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Comment by blensor | Hacker News Reader

I am not a medical expert or even remotely tied to that field but don't livers regrow to some extent? If this process could be extended even further wouldn't that mean we could regrow complete livers from partial donations pretty soon, making the whole "waiting for a donor" gamble obsolete?

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Yes.

> The seven-day successful perfusion of poor-quality livers now allows for a wide range of strategies, e.g. repair of preexisting injury, cleaning of fat deposits in the liver or even regeneration of partial livers.

I assume that this might even assist in the growth of livers (extracellular matrix, liver and circulatory tissues) from stem cells.

I think I read recently (don't know where, not looking it up) that the liver can regrow in the sense that it is made of lobes, and you can lose a lobe and the others will expand to restore full function.

But the lobes themselves don't regenerate, so it's not a thing that can be done more than a time or two.

No expert either, but afaik you can divide livers into thirds and they will regrow. So when you transplant a liver you take two thirds from the donor, I assume to give the recipient more liver to work with, but I don't know why. (spelling edit)

Yeah seems 25% is needed for regrow. That number seems interesting, almost like the body’s parity raid bit.

https://en.m.wikipedia.org/wiki/Liver_regeneration

Funny to use “parity raid bit” on an SPOF organ such as is the liver.

Though, i have always been curious as to why the body only has one liver while having pairs of many other organs...

Adding to your question, why did the liver evolve to regenerate while other organs evolved to have spares? What makes it special?

The liver is responsible for clearing out the majority of toxins and since many of them can cause cell death, the organ needs to be able to regenerate itself.

I’m guessing it has something to do with the size of a liver. Organs that have spares are relatively small.

Lungs? They’re pretty big. My grandfather lived 60 years with only 1, and it stretched to fill most of his chest cavity.

a plastic surgery to build in Klingon like capabilities - take the piece of the liver like for transplant and transplant it into the other side of the body, and after some time for regrow the person would just have 2 full livers.

I'm not an expert but that won't stop me from guessing why!

Perhaps it would be far easier for the donor to regrow the majority of their own liver in their own body than it would be for the recipient, given the immune response and other factors that I would imagine complicate a transplant.

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