In this case study, Dr. Nicos Labropoulos and Dr. Adriano Souza provide instruction on how to conduct follow-up imaging after intervention for iliac vein stent evaluation on a 32-year-old female with persistent severe leg edema.
I'm Doctor Nikos Labropoulou from Stony Brook University Medical Center, together with Dr Adriano Sousa. We have prepared an interactive clinical case of iliac Winston and post robotic obstruction. A female patient, 32 years old presented with edema of the right lower limb. She had omar thrombosis on the left lim in 2011, treated with Warfarin. She was using oral contraceptives. At that time. In 2017, she went a Gila with the left common iliac Wes as she had persistent severe leg in April 2020. She had a second episode of thrombosis of the right iliac crane since she has been using Rivaroxaban. She does not take any other medication. Thrombophilia tests were negative. She had a positive family history of lower limb venous thrombosis and pulmonary embolism. On physical exam. She had normal pulses, mild edema of the right lower limb and bilateral reticular varicosis. We start the examination from the right groin, looking at the fela action. Next, the femoral bifurcation that is compressing nicely. We look at the vein now in the long view and the vein is wide open with color feeling wall to wall. We place the Doppler to obtain a wave form which is non phasing. Then we continue the imaging of the vein and we try to obtain augmentation. And now you see has modest augmentation as we squeeze it twice, we continue the examination more distantly actually, the vein is widely open, it continues flow. Now we're going to transverse for you ident to looking at the femoral union. Now we see the common femoral vein distally, the profunda and the femoral vein. We have been away from the co femoral vein distal, it's a game of low velocity and nosing. And then we move to the deep femoral vein. And here we have similar wafer. Subsequently, we examine the approximate femoral day and the waveform is almost identical. Then we move back to the junction and we see here that the valve and we fix the box to see feeling and place a Doppler. And again, here, low velocity non physic waveform. Then we move to the left side, start again, the common femoral next to the femoral. I see the vein is collapsible. See the ve the long view, the vein is wide open and it continues to flow with the color who plays a Doppler in the lumen. Now with the Doppler and the coal vein, we notice that the waveform is non physic and a flow velocity. The augmentation maneuvers the form I will see that there is good volume flow augmentation continue the valuation in cross section of you And then in long distantly, the man is collapsing nicely. Both the common femoral profunda and femoral. We see the base in the long view. Now the color and the color on the other side for better color feeling, which is the diesel coma femoral vein and obtain the waveform, which is similar to the proximal one being non physic and a flow velocity. Then we moved the December and May that has comparable way for and subsequently obtain a wafer from the femoral vein that has a similar way from to the left veins. Then we move up to the cove, look at the long view transaction valve. Again, we place the box in the proper rotation for maximum color feeling in the calories in the therapy acid on the top and then replace the Doppler in the second fe transaction. And again, here we see a low velocity which is non physic. Then we continue the examination in the abdomen, we match first the inferior vena cava. So we see the vena cava, the aorta and the spine. The K is on the right. Now with the problem on the long view, see the long view of the vena cava, that nice color feeling and within a wave form. And here the waveform is P and normal. Now we move distally, we see the vena cava and cross section has opposite color from the aorta. And then we continue the examination towards the iliac vein. Have you seen the left comac vein under the right comac carter below the base is the fifth labor vertebra. See the vein is narrow under the artery. And here we see a shiny structure, a bright one which is a stem. Now, we're gonna take a closer look by using hydro magnification. We gonna optimize the image by reducing the B mode to see clearly the lumen within the stem. And it is obvious that the stem is reducing diameter right under the artery, the color flow less than this patent. But you see clearly the mosaic color, the alien after the stenosis indicating the narrowing just past the right common iliac artery. And here we see black and black and white, the clear lumen of the stem and we're gonna visit the diameter from the near wall to the far wall. And the diameter here is just 7.2 millimeters which is half the size of the original diameter to the very. Now in oblique orientation. And there there are three and you can see even by using different view that stand still looks compromised. So look now, most of the length of the stent in the iliac is the distal part is much bigger than the stent under the artery. And here we're going to measure the diameter of the distally. For comparison, let's start the area of the stenosis. I hear the stand is seven millimeters more or less and distally, the standard measures 13 millimeters looks like at least borderline, 50% stenosis. Now, using the magnification again, we look at the area of the stenosis and with a color, it's very obvious to see the narrowing. And also the pono in turbulence is clearly demonstrated by the aliasing. Now, we're gonna obtain the V to VM ratio by measuring the velocity distal to the stenosis on the iliac vein. Here, we see the clear w below the baseline and the velocity here measures 34 centimeters per second. After this, we gonna move more approximately just after the artery or the area of the led that we used as a guide to obtain the maximum velocity in the area with RV two. And here you see the velocity is increased compared to the distal one and it measures 64 centimeters per second. So almost double. So this will probably make it a borderline, 50% stenosis. Now, a bit more distally to examine the lateral external iliac, as you see is narrow due to chronic disease and similar diameter to the adjusted artery or a bit smaller. Typically, even this fine position, the vein is larger than the artery here, diameter