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BackTable / VI / Podcast / Transcript #541
Podcast Transcript: Treatment of Acute Portal Vein Thrombosis
with Dr. Ben May
To TIPS or not to TIPS? More than ever, younger patients are presenting with acute portal vein thrombosis (PVT) that requires intervention beyond anticoagulation alone. These patients need safe, effective options that offer long-term resolution and a good quality of life after treatment. In this episode of the BackTable Podcast, Dr. Benjamin May, Interventional Radiologist at Weill Cornell Medicine, discusses the evolving treatment landscape for acute PVT. You can read the full transcript below and listen to this episode here on BackTable.com.
Table of Contents
(1) Understanding Portal Vein Thrombosis (PVT): Clinical Significance and Implications
(2) Diagnosing PVT: Imaging Modalities and Laboratory Evaluation
(3) Management of Acute Portal Vein Thrombosis: Options and Interventional Approaches
(4) Interventional Approaches to Acute PVT: Techniques, Medical Technology, and Patient Selection
(5) Practical Tips for Successful Portal Vein Thrombectomy
(6) Exploring Intervention Through PVT Scenarios
(7) Post-Operative Management After Portal Vein Intervention
(8) Reviewing the Relevant Literature & Current Practices in PVT
(9) Closing Remark on the field of Interventional Radiology
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[Dr. Christopher Beck]
Today, we're going to be discussing treatment for acute portal vein thrombosis. We've had Riad on the show, episode 223 for portal vein recan techniques, and we also discussed advanced TIP techniques for chronically occluded portal veins with Emmett Lynskey, episode 126. After over 500 episodes, we've only talked about chronically occluded or chronically clotted off portal systems, but never covered acute portal vein thrombosis. To help us with this topic, we have Dr. Ben May, and I have a right to say from Cornell, NYC, to help us with the topic. Ben, welcome to the show.
[Dr. Benjamin May]
Thanks so much for having me. It's a real honor, and I've been looking forward to this.
[Dr. Christopher Beck]
Real quick, just tell us about the practice over at Cornell, and not just the practice at Cornell, but also of your role within the IR practice over there.
[Dr. Benjamin May]
Sure. We're a big group, 20-plus IRs practicing in the heart of New York City, New York Presbyterian and Cornell campus on the East Side. Very busy practice, everything from managing all the inpatients in a huge tertiary hospital to UFEs and some PAD, and obviously oncology. I really focus my practice on hepato-biliary service, working really closely with our transplant team, liver transplant, hepatologist, surgical oncology, but surgical transplant hepatology as well.
[Dr. Christopher Beck]
When you have 20 interventional radiologists in a group, do you guys like decide, I'm going to focus on this, another doc's going to focus on that? How do you guys carve it out like for new guys coming in or for whatever?
[Dr. Benjamin May]
We have service lines with all those fields I mentioned and others. Things typically happen organically. For me, I was very lucky and I trained at Cornell, residency and fellowship. Just as that was coming out, 2016, we brought liver transplant to our campus. We also expanded NYP's liver transplant service and recruited a bunch of super talented hepatologists and surgeons. They needed a young, eager, available person to start taking on all that work. It's incredible how much IR and what roles IR plays within liver transplant from day one doing TJ liver biopsies to keeping patients within Milan with local regional therapy.
You mentioned transplanting portal vein recans, making them eligible for transplant, and then managing complications after portal vein stenting, hepatic artery stenting, you name it. It's been really great. You get to collaborate with really smart people at the top of their game in transplant hepatology on the medicine side, but the surgical side as well, keeps you really busy, really cool complex cases, and a lot of problem solving. It was perfect for me and it was very organic. Fell in my lap and I ran with it.
(1) Understanding Portal Vein Thrombosis (PVT): Clinical Significance and Implications
[Dr. Christopher Beck]
Wow. What a service line to like open up right as you're coming out. That's pretty fortuitous. Super good. I was making the outline for this and there are a couple of ways we could start it, but I just would jump in and say portal vein thrombosis, what is it and why do we care?
[Dr. Benjamin May]
Anytime I think about thrombosis on the venous side, you think about inflow and outflow. Obviously most people are familiar, in the legs or the systemic venous system, portal system in some ways is no different. We have inflow from the intestines, inflow from the spleen, outflows to the liver. When that's occluded, especially acutely, you can have problems in those organs, in particular the bowels. The dreaded complication after portal vein, acute portal vein thrombosis is bowel ischemia and infarction and can lead to death. That's on the acute side.
If it's untreated and becomes chronic, then you have all the sequelae of chronic mesenteric hypertension. Varices, even if you get through that acute phase, if you don't open up the portal vein, those mesenteric vessels are going to be under pressure, they're going to be forming collaterals, varices within the small bowel, which are incredibly hard to treat, ascites, pain after eating, it's miserable. If they do become or are transplant candidates, keeping that portal vein open is obviously very important for transplant candidacy. We can avoid those chronic sequelae. It's a huge plus and prevent, of course, some of the more acute dreaded complications like bowel infarction.
[Dr. Christopher Beck]
As far as the timing that differentiates acute from chronic, do you have a cutoff?
[Dr. Benjamin May]
That's up to the debate. I think within the first month, I consider acute. The hepatologist sometimes will quote within six months, but we know that clot starts to evolve, becomes sub-acute at that four to six-week time period. We know with our devices in that clot, it's a very different beast. It's not soft, it's not gel, it has strands, it's hard to get out. If we're going to intervene, I like to do so within the first month.
