Venous thromboembolism

A Clinician’s Experience in Developing a Practice With the AngioVac System

Cath Lab Digest talks with John M. Moriarty, MD, Assistant Professor of Radiology, Director of Cardiology-Interventional Radiology Innovation, University of California-Los Angeles (UCLA) Health, Los Angeles, California.

Cath Lab Digest talks with John M. Moriarty, MD, Assistant Professor of Radiology, Director of Cardiology-Interventional Radiology Innovation, University of California-Los Angeles (UCLA) Health, Los Angeles, California.

Disclosure: John M. Moriarty, MD, reports no conflicts of interest regarding the content herein.

Dr. Moriarty can be contacted at jmoriarty@mednet.ucla.edu.

Can you tell us about your background and practice?

I am an interventional radiologist, and also a member of the UCLA Department of Radiology. I did a medical residency, a radiology residency, and then did fellowships in both cardiovascular and interventional radiology. I have spent most of my time working in the venous and arterial systems, doing embolization, stenting or angioplasty. The majority of my focus now is on clot removal, deep vein thrombosis, and pulmonary embolism.  

Why use the AngioVac System as compared to other treatment options?

When people have clots within the veins of the legs or within the ileo-femoral vein, inferior vena cava (IVC), superior vena cava (SVC) and right atrium (RA), these clots can be removed in a few different ways. One option is to try and dissolve them with medication, second is to attempt to break them up using catheter directed therapy, and a third option is surgery. Recently, an additional method has been developed, and that is to directly remove the clots by using the AngioVac System (Figure 1). Typically, the AngioVac System is used when clot needs to be removed quickly, because it is endangering the patient, or in those cases presenting with massive clot, that it may not respond to any of the other treatments. We have used the AngioVac in a few different settings. We have removed clots from the right atrium and clots from the ileo-femoral veins, IVC and SVC.  We have also removed clots in patients with congenital heart disease who have had surgeries that alter the blood flow through the lungs and are at risk of venous clots going through to the brain. We have used the AngioVac in many different areas and generally always obtained good results. 

What are some of the criteria for selecting patients to treat with the AngioVac System?

Some patients have no other options and that is where AngioVac is really excellent. For example, a patient that just recently underwent spine surgery was referred to me from another hospital. She had developed a clot in her leg while recovering, and then had an IVC filter placed. This immediately clotted off and her legs and belly swelled up hugely. She couldn’t be given blood thinners because of her spine surgery, and couldn’t rehab because of her leg swelling. A physician in her home hospital gave me a call as we had helped each other with patients in the past, and I thought AngioVac would be a good option to rapidly remove the clot. We transferred her over, used the AngioVac System, and the whole procedure took about 2 hours. The patient did very well, all clot was removed, and we sent her home from the hospital after 48 hours, walking. So as you can see, in cases where there are no other options, the AngioVac is very good. 

However, we are now seeing that even in some cases where there are other options, the AngioVac may be the preferred option, because it allows you to get the clot out very quickly, it allows you to do it all in one procedure, and it allows you to reestablish flow. Other options might also work, but not work as well. We are lucky here at UCLA to have a multidisciplinary team, so that patients are presented with different points of view. If patients can have other treatments, we describe the different options to them and talk it through, so that they are part of the whole process. We would recommend maybe one or two of the discussed therapies to patients as appropriate treatment. In some patients, we might recommend more strongly that they get lysis, for example, or that they have the AngioVac procedure performed. The opposite of this scenario is for patients who have no other options, and in that case, we talk to them about AngioVac, telling them that this procedure is something that didn’t exist a few years ago, and that we are lucky that we have it now, because the AngioVac allows us to offer a type of treatment that otherwise we wouldn’t have been able to consider. 

Can you tell us more about the treatment program you are involved in at UCLA?

Yes, I have been really lucky to work with a great staff of physicians, nurses, technologists and administrative staff in building up a very active DVT and Filter program here with UCLA Interventional Radiology. We work hand in hand with hematologists, pulmonologists, cardiac surgeons and cardiologists so that a dedicated group does most of the clot work, whether that is in the legs, in the abdomen, has to do with filters, or is in the lungs. We have a dedicated filter clinic and a dedicated clots clinic, where patients from all around the area and some from further away, come because they know they are going to see clinicians who treat clot almost exclusively. My colleagues and I see patients and give them all the different options available in our program. We have built very good relationships with our hematology and intensive care colleagues, who have all bought into this program. We are able to offer patients every potential to help them with their problem. Over time, the success of our program has also hopefully built up trust that we will help with patients our colleagues aren’t otherwise able to help. We take on the cases that are difficult, and also offer 24/7/365 referral. Physicians can get in touch with us any time, even just for an opinion as to whether a patient might need a procedure or not.

Do you get outside referrals?

We do get a good amount of outside referrals. We have a regional center within the southwest, and so patients come to us from southern California, but also from northern California, and from the neighboring states of Arizona and Nevada. A few international patients have come as well. Last week, I had a patient who came from Thailand for a particular treatment with us. I feel lucky that we are developing the program as a team, because we want to be able to offer patients everything. Patients seem to appreciate that.

How are you reaching outside physicians?

At the moment, we have been doing it via word of mouth. It is something we could be better at doing. We have been talking to people individually and going to their individual practices. We have recently been doing more dedicated work with advertising and will continue to do so. We are also presenting our results at different meetings, so that people can see that the results from the AngioVac System are not just all talk and pretty pictures. Our results demonstrate that if our colleagues consider this procedure, they may be able to achieve improved outcomes for their patients as well.

