Promising Tissue engineered AVR trial in Germany

[Guest]

Please have a look. If this works, mechanical valves will be a thing of the past:

http://arise-clinicaltrial.eu/home.html#2

 

[pellicle]

I don't see anything in that that spells the end of mechanicals ... only that the tissue typing issues for homografts are being overcome by decellularisation. I had a homograft which was among the most successful in my study group (my hospital studied and followed up on 99% of us over 27 years). I got 20 years out of my homograft which was put in at 28.

I would expect these offer no more.

you language "thing of the past" is as emotive based as theirs is:

they have to choose either a mechanical valve replacement option, which directly affects their quality of life as strict life-long blood anticoagulation is needed to avoid cerebral thromboembolism. These “blood thinners” have an inherent risk for severe bleeding episodes, which needs to be considered in both professional and leisure activities.

which we know that "inherent risk" to be quite low ... especially if well managed, some thing they love to ignore because it can sensationalise their claims.

Then they make seemingly wrong claims that the only choice is a mechanical or a bioprosthetic (and assuming you read through the paragraph carefully mention the Ross, and only to tie off their deception at the end:

Young patients who do not want mechanical prostheses can opt for a biological prosthesis, e.g. a pericardial xenogenic heart valve, which unfortunately does not provide satisfactory durability in young patients, and rapid valve degeneration can occur within months. These patients further have the option for the so-called Ross procedure which is an extensive operative procedure where the diseased aortic valve is replaced by the patient`s pulmonary valve as an autograft. The pulmonary valve itself has to be consecutively replaced by a heart valve prosthesis leading to a “two-valve” diseased heart, as almost all autografts are impaired by progressive dilatation and the pulmonary valve prosthesis, often a conventional cryopreserved homograft, degenerates in the same way as all biological valves....*

They do make the important point however that everyone seems to ignore when spouting how good tissue valves are as a choice.

... thereby leading to frequent reoperations. Reoperations have a substantial higher mortality due to postoperative adhesions.*

although strangely that "substantially higher mortality" disappears from the landscape when pro-tissue valvers deride the dangers of
<organMusic>Blood Thinners</organMisic> and promote the limited differences in reoperative dangers.

So all in all it seems like a nice bit of research which might make for an increase in availability of homografts. Like the Mark Twain quote I'm going to say "so the rumors of Mechanical Valves deaths have been greatly exaggerated"

I encourage always a reading of the details and take a considered approach (often called a critical approach) to reading all claims. Think when reading ...

 

[neil]

hi, I am not an expert on ohs or valves , I know a bit through my own experience and what ive got from various forums, To me any good news or breakthroughs is exiting news for future surgeries imo, The people who work on these projects are wonderful and clever people and imo in the future will lead to a uniform valve that needs no reop or anti coags,

 

[Agian]

Interesting. Are these decellularised homografts supposed to be a permanent fix? If so, then that's great news.
No miracle cure, as yet, but people are working on it... which is great!

 

[pellicle]

Interesting. Are these decellularised homografts supposed to be a permanent fix? If so, then that's great news.

they say nothing about the longevity of the valves at all. Indeed there is little reason to suggest they will last longer than existing homografts, just perhaps be more available. Indeed one of their stated goals is to have greater availability in sizes (which is a key issue in finding a suitable homograft)

I followed up on one of their publications

http://ejcts.oxfordjournals.org/cont...zw013.abstract

RESULTS Thirty-nine patients (57%) had a total of 62 previous operations. ... To date, no dilatation has been observed at any level of the graft during follow-up; however, the observational time is short (140.4 years in total, mean 2.0 ± 1.8 years, maximum 7.6 years). One small DAH (10 mm at implantation) had to be explanted due to subvalvular stenosis and developing regurgitation after 4.5 years and was replaced with a 17 mm DAH without complication. No calcification of the explanted graft was noticed intraoperatively and after histological analysis, which revealed extensive recellularization without inflammation.

so not many, and not long ... that recellularization occurs is normal (with proper tissue typed donor valves, which I had) and this process of stripping cells to allow the body to recellularise it is a good idea.

but ... if anyone gets more than 20 years it will be interesting. You and I won't know for another 13 years!

 

[tommyboy14]

Hello,

I was the original poster on that one.
I agree with Pellicle that we need more time, but if these are really more prone to failure, you should see some of them failing after 10 years, as even conventional homografts do not last 20 years in everyone.

But there is one interesting piece of information:

http://www.espoir-clinicaltrial.eu/...ay]=01&cHash=2d06951bd7f1cd2ae2e44d5ee4cdf216

They tried the same decellularization technology on the pulmonary valve first. After 10 years, freedom from explantation was 100%.

Of course, the aortic valve is subject to much higher pressure, but this is nevertheless promising.

they say nothing about the longevity of the valves at all. Indeed there is little reason to suggest they will last longer than existing homografts, just perhaps be more available. Indeed one of their stated goals is to have greater availability in sizes (which is a key issue in finding a suitable homograft)

I followed up on one of their publications

http://ejcts.oxfordjournals.org/cont...zw013.abstract




so not many, and not long ... that recellularization occurs is normal (with proper tissue typed donor valves, which I had) and this process of stripping cells to allow the body to recellularise it is a good idea.

but ... if anyone gets more than 20 years it will be interesting. You and I won't know for another 13 years!

 

[Catie]

I'm glad to see this. Every bit of study and new technology in this arena is valuable and encouraging.