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BackTable / VI / Article
The Fundamentals of Managing Venous Stent Rethrombosis
Rajat Mohanka • Apr 11, 2024 • 31 hits
Venous stents are frequently implanted when adequate venous patency is not achieved following angioplasty, often in cases of iliofemoral thrombosis or post-thrombotic syndrome resulting from chronic iliofemoral thrombosis. However, these stents commonly experience rethrombosis due to various factors, including incorrect placement, undersizing, and insufficient coverage of the diseased vein. Inadequate inflow through the stent can ultimately lead to thrombosis.
Vascular surgeon Dr. Steven Abramowitz and interventional radiologist Dr. Angelo Marino team up to explain how to manage the distinct etiologies of venous stent rethrombosis. This article includes excerpts from the BackTable Podcast. You can listen to the full episode below.
The BackTable Brief
• Placement errors of venous stents significantly contribute to the risk of rethrombosis.
• It is important to assess inflow and clear segment venous disease before placing a stent.
• For patients with post-thrombotic syndrome, it can be necessary to stent below the inguinal ligament.
• In order to use devices such as the RevCore to open occluded venous stents, it is important to utilize sharp recanalization techniques to effectively cross stents.
• Treatment approaches should be tailored based on the acute or chronic presentation of symptoms.
• Utilize duplex ultrasound as the primary post-operative imaging evaluation, with CT venography reserved for instances where ultrasound may be limited by patient body habitus.
• Initiate anticoagulation, such as Lovenox, post-operatively for its anti-inflammatory benefits. Follow this with a transition to DOACs for long-term management.
• Placing patients on antiplatelet agents like Plavix, in addition to anticoagulants, can further support stent openness.
Table of Contents
(1) Addressing the Etiologies of Venous Stent Rethrombosis
(2) Operative Decision-Making for Treating Venous Stent Thrombosis
(3) Optimizing Post-Procedural Care in Venous Stent Thrombosis
Addressing the Etiologies of Venous Stent Rethrombosis
Venous stent rethrombosis primarily arises from improper placement of the stent's distal end within the affected vein. Achieving optimal inflow, which is crucial for preventing rethrombosis, requires meticulous pre-placement assessment and necessitates that segmental disease is addressed. Failure to fully clear residual clots from the diseased vein before stenting heightens the risk of rethrombosis. Furthermore, post-thrombotic scarring or vessel narrowing, coupled with the anatomical tendency for the vessel to deform around a rigid stent, amplifies this risk. Another critical consideration during stenting is the potential need to extend the stent below the inguinal ligament, a technique fraught with challenges due to anatomical and flow-related complexities.
[Dr. Ally Baheti]
Now, both of you are at tertiary care centers, academic centers. In your case, Dr. Marino, I'm guessing you see a lot of cases of venous stent thrombosis from the community. Can you just run me through the different scenarios that you see which cause venous stent thrombosis? Dr. Marino, we can start with you.
[Dr. Angelo Marino]
Yeah, sure. One of the most common causes that we find is when the distal landing zone is not the correct spot where the stent is placed. Then the other is if the stent is undersized or poor overlap or protruding more into the IVC than it should be. Those are the main things that we find. A lot of these patients have had multiple procedures over the years, and they've had relining of the stents and sometimes poor inflow.
[Dr. Ally Baheti]
Dr. Abramowitz, anything to add there about how you see these venous stent re-thrombosis cases present?
[Dr. Steven Abramowitz]
Yeah, I can't echo that enough. Predominantly, I really think back to [unintelligible 00:05:16] and a lot of his data and work that he's done looking at inflow disease and an assessment of inflow prior to placing a deep venous stent. When we're dealing with post-thrombotic patients or those patients who have had a venous stent placed in a setting of an acute DVT, one of the big things that we see as a predictor or a causal reason for re-thrombosis has to do with inflow and really clearing out that landing zone or a segment disease from the common femoral profunda or femoral vein confluence.
[Dr. Ally Baheti]
How often do you find yourself stenting below the inguinal ligament for a post-thrombotic syndrome patient? Dr. Abramowitz, we can start with you this time.
[Dr. Steven Abramowitz]
Pretty frequently. I think that one of the big things that we see in terms of a leading because of stent failure is when people are reticent to crossing inguinal ligament and that stent ends immediately proximal to the ligament itself. You end up with a stent almost facing downwards in the vein prior to that external iliac vein, reflecting anteriorly to come up under the inguinal ligament.
