Assessing Venous Disease For Optimal Endovascular Stent Placement

[Isabel Newton]
… Can you describe the access points that you prep so that you have many different options? I thought that was pretty interesting.

[Brooke Spencer]
Well, I would say that 90-plus percent of my patients with chronic venous occlusions, I prep their IJs and their ankles. I use the jugular vein so that I can use intravascular ultrasound in the pelvis. If I have someone with a chronic fem-pop DVT that's been really symptomatic or has a wound and we're going to go in and re-cannulize that, I check every single one with intravascular ultrasound.

The more CTs and MRs that I do, the more inaccurate I'm realizing those studies are, in terms of determining whether there's significant flow. What I mean by that is that they're only very small studies, right? The VIDIO trial, which was industry sponsored, was 100 patients looking at multiplanar venography versus intravascular ultrasound for a diagnosis of a greater than 50% lesion, and all those patients were CEAP four through six, so these were advanced patients. These aren't just your non-thrombotic May-Thurners, right?

What they found is that the cross-sectional area narrowing is the most accurate in predicting clinical improvement, quality of life, and ulcer and wound healing. So you want to be able to measure the area of the vessel distal to the obstruction and then the area of the vessel in the obstruction and see what percent stenosis you have.

Now, if it's a 50% stenosis in an non-thrombotic 19-year-old who just has a chronic fem-pop DVT, you're probably not going to put a stent in that patient, right? But if you have a 90% stenosis in that patient, and you have filling through collaterals in the spine, para-lumbars, epidurals and parametrium, and they have pelvic pain, heavy periods, and back pain, you're not doing them any favors by not stenting that. The vessel's 90% occluded, and I really believe that those patients benefit from that. We still have a lot of data that needs to be gleaned from all of this.

[Brooke Spencer]
Now what do you do with a person who has an 18 millimeter common iliac and a 90% obstruction, but their external iliac is 10 or 12 millimeters, and that looks like their normal size? These are challenging, challenging cases to fix. What I would say is that a lot of people are doing all these May-Thurners from the groin, and I've done that, but if you have a large vein, and you need to deploy a Wallstent, I will tell you that you're going to do a better job if you have a jugular approach.

And the reason is that if you have to put an 18 millimeter Wallstent in, and you know it is not going to open to 18 millimeters at the level of the obstruction, but maybe in order to get just a wall apposition, you have to do that. You want to deploy the Wallstent from above so that you can force the Wallstent out to have wall apposition before you've deployed the portion of the stent in the stenosis. If you deploy the portion of the stent in the stenosis first, the distal part of the stent will often not open, and then you'll have what looks to you like a floating stent. It can be really scary because now you don't know what to do, and now you've got this huge stent, it's floating in the vein. Do you overlap a second huge stent that now goes into a very small area of the vein, and the patients having an enormous amount of pain?

It can be really challenging, but if you do a larger stent like that from above, and you leave the point of no return exactly where you think that stent needs to land, it's very rare that you extend all the way into the inferior vena cava across the wall of the vein after dilating. It's also very rare that it pulls all the way back out of the stenosis. So if it does pull all the way back out of the stenosis, you have to put another stent in.

And so that's the other thing I would say is that, if you're young, and you're doing this early on, you're going to misplace the stent several times in the process of doing these. Just put another one in. Use how short your current one is, put the same size stent in, and put it another centimeter or two centimeters or whatever it is. If you put in an eight, don't put a four in to overlap at the top because you don't have a great way of measuring exactly where that's going to land. Just put another eight in, and if it was two centimeters too short, leave it two centimeters further in and overlap it.

These are just some of the tricks that I've learned over time, but I do think that non-thrombotic May-Thurner stents can be some of the most challenging cases. The last thing that I'll say is that if you have incomplete wall apposition, as long as you have a couple centimeters of wall apposition proximally or distally in the common iliac vein before the obstruction, and as long as the stent is open but being held by the obstruction, I've seen all of those patients remodel around the stent. I haven't seen any migration from those stents, and I know migration is a big concern for people.