U.S. surgeons transplant pig heart into human patient • Hacker News Board

Re: U.S. surgeons transplant pig heart into human patient

#221

Post by dekhn » Tue, Jan 11, 2022, 1:36 AM UTC

OJFord wrote: post #183

tombert wrote: post #131

Earlier quoted context omitted.

I was about to say, aren't pigs smarter than dogs generally? Seems like a strange line to draw.

Obviously it's very culture specific, but pigs are quite far from 'man's best friend'.

My sister has a pet pig (a 150+-lb https://en.wikipedia.org/wiki/Vietnamese_Pot-bellied); it lives in the house with everybody else and forages in the backyard. I can't say I'd ever thought of keeping a pig as a pet, but it's a perfectly fine creature, gentle when it's not being provoking, and intelligent and quite communicative.

I can't see it being "man's best friend" (dogs have a bunch of special abilities that pigs don't) but both pigs and goats play an important enough role to call them "man's best helpers"

Re: U.S. surgeons transplant pig heart into human patient

#222

Post by iancmceachern » Tue, Jan 11, 2022, 1:36 AM UTC

Blikkentrekker wrote: post #201

dnautics wrote: post #69

Earlier quoted context omitted.

I could be wrong but I believe those valves are harvested for their cartilagenous (non-alive) components, their cells stripped, the valves throughly cleaned, and implanted in place. This is not quite the same as implanting an organ with live cells autonomously producing potential antigens on a daily basis

Would artificial valves then not work as well or even better?

Nope, the ball and disc valves were where they started and they had any issues including wear, blood clots and strokes. You could also hear many of them outside the patients body.

Re: U.S. surgeons transplant pig heart into human patient

#223

Post by cipheredStones » Tue, Jan 11, 2022, 1:37 AM UTC

Blikkentrekker wrote: post #196

TravHatesMe wrote: post #163

Earlier quoted context omitted.

Bit of a tangent: I read the article to my wife and she mentioned that there is an episode of Grey's Anatomy where they wanted to perform a transplant of a pig's bowels but the Jewish (or Muslim?) lady refused. Interesting how one might choose to their faith over their life.

On the axiom that betraying such faith leads to æternal damnation in the afterlife, it seems a strategic choice to me. It would perhaps only be strange that a man might hold such an axion, not that he acts in accordance with it.

Few (if any) Jews believe in eternal damnation. Generally speaking, Judaism places very little emphasis on the afterlife, and there's no widely-held doctrine about it. To the extent there's a shared belief at all, it's that everybody goes to a place called Sheol, without differentiation by merit.

Re: U.S. surgeons transplant pig heart into human patient

#224

Post by AmericanChopper » Tue, Jan 11, 2022, 1:37 AM UTC

mizzao wrote: post #171

TravHatesMe wrote: post #163

Earlier quoted context omitted.

Bit of a tangent: I read the article to my wife and she mentioned that there is an episode of Grey's Anatomy where they wanted to perform a transplant of a pig's bowels but the Jewish (or Muslim?) lady refused. Interesting how one might choose to their faith over their life.

That was actually an inaccurate portrayal of Jewish law and Orthodox Jews "condemned the episode": https://www.myjewishlearning.com/article/ask-the-expert-kosh...

All of the “well actually” when it comes to religious laws misses the reality of the situation imo. Well educated religious scholars will debate religious laws and frequently fail to achieve consensus on much. Ordinary religious practitioners will simply adopt whichever interpretation they identify with. There are no truly correct interpretations of any religion, and for any religion there are as many different interpretations of what it means as there are people interpreting it. Even in Judaism, which is really quite homogeneous as far as most religions go.

Re: U.S. surgeons transplant pig heart into human patient

#225

Post by iancmceachern » Tue, Jan 11, 2022, 1:39 AM UTC

bufferoverflow wrote: post #150

tombert wrote: post #144

Genuine question: why is an artificial heart such a hard thing to make? At least from a lay-person's perspective, it's just some pumps and valves, which we've gotten pretty good at making. Obviously I'm wrong about that because there really isn't a permanent artificial heart yet, but it's something I have wondered for awhile.

There are artificial hearts, and people survived for years on them. The record is 7 years, I think. They aren't cheap, $100K to $300K for the first year, depending on the device. Then it's around $18K/year to maintain. I don't know why they are that expensive.

And LVADs too, folks have lived over a decade on those. Tens of thousands have been implanted.

Re: U.S. surgeons transplant pig heart into human patient

#226

Post by iancmceachern » Tue, Jan 11, 2022, 1:42 AM UTC

Blikkentrekker wrote: post #208

jacobn wrote: post #151

Earlier quoted context omitted.

See "total artificial heart": https://en.wikipedia.org/wiki/Artificial_heart Layperson speculation: hard to power 24/7 without an external power source, it must connect seamlessly to the blood stream (can't have it disconnect from the aorta after five weeks), and the surfaces exposed to the blood must not cause blood clots (so careful at the seams).

