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Valve replacement

Posted: Thu Feb 10, 2011 2:19 am
by Nunzio
I think I have already seen this here but I have some nice picture to show you.
If you cannot read the description below it is made of bovine tissue sewn into a collapsible metal stent, delivered via catheter and balloon-expanded within the diseased valve.
Image
Here is a picture of the stent itself.
Image
and now the technique used:
Image
This is for the aortic valve but it should be possible to modify it for use at the base of the jugular vein if it was felt that the presence of a functioning valve in that location would be beneficial.

Posted: Thu Feb 10, 2011 8:49 am
by pairOdime
Great pics Nunzio....I was also curious about the specific materials used to develop the valve. These are very interesting and hopeful times.

Re: Valve replacement

Posted: Thu Feb 10, 2011 11:38 pm
by NHE
Since some of the materials used to construct the replacement valve are of bovine origin, do you know if patients receiving these valves have to go on immunosuppressant therapy to prevent rejection?

NHE

Interesting but

Posted: Fri Feb 11, 2011 2:17 am
by MarkW
Being my usual pedantic self - these are replacements for valves in the aorta not veins so is unlikely to be useful in CCSVI syndrome. (Pharmacists are inexpert at anatomy but this is fairly basic).
Yes NHE they will be rejected as a foreign body unless some very clever genetic engineering has been done on the bovine tissue. Finally as a pedant - has anyone needed vein values replaced in CCSVI syndrome ???

MarkW

Re: Interesting but

Posted: Sat Feb 12, 2011 4:14 am
by Nunzio
MarkW wrote:Being my usual pedantic self - these are replacements for valves in the aorta not veins so is unlikely to be useful in CCSVI syndrome. (Pharmacists are inexpert at anatomy but this is fairly basic).
MarkW
Yes, I noted that in my initial quote; the valve needs to be modified in size at least. Keep in mind the valve area in the jugular vein is particularly strong due to the fibrous annulus, in fact, to dilate it very high pressure balloon have to be used. I am sure scientists can come up with the proper size and strength to be used in that area.
MarkW wrote: Yes NHE they will be rejected as a foreign body unless some very clever genetic engineering has been done on the bovine tissue.
MarkW
The above is not correct. The tissue is bovine pericardium modified chemically and is already used together with pig valve in surgical valve replacement in human for a very long time without requiring immunosupression of the host.
MarkW wrote: Finally as a pedant - has anyone needed vein values replaced in CCSVI syndrome ???
MarkW
That is an interesting question and my gut feeling is " not really" It is definitely important in quadrupeds where the head is below the heart level often.
In human, unless you do a work that require you the bend down or hold your breath (Valsalva maneuver), you should be OK without a valve.
Here Ricci apparently had a lot of problems related to his missing Jugular vein valve.
MarkW wrote:Being my usual pedantic self Finally as a pedant
MarkW
Do not worry Mark, we know pharmacist are pedant; sometime they think they are doctors too.
We do not fault you for that.

Posted: Thu Mar 03, 2011 2:33 am
by Liberation
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Posted: Thu Mar 03, 2011 6:27 am
by 1eye
Given all this talk of clotting and the different diameters, as well as the fact it is a vein, and possibly a poorly nourished one, isn't jugular valve replacement just as likely to cause problems as fix them?

My friend's mother (dear me am I starting to sound like von Munchausen?) has had pig valves for a few years, but again, aren't they more likely to succeed with all that oxygenated blood around? Actually I don't know *which* side she has them on. I do think it is very risky, maybe more so than jugulars, but an easier size to work with.