Ultrasound
liver biopsy
Q: Dr. Richards,
Thank you for the quick response. My vet wants a radiologist to do an
ultrasound, needle biopsy on the liver this Thur.
Is this an invasive procedure? We seem to be making some progress and
I'm
hesitant to want to do anything that might set her back.
Are the blood clotting tests and bile acid tests recommended prior to
a
needle biopsy?
Thank you.
A: RTV-
A needle biopsy is an invasive procedure. It is considered to be safer
to
do an ultasound guided biopsy than to do a "blind" biopsy -- but there
is
still some risk of hitting a blood vessel and it is best to know that
the
blood is likely to clot before taking that risk. I think that a mucosal
bleeding time test, which can be done in the vet's office, is a reasonable
choice for this test but some vets prefer to do more complex testing
done
through a reference lab. We rarely see clotting problems even with
liver
disease but it can happen and it is best to be cautious. We have never
had
a patient have a serious complication from liver biopsy that
I can
remember but we have elected not to do the procedure on at least one
occasion when blood clotting problems were present.
Liver biopsies are often the only way to be sure what liver disease
is
present but I still think that it is reasonable to do bile acid testing
first, just to be sure that there really is a change in liver function.
This is one of those issues in which having the opportunity to actually
see
the patient can be a really big advantage so I can't say that your
vet is
wrong in this choice. He may have really good reasons to feel that
liver
biopsy is a better choice. Bile acid testing is not considered to be
a
prerequisite to liver biopsy as changes in the bile acid response would
be
a good reason to recommend liver biopsy and normal bile acid response
testing does not rule out liver disease, it just makes it less likely
that
severe disease is present.
Hope that helps. It is always hard to figure out what to do in these
kinds
of cases. Clinical signs are important and if you are sure your
dog is
improving you have to consider that in your decision making.
Mike Richards, DVM
5/12/99
Bile acid response
test
Q: Hi Dr Richards
We are at the next step with Roquefort and I need some help with decision
making.
He had the bile acid response test on April 16th. I don't
have numbers in
front of me but the test result was that the post-meal test showed
a liver
dysfunction. If it's important I can get the actual numbers.
What the vet is recommending now is a clotting panel ($75), then an
ultrasound where a biopsy will be done at the same time ($375).
This is a tremendous amount of money for us but when I questioned the
vet it
sounds as if we should get these tests done as soon as possible.
Is there anything else we should consider and are we on the right path?
Many thanks
Jane B
A: Jane-
If there is a significant elevation in the postprandial (after eating)
bile
acid value, there is probably a significant decrease in liver function.
It
is a good idea to figure out what is going on. Before doing liver biopsies
it is best to make sure that blood clotting is normal because the liver
produces some of the clotting factors. If it is damaged to the point
that
it isn't doing that, severe bleeding and even death can result from
attempting to biopsy the liver. If blood clotting is normal then ultrasound
guided biopsy is safe enough to be a good choice for trying to determine
the exact nature of the liver damage. In some cases there are problems
that
can be corrected surgically (some forms of portosystemic shunts) and
in
other cases knowing the cause of the liver damage can help in determining
proper medical treatment. There are times when liver biopsies don't
help
much but they are the best way to determine what is happening
when the
liver is damaged.
If the biopsy is being done by a specialist in the area it would be
worth
asking them to review the lab results first. Bile acid tests have an
overlap where values are normal in some pets and abnormal in others
so if
the elevation on the postprandial test is small it would be more important
to have a second opinion on the need for ultrasound exam and biopsy.
Sometimes we repeat the lab testing to see if the results are the same
in
these patients prior to moving on to more aggressive diagnostic procedures.
Mike Richards, DVM
4/20/99
Bile acid
testing - Liver Disease
Q: Dear Dr. Mike
Thank you so much for your evaluations. You cannot appreciate
how important this resource is for me, and probably many many others.
(I would certainly pay for each "consult," if you asked. I spent
10 days reading everything in your archives and other files before I wrote.
First question, is there a scientific or special name for a bile acid
test? The vets down here don't seem to get it when I say bile acid
test (in Spanish or English; that's why they did the bilirubin instead).
And, one other probably unimportant, question: Natasha's rectum.
It looks perfectly normal (based on my experience with other dogs) most
of the time, but when her bladder is almost full or she's considering defecating,
there is a partial opening, like a little hole, until she decides to go,
which could be an hour or two later. With other dogs the rectum usually
just sort of bulges when they're full. Is this anything to be concerned
about?