It does make me wonder how the transplanted pig heart or any transplanted heart connects so seamlessly. The issue simply heals and grows together with the foreign tissue?

They use a common medical technique called anastomosis. Basically they just sew the two arteries/vessels together with suture and the blood and tissue seals it as any other cut or nick in the body. Sometimes they use "bioglue" but its not strictly needed, just a timesaver.

Re: U.S. surgeons transplant pig heart into human patient

#227

Post by kashunstva » Tue, Jan 11, 2022, 1:42 AM UTC

Blikkentrekker wrote: post #201

dnautics wrote: post #69

Earlier quoted context omitted.

I could be wrong but I believe those valves are harvested for their cartilagenous (non-alive) components, their cells stripped, the valves throughly cleaned, and implanted in place. This is not quite the same as implanting an organ with live cells autonomously producing potential antigens on a daily basis

Would artificial valves then not work as well or even better?

The tissue component of bioprosthetic valves is treated ex vivo in such a way as to greatly reduce the immune reactivity. It's practically not a consideration.

Mechanical prosthetic heart values are generally favoured only in older patients where re-operation is not likely to be required. The reason being that bioprosthetic valves have a more limited long-term durability. So why not always use mechanical valves? Their clotting risk is considerably higher and so they require higher intensity anticoagulant therapy - along with all of the attendant complications of that...

Re: U.S. surgeons transplant pig heart into human patient

#228

Post by JetAlone » Tue, Jan 11, 2022, 1:42 AM UTC

TravHatesMe wrote: post #163

dexwiz wrote: post #61

Earlier quoted context omitted.

Pigs are really common in biomedical testing. They are physically a similar size and weight to humans. They also reach maturity in about 6 months. Much cheaper to raise than primates, and more likely to get approval for testing. My friends in biomed grad school named one of theirs cyber pig because it has about 30 different experiments ran on it before it was killed, and afterwards it was portioned out for further te…

Bit of a tangent: I read the article to my wife and she mentioned that there is an episode of Grey's Anatomy where they wanted to perform a transplant of a pig's bowels but the Jewish (or Muslim?) lady refused. Interesting how one might choose to their faith over their life.

I'd want to question why I'm doing it. For example do I have kids I need to stick around to support? Or am I just going to be discharged to mostly play video games, alone? Because I don't see a need to extend that life.

Then I'd want to think about what it symbolizes. Is it really so irrational to just let my body die when my God-given guts fail instead of depending on the hands of man to possibly convert my body into an abomination just to keep me alive here longer?

I read in a book about a monk refusing to get a pacemaker, saying "Imagine, God is calling me up to Heaven because it's my time, and this machine holds me down here on earth!" and while I may not be a monk, his decision seemed fairly wise to me. So I already have an example of a devout faithful man eschewing a life extending operation that involved no replacement of human with animal parts.

Re: U.S. surgeons transplant pig heart into human patient

#229

Post by iancmceachern » Tue, Jan 11, 2022, 1:43 AM UTC

toss1 wrote: post #174

tombert wrote: post #144

Genuine question: why is an artificial heart such a hard thing to make? At least from a lay-person's perspective, it's just some pumps and valves, which we've gotten pretty good at making. Obviously I'm wrong about that because there really isn't a permanent artificial heart yet, but it's something I have wondered for awhile.

It has been done, as mentioned by other comments. My recollection is that aside from power & control, the hardest problem is clotting. The natural heart apparently causes the blood to flow in a way that there is no pooling or stagnation, whereas almost any fixed-shape chamber apparently has locations where the fluid will stagnate, and with blood, that will cause clots in a very short time. When those clots get loose,…

Indeed, but they've done it. Check out LVADs like the Heartmate 3 and Heartmate 2.

Re: U.S. surgeons transplant pig heart into human patient

#230

Post by Sporktacular » Tue, Jan 11, 2022, 1:43 AM UTC

dexwiz wrote: post #61

tricky wrote: post #26

You might be asking, why a pig? I don't know, but forever ago I wrote software for a cardiovascular imaging lab and pigs were their primary test subjects. I was like, "why pigs?" and the PI was like, "Imaging-wise, pig hearts aren't too different from humans. Plus, we can give them a heart attack in the scanner and not go to jail. Some labs use dogs. I just can't do that."

Pigs are really common in biomedical testing. They are physically a similar size and weight to humans. They also reach maturity in about 6 months. Much cheaper to raise than primates, and more likely to get approval for testing. My friends in biomed grad school named one of theirs cyber pig because it has about 30 different experiments ran on it before it was killed, and afterwards it was portioned out for further te…

Weird how this is said without a shred of sympathy or concern for an intelligent, helpless creature. Weirder how it can be said without a sympathetic or concerned response. I hope we can someday move beyond seeing animals as a mere resource.