of the iliac vein and measures of 7.8 millimeters typical this vein is 12 millimeters or more. Now put the color and you see here the feeling of the vein as opposite color, not the artery, the arteries on the top and avenge the bottom. And you see that vein is smaller than the and I will move a bit more proximal towards the union and the car on the bottom. And you going to measure the velocity at the proximal external vein. And as you see, the vein is low velocity and it is not phasing, we look in more detail in the area. Here you see the stem coming from there, distal common iliac and paradoxically, he goes to the iliac vein. The stem typically goes to the external look to the internal eac vein. But here we see it's unusual situation with the stem being wide open on the ipsilateral internal eac vein. And again, the stem here and look at the diameter of the stem. It enters the iliac and it measures almost 14 millimeters which is the nominal size of the stem. Now we go back to the exter iliac vein. I see the connection between the two veins of the area. And you can see that the vein is narrow as it goes towards the stem and it's significantly smaller, half the size of the stamp. See the cat in a blue color and on the top, she, the accel cat is the red color in the middle. We have the external iliac vein approximately which is narrow leading to the area of the stenosis. You see that post turbulence just above the inter iliac artery as you move further down, we should extend iliac vein going back to the area to indicate the stenosis. There in terms, aliasing as the external unites, the internal are the area of the stem. Here, we can take a velocity in the area of alien. And you can see here very high velocity due to the stenosis, it's a combination of the Mabo damage of the exterior iliac vein and the fact that the vein unites the stem that goes to the eternal to go a bit further down to look at the velocity of the vein. The velocity is much lower, right, in comparison to the area of the stenosis and it measures 17 centimeters per second. So now we have established that there are post robotic changes on the external iliac vein. We look at the high Zoo Ma and you can see the snake here inside the external iliac vein. I can look the diameter this area which means only six millimeters and typical this vein should be more than 12 millimeters in this area. So the vein has reduced diameter to the poster disease here in zoo mag. You see again the highest the area above the stem that goes into the tera IAC vein, the a very bright color indicating the high velocity in the area. Now, we're going to the cross section of you to look at the diameter of the vein and the artery and also look at the stem at the same time as you go up and down slowly, you see the stem iliac vein and iliac artery or cross sectional view that art is bigger than the vein. Now we gonna go on the right side to look at the external iliac vein. And you see here, the external vein is also small and we see a big vein, collateral diverting the flow and see the external iliac cat has opposite flow that the vein. It is big collateral diverting the flow. As the proximal external iliac vein is included. We continue to image the area we obtain a velocity on the external iliac vein distally just before the occlusion. And you can see here the velocity is low and non physic similar to what we observe in the ipsilateral common femoral vein. And I work at the collateral, the collateral has similar flow pattern, diverting the flow from the crude external to the inter iliac vein tributaries. And now we're going to look a little bit higher up to identify the area of the occlusion. And you see below the artery, you cannot tell clearly the l of the vein because the vein is fibrotic. In fact, you see the vein now fibrotic and include it and the diameter here, it's only 4.5 millimeters smaller than the other side, which was 6.4. And I use the color it is absolutely no law in the external iliac vein approximately due to chronic occlusion, which is the collateral list but no flow at the middle and proximal segment of the external iliac vein. Colonial olu with significant reduction in diameter and a flow as to go more approximately. Now, you see the Kia K by fur and the vein of the list and going back a bit more approximately. And there is no external iliac vein to connect to the common iliac. We see the external vein basically being included. Does his bi collateral veins from the contralateral system, the di divert the flow from the collateral, the terra iliac right to the terra iliac. This is big collaterals from the external iliac and internal iliac veins. The exterior iliac vein got a distal of the image on the far right and on the bottom in the middle of the box at the collateral of the entire iliac vein is further down. We see multiple collaterals. Now that the fast flow and spontaneous indicating there are a large veins by passing the obstruction. Here is the artery it laterally, but we don't see the inter iliac ve on the side, basically collaterals from the external and theories of the internal send the flow to the contralateral side. See what indicated. Now here there is occlusion, chic occlusion of the ipsilateral iliac vein and the main trunk. Now continue the examination in the middle of the abdomen. In the uterine area is big collaterals. The peri and tritter veins are well developed due to the obstruction on both sides. We now focus both on the left side. You see collateral veins in the uterus and outside the uterus with the bigger side being obviously in the per U space. And also I see further on the bottom are collaterals from the internal iliac vein. And I sit on the both side, on the right side as well as the big veins as well. I got to see the flow pattern in his veins. You see it high flow typically, these are tiny and this is very slow flow here. The events are dilated with high flow indicating that the acts. Now we change to the linear transducer to obtain better images. And it will look at the end of the stem. First, you see again the narrowing of the stent under the artery and above the fifth vertebra. So with this problem, much better resolution than the abdominal one and we can liberally use it is just a lower BM I it's going up and down from the cover to the racom car to the stand. It's easy to notice the narrowing in the area. Then