Aorta and EVAR - HD

Examination of the Aorta

My first topic is the aorta and if we look at the guidelines, there's a couple of recommendations.

I will start with the normal order how much contrast enhanced ultrasound or harmonic contrast bubbles are needed. And then we speak about the indication and finally a couple of the indication will go underwent endovascular repair.

The question is did we need for every examination the contrast enhanced ultrasound setting the baseline every time is the gray scale setting as we seen it here in the axial and even in the longitudinal plane.

And the next step we are looking whether we find an endoleak has not, whether lumen seems be find has not, and we shift it to the color doppler.

So if look at the color Doppler and axial plane on also in the longitudinal plane, so complete vessel seems to be fine. And finally we look at the curve of the spectrum. Even here we have got a freeze slow window.

So in this case probably my recommendation will be not just to inject some contrast agent because everything seems to be fine, but in case a surgeon ask you does this patient suffer from isolated dissection of the aorta, you will see later that's maybe a good indication.

So how much contrast you have to spend, I think it's really a low amount of contrast. It's about one cc of contrast and that's fine for you doing the examination about two to three minutes.

Aortic Aneurysm

If we speak about the aneurysm, we know that in the western world we have got a higher risk to develop an aneurysm. Unfortunately most of the men are involved in this problem an abdominal aortic aneurysm if the diameter is more than three centimeter and the risk of rupture increase if the diameter also increase.

The next couple slide I would like to show the difference between gray scale and contrast ultrasound.

So the question is if you look starting at the gray scale examination, does this aneurysm has thrombotic changes? Probably most I will say yes. When I ask you where are the thrombotic changes, probably most of you will say I see it clearly here. Here I'm not really sure, maybe I use the color.

Of course you can use color, you can see here there's no flow. But he also sees limitation due to position of the flow there seems to be an overriding of the perfused lumen.

And now if you look at the same plane axial plane, you see only the perfused lumen without overriding artifacts and it's not limited to the scanning angle

If you repeat the examination and the longitudinal plan, of course the surgeon would like to know what the diameter of the neck of the aneurysm and if you look at the quality of this contrast compares to the quality of the gray scale or color.

You'll see very easy that there seems to be some advantage in using this technique.

Aortic Dissection

Arterial dissections are not so common. If there's a demand for extra dissect you have to see whether you find a flap, another flap or a hematoma just adjacent and all we would like to answer. What about the perfusion of the kidney or the liver?

As I told you, gray scale at the baseline, everybody sees the flap here probably, but the question is getting more difficult. When I ask you where's the true lumen where the false lumen?

For those who have more experience, they would say probably it seems to be that this calcification here belongs to the wall. Here it seems this is a true lumen, this the false lumen. But who knows, maybe we look at the same image in color even we see that the flow direction seems to be a little bit different in occurring here.

And the next question is, is this now really true lumen or not?

We repeat the examination and we see in the most time contrast arrive in the true lumen first. That is then it arrive in the false lumen and finally we see also the right renal artery. Did any one of you see the left renal artery?

I have some problems and I'll tell you also later why just the right renal artery.

So after the examination of the aorta, you have enough time to look at the perfusion of the kidney and compare the perfusion of the kidney in comparison to the liver. It seems to be fine and I tell you honestly why we have the problem to see the left renal artery because this patient has got only one kidney and unfortunately the right renal artery and third also from the false lumen,

the same information is also here in ct we see the perfused true lumen false lumen and the entire renal artery from the false lumen.

This was an easy case because everybody see it in the gray scale. Now you get a more challenging case because now ask, did you see that dissection?

Probably most of us will say not really directly maybe could you give me a high resolution and say of course I will offer you a high resolution. I give you a ninety probe. Do you see that dissection?

What do you write in your report? Not a dissection visible.

So in this case if somebody asks you does this patient suffer from dissection, my recommendation will be just bend please one cc of contrast because you will see immediately that this patient has good dissection and you'll see how difficult it was to see it in the gray scale even if you use the high frequency probe.

So good chance to miss a dissection.

