X-Message-Number: 2792
Date: 2 Jun 94 07:16:28 GMT
From: 
Subject: CRYONICS Latest Alcor Suspension

[This is my addendum to the article posted by Alcor about their latest 
suspension.] 

Saturday Morning--There is a break in the Extro-1 conference in 
Sunnyvale just after Dr. Mike Perry had given a talk about what it 
takes to keep information "forever."  Word has come from Alcor that a 
standby is going in New York.  Hour and a half later I put Tanya and 
Hugh on a non-stop from San Francisco to JFK Airport.  Patient is 
pronounced just after they are airborne, but they manage to do a field 
washout late that night with the help of a mortician in spite of a 
long delay after the patient deanimated. 

Before they leave, Tanya asks me to assist, so 6:30 Sunday morning I 
fly off to Scottsdale.  Leak problems in the box delay the patient 
four hours beyond when Tanya and Hugh get into Phoenix.  The patient 
is whole body, but is known from the washout to have serious leaks in 
the body vascular system  (i.e., they did not get much return flow 
while doing the ViaSpan flush).  After some discussion a decision is 
made by Hugh and Tanya to concentrate the perfusion on the brain, that 
is, set up as if the patient was a neuro instead of uselessly losing 
most of the perfusate into the abdomen.  This also gives us a chance 
to use a high ramp rate in the hopes of reversing the brain edema 
which stops most perfusions on patients with ischemic damage.  

[Jerry Leaf, who had a similar history of ischemic damage, only got 
minimal 1.5-2 molar glycerol before brain swelling forced a stop. High 
ramp rate means that we raise the concentration of glycerol faster 
than we usually do.  Normally we raise the concentration slowly to let 
the tissue "equilibrate" with the perfusate in the blood vessels, and 
not to dehydrate them.  In this case, we *wanted* some dehydration to 
counter the expected swelling.] 

So we mixed 60 liters of perfusate (a process similar to making lump 
free gravy), and are well into the filtering process before the 
patient arrives.  About this time I find out that the patient has a 
history of heart bypass surgery . . . . 

Slight digression.  The very first suspension I was ever on was for 
someone who had had *two* bypass operations.  The scarring--produced 
when the body heals up--results in a mess.  The heart structures are 
hard to identify, and everything is stuck together with scar tissue.  
The only way Jerry Leaf was able to identify the aorta that time was 
by finding the purse strings left in from a previous operation.  
Previous heart surgery means we are in for a rough time. 

Alcor's surgeon, Dr. McEachern, came in and was briefed.  Dr. Munson 
flew in from San Diego and took the instrument position.  After prep 
and drape, Hugh started on two burr holes while Dr. McEachern and I 
started to open the chest.  She went through the skin on the old 
incision line with cautery.  We opened the sterile package for 
removing chest wires, and Dr. McEachern used the large wire cutter to 
clip the wires holding the sternum together from the patient's bypass 
operation many years ago.  I used a pair of vice grips from the kit to 
pull out the wires. 

Because the bypass operation had cut through the sternum, weakening 
the bone, I thought we might be able to reopen the old saw line with a 
pair of super scissors--something I have done in practice with 
animals, but is not possible on people without a history of bypass.  
It wasn't easy, but it went a lot faster than having to use a saw.  
Once through we inserted a sternal spreader and opened the chest up 
enough to give us a good field (4-5 inches). 

Dr. McEachern started blunt and sharp dissection to get down to 
recognizable structures.  We located part of the pericardium, and the 
left ventricle.  From these landmarks we were able to guess where our 
targets were.  The right atrium did not take too much dissection, but 
the aorta eluded us until (just like Jerry did) Dr. McEachern scraped 
through a deep mass of scar tissue and located the old purse strings.  
Now the hard part started.  We needed to trace the aorta down and tie 
it off so the perfusate would not be lost by leaking into the abdomen.  

I have seen the way Alcor's other surgeon did it--more accurately, 
felt how he did it (since the tie off place is *way* down under the 
heart.  Both of us could feel where we needed to place the tie, and 
neither of us wanted to try freeing up the tightly attached aorta for 
fear it would rip in the process.  (This has happened before, and it 
causes leakage problems from which it is very hard to recover.) 

We finally come to the conclusion that we would try to block the aorta 
with a Foley catheter inserted through the femoral artery to about the 
right level and inflated.  This was an untried method, but was the 
best we thought we could do.  So we went ahead and put in the aorta 
purse strings and cannula.  (Purse strings are just a loop of a few 
stitches the surgeon sews into the wall of a vessel, for the aorta, 
half an inch in diameter.  A cannula is a stiff tube, in this case a 
little over a quarter of an inch in diameter which you insert into a 
slit made in the center of the purse strings.  The ends of the purse 
strings go through a small rubber tube, are tightened and then clamped 
through the tube.  This makes a tight seal on the cannula.) 

At this point I had a suggestion which we tried.  We inserted the 
canula way down into the aorta, past the arch.  I was on the side of 
the table with the right orientation, so I followed the cannula down 
by feeling it through the aorta wall.  I was able to trap he cannula 
between two fingers.  I then passed a large curved Satinsky clamp over 
the tops of my fingers.  I pulled the clamp toward me while pulling 
the cannula inside the aorta the other way.  Dr. McEachern put light 
pressure on the clamp while I pulled the cannula up and out of the 
grip of the clamp.  She then closed the clamp, and we had managed to 
clamp off the aorta *without* freeing it from its attachments!  We 
installed the venous and pressure monitoring lines, filled the lines, 
and closed the extra corporeal loop. 

Perfusion startup was relatively routine, except that there was a 
*lot* of color in the flow from the venous side, indicating marginal 
washout (no surprise).  After initial washout, Ralph cranked the ramp 
up to try to reduce brain swelling.  It seems to have worked.  While 
the brain did not recede from the burr holes, it did not expand much 
either.  There was minor leakage from the burr holes.  We sampled this 
fluid, and while it turned out to be lower in glycerol than that going 
through the circuit, it was still at a gratifying level (nearly 5 
molar at the end). 

We were very near our target when perfusion was terminated by loss of 
arterial pressure.  This is something we have seen before.  Since 
there was no jump in perfusate loss it was almost certainly due to 
heart valves starting to leak as they were deformed by glycerol 
dehydration--something we have seen in a number of suspensions. 

Dr. McEachern and Dr. Munson remove the cannulas and closed the chest 
(as usual, with wire).  I had gotten out of my gown to help process 
samples, so I stayed that way while I closed the burr holes (bone wax 
and sutures) and installed one of the temperature probes.  I noted 
that both eyes had shrunk about the normal amount from glycerol 
dehydration and were quite symmetric.  Because blood flow to the eyes 
is through the brain, this is further evidence that we had managed to 
get a lot of glycerol into the patient's brain. 

It is easy to do a good perfusion on a patient when you can do a blood 
washout within minutes of deanimation--something which we cannot do 
for patients who deanimate without much warning.  To date, we have had 
rather marginal perfusions on patients who had suffered a few hours of 
ischemia.  We definitely did a lot better with this patient. 

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