(2) Diagnosing PVT: Imaging Modalities and Laboratory Evaluation
[Dr. Christopher Beck]
Diagnosis of portal vein thrombosis. First thing I want to start out with, how do the patients typically present like in your system if they have acute PVT?
[Dr. Benjamin May]
I think it's important first to think about two different patient populations. One are cirrhotics with portal vein thrombus and one are non-cirrhotics. For today, we'll probably focus on non-cirrhotics, happy to talk about cirrhotics, is they present differently. They tend to have acute on chronic portal vein thrombus because they just have stagnant flow in their portal system. There's a whole separate patient population, otherwise healthy, just living their lives, oftentimes young, and they present with basically acute abdominal pain. It's nonspecific. They bounce around to EDs. Their primary care doctor, maybe they ignore it, think they have a GI bug.
Usually within a week, 10 days, they ultimately get a scan that shows, at least when they, by the time they get to me, expansile occlusive thrombus involving oftentimes their entire portal mesenteric system from the intrahepatic portals down to the main portal into the SMV splenic vein. That's a common presentation for me. If you look at the literature, it'll say this disease entity is rare. It's not rare in our hospital, being a transplant center as well as a center, there's a lot of bariatric surgery.
There's one population that just, if you take all non-cirrhotic patients who present with PVT, a third will have some sort of underlying hypercoagulable state and present just with an acute presentation. A third will be related to either a pancreatitis or a surgery or a diverticulitis. Then a third are just idiopathic. They don't have a hypercoagulable state, but just present that way. I think that answers your question, a vague onset. They may have some ascites and some pain with eating, things like that.
[Dr. Christopher Beck]
It answers my question. It also sets the table stakes for what we're going to talk about. I was going to exclude the cirrhotic population and just stick with acute portal vein thrombosis in non-cirrhotic patients. That's perfect. As far as diagnosis, let's just pretend there's a world in which they don't come fully baked to you. If you're suspecting portal vein thrombosis, what's the imaging algorithm that you go through to diagnose it?
[Dr. Benjamin May]
You can think about ultrasound and things like that. Cross-sectional imaging is the best. I prefer a CT, either triple phase or most importantly, a portal venous phase for obvious reasons. MRI is acceptable. It's often gives you great imaging, but it's not as reliable. Patients have artifact, breathing artifact, et cetera. Many of our patients do present having had an MRI. I don't always get a CAT scan for them if I can see the portal system well. Obvious expense cell clot, but a CT with contrast, portal venous, including obviously abdomen and pelvis, because we care about where inflow is, if clots going all the way down into these small mesentery branches or not.
[Dr. Christopher Beck]
I'm going to come back to what you're looking at on that CT. The other thing I wanted to touch on, any lab work that either you order that you find helpful to gauge where your patients at and understand where they are in their disease process.
[Dr. Benjamin May]
The basic labs, of course, liver function tests and CBC and I know in that stuff. In addition, a lactate is very helpful. The big thing in the back of our mind is this patient at risk or tilting towards bowel ischemia? If so, it's a real urgency or emergency. If not, we have some time to make our plan, trial AC, et cetera.
[Dr. Christopher Beck]
Going back to that CT, whenever you're looking at the scan and you're either thinking about an intervention or thinking, maybe this patient's not a candidate for intervention, what's going through your mind? It's like you're looking at the CT scan, what are you looking for as far as like extensive clot? Are they a cirrhotic, et cetera?
[Dr. Benjamin May]
Some big points are how much of that portal mesenteric system is involved. If intrahepatic portals are open, it may change whether I think I need to leave the tips behind or not, actual stent, oftentimes it's all occluded. Sometimes you have occlusion of intrahepatic portals, main portal, but inflow from the spleen or inflow from the SMV, which makes, A, life much easier if you're going to intervene. Also in a borderline patient who may not be a great candidate for intervention, we know from the data that patients who have clot extending into those branches are less likely to recanalize spontaneously with AC than when it involves all those branches.
[Dr. Christopher Beck]
What about anything as far as trying to differentiate tumoral-- I guess that's not really in this patient population, so we can leave that out. One of the things I had to talk about was whether it's tumoral thrombus versus bland thrombus, but not really.
[Dr. Benjamin May]
That's a good point. For that, certainly MRI is a little more sensitive, but the triple-phase CT, if we have some knock-on, it shows some enhancement, often a mass. It's typically not a subtle finding, absolutely tumor thrombus, I would put in a different patient population. Like a lot of the studies and whatnot, we're separating maybe a third category of cancer-related thrombosis and things like that.
(3) Management of Acute Portal Vein Thrombosis: Options and Interventional Approaches
[Dr. Christopher Beck]
Portal venous acute PVT thrombosis, what are the management options? Then once we talk about the management options, we'll walk through each of them and then really dig into the IR part of it.
[Dr. Benjamin May]
Important not to forget the gold standard is anticoagulation. That's established with good data, with consensus statements, et cetera. AC is upfront, is critical, and it's important when we think about other interventions because we don't want to limit what is the gold standard. Beyond that, people have talked about really three different buckets of ways to approach clot in the portal vein.
One is transhepatic access, and then doing some combination of catheter-directed lysis or a thrombectomy. Another is a TIPS approach with or without lysis, but thrombectomy. Then a third is accessing this SMA and dripping TPA into the SMA, which has largely fallen out of favor, associated with a lot of bleeding. It's something I've never tried, but it's usually talked about when you read review articles and whatnot.
[Dr. Christopher Beck]
On dripping TPA into the SMA?
