare different valves since the studies are comparable.

Regarding leaflet opening for all valves, this is dependent upon activity level. All valve leaflets are passive and only open to their needed angle as they simply align to the path of least resistance. With exercise, valve leaflets open more. At rest, leaflets settle to a lesser opening. This is true for both mechanical valves and tissue valves. You would not want a valve to open less than what full flow output wants. If that happens then the valve leaflets are creating resistance to flow through that valve and creating turbulence behind a leaflet not following the path of least resistance.
 
I think every heart valve comes with an instructions for use manual. This is the company's FDA approved labeling detailing the clinical and flow results that the company found in their study for FDA approval. This would be the best way to compare different valves since the studies are comparable.

Regarding leaflet opening for all valves, this is dependent upon activity level. All valve leaflets are passive and only open to their needed angle as they simply align to the path of least resistance. With exercise, valve leaflets open more. At rest, leaflets settle to a lesser opening. This is true for both mechanical valves and tissue valves. You would not want a valve to open less than what full flow output wants. If that happens then the valve leaflets are creating resistance to flow through that valve and creating turbulence behind a leaflet not following the path of least resistance.
Your opening theory only applies to tissue valves, the opening angle for mechanical valves is a design "feature" (which may be good or bad) and cardiac output has little to do with the angle the leaflets open to. There is no fluid dynamics reason to limit leaflet opening. You want the leaflets (mechanical valve) to open fully regardless of cardiac output.

Also, the hydrodynamic studies you mention in the instructions for use go all over the place. It has been proven that different pulse duplicators from different manufactures give different results, thats why people want to see a comparison by an independent lab or university, using the same test equipment, the same operator, in the shortest reasonable time frame.
 
By training, I am an engineer specializing in hydraulics, so when my mitral valve repair worsened my situation; I went at the problem from a hydraulics standpoint. I went in to a different cardiologist with the pressure/flow curve of a mitral valve and said this is what is going on. This doctor/cardiology group was quite sharp and we quickly found some common language and were in agreement that the repair made the valve effectively stenotic. This (because of my activity level) resulted in a backpressure (engineering term) which caused pulmonary hypertension (medical term) and I would bleed in my lungs with exercise.

Knowing the basic problem, I did a fare bit of studying valve haemodynamics . . . from an engineers perspective. The most basic finding is reflected in the following which was published by Gorlin and Gorlin in about 1950.

Abstract

1. Standard hydrokinetic orifice formulas have been applied to stenotic mitral, pulmonic, tricuspid, and aortic valves, patent ductus arteriosus, and atrial and ventricular septal defects. These formulas were considered applicable because of the high kinetic energy losses through small orifices or in the presence of high volume flow.
2. In its general form, the formula is as follows:

A=FC2gh

where A = cross-sectional area in cm.2 of the orifice F = flow rate in c.c. per second C = empirical constant g = gravity acceleration h = pressure gradient across the orifice in mm. Hg.

The younger Gorlin was a doctor (cardiology I believe) and his father was . . . .. a hydraulic engineer! And therein is actually my point of this note: that formula pasted above is the standard orifice equation that has been used for a very long time for all kinds of hydraulic systems. I.e. the basics are indeed nothing knew.

What this really is saying, is that - by far - the largest factor in maximizing flow and minimizing pressure drop across any valve - including heart valves! - is the area of the valve. In my case, the surgeon in my second surgery made a very conscious effort to bump up the valve size (because we knew I was having trouble with exertion).

Human mitral valves are much larger than aortic valves . . .. and they are elliptical in shape. Replacement valves are round. A typical normal mitral valve is something like 5-10 cm**2 but replacements are closer to 2. A big reduction no matter what. Further, a lot of the "circle" is the cuff required for installation rather than part of the actual orifice. The surgeons have some limited flexibility in sizing the replacement valves but it is limited by the actual structure of the persons heart. Both too big and too small cause problems.

