Interventional Treatment of Deep Vein Thrombosis (DVT) at St. Charles Hospital

Can you tell us about your hospital?

Wayne K. Nelson, MD, FACS, RPVI: St. Charles Medical Center in Bend, Oregon is a regional hospital that provides care to central, eastern, and southern Oregon. There are several satellite hospitals as well. The hospital itself is about 280 beds and we have a state-of-the-art hybrid operating room where we can perform both open and angiographic procedures. Bend Memorial Clinic’s vascular surgery department is the vascular service that serves the hospital system and all of the patients in the state east of the Cascade Mountains. 

What types of patients do you see coming in with a deep vein thrombosis (DVT)?

Jason P. Jundt, MD: We see a wide range: young patients all the way up to very old patients. You can’t exclude people just on the basis of age. We see a range of demographics as well, including young females, those patients struggling with different forms of cancer, and other clinical presentations. DVT does not discriminate. 

Why offer DVT patients an intervention?

Dr. Jundt: You can make a difference and improve quickly with durable results by intervening on a DVT patient, improving their quality of life dramatically. Patients would otherwise have to deal with a swollen leg and ulcers for the rest of their life, and potentially face the challenges of post thrombotic syndrome, which is an irreversible condition that permanently damages valve function. We are able to dramatically alter that course and it has become very attractive work as a result.

Dr. Nelson: We have an opportunity to make a meaningful difference, acutely, with relief of pain and swelling, restoration to ambulation, and occasionally, limb preservation. Aggressive treatment of DVT using devices can also minimize the risk of long-term complications.

What are your current treatment methods for DVT?

Dr. Nelson: Historically for DVT we have used catheter-based drip systems with tPA. The AngioJet ZelanteDVT thrombectomy catheter (Boston Scientific) is a recent addition to our device arsenal. The ZelanteDVT catheter is a larger mechanical thrombectomy device. It goes through an 8 French sheath and is able to remove a significant amount of clot, making it possible to treat patients in a single setting instead of multiple overnight stays in the ICU. With the use of this device, the patient goes to the hybrid operating room and is treated in one setting. We are able to clear the vast majority of the thrombus, if not all, and it eliminates the extended hospitalization that our patients used to require. 

Our other current options include catheter-directed thrombolytic (CDT) therapy to deliver tPA over the course of 12 or 24 hours, or sometimes longer. Some of these CDT catheters come with the addition of ultrasound propagation of the tPA.

Dr. Jundt: With the use of the ZelanteDVT catheter, I have seen a dramatic change from having to keep my patients in the intensive care unit (ICU) for several nights on a catheter-directed thrombolysis (CDT) drip, then watching them on the ward for a day or so, and then finally, sending them home. Now I can usually do the procedure in a single setting, transfer the patient to a lower level of care, and discharge most patients within 24 hours.

Is the ZelanteDVT only for use in acute patients? 

Dr. Nelson: That is how we use it. The ZelanteDVT catheter can be used to provide an infusion of clot-busting drugs followed by thrombectomy, providing an increased ability to clear acute thrombus. 

How do you decide whether a DVT patient receives medication or an intervention?

Dr. Jundt: I use ultrasound to analyze the lower extremity venous system and I will typically get a computed tomography (CT) venogram if I am considering intervention. I look for any other pathology in the abdomen, but also check to see if they have any signs of May-Thurner syndrome, cancer or other potential issues that could have caused the DVT. If the patient doesn’t have any contraindications and there is clot that extends up into the iliacs, then I am usually very aggressive and will do an intervention and utilize mechanical thrombectomy to remove the thrombus. 

How often are you seeing acute vs chronic DVT?