Covered Ruptures

If we speak about covered ruptures, we know that patient have a hematoma around and the question is before treatment, this vascular surgeon would like to know how far is the dissection away from the renal artery. Because if the, if the covered rupture is very close to the renal artery, a normal stent graft will not fit then in special customized stent graft.

But as I told you, baseline is gray scale and color we see hematoma here we see a covered rupture. Here we see some flow in the covered rupture. This is a right renal artery and if you see more, if you use contrast, so I repeated the examination, you'll see there's a right renal artery, there's a true lumen covered rupture, there is an active bleed because you see the bubble move from the aorta in the hematoma and the question is aware of the left renal artery,

the left renal artery is just adjacent to the covered rupture. This mean a normal aortic stent graft will not fit and this is very important information for further treatment of this patient.

If you now compare this just to the ct, we get immediately the same information. You see the covered rupture is just adjacent to the left renal artery and here are the hematoma also seen by CT by contrast and ultrasound but the active bleeding we've seen by contrast ultrasound, it's not really visible in this case by using the CT information,

if you look at this image you will say probably I've seen something else or something very similar in a different organ.

So if you look at the vascular diseases after intervention, you find a similar image very often in the femoral arteries after intervention of coronary artery intervention or just intervention. It seems to be that this patient has got a fistula here but where does the fistula belong? Is it belonging from the aorta with the IVC? Is it only one fistula or two? This has also a major influence on the treatment.

Arteriovenous Fistulas

So repeat the examination. You'll see there's conjunction between the aorta and the IVC. It's not only one fistula, this patient has got two fistulas also here this patient has additional also an aneurysm is thrombotic change inside.

Now we've got a a-v fistula between the aorta and the IVC and unfortunately even two this patient I think was treated with a stent graft.

We would like to confirm this in the MRI or CT examination. You see very similar. First of all you see the contrast uptake in the aneurysm with the ectasia of the iliac artery. You see no contrast in the iliac veins but a very, very fast contrast uptake in the IVC.

So this is the resolution. Why? Because the patient has got a fistula between the aorta and the IVC. Same information, CT optic aneurysm and the fistula between the aorta and the IVC inflammatory aortic aneurysm was first described by walker in the 72.

Inflammatory Aortic Aneurysm

Often we find on a enlargement of the aortic wall probably most of time in the ventral part of the aorta at also on the left right lateral part. The dorsal part of the aorta seems to the most time in the normal diameter.

Here we see an aneurysm which was already treated with the stent graft inside. But you see typically the enlargement of the lateral wall of the aorta, the ventral part and lateral part. But the dorsal part here seems to be normal.

The question is does our normal settings like color doppler and power doppler are sensitive enough to show any flow in this inflammatory part? You can keep build your own mind and ask yourself did you see any flow but maybe there is no flow in this inflammatory part of the aortic wall here.

So in order to prove this you just have to inject a bit contrast. You see united perfusion of the stent graft, there's no leak here and then you see the enhancement of the aortic wall.

So you see the micro vessels which are not visible by using the color doppler or power doppler settings.

If you just shift the plane and repeat the examination further, all you see the aneurysm here and also here in the longitudinal plane you see the enhancement of the aortic wall.

After successful treatment the enhancement will be less. So can you use this tool for monitoring? And if you think about our, our last speaker regarding quantification problems will be also a good recommendation to quantify the contrast uptake before treatment and follow up the treatment with quantification.

Follow-Up After Endovascular Repair

In order to monitor directory results there's a couple of studies which compare the outcome between open and end repair.

So if you have a open repair then you've got a high risk at the beginning but the later risk later if you have got a endovascular repair, the risk is less at the beginning but you have more complication in the future. Therefore the patient which undergo endovascular repair have to have a follow up until the end of their life.

And this mean you see the patient at least once or twice a year for 10 or longer times. So 21 times 3 times.

