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Comment by signa11 | Hacker News Reader

fwiw, biological heart valves, as opposed to metallic valves, are already quite commonly used today.

biological ones are typically made from either cows, or pigs (bovine, porcine respectively).

but this is on another level altogether.

I had heart surgery 2 months ago to repair my mitral valve. In the lead-up to that, I had to make a decision what to do if it turned out replacement was needed instead of repair. Choices were metallic valves requiring me to be on warfarin the rest of my life or pig-derived valves. I chose the latter, mostly to avoid warfarin for life, but also because my surgeon was a PhD for work on creating biological-derived valves that didn’t trigger the immune system. Just mind-blowing what can be done. But I’m glad repair and not replacement worked out - and I now have GoreTex fibers attached to my valve.

GoreTex being the brand of a material that was put into your heart sure sounds amusing.

At heart, he's a GoreTex™ guy.

I'll just get my coat...

I’ll have to remember that one

> I'll just get my coat

And what fabric is that coat made of?

Sheepskin (the “I’ll get my coat” reference is from The Register).

https://theregister.com? It's much older than that.

I am not surprised, but that's where I learned it.

Pig and cow valves will calcify and fail eventually. But it’s a slow process so you have time to plan and make decisions for replacement. Mechanical values are great until one day the clicking sound stops and you need to get to a hospital ASAP.

Back in the 90’s there were a series of values where the flipping plate shattered-sending shrapnel into the heart and beyond. Typical failure mode is stuck open which is survivable. Stuck closed is very bad.

But why cows and pigs and not chimps?

Presumably because we already farm pigs and cows so there’s a supply chain and the ethics are ok in most people’s heads.

most likely because their (heart) valve anatomy is similar to humans ? this is just a guess btw.

Size. Pig hearts are the same size as human hearts, cow hearts are larger, so easier to cut up for parts. Chimp hearts are usually smaller.

Also, the risk of transmitting zoonosis is larger in primates than in other mammals, because with humans being primates as well, more viruses/prions/fungi might be infectious to both.

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