[Dr. Benjamin May]
Yes. There's groups who have left a catheter, transradial or transfemoral, within the SMA and sent the patient to ICU and dripped TPA. A couple papers out of Asia showed 100% success rate with zero complications, and it has not been replicated in other studies, which showed a very large bleeding rate, as high as 60%, and so it's largely fallen out of favor.
[Dr. Christopher Beck]
Fair. Just talking about the anticoagulation arm of treatment, I guess, what's the anticoagulant of choice? You mentioned trial of AC, and so the real part that I want to dig into, how long do you trial them out? Excluding if they have imminent bowel ischemia. Go ahead.
[Dr. Benjamin May]
If imminent bowel ischemia is a no-brainer, we start on AC and we're going to intervene. In the absence of that, things are changing. All of those techniques, interventions I talked about that are all written up, they're really were before an era of having large suction thrombectomy devices. I think things are changing. They're certainly changing in our group. I know Beth Israel just published a nice series in JVIR a year ago on 32 consecutive patients with TIPS and oftentimes mechanical thrombectomy, which I'd like to dive into later. Before that, we were using TPA more. We didn't have large-suction thrombectomy devices, and we were having more bleeds. I can get into that and tell some of those stories. That started an era, at least our institution, of putting people on AC and seeing if they–
When I say trial for a week, seeing if their symptoms got better, making sure the lactate went down. If you re-image them, really you didn't see much change in terms of the clot. If they were feeling better and they weren't making lactate and it seemed like their bowel wasn't threatened, a lot of those patients were just getting treated with AC alone, which is fine. You're going to get most patients. There's a great study out of Europe that I'll go through. Most patients will do just fine in the short term or medium term with AC alone.
I say that because the study I'm referencing followed 102 patients prospectively in multi-centers throughout Europe, non-cirrhotic portal vein thrombus, AC alone. 2 out of 100 had bowel ischemia, 9 had subsequent bleeding within the first year, GI bleeding. The rest didn't. However, only 35% actually cleared clot from their main portal. They ended up with chronic PVT and all the sequelae of chronic PVT. AC alone, you have a 65% chance, of our best data, of not clearing portal thrombus.
Then you're left with cavernous transformation, which causes portal biliopathy, so compression of the biliary tree. You have patients with just feeding intolerance, pain after eating, ascites, encephalopathy, and small bowel varices. It's a very difficult group to treat because on one hand, you want to treat them with AC, many of them have hypercoagulable states, JAK2 mutations, et cetera. They also have varices. Now they're prone to bleeding and prone to clotting.
If you have a small bowel, we've had patients die in our hospital with small bowel varices because the GI docs couldn't get to it, we couldn't get to it, chronic PVT, there's no great access point, and they're really hard patients to manage. It's a decision that, yes, we want to treat these patients with acute clot, and Yes, most of them will do fine with AC alone, but with a high chance of really chronic life debilitating and potentially deadly repercussions years down the road.
[Dr. Christopher Beck]
Some of these thrombophilic patients can be really young when they present with this. It's not like these are 70-year olds and you're like, oh, we just get them to anticoagulation then they'll be fine. These patients can be really young and like being susceptible to the chronic PVT that can have a lot of morbidity and certainly mortality associated with it.
[Dr. Benjamin May]
Exactly right. We're presenting the last 10 patients we did in this modern era of having suction thrombectomy devices. Our mean age is 39. It's probably a story worth telling. I should even go back. When I started, as I mentioned, not only was liver transplantation really establishing itself at Cornell, but so was bariatric surgery. Portal vein thrombus is a known complication of bariatric surgery. We were seeing every two, three months a patient with acute PVT in the postoperative setting. I was charged with doing a lit search and coming up with a strategy within our institution.
I went through the data, which I reviewed earlier and I said, we should do TIPS approach. I was borrowing a lot from the venous side where in that era, before large-suction thrombectomy, we were doing lysis, dripping TPA, AngioJet, the biggest suction device we had was an 8 French device. We treated about eight patients and it was technical success was high. We're good at doing tips. We're good at getting these devices in, you're trying balloon maceration. It just wasn't great outflow.
Two of them, one had a large subcapsular hematoma, but with just a couple milligrams of TPA, which doesn't sound like a big deal, but now you have to pause AC, which is the gold standard in these cases. That patient was hospitalized for a while. We then restarted AC. I had to reopen the TIPS, I had to reopen everything. She did okay, but with some morbidity. Another patient had an extra capsular puncture as just part of the TIPS, which we get away with all the time, but not when you're dripping TPA and using AC.
I had big intraperitoneal hemorrhage, had to go to the OR and the surgeon confirmed one tiny little, puncture in the capsule was enough to really threaten her life. She ultimately did well also, but we had a, essentially a 25% complication rate. This is early on, and so we paused. We only treated patients at that point for the next five years who were tilting towards bowel ischemia. Everything changed one day when young guy, 25, healthy, professional, good looking guy was–
[Dr. Christopher Beck]
Like us.
[Dr. Benjamin May]
Just like us, exactly, so you feel for them. Training for the marathon and just felt like crud the next morning. Came in, got scanned, expansile thrombus, everywhere, small bump in lactate, some ascites, started on AC, getting a little bit better and then got much worse, lactate started to rise. They decided, oh, he has HIT, we'll send off antibodies, we'll start him on argatroban, but stay tuned. I think he'll get better.