When you have post-thrombotic scarring there or narrowing of the vessel in conjunction with the anatomic predisposition for the vessel to deform around the stiffer stent, that is a prime reason for rethrombosis. Then when you have poor inflow from [unintelligible 00:06:31] disease, [unintelligible 00:06:32] or residual thrombus burden that's become really calcinated and scarred in at the femoral profunda confluence, that is a low flow state that also predisposes patients to re-thrombotic events.
[Dr. Ally Baheti]
Anything to add there, Dr. Marino?
[Dr. Angelo Marino]
I 100% agree with everything he just said. It's really important to get good inflow and land the stent so that you're in a normal vein or a normal-ish vein, as normal as it can get post-thrombectomy or intervention.
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Operative Decision-Making for Treating Venous Stent Thrombosis
Managing venous stent thrombosis entails various approaches, highlighting the need for customized interventions tailored to individual patient needs. Dr. Marino emphasizes the pivotal initial step of crossing the stent with a guidewire in order to utilize the RevCore device to open the venous stent, often employing sharp recanalization tools like the transjugular liver biopsy cannula. In some cases, administering general anesthesia ensures patient comfort during these intricate procedures.
Dr. Abramowitz introduces a nuanced perspective on patient presentation and treatment selection, advocating for a patient-specific approach that may involve initial lysis or mechanical thrombectomy depending on the thrombosis's acute or chronic nature. When patients manifest acute symptom changes, thrombolytic or thrombectomy solutions are typically pursued. Staging the procedure may be necessary to ensure optimal outcomes, indicating a shift towards more personalized and meticulous management of venous stent thrombosis.
[Dr. Ally Baheti]
Since both of you are treating a lot of venous stent thrombosis, could you walk me through your algorithm for how you approach a venous stent thrombosis? Is RevCore your first go-to device now or do you have some other troubleshooting tips and tricks you do before you get there? Dr. Marino, let's start with you.
[Dr. Angelo Marino]
The hardest part of these cases usually is crossing the stent. Once you establish that, then I use RevCore 100% in these cases. In terms of crossing the stent, there are many different things that we use. I end up most often having to do sharp recanalization, and sometimes I'll have to use the TIPS set, or more often than not, because it's probably cheaper, the transjugular liver biopsy cannula to get me through the stent, because when you get that dip in the pelvis from the external to the iliac vein, a lot of times the sharp recan will end up wanting to poke out of the stent.
[Dr. Ally Baheti]
Then do you do all of your cases under GA if they're going to be recan cases?
[Dr. Angelo Marino]
For these cases, I do just because they can be a little uncomfortable with the balloons you use, and the sharp recan sometimes you perforate out. They take time prepping all the different sites and getting the accesses and crossing the occluded stents can take some time. I personally do them all under GA.
[Dr. Ally Baheti]
You guys alluded to this earlier, but just to clarify, when you're doing your popliteal access, it seems like the patients are supine and so you're doing them all with a frog leg. Is that right?
[Dr. Steven Abramowitz]
Yeah. I think the interesting thing for me in hearing about different anesthesia techniques and different access options is it's made me rethink about how the patient's presenting. For a lot of these patients, if they present with an acute change in their symptoms, that's some sort of indication to me that they may have had chronic instant thrombotic disease and then suddenly had an acute event. That's the type of patient where I may lyse them first or some other mechanical thrombectomy solution or rheolytic therapy to really evaluate what's happening within the stent from a chronic standpoint prior to engaging in the use of something like RevCore.
For those patients who are presenting with a wound and they walk into your office and they're like, "I've had this stent for 20 years and I've never looked at it again." Most likely that's a different algorithm. What's been surprising to me is I used to from the start say, "This is just going to be a honker of a day. Dive in with general and block out four to six hours." I've become much more open to the idea of the recanalization or the assessment of the stent being potentially a separate intervention or a separate procedure from the RevCore or from the use of another tool to treat the chronic instant disease.
[Dr. Ally Baheti]
How do you stage that procedure? Because once you've crossed your stent, if you leave it alone, won't it just re-thrombose?
