Why is Thrombectomy not used more often to treat DVT?

From Medscape Medical News
Thrombectomy Can Improve DVT, VTE Outcomes

Alice Goodman



December 1, 2009 (New York, New York) — Major changes in the most recent version of the American College of Chest Physicians (ACCP) guidelines could lead to improved outcomes for patients with extensive deep vein thrombosis (DVT). All physicians need to do is follow them, but widespread adoption of these changes will take time, experts announced here at the 36th Annual VEITH Symposium.

"The most remarkable change in the guidelines is that venous thrombectomy is now recommended for extensive DVT [i.e., iliofemoral DVT]. Before 2008, anticoagulation was the standard of care. Currently, with these new guidelines, most physicians just leave that type of clot where it is and use anticoagulation. We have a long way to go, although there is increasing recognition of the benefits of clot removal. Even some academic centers are not using thrombectomy," said Anthony J. Comerota, MD, director of the Jobst Vascular Center in Toledo, Ohio, speaking at the symposium.

Thrombectomy was added to the ACCP guidelines for the treatment of extensive DVT on the basis of data from a randomized controlled trial showing that thrombectomy with arterio-venous fistula was superior to anticoagulation. Arterio-venous fistula added to thrombectomy increases the blood flow velocity after the clot is removed, reducing the likelihood of rethrombosis.

In addition, 2 randomized trials from Europe showed that catheter-directed thrombolysis of iliofemoral DVT improved patency, reflux, and length of hospital stay compared with anticoagulation. Now clot removal with either thrombectomy or catheter-based thrombolysis should be the new standard of care, Dr. Comerota told listeners. The guidelines suggest pharmacomechanical prophylaxis instead of catheter-directed thrombolysis alone to shorten treatment time.

"There is a 'culture of anticoagulation' among physicians, even for patients with the most extensive DVT. Unfortunately, physicians accept leaving large burdens of clot in the venous system, which obstructs venous return and causes venous hypertension and severe postthrombotic morbidity. Quality of life can be preserved if the venous system remains patent, and many patients will continued to have normal venous valve function after successful clot removal. I believe that this should be the goal of therapy in patients with extensive DVT," Dr. Comerota said.

At present, catheter-directed thrombolysis with or without mechanical techniques may be used for extensive [iliofemoral] DVT," Dr. Comerota explained. "This practice change needs to be recognized and implemented by physicians in the community," he added.

Professional Education Needed

Thrombolysis is generally reserved for extensive clot, such as iliofemoral thrombosis. In 2008, ACCP published new evidence-based clinical guidelines for the treatment of venous thromboembolic disease, which, for the first time, suggested the use of pharmacomechanical thrombolysis in the treatment of certain cases of acute DVT, such as iliofemoral thrombosis. It is important that we, as vascular surgeons, continue to educate the numerous physicians who treat DVT about the appropriate and recently updated guidelines to ensure that patients are getting adequate therapy," said Frank R. Arko, MD, chief of endovascular surgery and associate professor at University of Texas Southwestern Medical Center in Dallas.


More on the same topic

http://vasculardiseasemanagement.com/article/8083


http://www.healthtree.com/articles/deep-vein-thrombosis/treatment/surgery/

http://bmctoday.net/evtoday/2007/10/article.asp?f=EVT1007_04.php

I actually had thrombolysis performed on my leg, as well as in my lungs, as the clot had already produced massive PE.

So, as evidently the only person in this conversation who has received this treatment for DVT, I'll tell you what I know as to why the procedure was done, and how I am nearly two years after the whole issue.

In my case, the reason it was used was because I was going to lose my life without it. Well, in the case of the PE's. But the DVT in my leg was also extensive enough to necessitate thrombolysis there too. I was told I had nearly no blood flowing in my leg, period. All of the veins were considered totally occluded from my pelvis to my ankle. No pulse at all could be found in my ankle or leg. The risk of having thrombolysis is big because it causes bleeding, though I think if doctors were well trained in administering them it could be used more frequently, but basically the doctors don't want to risk putting a patient into a life threatening situation when it's not necessary. The bleeding risk for DVT treatment is beyond just the risk of possible internal bleeding, but a catheter has to be placed into a vein and taken out again, in an area which has just been treated with medication to avoid clotting - so you should be able to imagine the mess that can cause in terms of blood loss, considering if a large vein were cut open in normal circumstances it would be easy enough to bleed to death. There was as much time spent on me trying to get the bleeding from the removed catheter under control as there was in the actual surgeries. When I was presented with the treatment options, my doctors were clear that the treatments were very risky, but in my case absolutely necessary. Even at that, I didn't jump right into it and I gave it a lot of thought. So I think to people who haven't had it, it sounds a bit like a miracle cure, which it kind of is, but it's a miracle that comes with an awful lot of risk to it. Unfortunately, doctors also have to be concerned about recommending especially risky treatments because our society is so litigious and it's easier for a patient to win a case of malpractice for something a doctor did rather than something a doctor didn't do. i.e. - 'This doctor gave my husband thrombolysis to help treat his DVT, but now he's dead from bleeding, and he wouldn't have died with the regular treatment.'

Okay, I have also read some of the studies which go on about how perfectly well the patients who receive thrombolysis are. I would caution that studies can often be skewed, depending on the desired conclusion. My experience has not been that I have, or ever will, completely recover from my DVT. I do believe my leg is in very good shape considering everything, and it continues to improve even as I get two years in recovery. But I have chronic venous insufficiency due to valve damage, which by the way, thrombolysis and other types of clot removal cause as well. So you can't think that if you'd only had X treatment you'd be perfectly well. Sticking and winding tubes through your veins isn't exactly good for your valves, and they pretty much get destroyed in the process. So a doctor is presented with the dilemma - do I proceed with a treatment which could put the patient into further danger if I don't do it just right, besides knowing that it's still going to cause all the same damage inside the vein, or do I stick with the regular protocol for treatment and play it safe?

Also, for some of you who were considering the time frame and such, it is true thrombolytics only work on newer clots. The tech who did my venous doppler, who I've gotten to know well since my event, told me that they can tell in the doppler whether a clot is new enough for the thrombolytics to have a siginificant effect, that the appearance changes as they age. So in some of your cases, though you had extensive clots, it's possible thrombolytics were never considered because the doctors could see that the clots were too old to have enough of an effect to justify the treatment risk.

Also, every person heals a little differently, and this is something else a doctor can't really know in the beginning. I was told that I'm extremely fortunate that I have grown extensive peripheral veins, that some people don't. My doctor commended me because he said that usually when these have grown well it's evidence that a patient has been doing as they should and using the limb as much as possible - that exercise actually kind of jump starts the body to make alternate routes for blood flow to make sure those muscles are properly oxygenated since they are being used. However, as I said, even with many things in my favor and having received this treatment, I still have issues to work around in regard to my leg health. I still even have rather extensive clotting up in my upper thigh and pelvic area. So again, while I'm very thankful I had the treatment, and I probably would be minus one leg if I didn't have it, there are still long-term issues. I just think it might be a bit of an over-simplification to think 'I didn't get this and I should have then I'd be all better.' In any case, all any of us can do is make the best of the situation which we have, because what possibly could have been done in the past is kind of a moot point, we just must focus on doing all we can now to regain as much of our health and former lifestyle as possible.

Also, for those of you who aren't too far into recovery, please don't get discouraged if you're not feeling as well as you hoped. Things do continue to get better very slowly and over a pretty long period of time. I'm so much better than I was this time last year that I can't even believe it. Likely most of you will see the same thing in your cases as well.

Best wishes to all...
Sarah