So I am writing this lengthy post to summarize my assessment of the mechanical valve designs. Fundamentally it is the size which most determines the functional performance (lots of flow with little pressure drop). The design details optimize this and very importantly minimizes the turbulence (which damages the blood). (most of the design details are about tuning C in the above equation.) Of course it is rather important that those leaflets open correctly and quickly every time, millions of times.

To this day, I am still bothered by the size difference between the mitral and aortic valves. It does not make sense to me hydraulically! (I am trying to be both serious and humorous in this final sentence!).

Hopefully this was a little entertaining . . . or helpful initiating sleep!
 
C'mon folks, it's kind of silly to compare the attributes of one mechanical valve with another..........they are both FDA approved. There are also several valves not listed that are good, long-lasting valves.......but not listed in your arguments.

My valve is the granddaddy of them all, having been the first commercially available valve in 1960........and has proved its durability by lasting well over 40 years in many patients.........and yet it is no longer on the market. I guess it would not meet todays FDA standards.........but don't tell my valve:censored::p
 
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C'mon folks, it's kind of silly to compare the attributes of one mechanical valve with another..........they are both FDA approved. There are also several valves not listed that are good, long-lasting valves.......but not listed in your arguments.

My valve is the granddaddy of them all, having been the first commercially available valve in 1960........and has proved its durability by lasting well over 40 years in many patients.........and yet it is no longer on the market. I guess it would not meet todays FDA standards.........but don't tell my valve:censored::p
Exactly. Sir. My point was mechanical valves are better than tissue..as they stay 30-35 yrs as per the mentioned literature..90% had event free survival even after 30 years..its good news to me.. that I can expect my wife to live 30 years atleast on this On-x valve if I take care of INR...thats all..
 
"when it comes to mechanical valves, TECHNOLOGY is always improving,"

Technology is always CHANGING. This doesn't mean that it's always improving.

Remember the Edsel? It had some technology improvements - including pushbutton transmission selector. It probably worked - but may have had some technical problems.

The Fuel door on my Toyota probably had new technology. There's a spring that pops the door open when you lift a lever. The spring breaks - new technology gone bad.

Look at the new cars - lots of 'technology improvements' - GPS, video displays, smart headlights, etc. etc. They fail. Different models in each model year make it hard to replace.

Even things like replacing headlights require a RESET OF THE COMPUTER to do properly. Are these technologies IMPROVING things?

Bringing this to heart valves - just because a new type is developed - this doesn't make it better. That's what testing, the FDA (and the similar bodies in other countries) are for.... validating whether the new technologies are safe to use.

----

Going back to the original post in this thread -- long term follow-up success.

I used to run a Tumor Registry - one of our main functions was to follow up patients. We wanted to find out how patients are doing, whether or not they were still alive, whether the cancer returned, if it metastasized - stuff like that.

I've seen some reports giving survival rates (not for cancer) that eliminate subjects that they can't find. I wonder if the people in this study were included even if they dropped out of the sample (and if, possibly, they dropped out because of death from valve failure, or from other causes). If you leave out bad outcomes, you WOULD have high survival rates for those that are still alive - and in the study group.
 
Saying that mechanical valves are better than tissue is missing the point.,

I have a mechanical valve, and it was the right choice for me. But mechanical may not be 'better' for some people than tissue valves.

Mechanical valves require weekly anticoagulation testing. They necessitate daily dosing of warfarin. They click. They're not always perfect - some on this forum have had mechanical valves replaced (though I'm not entirely sure why).

Tissue valves wear out. Recent developments make them longer lasting. They wear out more rapidly in younger, more active people than they do in older recipients.

One thing that people are predicting is that the time tissue valves start failing, there will be non-invasive (or minimally invasive) ways to take care of the problem (TAVI, TAVR - already being used - is a strong, but somewhat limited 'repair').

Mechanical valves may be 'better' for many people, but there are still many people who choose a tissue valve - and you can't knock people for making that choice.
 
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