Chapters Transcript Video Patient Selection- Who Truly Needs a Filter Back to Symposium Now we're gonna talk about IVC filter who actually needs it, and this is, I would say probably the easiest talk when I was reading all the list of, of who is giving talks this is by far the easiest, so I appreciate whoever decided on this one. this has been, if you just look up either the chess guidelines or or the, uh, Society for Interventional Radiy guidelines, it's all written out. It really doesn't ever change because I think that this is actually good science behind this, but. In the clinical context, so standard management is anticoagulation, therapeutic anticoagulation. The days of just using Coumadin or Lovenox are over. We have these DAs now. We have all sorts of orals that we can use, and I, I think it has really helped, uh, simplify treatment for these patients. IVC filters are really reserved for the, the that small subset of patients that can't be anticoagulated or in those that we've kind of talked about. So we look at this. So this was, if you look up IVC filters, if you use the Google machine, what you see is all of the black box warnings. You see all of the litigation sites, and so it's interesting. So there was this huge influx. Everybody was in planning, as I said, 2010. If you look at this is an early study, 2006 to 2010, you looked at that trend line was going, you know, up not exponentially but rather, you know, linearly. And then all of a sudden there was all of this, the filter fractures. There was the, you know, the optis thrombosis of the, uh, of the cava, and all of a sudden it, it kind of struck that this is a, this could be a problem. So there was a second, the, the first was in 2010, the second was. In 2014, the FDA warning had this black box and all of these lawsuits came out. So if you had a filter or if you've ever had a filter, even if it was removed and you know your son didn't get into Harvard, it's probably the filter's fault. So everything, you know, it kind of followed that and so what was interesting about it is over time you can see that the trend line went the exact opposite way. So I think as much as I hate to say it, I think out of those lawsuits grew good medicine. And I think we're able to start to apply what we kind of knew conceptually was that these things have serve a purpose and they're great in the right patients, but in the wrong patient they can really have a lot of problems. So this trend line I would make the argument is the correct and accurate trend line, and I, and I like to see how it's continued all the way through 2022. You see the number of implants that has gone down. Of note, the little tiny green bar at the bottom is the number of retrievals, so again it is a fraction of what has been placed. So what does an IVC filter do? So number one is an IVC filter does not break up blood clot. So people will say, oh yeah, if, if there's clot and it gets caught in there, it auto lysis. I don't think any of that stuff is true. It's never been shown, but what it does do is it prevents a big pulmonary embolism. So there's a couple little caveats to this. So this picture here, I will be the first to admit it's a little low. I don't like that, but. We like to have the, the top of that filter really at the renal veins because there's a dead space that occurs if you were to form a clot here you'll get a dead space above the filter that dead space can then thrombose so you get supra super filter thrombosis so. What it does is it prevents these catastrophic pulmonary emboli or paradoxical strokes, so they are really, really good like we've talked about in the select patients, but what it doesn't do is again it does not treat existing clot. It doesn't prevent new clot formation. In fact, as we say, clot begets clot. So if you have thrombus in here, it is possible that you can get new clot. The other thing too, and of all the studies we just reviewed, you can see a higher rate of DVTs after you've placed the filter if it's in too long. This is the evolution, um, I, this was like the, you know, like Neanderthal all the way up to, you know, modern man who's now I would say probably regressing, but this is the kind of the latest iteration so Denali 2013, I think that they kinda nailed it on the Denali. This slide while it's impossible for you guys to read. In general this was an early study and it basically was looking it's 200 patients and it was looking at comparing just to the option filter and what you can see is there's much better migration uh resistance so the Denali didn't move as much um there's much better clot trapping the volume of clot was was trapped it was much higher. There was less tilt so you can make the argument if you think about just the physics of of it if you have a, a. A filter that tilts the tines that are on the opposite wall from the the hook will have splayed open more and theoretically you're gonna have more clot migrate through. There's a, I've never had this happen, but I've seen it described where you try to snare one of these things and you're pulling hard and the top disconnects doesn't happen with the, the, uh, Denali so. In essence this has really prevented a lot of the problems with the early filters. Uh, they have these things called, um, there's, it's basically a, a penetration limiter so it's like these little things that sit down so you will get penetration like through the cava but it's, it's mitigated with these as well. So in general we're just gonna look at just a snapshot again if you take anything from anything I've said this is a good slide, right? So the guideline consensus, and this is amongst almost all of our guidelines through Europe all the way here chess guidelines, the Society for Interventional Radiology. Uh, consider filters for acute proximal pulmonary embolism DVT with contraindication anticoagulation. Recommend against routine IVC filter placement when therapeutic anticoagulation is feasible or advisable. Recommend against IVC filters in addition anticoagulants and