Overnight or throughout the course of that day, I should say, just took a turn for the worse. Lactate shot up and started getting into DIC. You know someone's sick when the head of the SICU comes in, because usually it's the surgical resident and then maybe their senior, and then at most the fellow, the surgeon came down himself and said, you need to take this guy right now, which we did, and had a couple of changes. I said, you know what? I don't want to have any extra capsular punctures. I should shout out my colleague, Brian Curry, who was very involved in this case. He was actually following this patient earlier, but both of us work together on a lot of these cases. It's very helpful to have a colleague, all hands on deck for these.
Used intracardiac echo or side-firing IVUS to guide our puncture. Didn't stop argatroban for one second. Didn't use TPA, but got our larger-suction thrombectomy devices, 12 French. In that case, I think we used the 12 French with the cleaner through it. Used the cleaner and the suction thrombectomy and cleared all that clot. I got those beautiful pictures of huge clot. Guy did great. Usually, he infarcted part of his bowels that operated on him, but that was occurred before we intervened. Survived and is back to his life.
That really prompted me just to say, you know what? We have better devices now. We can stay away from TPA. We're getting more facile with IVUS guidance and we should be intervening more. I think I can do this safely. That, I don't know if it was serendipity or what. I sent an email off explaining my rationale. Within that first year, we had 10 patients show up with the same exact presentation. It was very bizarre.
I don't know. My theory is that maybe COVID has something to do with it. I know patients with COVID are more prone to getting clot. I can't tell you why. We just see patient after patient in their 30s and late 20s present often with JAK2 mutations, but no surgery, no other reason. We've been intervening without any bleeding complications. It's been a game changer. I think now with these new devices, new techniques, we can do this safer. Some of those high bleeding risk, this data says, oh, there's a 20% bleeding risk, 30%, 40%. I think with those techniques seems to be, we've had zero. I know Beth Israel in their series had zero. Knock on wood that it will be very low and we can intervene more.
(4) Interventional Approaches to Acute PVT: Techniques, Medical Technology, and Patient Selection
[Dr. Christopher Beck]
That sets the stage perfectly because let's just get into it. Let's talk about the new techniques, your practice as far as intervening on acute portal venous thrombosis. Just open mic, however you want to start it, how you approach the procedure, the patient. Just go for it.
[Dr. Benjamin May]
In my mind, as I said, AC is gold standard. I want AC on as long as possible. I'm putting them on heparin drip and unless their bowel is threatened, I'll turn it off at the very beginning of the case, just so I can be sure I've established safe access without any extra capsular punctures. We almost always have two attendings present where I puncture the IJ in two spots, one for the TIPS and second for the ICE catheter, side-firing IVUS. Get that device down. Get the TIPS in place, to make passes. I like the Colapinto. I usually put through that Colapinto, a 21 gauge Chiba. It's almost like a micropuncture TIPS.
I really like that, especially for this, because you're watching that needle. I feel like I have a lot of control of that thinner needle. The Colapinto, you have to push hard and makes these jumps through the liver. Whereas with the 21 gauge, I can just, I have a lot of control. We're just inching it towards the portal, all under line of sight, even we're puncturing pretty central for these. You can see even there where the artery is. We're very comfortable that we've made a safe pass.
You do have to place an 018 wire through that 21 Chiba, but we usually use a Navi cross. You can nest an 018 through an 035 and basically a long micropuncture set. Then get to work. At that point in the case, I should add for our listeners, usually you do a TIPS. I don't use IVUS for every tips. I usually don't use it. I find it's just an extra step I don't need. When you're doing a normal TIPS, there's flow in the portal vein.
You can get blood back. You can tell you're in flow. That's not the case when it's all clotted. You either have to figure things out by outlining the clot with contrast and seeing how your wire behaves. If you can watch with IVUS, it's such a gift. For these cases, I think it's critical for two reasons, A, to see that you're truly in, and B, so you're not poking around making extra capsular punctures.
[Dr. Christopher Beck]
Good plug for the ICE device. That's such a well said thing, because if you talk to enough people, they're out on the ICE. I do TIPS all the time and I know what I'm in, and I've done enough and I think under experience hands. It's just one more tool in the toolbox to do something when it's not the standards like standard TIPS.
[Dr. Benjamin May]
I'm a big believer in, as an analogy, and some people I don't do transradial. I only do transdermal, or whatever. All these tools are good tools to have in your toolbox. As certainly as the trainees listening, learn everything because you never know when it may be very, very valuable to have transradial access and you might as well have that tool. The same thing with this. I don't do CO2 portograms anymore. I don't do IVUS for the most part. For these cases, it's a lifesaver. I think it's just right for patients and will keep our bleeding risk very, very low. I'm a big believer for that.
At that point, you have to decide, are you going to go straight to suction thrombectomy or are you going to lay a TIPS down, a stent? Sometimes it's nice just to have that TIPS, it's stable access, you're not going to lose access. I get it. The other thing, though, and I'm starting to transition from is once you deploy that TIPS is certainly a traditional viator. That non-covered portion that sits in the portal is going to jail your suction device off from all that clot in the intrahepatics.
Even if you're going to leave a TIPS stent behind, it's really nice to be able to run that suction device without any-- just in the native clot and get as much as you can out up front. It's always a game time decision for me, except for patients who are not good TIPS candidates. Somewhat we've treated two patients at this point who are post-transplant who have direct clot and they do very poorly if you leave a TIPS behind, but a TIPS approach is beautiful for them.
Other patients who may have intrahepatic portals open, I mentioned that at the beginning, then you don't need to leave a TIPS. You have good outflow. The liver is not diseased, but they just have the clot's the problem. If you can clear that clot, no need to leave a TIPS. For most patients, they're having clot all the way up in the intrahepatic portals and the hallmark is connecting inflow to outflow. If you don't have good outflow, the whole system is going to go down. In those cases, I very much believe in leaving a TIPS behind.