Dr. Jundt: The chronic patients will show up at our clinic, typically months after the initial onset. Chronic patients require a different approach. Many have had inferior vena cava (IVC) filters placed previously and have veins that are either slightly recanalized or not recanalized at all. These patients get a CT venogram to evaluate their outflow and then we try to recanalize those veins. I usually am able to do that with just a Glidewire (Terumo) and a NaviCross catheter (Terumo). I will remove the IVC filters and may stent* through the previously occluded section, generally with very good success. People who have had swollen legs for a long time have experienced dramatic, durable results following this type of intervention. For acute patients, not all of them receive an intervention, but it is a significant portion (90%). Acute patients will come in from one of our referral centers (one of the surrounding hospitals that Dr. Nelson mentioned) or will come directly to our emergency room. Our volume varies. Some weeks we see several and then some weeks we see very few, but on average, we probably treat 4-5 acute patients per month. I do the same workup with acute patients, so they first get a CT venogram. In our practice, we are now able to treat DVT aggressively with interventional options. We are hoping to intervene earlier and that eventually this will lead to seeing fewer chronic patients.

Dr. Nelson: The whole idea of intervening up front is so you don’t end up having to treat chronic DVT patients. You always want to restore the patient, if possible, to their native situation with open thrombus-free veins and no stent. If we can do this, I think everybody would agree it is preferable. Now that we are being more aggressive with acute DVTs, hopefully we will be seeing less chronic DVT.

Can you talk more about how intervening with acute DVT might lead to a reduction in the number of chronic DVT patients?

Dr. Jundt: I just saw a patient today in follow-up where the initial treatment had been very aggressive. This young lady had May-Thurner syndrome and had come in with an extensive DVT, extending from her knee all the way up into her IVC. I used the ZelanteDVT catheter to remove the clot and stented her left iliac vein. Today was her 6-month follow-up and she is back to normal. Her DVT was the culmination of months of symptoms of venous outflow obstruction and caused symptoms including venous claudication. Seeing treatment success with these patients is really what makes you want to continue aggressively treating these types of conditions. My hope is, over time, we will see a resulting drop in our chronic patient population. 

Before the use of devices for intervention in DVT, what was the standard of care?

Dr. Jundt: It was common to put someone on chronic anticoagulation, so they would get enoxaparin (Lovenox) and warfarin. Then, over the past several years, the novel anticoagulants like apixaban (Eliquis) and rivaroxaban (Xarelto) came into play, and are being commonly prescribed. Typically, you would put someone on anticoagulation with a compression stocking and then have them go home. More than one-third of patients with DVT will develop post thrombotic syndrome, and 5% to 10% of patients will develop severe post thrombotic syndrome, which may manifest as venous ulceration.1 Post thrombotic syndrome is what we are trying to avoid, because caring for ulcers and venous disease is such a burden to the patient and a burden to society. 

What are the long-term symptoms of post thrombotic syndrome?

Dr. Jundt: Leg pain, leg swelling, ulcerations, and the development of wounds. Many of these symptoms are so disabling to patients that they can no longer work. There is no cure for post thrombotic syndrome; therefore, it is best to treat these patients early to remove the thrombus, which provides the best chance to avoid the development of post thrombotic syndrome. 

How long has your program to intervene in DVT been active?

Dr. Nelson: It’s not a program per se, but an increasing awareness of the problem. We became more active in reaching out to all of the primary care providers and hospitalist teams about the need to treat some DVTs to prevent acute and long-term problems. We encourage them to call us about DVT patients so that we can offer treatment to them, provide a quick removal of thrombus, and prevent chronic problems. 

Dr. Jundt: We also reached out to the emergency room physicians in order to increase their awareness and let them know that there are new options for the treatment of DVT. As a result of providing this education, our reach has blossomed to the point where we are treating DVT and now pulmonary emboli** as well. We are fairly aggressively treating patients that come in with systemic symptoms of what were DVTs and are now pulmonary emboli, with very good results.

What have been some of the barriers you have experienced in getting patients to come to you?