So if you start to follow up of this examination you see the perfusion of the aneurysm seems to be perfect. I mean the perfusion of stent graft, there should be no contrast uptake in the stent graft after looking at the axial plane, you just shift your plane in the longitudinal view then you see the main part of the stent graft and the right and left iliac stent graft legs here finally,

and don't forget to measure the diameter because this have to remain in your report because if the patient come again in a half year and there's a growing of the diameter, this patient probably suffer from an endoleak.

What are the complications? Either we have got the early complication like infection and/or hematoma and the late period we have often late dislocation or occlusion of selects

regarding the classification of leaks. There different, different kind of endoleaks. So the most common endoleak is type two. This mean either the feeding vessel over the lumbar artery or the IMA type one endoleak is when the contrast arrive between the aortic stent graft wall and the aortic wall.

Here in this area it's type one A within the proximal part of the stent graft, it's type one B within in distal part and if there's a disconnection or hole in the stent graft you have probably type three endoleak. These are the endoleaks we probably see in the most time.

Type One Endoleak

So if you start with type one endoleak. So some contrast should be arrived here in the peripheral but using the color like we could only see perfusion of the stent graft, no leak is visible of course we look for type one endoleak, therefore we look for axial plane and you can ask yourself did you see a leak?

You see a perfusion of the stent graft but we couldn't see major leak and now we repeat the examination. And what about this small leak Here you see it very easy even if you magnify the image you'll see a small leak that's a type one leak but this means it has to be treated very soon.

Either you do implant and another stent graft and press the old stent the wall or you have to inject some glue here in this area for type two endoleaks you have time and can wait.

Type One B Endoleak

What about the different type one B? That mean a similar leak just on the distal part of the stent graft. Remember the baseline is the gray scale examination. We see the main part of the stent graft in the right and left leg of the stent graft. We don't see major leaks inside by using the color.

We see already some flow but now the key question is where is the entrance? Where is the exit?

So if you look see at this kind of flow, it could be also a leak over the IMA and this mean a complete different treatment. In comparison it will be a type one B endoleak.

So you see here the bubbles arrived and in this case I used just a trick, I burst all the bubbles in a single plane and then you see the flow direction of the bubbles and you'll see the flow direction stops from the peripheral entire here the aneurysm and the accident in this case is the IMA

Type Two Endoleak

type two A endoleaks are the most common endoleaks. So it's either the lumbar artery or the IMA in this case you already seen some flow here inside. So high suspicion probably of a lumbar artery endoleak.

By using the contrast we see nice perfusion of the stent graft type two endoleaks. We have to wait a bit longer since contrast arrived. And finally see also here the amount of contrast. This is typical for lumbar artery. The IMA will be in this area here.

So another case also starting with the grayscale examination. No major leak inside. And if you look at the color, it seems to be that here is a vessel. This is just an artifact twinkling artifact. But here seems to be a vessel but the question is really a vessel or pulsation artifact.

Also in this case the recommendation will be to use contrast. You'll see a nice filling of the stent graft. Everything seems to be fine but then we wait and you'll see there some bubbles appear just here. You see due to the pulsation of the hearts, the bubbles are in the aneurysm and out of the aneurysm.

And also if you just change your plane and the longitudinal plane, you'll see the IMA which is here in this area. And here you see the entrance of the bubbles.

So that's an endoleak type two probably this will be gone in a couple weeks but you have to follow it up at least in three months.

Type Three Endoleak

Now we are starting with really more rare endoleaks. That's type three endoleak. That's mean disconnection of the stent graft or hole in the stent graft. Often you have got a very strong flow inside and if you have got type three endoleak, if you inject bubbles, the bubbles will be immediately in the old aneurysm sac.

So you see in the stent graft and also of the stent graft typical for type three endoleak and of course this kind of leak have to be treated very soon because there's a very, very high pressure on the aneurysm, on the old aneurysm sac and the risk of rupture much higher in comparison to type two endoleaks.

Type Four Endoleak

One really rare case is a type four endoleak I have only seen twice in the last 10 years. So if the anticoagulation is not correct, it's more to liquid the blood then there is a risk that the blood could enter the wall of the aortic stent graft and appear in the old aneurysm sac.