Thank you very very much.
Wendy
A: Wendy-
I have been thinking Natasha's symptoms and labwork since you wrote.
It may be simplest to just sum up my thought process and let you decide
if any of it matters.
First, the labwork.
Bilirubin is a by-product of the breakdown of hemoglobin when red blood
cells die. Since red blood cells are constantly dying and being replaced
it has to be dealt with. The liver breaks it down. Bilirubin levels in
the bloodstream rise for several reasons:
1) Breakdown of red blood cells in numbers sufficient to overwhelm the
liver's ability to handle
the bilirubin produced by breakdown of hemoglobin
2) Damage to liver cells so that they can not perform the task of bilirubin
breakdown.
3) Blockage of bile ducts in any manner (gallstones, cancer, tissue
swelling)
4) False elevations due to lipid levels in the blood stream being too
high (Kirk's Current Therapy XII, page 737)
5) Lab error
A bilirubin level above 1.0 mg/dl usually will cause bilirubin to be
present in the urine. Most urine test strips include bilirubin as one of
the tests. Since you don't indicate the presence of bilirubin in the urine
it is possible that there is a false reading in the blood OR that the level
is just slightly below the level that spillover would occur. The lab values
given left out two important clues to this mystery. If she is anemic that
would make it easy to understand why her liver values appear to be normal
but bilirubin is a little high. If she is not anemic it would be really
helpful to know the serum alkaline phosphatase (ALKP, ALP) values because
high ALKP levels can indicate bile duct blockage. The SGOT (also known
as AST) value and SGPT (now known as ALT) value are normal indicating a
lower probability of damage to the liver cells.
Bile acid testing. As far as I can determine this is the only name that
is used for bile acid testing. Bile acids are produced by the liver from
cholesterol. This is work. In general, animal bodies hate to do extra work.
So bile acids are recycled in the body. They do their job (which I think
is to stimulate bile transport) and are thus released into the intestinal
tract. They are reabsorbed by the digestive tract and into the circulation.
The liver recycles them rapidly. Therefore, there shouldn't be high levels
in the blood stream at any time and there isn't much difference in levels
before and after meals. High levels of bile acids indicate that the liver
can't handle the recycling job due to damage or diminished capacity.
When do you need bile acid testing? If a dog has bilirubin levels above
normal and is not anemic there is probably liver disease. If this is the
case, then there isn't all that much need to run a bile acid test. When
there is reason to be suspicious of liver disease but bilirubin levels
are normal or close to normal, then bile acid testing can be very useful
since it is a more sensitive indicator of diminished liver capacity.
Natasha has some signs consistent with chronic liver disease, including
seizures, vomiting, slight elevation in bilirubin and tiring easily. Dobermans
are prone to liver disease. So bile acid testing seems reasonable to pursue.
If your vet's local lab doesn't run this test it is possible to send bile
acid samples to labs in the U.S. by Federal Express or U.P.S. or by mail
if it doesn't take too long. Checking on the other lab values (ALKP and
the hematocrit, or percentage of red blood cells) may make this seem less
important. If both are normal there isn't a whole lot of reason to worry
too much.
I would also worry a little about bladder stones with the history given,
since they can cause frequent urination, blood in the urine and because
at least twice in my practice people have seen episodes that appeared to
be seizures associated with bladder stones. I do not know if this was coincidence
or if passing a small bladder stone is so painful that it looks like a
seizure or perhaps even leads to one or to fainting resembling a seizure.
Cystitis and incontinence both also seem possible. Even a disorder
leading to increased drinking and urination (can occur with liver disease
on occasion) may be causing incontinence that might not otherwise be present.
I would also worry about an orthopedic problem, such as hip dysplasia,
with the reluctance to walk with you.
A lot of dobermans have the relaxation of the anal sphincter that you
have noticed and I really think that is normal just based on my own observations
of dogs.
Anyway, that is what I have been thinking about. As you can see, I think
that there is reason to suspect several things and the only way to sort
through them is to start somewhere. Hip X-rays and bladder X-rays may be
worthwhile or bile acid testing may be an easier first step. You'll have
to work with your vets there to decide what you and they think is the most
likely first step to produce useful information. Sometimes you just have
to keep looking until you find an answer or decide that there it doesn't
look too likely that there is one. If you reach that point then you can
worry about whether you worry too much.
Mike Richards, DVM
Last edited 08/30/02
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