X-Message-Number: 32687
Date: Thu, 1 Jul 2010 08:41:20 -0700
Subject: Cannulation and washout
From: Keith Henson <>

On Thu, Jul 1, 2010 at 2:00 AM, "sbharris1" <> wrote:

> MY COMMENT: The statement "SA's cannulation procedures should be identical
> to those that have been performed, by vascular surgeons in conventional
> medicine, millions of times  is quite wrong. Cannulation in medicine for
> femoral bypass is done on patients with a good blood pressure, and this is
> true even if the patient is intended to be cooled later. That means the
> arteries are pulsatile and pinkish white, the veins properly blue and fat
> with pressure, and everything looks like an anatomy diagram.
>
> In cryonics, femoral cannulations are considerably more difficult, and are
> not "identical.   There is no good pulse even with the thumper (and the
> surgery cannot be done with the thumper running in any case),

This is really excellent material from Steve.  It can be hard to find
a pulse and locate the vessels even before death.  Marking them with a
Sharpie helps, but we failed to find them on one side and had to
switch to the other once.  Edema makes finding them even harder.

But I wonder about leaving the thumper on.  I have only done two and
watched two others, but my memory is that the thumpers were left on.
They didn't induce enough motion to interfere with the surgery site
(as I recall that is).  The more energetic thumpers we use now might
be a different story.

> and time
> without blood pressure has usually resulted in enough capillary fluid uptake
> that there is little pressure in the vascular system.

There was so little in one washed out patient that inserting the
aortic arch cannula would have obviously introduced air.  I put in the
pressure monitoring line first and bled perfusate from the circulating
loop into the vascular system.  That filled the vascular system up so
there would be a slight outflow while sliding in the aortic arch
cannula.  Is it possible to increase the flow in the meds line to help
fill the vessels?  Would it be worth adding a dye to better see them?

> The major proponent of field femoral washout in cryonics has been myself,
> and the only person who has done it consistently is also myself. Even so, I
> have failed occasionally, and had to use the (much more straightforward)
> carotid/jugular system in the neck for either perfusion or drainage or both,
> if the femorals cannot be used. I recently used such methods to perfuse to
> vitrifiable cryprotectant concentration in the field, so even this can be
> done by these methods.

> Elsewhere, at the main facilities at both Alcor and CI, the standard has
> been perfusion via aortic arch in the chest, with right atrial drainage, as
> in standard bypass. This is easier if one is willing to open the chest, but
> people have been less likely to want to do open-chest procedures in the
> field. It's possible to teach, but it's even more of a mess,

Having done this a few times, I agree.  There is no graceful way.
It's bad enough to do a femoral  washout in someone's living room.

> I think that part of the solution is to teach neck cannulation as a backup
> to femoral cannulation for field washout procedures.

I would like to see how this is done and learn it.

snip

 > It remains unsolved; for the money available, it may continue to
remain at least partly unsolvable.

This is really on target to the practical and economic issues of cryonics..

Keith

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