[Dr. Christopher Beck]
Ballpark, if you just had to put a rough number on it, how many are you leaving a TIPS in the end?
[Dr. Benjamin May]
75% leaving a TIPS. The rest are either transplant candidates or I think I can get away without it. Are not candidates, but post-transplant patients. That may change over time. That's where I'm at right now.
[Dr. Christopher Beck]
Let's say in the patient, either you're going to make it a game time decision. You're not ready to put the TIPS down, but you're going to clear it out first. Will you just walk us through the blocking and tackling of-- if you're going to use one of these large-bore thrombectomy techniques about how you're getting your devices down and then just how you're, how you're activating them. Also if you're comfortable, you can talk about devices, specifics.
[Dr. Benjamin May]
Let's say we're going to do suction thrombectomy upfront and not leave a TIPS, but it does matter because it's harder to get these devices, believe it or not, through a TIPS stent, that uncovered portion, just your device catches on that uncovered portion and there's a curve there. Swallowing a balloon is quite helpful. I'm just constantly putting up a millimeter balloon and pushing hard and pulling back, and swallowing to get our devices in place.
We started using the 12 French and then quickly started using either the 16 Lightning, which is Penumbra's device, or Argon now has a CLEANER Vac 18 French, which is also nice. I think both are great. I do another, again, not to hear the plug devices, but the rotational cleaner that is used, I think probably designed for dialysis work is also quite helpful. The portal vein is big, it's expansile, and it's hard to get your wall-to-wall suction. These are stiff devices. Putting the rotational cleaner through either of those suction devices, either the CLEANER Vac or the Lightning is quite helpful in mobilizing clot off the wall and just getting everything sucked through.
Device-wise, that's what I go to. It sounds scary to put an 18 French sheath through the liver. I certainly was nervous about it. I swallow a balloon to do it, but it goes really smoothly. I've been using the GORE DrySeal, but there's others as well. It's 30 centimeters. For most patients, it gets you just in. If you're nervous, you can leave a safety wire through. There's options there. Those are the device I'm using.
Not going into nuts and bolts. There's a lot of turns in the portal system and these devices are big, so they work best. The reps will tell you that they work best without a wire through them. What I usually do is for first pass, I'll get a wire out the splenic. That'll draw the device off to one wall of the portal. I'll advance the suction devices far into the spine because I need to or can. If I need to swallow a balloon, I will, and then make one pass just pulling back over the wire. Oftentimes. If not, maybe I'll pull the wire and then reintroduce it because you don't want to lose access.
Then do the same thing down the SMV because that will get you on the opposite wall. Then once, assuming flow is starting to get better, I'll pull the wire and do it again. That's usually what I do. It's also, I'll add, super helpful to have the reps in the room with you. Both of those companies, certainly New York City, have excellent-- they're just so helpful, not only with their devices, but these little tricks and tips that they've seen. I'm a big believer in having them in the room with you, because it just can, it can really make the difference.
[Dr. Christopher Beck]
As far as the actual procedure, so you're going to go in, make a couple passes with the thrombectomy. If you are going to use the cleaner, you use it as troubleshooting afterwards and you just run it through with like, you got some residual clot or something.
[Dr. Benjamin May]
I should have mentioned, no, I'm nesting. The cleaner will go right through both of those devices and you can run them simultaneous. That's actually what our presentation at SIR is going to be about, simultaneous rotational and suction thrombectomy for portal vein thrombus, a newer technique, but they work so great together. You don't have to. You can run one and then switch it out. The rotational cleaner is long, it goes right through, it's whipping up that clot and you can be sucking at the same time and just clears out a lot of clot. It is really great.
[Dr. Christopher Beck]
You mentioned whenever you were sticking, if you're accessing the portal system under IVUS, you do central sticks for this. Is that by design in that you're thinking ahead, I'm going to do a slightly more central stick rather than my traditional patient, because you're trying to just eliminate one more vector that's going to, you're going to be fighting against when you're doing your bigger devices?
[Dr. Benjamin May]
It's both. It's fortuitous. If we have time, I'll talk about my ICE technique because it tends to bring you pretty central within the portal, but it's the most reliable way I know to use the ICE catheter. I'll tell you the way I used it, I'm used to just getting into the right hepatic vein, making a pass. Then I was using the ICE to find my needle, find my target. I'm a little posterior, I'm a little anterior. Okay, I'm unlined. That's a tough way to do it because you're going back and forth between where your needle is and where your target is.
A different way is to work backwards. Shout out to my co-fellow and good friend, Normad. He's the one who changed my practice and he's been on the podcast. I got to give him credit for this. At least for me is I put the IVUS in and I just start getting my orientation and finding a view in which I have a portal target and a hepatic vein in the same screenshot. Then wherever that vein is, very often, it's middle to right, which is different than my normal practice. Then I'm just taking my catheter in the hepatic vein and puffing saline and figuring out where that vein is.
Then it's very obvious once you're in that vein, you'll see this rush of little micro bubbles on your catheter and then putting in a wire and dragging my sheath right to that spot. Now I'm on one view, I can watch my needle come straight out of the sheath, straight down towards the portal. Then you just figure, I'm in a little too anterior, I'm a little posterior, but everything's in one plane.
That technique very often will bring you relatively central near the crotch of the right and left portals, which is maybe not ideal. I think for this it is because yes, those devices don't want to make a lot of turns, but it works out fine. It really does. As long as your uncovered portion is where you want it to be, whether you're doing traditional TIPS or not, being a little central I found is not an issue.