Are you typically getting referrals from primary care physicians or do patients usually come through a specialist?

We have some primary care groups that refer directly to us, but mostly it is from specialty groups. As the primary care physicians get comfortable with how we can help them, they are referring more to us. I think that is going to be a big growth area for us.

What is the referral pattern within the hospital?

Some people will come to us as outpatients, and they are typically patients with clots in their legs. Some with massive thromboemboli are gravely ill and need to be seen emergently. 

What is the message that seems to resonate with your colleagues?

Our referring physicians want the overall package, meaning their patients are seen quickly, are adequately and appropriately medically managed, a procedure is performed if necessary, that procedure is done safely and effectively, and the patient is returned to them quickly. What we try to do is provide that entire process. When we present our results, we show that the rapid removal of clot with AngioVac is of real benefit. People want to get on with the rest of their lives. They have big, swollen legs and are unable to walk, unable to play with their grandkids, unable to golf, or go about their jobs — anything that is their reason for living. If they are able to get back to their way of life, by breaking up and getting rid of their clots as quickly as possible, that is of real benefit to them and their families.

What are the specialties that you are normally interacting with when your patients come to you?

Hematology, emergency physicians, CT surgeons, and pulmonologists. We also work closely with cardiology. These are all primarily hospital-based specialties, at the moment, and we need to move clot therapy into the primary care physician world, so we are trying to get more and more involved with PCPs.

If a patient visits their primary care physician, it probably wouldn’t be in an acute state. Is the AngioVac System of benefit in less acute patients?

I think it is, because as our imaging gets better, we are realizing that for a large portion of patients who have “heavy legs”, it is the result of chronic clots in their system. They may not realize that the reason they are having difficulties with their walking and/or balance as they get older is because of clots within their system. So as our imaging improves and we find more of these clots, we are realizing that removal of them, perhaps with the AngioVac system, will benefit patients who may not previously have been considered to have clot problems. 

Can you tell us about your involvement with the RAPID registry?

I am the national principal investigator for the RAPID registry (Registry of AngioVac Procedures In Detail), which is going to be looking at usage of AngioVac throughout the country. We want to gather additional data concerning procedural outcomes and patient benefits. We have had a lot of interest across the country — so far, in 31 states. People want to be part of the registry for several reasons: they want to see that their patients are doing as well as other patients receiving similar treatment throughout the rest of the country; the registry is a research-driven, data-driven process, and will be part of making sure that in the future we have collected experience and evidence to support this technology, and teams want to be part of that; and finally, the registry is a way to communicate with other physicians, nurses, and technologists who are working in this field. This will be a group effort, so there will be resources and backup from someone who may not be anywhere near you geographically, but by going through this registry, you can talk to someone who may be able to help you.

What role might a registry have in expanding AngioVac System practice?

The registry is going to be a learning mechanism for everyone. Certainly as I have seen how other people have worked and learned from them, I have found that we are able to incorporate that knowledge and experience into our practice and therefore, build our practice.

What do you see happening in the future?

I see AngioVac use growing in three ways. The first we have already talked about, which is primary care. We hope to have better contacts with primary care in order to get early referral of patients and perhaps use the AngioVac System to remove clots in these patients as well as help to prevent problems in the future. The second thing that I see happening in the future is treatment of problems related to inferior vena cava (IVC) filters. IVC filters are very common and very effective at preventing clots from going to the lungs, but they do cause problems. In centers like ours where we have a filter clinic, we see a lot of referrals of patients who have had troublesome filters for sometimes a very short time and sometimes a very long time, and who have developed problems with either the filter being in the wrong position or with acute thrombosis of the IVC to the level of the filter. I think that will be an area in which AngioVac will be able to help, by clearing up clot to make sure we can remove the filter safely. Finally, while pulmonary embolism is not currently part of the AngioVac indication, future clinical investigations may establish a role for the product in that area as well.

Are patients who have problems with clots typically repeat patients?

One of the benefits of AngioVac over certain other types of procedures is that it can turn someone who might be a repeat patient into someone who is a one-time patient. Sometimes with AngioVac we have seen such good results from being able to remove so much of the clot that the patient can then go on anticoagulation and doesn’t have to come back for another procedure. It is one of the benefits of this device, that we may be able to perform one procedure and prevent the situation from potentially developing into a chronic condition. n

Caution: Federal law (USA) restricts this device to sale by or on the order of a physician. Please refer to directions for use provided with the device for indications for use, Contraindications, Warnings and Precautions.

CANNULA INDICATION FOR USE: The AngioVac Cannula is indicated as a venous drainage cannula during extracorporeal bypass for up to 6 hours. The cannula is also indicated for removal of soft, fresh thrombi or emboli during extracorporeal bypass for up to 6 hours.

CIRCUIT INDICATION FOR USE: The AngioVac Extracorporeal bypass circuit is intended for use in procedures requiring extracorporeal circulatory support for periods up to six hours.

Reference

  1. Gurley JC, interview. Percutaneous removal of large, fresh thrombus in central venous disease with the AngioVac System. Cath Lab Digest. 2014 June; 22(6). Available online at http://www.cathlabdigest.com/articles/Percutaneous-Removal-Large-Fresh-Thrombus-Central-Venous-Disease-AngioVac-System. Accessed November 19, 2014.