Aneurysm treatment | Circulatory System and Disease | NCLEX-RN | Khan Academy

Aneurysm treatment | Circulatory System and Disease | NCLEX-RN | Khan Academy

January 3, 2020 13 By Kody Olson


– [Voiceover] So here
I’ve drawn an aneurysm. You might remember that an
aneurysm is a full thickness dilation of the wall of
the aorta or any vessel. By full thickness, I mean that the intima, the media, and the adventitia are all involved in the
dilation, so they all dilate out. This type of aneurysm in particular is called a fusiform aneurysm which just means that it
dilates out on both sides. So how do you treat aneurysms? Well, it depends on a couple of things. It depends on how big your aneurysm is, it depends on where your aneurysm is, and it depends on if you
have any symptoms or not. So let’s say we’re dealing
with small aneurysms. Let’s say you’re dealing with aneurysms that are four centimeters
in diameter or smaller. That qualifies as a small aneurysm. And let’s say you have no symptoms. Because when we’re talking
about the aorta at least, when you have an aneurysm that’s less than four centimeters, generally you won’t get any symptoms. So in a situation like this, your doctor might suggest
a watch and wait approach. Something like an observation approach instead of doing surgery. And the reason for this is because surgery isn’t really needed for small aneurysms because the risk of the
surgery usually outweighs the risk of the actual
small aneurism rupturing which is when it would cause
all of its bad symptoms. So usually a watch and wait
sort of observation approach will be recommended by your doctor. So I say watch and wait,
but what does that mean? Well, basically it means that your doctor will check up on your aneurysm
every six to twelve months. So you’ll have to go in to a doctor and you’ll get an
ultrasound on your abdomen to check out the size of your aneurysm to make sure it isn’t getting any bigger. Now what if you have a medium aneurysm? Let’s do that in a different color here. A medium sized aneurysm is
something that’s defined as being between about 4 centimeters to
about 5.3, 5.4 centimeters. You might notice that I’m being pretty meticulous with these numbers here. I’m saying 5.4, 5.3 and that’s because there’s been a lot of
studies done on aneurysms to determine just what size is more at risk of rupturing. It turns out that aneurysms
that are under 4 centimeters or equal to 4 centimeters are just less at risk of rupturing. Maybe that’s due to the tensile
strength of the aortic wall. It’s still strong enough at that point, so it just poses less
of a risk of rupture. Then the ones that are 5.3 or
5.4 centimeters in diameter, these ones are at a
higher risk, of course, but they’re not at the greatest risk. So that’s where these
specific numbers come from. It all has to do with risk of rupture based on studies that have been done. So, anyways, medium aneurysms. It’s not as clear how the risks of surgery versus a watch and wait approach stack up. In other words, which is better. If you have a medium sized aneurysm then you’ll just have
to have a conversation with your healthcare professional about what’s better for your situation. Whether you should stick with
a watch and wait approach and get follow up ultrasounds … And actually let me just right here, under small aneurysm treatment that the watch and wait approach involves ultrasound, 6-12
monthly, just for monitoring. Back to the medium. You’ll have to have the chat with your healthcare professional about the benefits and the risks of waiting and doing a
watch and wait approach versus surgery to just get in there and repair the aneurysm. In making that decision, the healthcare professional
will take into consideration lots of different variables. What your preferences are, what the risks of the surgery are, if you have any other comorbidities like pathologically high blood
pressure, so hypertension, or what your previous
medical history looks like. Things like that. You’ll just have to sit down
and have a really good chat with your healthcare
professional if you have a medium sized aneurysm. Now what if you have a large
or a fast-growing aneurysm or if it’s already ruptured? If you have an aneurism that’s large, so saying it’s bigger than
5.5-5.6 centimeters in diameter, or if it’s growing really fast, that means if it growing more than about half a centimeter in 6 months, you’ll probably need surgery. Furthermore, if you already
have a ruptured aneurysm, then you’re really going to need surgery. There’s two typed of surgeries
for aortic aneurysms. The first type is called
open abdominal surgery. In this type of surgery, the surgeon will actually make an incision. So here’s my incision on the
skin overlying the abdomen. I’m not actually incising the aorta here, this is on the skin. The surgeon will make an incision down the front of your abdomen and then once you abdomen is opened up, they’ll get down to your aorta and actually remove that
diseased part of your aorta. Let’s say that your
aorta was diseased here, Let’s say that you had a
big aneurysm right here. Here’s your aneurysm. What the surgeon will
do is they’ll cut out that diseased part of the aorta. So they’ll cut out from the top and then they’ll cut out the
bottom of it and remove it all. All that gets removed. Then they actually
replace it with a graft. So a graft is a synthetic tube that can sort of simulate an aorta. Then that graft gets
stitched in at the top. You can see my stitches in purple here. Then it gets stitched in at the bottom to connect it to either side
of your aorta that’s remaining. So now you have a new aorta