(5) Practical Tips for Successful Portal Vein Thrombectomy
[Dr. Christopher Beck]
Whenever you're doing your thrombectomy, is there anything that you just learned along the way, like little hiccups along the way where you're like, now I'm going to do it like this or how many paths? Anything that you could give someone who's just getting into this practice some just helpful boots on-the-ground tips, have a more successful procedure?
[Dr. Benjamin May]
I've been trying to drop my little pearls along the way. Having a colleague that you can double scrub with, I think is really helpful. Our fellows and residents are excellent. It takes six hands. You got somebody on the ICE catheter, someone on the back table. It's a lot. Having someone, and then you build your expertise together. I mentioned having reps in the room. I think if you're using their devices, it's really helpful until you become very facile. Swallowing balloons is something I didn't do an awful lot of, but I started to with these devices, just getting them to make these turns.
Yes, it's tempting. Oh, I want to go 12 French or smaller and smaller Nick and the IJ, et cetera. The cases take a lot longer. Yes, we were successful with it, but once we'd bumped it up to 16 or 18 French, that's when you turn on the device, turn it off. You just have this huge clot in the device filter, and you do the next puff and flows rushing through. It's a little bit more of a pain to navigate those devices, but not impossible by any means. They track out a lot farther than you might think.
I was always surprised that even though I might advance it to the mid SMV, and I knew there was clot in all those little tributaries, once you clear out that main SMV and up, and if you have outflow through TIPS in particular, next thing all that little stuff is gone. Either it came out in one long strand, I'm not sure, or it passed and went to the lungs the same way we do with the dialysis work, but tiny little clots. I've never seen a patient have any change in their O2 sat or any signs of PE. We scan them after, we don't see any PE for the most part in the bottom of the-- in the lung bases or anything like that. It works really well. I wouldn't worry about that little clot. It will clear.
The other thing I'll say is sometimes we're treating patients closer to three, four weeks. There are long cases where you use, we leave a little clot along the wall, leave a little clot in some of the tributaries, decide to come back or scan them. It's gone. It's amazing how once you reestablish flow, you keep these patients on blood thinners. It's incredible how well the blood thinners work. It's just when the clot's so occlusive, so expansile, the drug has no way to work. Once you establish good flow, inflow and outflow, then, and keeping patients on AC, it's really a game changer.
[Dr. Christopher Beck]
Is it always, I don't want to say necessary, but best practice, if you're going to establish inflow, you always treat to the splenic and then always treat to the SMV, assuming there's clot in both?
[Dr. Benjamin May]
Where you start, I'm not sure that matters.
[Dr. Christopher Beck]
Oh, no, I meant just treating both of them, not necessarily where you start.
[Dr. Benjamin May]
Yes, I like to, for sure. If you leave splenic clot, might it clear? Yes. It's still typically expansile and occlusive there. The spleen is going to drain through short gastrics and you may end up with gastric varices and all the things we see patients with like pancreas cancer and those varices. Those are real. Then the IMV often drains there. It's nice to have the IMV open and certainly SMV is number one. If I had to choose, you're obviously going to open up the SMV. That's where we see the highest morbidity. It's not hard to get out the splenic. I think certainly makes for a prettier picture afterwards, but I do believe it's the right thing to do.
[Dr. Christopher Beck]
Any role for IVUS in this procedure?
[Dr. Benjamin May]
IVUS, not the side-firing to guide, but IVUS within the portal.
[Dr. Christopher Beck]
Yes, exactly.
[Dr. Benjamin May]
It's funny that you bring that up because all the venous guys that treat legs, they love just to run-- yes, we should run IVUS through that. I'm like, why? We know exactly what's going on. You might be able to tell, I'm not a big extra step guy. I'm really trying to eliminate what I can to keep these cases under, three, four hours. Sometimes they go longer. You could, and see the clot along the wall, but I think that a good venogram is going to show you everything you need. Again, it's the flow is your friend. The flow is the most important thing, if you're good inflow, good outflow.
I'm telling you, we've gone back. Then the group that published out of Beth Israel and JVIR 2023, blinking on the author's name, but easy to find, their primary patency was something like 70, but primary assisted was, high 80s, and then secondary close to 100. I think was 100. The point being it's nice thing about leaving the TIPS behind is it's very easy to go back. It's a low-risk procedure. You can clean out a little more clot if it's been a long time. Patients, you got to get them off the table, totally reasonable. That's one really nice thing about leaving a TIPS behind.
[Dr. Christopher Beck]
The 25% of the patients that you're not leaving TIPS behind, what does the venogram look like afterwards? Which patients can you get away with it with not having a TIPS?
[Dr. Benjamin May]
As long as they have cirrhosis, obviously we're talking about non-cirrhotics, and they have intrahepatic portals open, you can do it. I've thankfully haven't had a transplant patient who was just clotted all the way up into the intrahepatic portals. If I had a case like that, I'd be working real hard to get a smaller catheter, balloon catheter, Fogarty, that clawed out trying to get outflow through the liver. Our transplant surgeons really want to avoid TIPS after transplant. Patients just do poorly. The venograms look great. It's been a minority of patients. Again, it's people really with clot isolated to the main portal, but not intrahepatic portals.
I will say, interestingly, that little portal, the track you made and pulled the sheath afterwards, you can still see flow going through that. There's still a little portal venous shunt going right to the liver. I was surprised because the teaching is even an uncovered stent goes down really fast and et cetera. I'm not leaving any stent, I'm just pulling everything. She had a little bit of flow, but it didn't reflect on her LFTs at all. If anything, it may have helped a little bit. Granted, my experience isn't huge. This is particularly not leaving a TIPS behind, but the ones that we haven't were by choice. There's a little bit of selection bias, but they did great. The venograms look great.
