From: "Howard McCollister" <hmac@nospam.net>
Newsgroups: sci.med.cardiology,sci.med
Subject: Re: 5.3 mm abdominal aortic aneurism, prognosis?
Date: 2 Nov 2003 19:42:37 -0600
Message-ID: <3fa5b1ed$0$49090$45beb828@newscene.com>

"Jeff" <kidsdoc2000@hotmail.com> wrote in message
news:bo3oo4$m0v@library2.airnews.net...
>
> "Patrick Coghlan" <coghlan@sympatico.ca> wrote in message
> news:xMapb.622$mB5.63366@news20.bellglobal.com...
> > Orac wrote:
> >
> > > It sounds to me like a standard abdominal aortic aneurysm. What wasn't
> > > said was whether or not it involved the iliac vessels and whether it
> > > was completely below the renal arteries. If it involves the area
> > > where the renal arteries branch from the aorta, then the surgery
> > > will require clamping the aorta above the renal arteries, cutting
> > > off the blood flow to the kidneys for the time it takes to sew the
> > > vascular graft in. This increases the risk of postoperative renal
> > > failure and is technically more challenging, particularly if the
> > > renal arteries have to be reimplanted.
> >
> > Ah, I wondered what they did while repairing the artery (clamping).
> > This must be why they don't want to operate if the patient's heart is
> > not in good condition.
>
> It is one reason. But the other reason is that this surgery is extremely
> stressful. TO get at the AAA, the abdominal contents are moved out of
> the way (mostly the intestines). This perturbs their function for a few
> days. There are also major fluid and electrolyte changes, with lots of
> fluids and blood and plasma administered by IV (the last time I saw this
> operation, there was something like 10 units of blood and 20 liters
> total fluid administered to a patient -- that is about 5 gallons of
> fluid, which is about 1/3 of the entire fluid volume of the patient (you
> know that those 5 gallon buckets around -- it is that big.) I usually
> make around 3 liters of urine a day. That is the volume of urine I make
> in an entire week. And 10 units of blood is a lot, too That is a lot of
> fluid. That is very stressful, especially if the kidneys' function is
> compromised for a few hours, because of temporary loss of blood flow.
> Remember, the kidneys play a major role in the regulation of the body's
> electrolytes and fluids.
> 
> This is very stressful surgery.
> 
> And the heart and kidneys are not the only organs that are at risk If
> the blood pressure drops too much because of the blood loss, the brain
> might not get enough blood. Let us just say this is not desirable.
>
> Jeff
>

There are many risks to AAA repair, but the one that causes death most often
is related to the cross-clamping of the aorta with resultant lack of blood
flow to the lower extremities for the amount of time it takes the surgeon to
sew in the graft. This lack of blood flow forces anaerobic metabolism to the
unperfused parts of the body with resultant buildup of lactic acid. When the
aorta is finally unclamped, a large load of lactic acid is dumped into the
circulation with resultant deleterious effects on the cardiovascular system
nor for the kidneys. The longer the clamp time, the more the ischemia, the
more lactic acid. Throw in a huge dose of the body's post-op reparative
hormones such as ADH, MDF, bradykinins and other such stuff and the body has
a lot of work to do in the post-op period.

It's a dangerous operation by comparison to most others, but AAA is a
dangerous condition with a *cumulative* mortality of 5-8 percent each year
once the aneurysm reaches 5 centimeters. Such an operation is done when is
represents a lesser risk than the disease it's going to fix.

HMc

From: "Howard McCollister" <hmacXX@nospam.net>
Newsgroups: sci.med.cardiology,sci.med
Subject: Re: 5.3 mm abdominal aortic aneurism, prognosis?
Date: 3 Nov 2003 07:09:09 -0600
Message-ID: <3fa65255$0$22061$45beb828@newscene.com>

"Patrick Coghlan" <coghlan@sympatico.ca> wrote in message
news:Djkpb.1016$Pg1.73847@news20.bellglobal.com...
>
> For her it's a quality of life decision.  Apart from a bit of arthritis,
> she's been in relatively good health, and if she can make it to 85 or so
> without becoming an invalid, she's happy.


I agree with Orac that rapidity of enlargement is a significant risk factor
that probably increases your mother's risk of AAA rupture beyond what would
be considered typical.

No one will be able to predict your mother's future. Doctors can only look
retrospectively at large populations of people in similar situations and
draw some rather general conclusions about your mother's case. That's not as
good as having a crystal ball, but it's all there is. Your mother's actual
operative risk might be substantially higher or lower based on undiscovered
facts about her medical condition, or a less-than-accurate assessment of the
clinical significance of the medical problems they DO know about.

Bottom line is that she gets to decide which risk to take. Her doctors will
try to give her the best information they can so she can weigh the pros and
cons as accurately as possible, but no one can predict the future. To a
lesser degree, that's what the other posters here are trying to do for you,
only we all have less information than her doctors, so the information
imparted here is necessarily more general.

HMc