Some info on me. I was born with a bicuspid aortic valve. Had replacement surgery in Jan 2009. Had enodcarditis on and off for the next two years (was in the hospital 3x due to this). They never could beat the infection per se -- it just kept coming back after laying dormant for a while.
So, I had re-replacement in March 2011. The surgeons also replace my aorta which had enlarged a bit and relocated some peripheral arteries.
My life style is about as healthy as you can possibly get and it has been for some time -- long before I ever had open heart surgery. I eat nearly perfect (zero processed food, zero added sugar, etc, ever basically), I exercise everyday(I miss maybe 5 days a year), practice stress reduction like meditation daily, take important supplements like omega 3's, live a low-risk life style, no drinking/smoking, healthy BMI, etc.
Anyway. I do everything I can to ensure that my heart and body stays low in terms of risk-factors for heart/health problems.
I understand that to a certain extent, how long my valve lasts will be out of my control. But certainly by maximizing all of these things, it will last longer than if I wasn't a bit of a health nut.
What is the longest you have heard of cow/pig valves lasting?
Back to the OP's question, I think Al has it just about right on the bovine valve, and it's extremely sensitive to the patient's age at the time of the AVR: the older the patient, the longer the average time before the onset of structural valve deterioration -- NOT apparently because the valves "wear out", but apparently because the blood chemistry of younger people leads to calcification and failure sooner. (But if the mechanisms were perfectly understood, the manufacturers or the cardiologists would have fixed the problem by now!)"Unmodified Porcine Tissue Valves typically last 8 to 12 years.
"The 'improved' Porcine Tissue Valves are 'hoped' to last longer but have not been out long enough to know at this time."
My CV surgeon (Dr. Koshal) figured i'd be up for re-operation at around 40 or 45.
I am 26 years old, so maybe it won't last as long due to increased calcification rate in younger people?
I shouldn't say I don't drink. I have a glass of red wine with dinner a few days a week. But I don't go out and have a 6-pack on my birthday or anything. Heck, I was just at a wedding this weekend on only had 1 glass of red wine. So... haha.
Ultimately, I guess it seems like it will be hard to say how long my valve lasts, but I was just curious how long some of the bovine valves were lasting. My CV surgeon (Dr. Koshal) figured i'd be up for re-operation at around 40 or 45.
I don't think ANYTHING in this field is linear! Heck, even failure rates for mechanical and electronic equipment aren't usually linear. With mech valves, there's a reasonable hope that accelerated "torture tests" can simulate long periods of normal wear in a short period, though even that won't indicate all the OTHER reasons a patient might need a re-op or have other problems. With tissue valves, I don't think we even have that hope, until the mechanisms of degradation and failure are better understood.I assume next generation tissue valves are always in the works...all trying to deal with the calcifying issue, particularly for younger adults. Whenever the next great "future of tissue valves" is unveiled, I'm curious, can any reliable data be gathered from the initial few years of trials, or do you literally have to wait 20 years (or at least 10), for example, to find out if a breakthrough tissue valve will in fact last 20 years (in a young adult)? I guess this gets to how linear is the failure rate?
I don't think ANYTHING in this field is linear!
Yeah, I'm with you on the general lack of linearity as well as the uselessness of expecting even averages to pan out. Anything can and will happen to any given individual. But let me rephrase my question, slightly:
I noticed a post of yours in a separate thread about the lifespan of your pig valve, as compared to the more common cow valve. I believe you said it was a 25 year study, and there was at least a few years difference in longevity according to the study/paper you cited. I've read a lot of posts recently and may have a foggy memory, though, so by all means, correct me if I'm misstating anything. Anyway, for purposes here, I don't care if the data is correct or not, let's assume it is. In this instance, I'm curious if evidence of the same conclusions would have been seen at the 20 year mark, or even at 15.
I guess the age of implant and the broader longetivy of the group is an important factor affecting this, in other words, a 15 year study on young patients might be more meaningful than a 15 year study on the elderly.
But anyway, to your broader points, all well said, I don't disagree. Obviously, though, for any of us in the tissue valve group, particularly younger patients, we are just buying time, so to speak. Any "early" evidence of new valve performance might make the difference between pre-surgery news for some, and post-surgery news for others. I'm not holding my breath waiting for it, but curiosity about "breakthroughs" seem to come with the territory too.
It's entitled "Hancock II Bioprosthesis for Aortic Valve Replacement: The Gold Standard of Bioprosthetic Valves Durability?" by Tirone E. David, MD, Susan Armstrong, MS, Manjula Maganti, MS, in Ann Thorac Surg 2010;90:775-781, abstract at ats.ctsnetjournals.org/cgi/content/abstract/90/3/775? .