Dr. Nelson: Awareness, mainly. Once the primary care providers see what we can do, they start referring their DVT patients. The traditional algorithm for DVT, if it is not limb-threatening, is anticoagulation. Through education, we have been able to change that perception and educate physicians about the interventional alternatives to treat DVT.

How did you present this information to your community physicians?

Dr. Nelson: We are the vascular surgery service for the area and we have a close-knit medical community. Essentially all of the contact with other physicians is one-on-one. For us, education about DVT is involves getting the message out there to the emergency rooms, hospitalist teams, and the primary care physicians that for their DVT patients, especially iliofemoral DVTs or pulmonary emboli that are causing heart strain or other systemic symptoms, we have a better solution. We encouraged them to call us so we can talk to the patients, offer appropriate treatment options for them, and hopefully make their life better in the years to come. Once these providers started seeing the results of what we can accomplish, it snowballed and we have gained a lot of momentum based on impressive results.

Are there any ER protocols in place?

Dr. Nelson: The ER will call us for any DVT that manifests with pain and swelling, and for any iliofemoral DVT. We haven’t formalized a protocol yet, although it would be a good idea. 

Are you aware of any economic impact using an interventional approach for treating DVT?

Dr. Nelson: Any time you can avoid an ICU stay or an extended hospitalization, you are going to be saving the hospital, insurance company, and the patient, money. 

Dr. Jundt: There are studies showing that chronic venous hypertension from post thrombotic syndrome is a very expensive condition to treat. We have also found that the use of the ZelanteDVT catheter can shorten the patient’s hospital stay by up to two days. Based on my experience with the use of the ZelanteDVT catheter thus far, people are in the hospital for less than 24 hours. In the past, using a catheter-directed thrombolytic, patients would stay in the ICU for 24+ hours with the drip going, return to the hybrid room for another angiogram to see if things have cleared, maybe another catheter is used or more tPA is injected, and then the patient goes back to the ICU again or is discharged if nothing more can be done. Now we have the opportunity to get everything done in one trip to the hybrid operating room. After removing the thrombus, we send the patient to the ward rather than the ICU, and then send them home within 24 hours. In most cases, it is a significant cost savings to the patient and to the hospital.

How has hospital administration supported your efforts?

Dr. Nelson: They have been very supportive in getting us the devices we need to effectively treat our patients. In addition, two years ago, they built a phenomenal hybrid room for us to work in, where we can take care of patients in a way that is on par with anywhere in the country. 

What is your DVT patient volume?

Dr. Jundt: I probably see at least 50 patients per month for some type of venous issue like DVT. It may be chronic venous hypertension, chronic venous ulcerations, or DVT. Perhaps 10-15% of the patients I see each month require an intervention. The others are treated medically. I am not as aggressive when patients have a tibial clot, for example, but anything above the knees, I am more aggressive. I tend to do an intervention if there is extensive clot burden above the knees. 

Dr. Nelson: Of the patients we see with an iliofemoral DVT, who have acute pain and swelling, and no contraindications to the procedure, 100% will undergo some type of intervention to remove the clot burden and restore normal venous flow through the pelvis. After I explain the risks, benefits, and alternatives to intervention, I don’t think I have ever had a patient turn the therapy down.

How long is an intervention with the ZelanteDVT?

Dr. Jundt: It doesn’t usually take longer than an hour to treat an acute DVT. 

Dr. Nelson: The ZelanteDVT catheter has a mode to deliver a clot busting medication directly into the thrombus. Part of the problem with leaving in an old-fashioned lytic catheter (CDT) is that the drug-clot interaction is only at the surface, but the ZelanteDVT catheter has what is called the Power Pulse mode, which will actually spray the drug into the acute clot. Dr. Jundt and I will always use the Power Pulse mode first in order to disperse drug throughout the clot. After a 20- to 30-minute dwell time, we remove the remaining clot using thrombectomy mode. I would say most of the procedures are completed in under an hour. 

How quickly does the patient improve once you intervene?

