X-Message-Number: 1439
From: 
Subject: CRYONICS Re: Skull removal
Date: Mon, 14 Dec 92 00:48:13 PST

Keith Lofstrom asked about removing the skull during perfusion.

The relative access to the brain from the surface as compared to the 
circulation system is very unfavorable, ratios of hundreds or 
thousands to one would be my guess.  But besides that, a reasonably 
intact circulatory system is critical to good perfusion.  If you read 
the recent accounts of suspensions, you might note that we have quit 
opening the dura.  The reason is that we get too much leakage from the 
tiny blood vessels we cut in the process.  If we took off the whole 
top of the skull, and cut through the dura all around, the leakage 
problem would get entirely out of hand. 

>Why are we preserving skulls with the brains?

Mostly for mechanical reasons.  The skull does a good job of keeping 
the brain from being bashed.

However, we *have* considered taking off the top of the skull (not 
cutting the dura) in some cases where there is considerable ischemic 
injury.  The reason is that swelling of the brain inside the skull 
terminates the glycerol perfusion too early in these patients, and if 
we could let the brain swell, we could get more in.

New ideas are always welcome, thanks to Keith L.

Short comments on two other items, first, Levy's comments on Charles 
Platt.  Considering how hard it is to find cryonics members in the 
population at all, I don't think there is any point in trying to go 
after groups which are *less* likely to join up than the general 
population. 

Second, Thomas Donaldson on Splitting Alcor.  I think Thomas has an 
excellent feel for the problems.  I recommend reading it carefully. 
And while it hit right in the middle of a mess of other postings, it 
is strongly related to them. 


Keith Henson

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