[Dr. Steven Abramowitz]
Absolutely. It's definitely not a definitive intervention. I think back to a couple of patients who had had endovascular iliocaval reconstructions where an IVC filter was jailed. They were left with bilateral stents. There was some concern or confusion based on the preoperative imaging as to whether or not both stents were patent, one was occluded, other was open, whether there was disease in the IVC stent. Those are very different procedures in my mind from a workflow standpoint and potential reconstruction options, and particularly, those patients who may have an IVC filter above an occluded iliofemoral stent.
I just share this because I don't want everybody to think that it has to be a one session go. You do have the opportunity, at least from the vascular surgery perspective, of doing that diagnostic angiogram before you jump into your bypass another day. In this setting, it would be doing that venogram, having the proof of concept that you can cross, that you can balloon a pathway, and coming back another day after having a different conversation with the patient about the chronicity or complexity of the reconstruction likelihood for patency in the future.
Optimizing Post-Procedural Care in Venous Stent Thrombosis
Dr. Abramowitz outlines a proactive follow-up regimen, advocating for initial duplex imaging within one month post-procedure, followed by structured imaging at three, six, and twelve months, then transitioning to biannual surveillance. This approach is complemented by a steadfast commitment to antiplatelet therapy and lifelong anticoagulation to prevent reocclusion. Dr. Marino echoes this strategy, emphasizing the significance of initiating anticoagulation with Lovenox, followed by a transition to a direct oral anticoagulant (DOAC) alongside antiplatelet therapy. Maintaining vigilant monitoring and providing ongoing medical management are crucial to optimizing long-term stent patency and patient outcomes.
[Dr. Ally Baheti]
Got it. Then what's your follow up for these patients after you've crossed and opened their occlusion? When do you see them in clinic, and when do you do repeat imaging? Dr. Abramowitz, let's start with you.
[Dr. Steven Abramowitz]
That's a great question. I tend to be very aggressive with these patients, because once they occlude their stents, I find that I don't want to have to go through all the work I did again. Typically, I will bring the patient back for a duplex at one month. I keep them on an antiplatelet agent and lifelong anticoagulation, and then I will reimage them at three months, six months and a year, and then keep them on a bi-yearly or a biannual surveillance plan. Usually one of the imaging studies is a duplex, and I will be very aggressive, and the other will be either an MR or a CT.
[Dr. Ally Baheti]
Dr. Marino, what's your follow up algorithm?
[Dr. Angelo Marino]
I do pretty much almost the exact same thing. If there's any questions, sometimes, depending on the patient’s body habitus. If we can't get a good view of the stent cell, I'll get a CT venogram, but most often, it's just ultrasound. Similarly, 1, 6, 12 months. Sometimes I'll do three months if I'm really worried about the patient.
[Dr. Ally Baheti]
Very cool. Do you have an anticoagulant of choice that you like for these patients? Dr. Marino?
[Dr. Angelo Marino]
A lot of these patients have been in anticoagulation for a long time. For stents, I typically try and do Lovenox for at least a month in the beginning and then switch to a DOAC with antiplatelet therapy like Plavix and then lifelong aspirin, if necessary. The patients who don't like giving themselves injections can be a problem, but usually they go on the DOAC. I try and do Lovenox first, at least for a few weeks.
[Dr. Ally Baheti]
That seems to be a prevalent theory amongst folks who do a lot of venous reconstruction, the month at least of Lovenox to help with anti-inflammatory effects and keeping the stents open. Dr. Abramowitz, what's your anticoagulation algorithm?
[Dr. Steven Abramowitz]
Very similar. We do have issues sometimes with the insurance approval for a short term enoxaparin or Lovenox bridge, and in those cases, I'll take anything over or for nothing, but generally two weeks to four weeks of Lovenox if I can get it, and then transitioning to a DOAC.
Podcast Contributors
Dr. Steven Abramowitz
Dr. Steven Abramowitz is a practicing vascular surgeon at MedStar Georgetown University Hospital in Washington, D.C.
Dr. Angelo Marino
Dr. Angelo Marino is an interventional radiologist with Yale Medicine in Connecticut.
Dr. Aparna Baheti
Dr. Aparna Baheti is a practicing Interventional Radiologist in Tacoma, Washington.
Cite This Podcast
BackTable, LLC (Producer). (2023, October 30). Ep. 380 – Managing Venous Stent Rethrombosis with the RevCore Device [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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