Dr. Jundt: When removing the DVT using the AngioJet ZelanteDVT catheter, patients often see symptom relief within hours of treatment. Their pain begins to subside and swelling begins to disappear. We had a lady come in with phlegmasia cerulean dolens, a complete blockage of the venous outflow from the leg. Her leg was completely blue and painful with decreased pulses. Forty-five minutes later, after performing an intervention with the AngioJet ZelanteDVT catheter, her leg was normal color, normal size, and her pain had resolved. It can be quite dramatic.

Dr. Nelson: I will add, she had a limb-threatening condition. She would have lost her leg otherwise.

Any final thoughts? 

Dr. Nelson: Using mechanical thrombectomy to treat DVT can make a dramatic difference in people’s lives. It adds to the number of procedures we offer that we feel very positive about doing and advocating for, because we always try to be our patients’ advocates. This is one procedure we feel strongly about, because it can make a big difference. 

Dr. Jundt: For acute DVT patients, the sooner, the better, so we fit them in at any time. For the chronic patients, it is great to be able to get them in on a lab day, and usually the procedure doesn’t take very long and makes a huge difference. That’s what we are looking for — the ability to make a difference in these people’s lives. Maybe they don’t realize it, but the impact is actually most significant 5-10 years down the road when these patients are able to avoid experiencing post thrombotic syndrome. 

This article is published with support from Boston Scientific.

Disclosure: Dr. Jason Jundt and Dr. Wayne Nelson report no conflicts of interest regarding the content herein. 

Dr. Jundt can be contacted at jjundt@bmctotalcare.com.

Dr. Nelson can be contacted at wnelson@bmctotalcare.com.

Reference

1. Kahn SR. How I treat postthrombotic syndrome. Blood. 2009 Nov 19; 114(21): 4624-4631. doi: 10.1182/blood-2009-07-199174.

Questions for the OR and Cardiovascular Services Director at St. Charles Medical Center

Wendell Witt, RN, CCRN, Interim Director Operating Room and Cardiovascular Services Operations, Bend and Redmond Campus 

St. Charles Health System, Bend, Oregon

Can you describe the hybrid operating room in use at St. Charles Medical Center?

The room was built as a full-scale hybrid suite that is large enough to also do teaching. It has a Philips Allura Xper FD20 with FlexMove for fluoroscopy, along with integrated intravascular ultrasound (IVUS). We also have a Philips CX50 ultrasound system, and a Maquet table with two tabletops: one is fluoroscopy friendly, and the other is a surgical tabletop. You can take one top off and put the other top on; they are interchangeable. Both Dr. Jundt and Dr. Nelson really like this table. Starting in September, the lab will be also used for transcatheter aortic valve replacement, with our first implant planned for September 29th.

How do DVT patients come to your lab?

We see them primarily emergently. They may come to the hospital with a pulmonary embolism or with obvious outflow occlusions on the venous side, whether from May-Thurner syndrome or some type of insult to the vessel. We also get scheduled cases, where people have leg pain or swelling, and are referred to Drs. Jundt and Nelson through their office. In the lab, we have two x-ray technologists, one will scrub and one will support the table, and one nurse in the room. All cases are currently done with anesthesia whether they are monitored anesthesia cases or general anesthesia. It depends on how sick the patients actually are, and what the need is. If the physician feels like they are going to do an open procedure, then we have general anesthesia ready for the case.

How are the non-emergent DVT cases scheduled?

We will schedule them any time, and obviously, emergent cases are done any time. We use multiple devices to take care of these patients. We have several different kinds of catheters to remove clot and currently, our most successful catheter is the Boston Scientific AngioJet ZelanteDVT catheter. We have seen very dramatic results with this catheter, to the point where you can see change occur as we are moving the patient off the procedure table onto their gurney for transport. Patients will come in with a swollen, disfigured, and discolored leg. We will go in, remove the clot, and see dramatic results. With our pulmonary embolism patients, once we have gotten them through the emergency treatment of the pulmonary embolism itself, we will bring those folks back in, take the DVT out, and try to find out why they have DVT in the first place, if there is no obvious reason. 