with no aneurysm in it. And again, that’s called a graft. So that’s one way. That’s open abdominal surgery. That’s one way. Now let me reset this. Look at that, like new. The second way is something
called endovascular stenting. This one’s less invasive. You don’t get that big incision down the front of your abdomen. So with this one, the surgeon
will attach a synthetic graft to the end of a tube called a catheter. So here’s our catheter here. It’s a nice tube and it’ll have
our graft on the end of it. It’ll have our graft here. I’m drawing it a little small here and you’ll see why in a second. So this white bit is our graft, our stent. First let me actually
explain what a stent is. A stent is something that
almost looks like this. It’s almost this mesh tube that’s made out of either fabric or metal. The ones that you put in the aorta are usually made out of fabric. So it’s the tube that
blood can flow through. So that’s a stent. That’s what we have right here. We have this thing stuck
right on to the end of this yellow tube here,
which is a catheter. We have a stent on the
inside of a catheter here. This will all make sense in a second. What happens in endovascular
repair is that the surgeon will actually make an incision about here, right at your femoral artery. The femoral artery actually takes blood down to your leg and your thigh. Once that incision is made
in your femoral artery, this catheter gets put
through the incision and up the femoral artery. We’re going to thread our catheter. This is our catheter in yellow here. We’re going to thread our catheter all the way up to our
diseased part of our aorta. Actually, I forgot to
draw in our diseased part, so let’s just do that. Let’s say you have a big
aneurysm right about here. So here’s our aneurysm. Whoops, that’s a little bit
big, but that’s all right. Here’s our full thickness dilation. It involves all the parts of the wall, the intima, the media, and the adventitia, because that’s what
make it a true aneurysm. So there’s our aneurysm,
and then this catheter is essentially going to head
up right toward that aneurysm, and then it’s going to deploy the stent. The stent is here, this
white bit on the end, and then when the stent
actually gets deployed, when it gets let off of the tip
of the catheter, it expands. The idea is to have it expand … This is a little bit big, they’re
usually smaller than this, but this isn’t drawn to scale, it’s just to give you an
idea what’s happening. So the stent will expand and
cover up that diseased part, that aneurysm part of your aorta. You can see effectively … By the way, it’s just tension
that keeps it in place because it’s expanded and now it’s pushing out against these walls here, right? It’s actually further reinforced by the surgeon putting
in little hooks or pins. So let’s put in our hooks and our pins to keep that thing in place there. Now that’s not going anywhere. You can’t really see that,
let’s use a different color. Let’s use orchid. Here we’ve got our little fasteners. We’re going to fasten
that mesh tube in place. That’s our stent now. Then we’ll remove our catheter. We’re just going to withdraw
the catheter out of the … Oh, I think i might get rid
of some of the artery here … And then we’re gonna stitch that up. Now you can imagine that now blood, as it gets pumped out of the heart and goes around the aorta, the aortic arch and down the descending aorta can just now pass through
the stent, the graft, and head down to where it needs to go. Now you might be thinking, “Well, look at this mesh thing. “I mean it looks like blood
can just leak right through.” That actually doesn’t happen because the mesh is made
out of a special material that makes it leak proof, so blood can’t actually
go out the sides here. Because now blood is going
through the mesh tube, it’s not putting undue strain on the bulged out aneurysm wall here. Let me just recap here. With an open abdominal surgery, you get your big incision down
the center of your abdomen. Then the bad part of the aorta is cut out. With endovascular stenting,
you use a catheter to put a stent into the
bad part of the aorta. So with either type of surgery, whether it’s the open abdominal surgery or the endovascular stenting surgery, you’re going to have to
head back to the hospital probably a couple of times a year for ultrasound follow-up. The idea behind that is to make sure that the aneurysm repair has gone well and that no other aneurysms
have come up anywhere else. One final note here. We’ve talked so far
about surgical treatment for each of the types of aneurysms: small aneurysms, medium
aneurysms and large aneurysms. I’ll just briefly touch
on some medications you may need to take to reduce your risk of worsening your aneurysm. The main type of medication
that’s given to people to reduce their risk of
making their aneurism worse is medication that lowers blood pressure, because high blood pressure
can make aneurysms worse. In fact, that’s usually how they begin, how they come on in the first place is due to high blood pressure. One of the more commonly prescribed blood pressure lowering
medications in the context of aneurysm treatment is the beta blocker. So whether you have a small or
a medium or a large aneurysm, you’ll probably be put
on life-long treatement with a beta blocker to keep your risk of your aneurysm developing or your aneurysm rupturing low, or at least lower than it would
be without the beta blocker. How do beta blockers work? Essentially they block
receptors on the heart called beta receptors,
that when stimulated make the heart beat stronger and faster. Beta blockers block those
beta receptors on the heart to prevent the heart from
beating too strong or too fast. By doing that, it causes
blood pressure to be lower.