we look a bit further down on the external iliac artery given this program has much higher resolution. And here you see very nicely, the bi collateral and external iliac vein, we're gonna rotate the box for proper rotation. And you see a flow on the distal external got the collateral, a high flow. And the external iliac above the collateral is include flow on the, on the I art it underneath the vein is fibrotic and it's not flow and now we go a bit higher up, continue the external iliac towards the common and go back to the stent area. And here we see the narrow of the ST and you use the color box and here it is very obvious the significant aliasing color after the stenosis, they are nicely on top and the alien just pass the art using the Tapao Widow. You can see a long view. I go back to rectangular shape and go to the exterior vein on the left side. And you see here, the left exel is bigger than the other side. It but there are poster bo chronic Luminal changes which are more prominent on the anterior wall of the bay. I use the highest magnification to focus in this particular area. And now you see very clearly the collagen inside the proximate celiac vein due to the previous thrombotic events. And with a color box, it's very easy to see the continuous non physic flow in the area. And the aliasing just above the ITAC artery where the vein would meet the common Iliac. The ITAC vein that has a stem here is very nicely how the luminous was compromised. And I go back to the standard area, you see the bifurcation of the aorta. So two entries there and underneath the aelia carry, you see the stem, I looking again at the exter iliac, you see very nice, the personal body changes and how it goes over the stent that dies in the iliac. And the lumen is further compromised on the external iliac when the stem is wide open, as you see here and the diameter of the stem as it dives into the iliac is 13 millimeters as we demonstrate, also the car linear transistor earlier. Now we're gonna take a closer look and further optimize the image with a high zoom unification and it goes here very nicely muscle, the stem under the artery with reduced beam gain to see clearly. There is not any Luminal changes. It just is a compromise the diameter from the compression and the sten meters here 7.1 millimeters like we saw earlier. And we're gonna look again from a different angle in the area. And we use the color box and you see now next to the extended area, the ovarian vessels with being dilated and having high velocity on the left side, we see very clearly with this transducer. Now that is 18 me Hertz is very high resolution. The most robotic change this that will be even more evident using the high definition of zoom as we see here. It is so clear to see the collagen in the near wall of the external vein. And using the color in this area, you see the flow tunnels and the difference in the color density due to the post robotic changes in the area here using different colors. It's easier to see and depict the flow tunnels inside the compromised Luminal diameter. Then we check the extended agreement on the other side. Here you see very clearly the bi collateral B mode and the occlusion just above the collateral. The vein is tapered into nothing with the fibrotic tissue. And you see the top the artery being so clear and the whole flow being diverted the collateral but the proximal ali vein is occluded. I go a bit higher up to see the occlusion see very nicely color flow on the external liar carry but the external vein is occluded. And here we magnify the image and you see very clearly the fibrous tissue in the exterior vein and we don't see any lumen because occupied by the collagen. So now this is even clearer. Here is the flow on the artery and the vessel directly below is small in diameter and has no flow just occupied by fibrous tissue. Now, using even higher magnification with a high definition zoom and we're gonna put a cursor to make the measurement of the diameter of the vein that is only 4.4 millimeters. It's probably three times smaller than the original size. This is due to coronary poster damage that cause contraction of the vein lumen. And it is here with a very high definition. You see the pure collagen inside the venous wall and you see it's all fibrous tissue with no flow and no important channels. If we look in the cross sectional view we see that the artery is much bigger than the vein and you see very nicely as you go towards the area of the occlusion. The vein is directly below the artery. I'm gonna miss the diameter of the proximal external iliac artery, which is 7.1 millimeters and the vein diameter at this level, it is only 4.3 millimeters. As you said, even spinal position, the normal exterior vein is equal or most often larger than the artery. Now go back to the stem area to use this 18 megahertz user to see they have very high resolution of in the air of stenosis. I see the artery beating on the top. I see the throat of the stenosis at 10 and I want to put the color. It's very easy to see the post of turbulence pass stenosis. And with a B mode view can see nicely how the dial part of the stem is enlarged and the area under the artery is reduced to half. And we're using the tripos view. You can see most of the stem in the proximate level, passing the aracoma artery and entering the distal part of Nefer vena cava. And here we obtain a very clear view of the lumen and we make a measurement directly under the artery. And here is 6.7 millimeters which will make it less than half the diameter of the stent. It's basically about 50% diameter reduction. In summary, there was significant anatomical obstruction in iliac veins on both sides. This explains the low velocity on physic waveforms in both common femoral veins. The right external and internal eac veins were included. The left acceler iliac vein had chronic post robotic changes. With a significant luminar reduction. There was 50% diameter, instant stenosis in the left common vein. The distal end of the stem was inappropriately placed in the left interior iliac vein. Despite the an atomic severity of the obstruction on both sides, the patient had only mild edema in the right lower limb. She had large collaterals that probably compensated well for the obstruction. And this concludes our case. Thank you.
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