00:01
All right. On this topic of Angiodysplasia,
we will spend a few minutes discussing
exactly what this is and how it presents
and what to do about it.
00:11
Angiodysplasia is a vascular malformation
that will occur somewhere within the GI tract.
00:18
It can occur anywhere from
the esophagus to the rectum.
00:22
Most commonly, it's going to occur in the colon and that's
what we're going to emphasize in this particular talk.
00:28
The epidemiology. Your typical patient with Angiodysplasia
is going to be elderly, over the age of 60.
00:36
Most of the Angiodysplasia actually
occurs in the left-sided colon.
00:40
Approximately 6% of lower GI bleeds and 8% of upper
GI bleeds are associated with Angiodysplasia.
00:51
The things that are associated with this
include aortic stenosis, the so called Heyde syndrome,
end-stage renal disease, the use of ventricular
assist devices, Von Willebrand's disease
which may be a hereditary form of
Angiodysplasia and Osler-Weber-Rendu syndrome
which is also a hereditary basis
for having Angiodysplasia.
01:17
The pathophysiologic is basically a malformation
between the arteriovenous side.
01:25
What is being shown here on the right-hand side
is an artery, the branches and the capillaries
that reconstitute into post-capillary
venules and then, into a vein.
01:36
What happens in an arteriovenous malformation
in Angiodysplasia is that we have direct connections
from the artery into the vein so that we bypass the very
low pressure in highly distributed capillary system.
01:54
The formation of such arteriovenous malformations,
Angiodysplasia between otherwise health vessels
can be associated with low-grade venous
obstruction of the submucosal veins
may be due to reduced precapillary sphincter tone
with the opening of arteriovenous communications.
02:14
The association with Von Willebrand's disease or with abnormalities
in the processing of Von Willebrand's factor
means that we have higher molecular
weight multimers of Von Willebrand's
which tends to drive these AVMs
or Angiodysplasia for unclear reasons.
02:32
And then, the congenital vascular
hyperplasia associated with Osler-Weber-Rendu
are a variety of mutations associated
with vascular hyperplasia.
02:41
The clinical presentation is typically
painless GI bleeding.
02:46
The patient doesn't even have any other symptomatology
and depending on the amount of blood,
may be completely unaware that there
has been ongoing bleeding.
02:55
If there is a lot of blood and because of the
location typically on the left side of the colon,
then, you may have hematochezia
or bright red blood per rectum.
03:02
then, you may have hematochezia
or bright red blood per rectum.
03:06
If you were to have an Angiodysplasia
and arteriovenous malformation more proximally,
you may have hematemesis or vomiting of blood.
Clearly, if you're using blood chronically,
particularly, in a geriatric population,
these patients will have anemia.
03:23
And then, will have symptoms associated
with the loss of blood. They will be weak.
03:27
There may be hypotension. So, things that you
can figure out pretty much from first principles.
03:34
How do we diagnose this? So, we have a patient,
geriatric, who is - got clear anemia
and we don't have any bleeding source.
But we do have occult blood positive in the feces.
03:50
That makes us start to think that
this might be a possibility.
03:53
We can do a complete blood count and formally
document the anemia and the cause of the anemia,
whether it's iron deficiency or something else.
We can do endoscopy.
04:02
A colonoscopy will allow us to actually visualize these
legions if they are bleeding significantly enough.
04:09
And the gold standard overall is angiography
or we will inject radio contrast material
and see it extravasate as you see here on the
right-hand side into the lumen of the GI tract.
04:22
What's shown on the left-hand side is what
this legion would look like on colonoscopy.
04:27
It looks just kind of like a bruise or a vascular malformation
that is sitting just below the submucosa.
04:36
How do we manage this? So, we can do an
endoscopic treatment if you identify exactly
where this is with colonoscopy, you can go in
and radio frequency ablate it, just blast it.
04:49
You can do angiographic embolizations.
So, you can identify the vessel that feeds
the area where the bleeding is occurring and you
can put in material to cause vascular occlusion
and then, focal ischemia infarction of that area.
And for rather larger vessels or malformations
or for rather bloody, substantially bleeding malformations,
then, we can resort to surgery. With that, we'll close.