against routine prophylactic filters in trauma, major surgery without acute venous thromboembolism. So again, just a snapshot, and I think that this is a probably steeped in our literature really well. So the strongest indication The patient that comes in with acute DVT and absolute anticoagulation uh contraindications, these are the people that come in crush injuries, big injuries, um, hemorrhagic strokes with a DVT clear and present. You wanna put a filter in until they can be anticoagulated. I've even taken filters out on the inpatient side if a patient has prolonged stays. Uh, bridging, so when you have a patient that is basically they're on anticoagulation, they need to stop it for a long time and they have, they have a very high PE risk. Um, this is a multidisciplinary, uh, strategy, and you really wanna kind of talk to all your colleagues and say what do we think realistically the likelihood that they're gonna have a pulmonary embolism or a venous thromboembolism during this time where they're off the anticoagulation. The idea is you put it in, but then you have your exit plan, right? As soon as you restart the anticoagulation, you take the filter out, uh, structured follow-ups again. I, I hammer that point home. So then with anticoagulation given evidence again we've kind of gone over this uh basically if you can be anticoagulated you shouldn't have a filter placed that's really the. Uh, the main crux of this now I have seen and I have done where you have a patient that has a, a big thrombus in transit or you have somebody that has had a, a submassive pulmonary embolism with an ileofemoral DVT or a large femoral DVT with the argument being that yes there aren't anticoagulation, but in the one chance that it does fracture off and go to the, the lungs, then that could be catastrophic for the patient. I will in those situations entertain or place a filter. So recurrent, so this is one of my favorite ones like the, the patient came in there on anticoagulation and they uh have another thrombus, so they need a filter. I would say in my experience 80, 85, 90% of the patients are like oh I'm on anticoagulation. I mean I haven't been taking it, but I, I'm on it so it's like that theory of like it there's so many things that go into patient compliance. I mean with in in this environment now losing health insurance has really changed the way people address their own anticoagulation, right? It's something they can't see or feel. It's just a little pill that costs a lot of money. So if you can't take your insulin or you can't take your anticoagulant, they're gonna choose to stop taking their anticoagulant. So before we just throw a filter on everybody, really try to figure out what is the reason that they clotted again. It is very rare, but it is possible you could have resistance to DAx. I mean, we see it certainly Plavix resistance, but Coumadin, you know, they all of a sudden go on a diet, they eat all their green leafy vegetables, and their INR goes from 2.5 to 1.3, and that's a cause. So you really wanna sit down and go over why they had this and address that. So retrievable versus permanent, uh, I mean again I don't put permanent filters in very often, um, I don't see much of an advantage at all to them, so we use retrievable, uh, again unless it's a terminal patient or extremely old. I always work on trying to figure out how to get these things in and I scare the patient. I think that's it's the most helpful way, you know, just say this is a ticking time bomb as soon as they hear that they, they all panic and, and you see them a lot more. And then this is um a retrospective review Florida inpatient database um from one of my colleagues uh 130,000 IVC filters placed. This was and if you look at these, only 6.5% were retrieved, but what was interesting, it also stratifies by age. It's almost like that age where you would get to when you're 80 and they say you don't need any more colonoscopies only because the chance of you living long enough to have a big obstructing cancer are low, which is, I would probably argue is pretty depressing, but. These patients, only 1 almost 2% had them retrieved. Basically, if you're elderly, they put them in, and this is the patient that they kind of forget. This is also the patient population. If they have a complication, it can be absolutely catastrophic. So clinical decision checklist, does the patient have acute venous thromboembolism? Basically, again, all there's just the two slides. Just remember two things, you know, the, the indications and remember to retrieve these filters. That's the biggest thing. This is just a very simple. I let my my fellows do these procedures. Uh, I made the mistake one time of going to see a consult, and when I came in and it was a beautifully placed filter in the left iliac system which we then had to retrieve and put another one in. You lose so many style points when you put in two filters in one procedure, but in general access, I always do a duplex first to make sure that the femoral vein or the access site is patent. Um, do your homework. Find out if they have a, a thermal DVT. Don't puncture it again. It's style points. Um, you do that. You go up there. I do a venogram. I do, uh, I don't use ibis. I don't cannulate the renal veins unless I can't see them. Once you see the renal veins with wash out and you have kind of suggestion of it or a lot of these people have had CT scans, you know what level, you know what, what vertebral level you place your filter, uh, again, you wanna make sure that it has tilt less than 15 degrees. If it is really tilted, you may want to try to, to push it over with a balloon or even in the worst case scenario retrieve it and put it in a different site. But the idea is you want the filter to be washing out in the renal vein, uh, and that really kind of helps so that you're not gonna have thrombus that will occlude those renal veins. I think that is it and I appreciate you listening to me. Published Created by
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