We also see already here some flow by using the power doppler and if we repeat the examination by using contrast and ultrasound we see a nice filling of the stent graft. And then you see single bubbles entered here. The old aneurysm in this case it'll be only fine if you optimize the anticoagulation of the patient.

And then this ana, this kind of leak was gone. So really rare case of a type four endoleak.

Special Case: Identifying Endoleaks

I mean you are now the experts regarding endoleaks. So I have a special case for you. You could prove your experience right now. Key question is did you see a leak grayscale?

So take your time look carefully in order to confuse you a little bit. I give you the color doppler and power doppler and of course it's an easy case. So who agreed that there's a leak? Nobody probably will say we are in the contrast course. You need contrast. Oh, good answer.

So, but when I look at this image, most of my colleagues say the stent graft seems to be fine. But normally the stent graft have only two legs. Here we have got three perfused legs but we couldn't see any perfused legs in the gray scale. The third one, so high suspicion of a leak maybe feed it over the right lumbar artery.

If this will be the truth then we should see some contrast uptake. So we inject contrast, we wait about 15 seconds, contrast arrived, then graft looks nearly perfect. Unfortunately our leak which was visible clearly by color doppler our power doppler doesn't appear.

Maybe we just shift the plane. So we look into the longitudinal plane, there should be the leak. There is no leak sometimes due to kinking of the stent graft in the aorta and aneurysm there could be a leak which is not really a leak, it's just an artifact.

So keep in mind that sometimes all artifacts could, for could make a wrong diagnosis because if you only use the color probably will say there will be an endoleak.

So the question is how sensitive are you? If you use compare color doppler on the right of the image to contrast and ultrasound properly, you get the message very soon that you will miss a couple of leaks. If you don't use these contrast agent for follow up of patient, what are the options if there's a leak?

So either you have to inject some trobe glue or you need to have to inject the more expensive onyx glue. Or you can think about coiling and also implant a stent graft before making a decision. What three P is the best?

You have to think about where is the entrance, where is the exit? And this is really a challenge case because we see already some leaks in the aneurysm sac here and there's some flow here. So it seems to be big endoleak.

By using contrast you see nice perfusion of the stent graft and unfortunately see a also a lot of contrast uptake here. And if I just optimize the plane and look at this image, when I ask you where is the entrance, where is the exit? You have got a problem if you don't burst the bubbles because if you stay in a plane and you just burst the bubbles, you can see where is the flow direction.

So it starts from the left lumbar artery and the exit is the IMA. This mean the treatment will be complete different because a coiling will not work. You have to inject some glue in the lumbar artery area.

If you would like to inject some glue, my recommendation will be combined with contrast ultrasound. This aneurysm is already punctured with the needle. You see the needle inside, you could not see major flow here.

In order to prove the positioning of the tip of the needle, you can inject some contrast over the needle that you can confirm that the needle is really inside of the aneurysm. This is also a recommendation because it's really worth if you inject the expensive glue somewhere else, not in the aneurysm.

And also you see how much contrast uptake you see. It doesn't appear so much leak in the gray scale, but you see how much contrast is inside. Even if you use the gray scale, which is not optimized for contrast, you'll see a lot of flow inside.

We are the correct position here. So a good option just to inject some glue in this area.

After injection glue you have to make sure that you don't make a mistake because these are artifacts from the glue. Also here, some artifacts there. And finally also here you see just a small leak still exist but in comparison to the beginning I think it was a successful treatment and this is directly after the intervention.

You can also use modern tools to follow up these intervention. So 24 hours later we use just the CT information. You see this needle was placed on a CT guided. This was a tip we have seen during examination.

And finally we would like to confirm whether it was successful treatment or not. Nice perfusion of the graft. Unfortunately there is a very, very tiny leak there, but in the three months follow up this leak was gone. So successful treatment of the patient.

Conclusion

I hope you have seen that there's a couple of advantages by using this tool regarding detection of aortic diseases like aneurysm, dissection or covered rupture and even you have to use this tool for follow up after stent graft and you can use this tool for monitoring your intervention and immediately see the results of your intervention. Thanks for attention.