[Dr. Christopher Beck]
I just want to talk about potential other options. We talked about anticoagulation, the role of IR. You'll see in the literature that surgery is an option. Is this a real option for any patients?
[Dr. Benjamin May]
I suppose anything's an option. Our surgeons have not done surgical thrombectomy. In the era I've been there, they're not too excited for that. Even when they've operated on a bleeding patient, they're not too excited about doing a surgical thrombectomy. It's hard for me to talk about. I haven't seen it. I like talking IR when I go to a conference or whatnot, and I haven't heard anybody really talk about surgical thrombectomy for these cases. Shoot me an email if I'm wrong.
(6) Exploring Intervention Through PVT Scenarios
[Dr. Christopher Beck]
I just felt obligated to mention it, but I felt the same way as you. Some specific scenarios that I wanted to run through. These specific scenarios are straw men. I don't know how much they actually come up in clinical practice, but I'll just run them by you. You have a patient, non-cirrhotic, and you have asymptomatic portal vein thrombosis. Is there anything still intervening on that patient?
[Dr. Benjamin May]
First question I want to know is how much of the portal mesenteric system is involved. They're truly asymptomatic. It's hard to imagine that they're really involving, all the way down to the small tributaries. Let's say they have main portal, let's say a little bit in the SMV. Maybe, probably if they're asymptomatic, they've got some early collateralization forming. The reason why cirrhotics often don't present acutely is they have collaterals already. They already have splenorenal shunts or other varices that are draining the system, or rectal varices.
A patient truly just has expansile clot and no symptoms. Really, the way I think about it, we're trying to prevent chronic sequelae of portal thrombus. It would be a discussion, but I think the data is pretty clear. They have about a 65% chance of not clearing that clot. They might get lucky and just form a nice big splenorenal shunt that doesn't bleed, that provides enough outflow where it doesn't really cause symptoms. We don't really know which of those people with chronic PVT are going to be symptomatic.
They're going to be tough to transplant if they do need a transplant. They might develop portal biliopathy. They might develop symptoms later. They might develop varices that are hard to treat. We see plenty of patients like that. It's really a discussion. A lot of our patients are young, and they've been very eager to get intervened upon, especially, frankly, to show them a picture of what a normal portal looks like and what their portal looks like, and they get pretty scared.
[Dr. Christopher Beck]
That brings me to the whole second set of scenarios I was going to ask about. Whenever you're thinking about intervening, and whenever you're looking at that original CT, can you talk through about how you're trying to think about your procedure, whether they need one or don't need one, based off either the location of clot or the occlusiveness of the clot? Basically what I'm trying to, without going through every scenario, so if you have a patient with a couple side branch thrombus in the portal vein, that's a different scenario than a patient who has totally occluded portal vein thrombosis. I was also thinking if you could walk through what does partial portal vein thrombosis look like?
[Dr. Benjamin May]
If it's partial, a lot of times it's forming along one of the walls of the main portal. A lot of times it's creeping along the wall into the SMV or maybe in the splenic. You have to ask yourself at that point, the age is important. There may be nothing to do because it's just sub-acute or chronic. Sub-acute we can get to, but in any case, you're looking for other things like, there's symptoms, but are there signs of inflammation? Is the bowel looking inflamed? Is there a little bit of ascites even if it's not symptomatic ascites? How much collateral? One thing that can help you determine the age of the clot other than their standard things is are there early collaterals forming?
Is there early cavernous transformation forming? Things like that. Those are all things in my mind. Of course, there's just anatomy of the liver. Some people have these pancake livers that are not great for TIPS, but I still-- I'm an optimist. I'm like, I could figure it out. I'll get a TIPS in, but it might be a challenge. I'm looking at that. Obviously, if the hepatic veins are open, I've yet to do a DIPS for this procedure, but if the hepatic veins are-- for most now, we have another indication, which would be Budd-Chiari. That's another big problem. Those are things I'm certainly looking for. Yes, whether the bowel looks inflamed is a big one.
[Dr. Christopher Beck]
What about for the scenarios where you have, maybe it's not clot in the portal vein, but it's right portal or left portal's thrombosed? Anything to do with it?
[Dr. Benjamin May]
Just intrahepatic. No, I leave those alone. AC, of course, but patients do well with unilateral portal vein thrombosis. We do PVE and the contralateral liver hypertrophies and becomes a normal volume and function. You wonder why they formed it. You send them every patient that presents like this, non-cirrhotic, should get a hypercoagulable workup. Many of them do have, whether it's JAK2 or factor V Leiden, which may require lifelong AC, but just intrahepatics, we leave alone, even non-inclusive. Of course, the surgeons talk about, they have a classification, I'm blanking on the name, Yardle, I think, which is what percentage of the main portal is involved.
Is it greater than 50%? Is it extending into the splenic? I'm not a big classification guy. It's like, is there a tiny little channel that's probably going to go down? Oh, and are they symptomatic or not? Thankfully, I work with really great and experienced hepatologists and surgeons. We bring these cases to tumor board and we get consensus on, it's very nice to work in the environment I do where you don't feel like we're on an island. Nonetheless, we should have our opinions and we should have a frank discussion with the patients and know our data, but I don't make these decisions in isolation.
