New Procedure Helps Remove Deep Vein Blood Clots
A new non-surgical treatment for the removal of blood clots appears to be safer, faster, and more effective than traditional therapies, according to a report from the Society of Interventional Radiology meeting.
Removing blood clots reduces the risk for pulmonary embolism and disability among patients with deep vein thrombosis (DVT).
DVT involves a blood clot in a vein, usually in the lower leg or thigh. In some cases, the clot can break off and move up into the blood vessels of the lungs, triggering a potentially fatal condition called pulmonary embolism.
DVTs gained media prominence as so-called "economy class syndrome" after a number of passengers on long-haul flights developed the dangerous condition.
But the new clot-removal method, called the "rapid lysis" technique, could offer fresh hope to patients.
"There's a tremendous benefit to patients as a result of this technique," says study lead author Dr. Mark J. Garcia, an interventional radiologist in the department of radiology at Christiana Care Health System.
DVT clots develop in situations where circulation slows down, causing blood to pool. Although it can strike at any age, the risk is highest among men and women over the age of 60.
Patients being treated for cancer and those experiencing surgery, injury, or prolonged immobility are also at an elevated risk, as are women in the early stages of pregnancy and patients who have varicose veins or who are overweight.
Standard treatment typically involves injectable or pill-form blood thinners, also known as anticoagulants, which can prevent the formation of new clots and halt the growth of clots already formed.
Such treatment does not, however, help to dissolve an existing clot. While most clots eventually dissolve on their own, large clots provoking severe symptoms may not. In such instances, clots can be dissolved by means of a thrombolytic medication delivered by catheter.
This approach is not without its drawbacks, however.
According to the researchers, the clot-busting procedure can take as much as two to four days to work, significantly raising the risk for sudden bleeding. Physicians usually use the medication to address blood clots as a last resort.
But without quick and complete clot removal, permanent vein damage can occur over time, resulting in permanent disability.
This condition - known as post-thrombotic syndrome (PST) - is characterized by chronic leg pain and swelling, along with skin thickening and severe ulceration. In extreme cases, gangrene and amputation can ensue.
In fact, half of the patients treated with blood thinners alone for a leg DVT eventually go on to develop PST, the researchers say.
Dr. Garcia and his team tested the potential of the new "rapid lysis" technique to safely and quickly dissolve clots.
They focused on 102 men and women, averaging 47 years of age, who were all seeking care for extensive, large-volume DVTs. In most of these cases, the DVT ran the entire length of the leg - from ankle to pelvis, or even beyond.
Radiologists first used imaging equipment to direct a catheter through the affected leg to the point of the clot. Using a high-powered spray device, a diluted, clot-dissolving medication was then delivered into and throughout the clot, effectively breaking it up.
The remnants of the clot were then sucked up by a saline jet that essentially vacuumed the clot into the catheter, removing it from the bloodstream as the catheter was pulled down and out of the affected leg.
After a year tracking patient progress, Dr. Garcia and his colleagues found that the rapid lysis treatment achieved full clot removal and blood flow restoration in over half of patients.
In terms of PST, surveys up to one year after treatment revealed that just under 70 percent of the patients said they had no leg pain or swelling, and nearly 80 percent said they experienced no heat or burning discomfort in the affected limb.
Dr. Garcia concludes that the new technique is useful in treating the largest and most difficult clots safely and quickly, representing a significant advancement in DVT therapy.
Dr. Samuel Goldhaber, a professor of medicine at Harvard University School of Medicine, says that in his opinion, "This treatment would address only a small niche of patients.
"It could help those who need more than an anticoagulant but who have had recent surgery or have a preexisting bleeding risk of some kind, and so are not eligible for traditional clot-busting therapy," he says.
"This type of catheter - one that basically sucks up the clot - is one of several more aggressive options for treating DVT now under development," adds Dr. Goldhaber. "The example they looked at seems promising, and hopefully this will lead to larger trials that will test these catheters more thoroughly.
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Deep Vein Thrombosis Facts
There are a variety of factors that contribute to the development of deep vein thrombosis:
- surgery, particularly surgery of the hip or leg, or abdominal surgery
- a long period of bed rest or sitting for a long time (e.g., on an airplane or in a car)
- birth control pills or hormones taken for symptoms of menopause
- certain diseases and conditions, such as varicose veins, chronic atrial fibrillation, or inflammatory bowel disease
- lupus erythematosus, a disease of the immune system
- heart failure
- heart attack
- arterial disease
- spinal cord injury and resulting paralysis
- previous blood clot (thrombosis)
- intensive care treatment involving placement of a central venous catheter
- persons with cancer receiving chemotherapy
Deep vein thrombosis occurs without symptoms about 50 percent of the time. When symptoms do occur, they may include:
- swelling in the leg
- red, discolored, or white skin
- a cord in a leg vein that can be felt
- rapid heart beat (tachycardia)
- slight fever
- warm skin
- more visible surface veins
- dull ache, tightness, tenderness or pain in the leg (these symptoms may only occur while walking or standing)
The symptoms of deep vein thrombosis may resemble other medical conditions or problems. Always consult your physician for a diagnosis.
In addition to a complete medical history and physical examination, diagnostic procedures for deep vein thrombosis may include the following:
duplex ultrasound - involves using high frequency sound waves to look at the speed of blood flow, and the veins. Occasionally a blood clot may be visualized by ultrasound. This procedure is noninvasive (the skin is not broken) and involves placing ultrasound gel on the affected area and then moving a handheld device across it. A picture of the blood flow is displayed on a monitor. Duplex ultrasound is the most commonly performed diagnostic test for DVT.
magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body, is particularly effective in diagnosing deep vein thrombosis in the pelvis.
venogram - uses x-rays and intravenous (IV) contrast dye to visualize the veins. Contrast dye causes the blood vessels to appear opaque on the x-ray image, allowing the physician to visualize the blood vessels being evaluated.
For more information consult MUSC MED-U-NURSE or your physician.