Why do you think the ZelanteCVT catheter has been successful?

The AngioJet ZelanteDVT catheter has a window that sucks in clot on the side of the catheter instead of through the end like most of the other catheters. It’s not that these catheters don’t have their place, but the ZelanteDVT is made for work in larger venous vessels with large burdens of clot. The flow up the catheter past the large window creates a vacuum effect at the tip, pulling in and removing the thrombus. We have had some very, very good results with the ZelanteDVT. Better than I’ve seen in 15 years in the cath lab.

How difficult is the setup?

It is very straightforward. If you know how to set up an AngioJet, it is the same. You can interchange any catheter that is compatible with the system. You set up one catheter and you are set up for all of them. A nice option with the AngioJet is the variety of catheters available to treat many different vessel sizes and thrombus. 

Does your call team handle the acute DVT cases during off hours?

Yes. Our call team is made up of two radiologic technologists and two nurses, 24/365, and covers 5 service lines: electrophysiology, interventional cardiology, interventional radiology, interventional neurology, and interventional vascular.

All staff rotates through all 5 of those service lines — nobody is designated for one area or the other. Especially when on call, the team has to go to every service line. We have 19 people in the lab that are physically doing procedures. We have 24.5 staff total.

Where do patients recover?

If they have anesthesia, they will go to the post-anesthesia care unit (PACU). If it is an emergency case, we don’t always have anesthesia available, because there are only so many anesthesia providers. In that situation, the patient can go to our procedural care unit. Sometimes patients will go home the same day. They may come in emergently, but they could leave that very same day.

For venous access hemostasis, are you holding pressure?

Yes, there are no closure devices for venous access currently on the market. The length of time for the hold depends on the status of the anticoagulation. We will use heparin, so we can reverse it with protamine if needed, but we try not to pull any sheaths unless the activated clotting time (ACT) is less than 170. It takes a vein anywhere from 10 to 20 minutes of manual pressure to get adequate hemostasis.

What have you observed regarding the growth of interventional treatment for DVT in your center?

It has been about 2 years now that we have had a very robust vascular treatment program here at St. Charles. The hybrid room went live on April 7, 2014. More and more people are learning about what we can do. Last year, we did 3784 cases for all 5 service lines, and Dr. Jundt and Dr. Nelson added 556 cases to our volume set last year. 

What have been some of the challenges?

The integration in our endovascular treatment and open procedures has been challenging. We will do hybrid procedures where Dr. Jundt or Nelson will do an atherectomy, and then stent, or clear out clot, or clear out plaque with one of our atherectomy devices. Operating room (OR) staff wasn’t accustomed to these procedures, and probably one of our biggest hurdles has been to get all staff to integrate with the knowledge that each person has a valid place in the procedure and assist as a team. Our vascular program here is very progressive. Dr. Nelson is very dynamic and is always challenging the envelope of what we can do. Keeping the staff that is performing procedures educated is a challenge, because we are moving so fast. Procedure preparation and patient recovery are also challenging, because you are talking about different areas of the hospital that really have to integrate together. Currently, we have a management structure that communicates and works together well. The cath lab is in perioperative services and so we are all under a single director. If we can’t reach a final solution on our own, our director will help guide us through.

What do you think about the future of DVT intervention at your center?

With Dr. Nelson and Dr. Jundt, we are only going to grow and push the envelope of what vascular care can do. Both of them are highly involved with education of themselves and of the staff. We are trying our best to keep up with them by having solid competencies for the staff, and educating and training to those competencies.

Disclosure: Wendell Witt reports no conflicts of interest regarding the content herein.

Wendell Witt can be contacted at wrwitt@stcharleshealthcare.org.