(7) Post-Operative Management After Portal Vein Intervention
[Dr. Christopher Beck]
Post-care for these patients. Let's say it's a patient who you've treated with thrombectomy, got a good result, laid down the TIPS, just talking about immediate post-op care. I'm assuming all these are, I assume, but I haven't asked, these are under anesthesia.
[Dr. Benjamin May]
Yes, we use general anesthesia. If I hold a heparin, it's for a couple of hours, we turn it right back on once we establish access. Continue AC throughout. I'm not a believer in holding AC, even for 12 hours or something, if we don't have to. It's incredible. I love these cases. They're fun. You get instant gratification to see a large clot out on the flow and et cetera. Patients, they feel great the next morning. Of course, sometimes people have pain, et cetera. I'm not saying I'm trying to oversell it, but they were pretty miserable. They were not able to eat well.
They just know something's not right. The next morning, you see this big food trailer eating pancakes. Yes, they have a bandage on their neck and they go, oh yes, it's a little sore here, but they're so thankful. Even just the color on their face. It's pretty incredible, honestly, how much of a turnaround a lot of these patients experience. That's another super rewarding part of this procedure in particular. We're keeping a close eye on them for a day or two, make sure they don't have bleeding. They're going to get established care with our hepatology group.
We don't routinely put them on HE prophylaxis, lactulose or whatnot, but it's obviously want to keep a close eye and make sure they're not having any of the symptoms so we can get ahead of it. We're getting an ultrasound in a week. It's standard TIPS care. Then seeing them every three months just to make sure that TIPS is open. There are cases I mentioned that we got out a lot of clot, but we want to do a little more work. It was just getting late or whatever. Maybe we scan them and see clot or maybe we just do another venogram. I think in some of these papers, they're routinely doing a TIPS venogram on every one of these patients.
I don't find that to be necessary. A few of them, we've gone back. As I mentioned, if you put the TIPS stent in first, it will gel off some clot and it's always just sitting there. You'll see our ultrasound, just sitting there at the edge. Sometimes you want to go back and balloon that and work on that a little bit. Those are the things we've done. So far, I think we're up to 12 now since we started with the large suction devices with 100% technical success rate and no bleeding complications. We've had to go in, I don't want to quote the-- I have to look at the data again, but we've had to go in and maybe a quarter of them to just touch things up, maybe extend the stent, maybe do a little more a thrombectomy. Really good outcomes.
(8) Reviewing the Relevant Literature & Current Practices in PVT
[Dr. Christopher Beck]
You mentioned earlier that you might want to go in a little bit to the Beth Israel paper, their published results, or have we already covered it?
[Dr. Benjamin May]
We covered most of it. I don't want to speak for them. Their paper goes back to 2014. Some of their techniques, sometimes they left the stent, sometimes they didn't, sometimes they did thrombolysis, it was a heterogeneous group. It was just a breath of fresh air when I read that paper, because I'm like, I had the exact same experience. It was in the same timeline.
We were working in isolation and trying different things and realizing, oh no, leaving the TIPS and doing mechanical thrombectomy really works and we can do it safely. It's nice when we were working in parallel, but isolation to know like, oh, this has been replicated in real time. My experiences have been exactly the same as theirs, at least from what I could tell from their paper.
[Dr. Christopher Beck]
As far as lysis in this procedure, is there any role for leaving a lysis catheter down and dripping these patients or not in the ones that you–
[Dr. Christopher Beck]
It sounds like some people are. First of all, I've had good results with that. I dropped the TPA. Secondly, I use very little TPA. It's a very powerful medication. We're making holes in the liver or at least through the liver. Again, the one case with the subcapsular hematoma, I'm like, jeez, I know I didn't get outside the capsule in that case. I still had a bleeding complication, but that was with TPA. I'm not a big believer in it. I think there's a nice paper that talks about step-wise. Putting in the TIPS doing some mechanical, coming back, that makes more sense to me.
I think this is echoed. I don't do a lot of venous thrombectomy, but I think a lot of my colleagues are getting away from TPA even for that. If you can remove the majority of bulky clot and keep people on AC, the body does the rest. It's just when you have poor flow. I'm sure there's a role, and one day maybe I'll need it, but if I were doing it, I'd stage it and wait a good week, is just because I've been burned. Even a small bleed that you can manage, now you want to stop AC and all this other stuff. It's like, I get nervous, I don't know.
(9) Closing Remark on the field of Interventional Radiology
[Dr. Christopher Beck]
Ben, open mic, final thoughts, anything I didn't mention or something you wanted to touch on?
[Dr. Benjamin May]
No, just thanks for having me. I'd say one cool thing about our field is that, and people have been around a lot longer than me. I'll tell you, none of the stuff we get trained on is stuff we ended up doing. That's because it hasn't really been invented yet. We have such a cool opportunity to be innovative with new devices and push the envelope. This is certainly an area that I think we can make a big difference for patients. I'd encourage people just to think along those lines.
When you see a disease that you think you can have a serious impact on and combine techniques from other things, and it's worth doing, it's worth doing in the right way, by involving your colleagues, getting a consensus, having whatever, all the backup you need. That's the most rewarding part of our job. I truly believe that, certainly is for me. I'd encourage people to keep pushing our field forward in that way.
Podcast Contributors
Dr. Benjamin May
Dr. Benjamin May is an interventional radiologist at Weill Cornell Medicine in New York City, New York.
Dr. Christopher Beck
Dr. Chris Beck is a practicing interventional radiologist with Regional Radiology Group in New Orleans.
Cite This Podcast
BackTable, LLC (Producer). (2025, May 6). Ep. 541 – Treatment of Acute Portal Vein Thrombosis [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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