Deep Vein Thrombosis – Interventional Radiology Clot Busting and Treatments of DVT by MISS

The deep veins that lie near the center of the leg do most of the work of the venous system. Nearly all (85 percent) of the circulating blood is returned to the heart through these veins. DVT, the formation of a clot (or thrombus) in any one of these veins can be a very serious problem.

Typically, the clot comes on suddenly and without warning. If not treated, DVT can block the blood supply to the legs and cause tissue death or gangrene that requires the removal (amputation) of all or part of the leg. DVT can also lead to valve damage in the vein and a chronic condition, called venous stasis disease or varicose veins, that is difficult to treat. Some patients with DVT may be treated with mechanical or pharmacological thrombectomy using minimally invasive techniques.

Interventional Radiology Clot Busting Treatment can prevent permanent leg damage from deep vein thrombosis (DVT). DVT is the formation of a blood clot, known as a thrombus, in the deep leg vein. It is a very serious condition that can cause permanent damage to the leg, known as post-thrombotic syndrome, or a life-threatening pulmonary embolism. In the United States alone, 600,000 new cases are diagnosed each year. One in every 100 people who develop DVT dies. Recently, it has been referred to as “Economy Class Syndrome” due to the occurrence after sitting on long flights.

The deep veins that lie near the center of the leg are surrounded by powerful muscles that contract and force deoxygenated blood back to the lungs and heart. One-way valves prevent the back-flow of blood between the contractions. Blood is squeezed up the leg against gravity and the valves prevent it from flowing back to our feet. When the circulation of the blood slows down due to illness, injury, or inactivity, blood can accumulate or “pool” which provides an ideal setting for clot formation. DVT is typically brought on by two major factors:

  1. Sluggish Blood Flow: caused by sitting still or lying down for long periods of time, such as on long airplane rides or during prolonged bed rest after surgery or injury.
  2. Clotting Factors: Substances that regulate the formation of clots may increase in concentration after an operation or injury, as well as during pregnancy, consumption of birth control pills, severe infection (which causes an increase in red blood cells), certain types of cancer, or injury to the vein itself.

It is not unusual for the blood to clot from time to time, but most clots go unnoticed. They are small, cause no symptoms, are dissolved over time by the body, and need no treatment. There are times, however, when the body cannot dissolve the clot on its own, or the clot causes health problems that must be treated. Clots that interfere with the normal flow of blood or may affect organs that are vital to your health and survival must be diagnosed and treated early to avoid serious illness or death.


Risk Factors

  • Previous DVT or family history of DVT
  • Immobility, such as bed rest or sitting for long periods of time
  • Recent surgery
  • Age above 40
  • Hormone therapy or oral contraceptives
  • Pregnancy or post-partum
  • Previous or current cancer
  • Limb trauma and/or orthopedic procedures
  • Coagulation abnormalities
  • Obesity


  • Discoloration of the legs
  • Calf or leg pain or tenderness
  • Swelling of the leg or lower limb
  • Warm skin
  • Surface veins become more visible
  • Leg fatigue

Post-thrombotic Syndrome
Post-thrombotic syndrome is an under-recognized but relatively common sequela, or aftereffect, of having DVT treated with blood thinners (anticoagulation)
alone, because the clot remains in the leg. Contrary to popular belief, anticoagulants do not actively dissolve the clot; they just prevent new clots from forming. The body will eventually dissolve a clot, but often the vein becomes damaged in the meantime. A significant proportion of these patients develop permanent irreversible damage in the affected leg veins and their valves, resulting in abnormal pooling of blood in the leg, chronic leg pain, fatigue, swelling, and, in extreme cases, severe skin ulcers. While this use to be considered an unusual, long-term sequela, it actually occurs frequently, in as many as 60-70 percent of people, and can develop within two months of developing DVT. There is increasing evidence that clot removal via interventional catheter-directed thrombolysis in selected cases of DVT can improve quality of life and prevent the debilitating sequela of post-thrombotic syndrome.
Pulmonary Embolism

Left untreated, a deep vein thrombosis (DVT) can break off and travel in the circulation, getting trapped in the lung, where it blocks the oxygen supply, causing heart failure. This is known as a pulmonary embolism, which can be fatal. With early treatment, people with DVT can reduce their chances of developing a life threatening pulmonary embolism to less than one percent. Blood thinners like heparin and coumadin are effective in preventing further clotting and can prevent a pulmonary embolism from occurring.

  • It is estimated that each year more than 600,000 patients suffer a pulmonary embolism.
  • PE causes or contributes to up to 200,000 deaths annually in the United States.
  • One in every 100 patients who develop DVT die due to pulmonary embolism.
  • A majority of pulmonary embolisms are caused by DVT.

If pulmonary embolism can be diagnosed and appropriate therapy started, the mortality can be reduced from approximately 30 percent to less than ten percent.

Symptoms of Pulmonary Embolism
The symptoms are frequently nonspecific and can mimic many other cardiopulmonary events.

  • Shortness of breath
  • Rapid pulse
  • Sweating
  • Sharp chest pain
  • Bloody sputum (coughing up blood)
  • Fainting

Vascular Disease Treatment – Treatments offered by MISS for DVT and Other Vascular Diseases

Treatments for Deep Vein Thrombosis

The traditional treatments for DVT are:

  • Bed rest
  • Elevation of the affected limb
  • Pressure stockings
  • Drugs to prevent blood from clotting (heparin and warfarin).These drugs, called anticoagulants, keep the clot from growing larger and may prevent clots from breaking off and traveling to the lungs to form pulmonary embolisms, but they cannot dissolve clots that have already formed. These must be dissolved over time by the body’s own system for breaking down clots, or by a new technique called catheter-directed thrombolysis.

Catheter-Directed Thrombolysis

This procedure dissolves blood clots in the veins without surgery. “Clot busting” drugs (thrombolytic agents) are injected directly into the site of the clot (the deep vein thrombus). Catheter-directed thrombolysis is usually performed in a hospital radiology suite by an interventional radiologist. The physician inserts the catheter into a vein in the leg and threads it to the site of the clot. With his special training as a radiologist, the doctor is able to expertly guide and watch the progress of the procedure on an X-ray video monitor. When the catheter tip is in the clot, the clot-dissolving drug (urikonase) is sent (infused) through the catheter tube.
In most cases, it takes a few days for the clot to completely dissolve. The interventional radiologist can “see” and monitor the treatment using special X-rays, called venograms, and ultrasound scans. With X-ray and ultrasound pictures, the physician also can see if – after the clot dissolves – the vein wall is narrowed or damaged, a condition that can potentially lead to more clots in the future. Any narrowing in the vein that might lead to future clot formation can be identified by venography and treated with angioplasty and/or stent placement.New interventional techniques that combine drugs with macerating devices are promising to greatly improve treatment for the extremely common and potentially dangerous blood-clotting condition, deep vein thrombosis (DVT).At the 30th annual scientific meeting of the Society of Interventional Radiology (SIR) in New Orleans in April, members presented three new pharmamechanical clot-busting techniques that are proving effective and also less costly and less time-consuming than conventional treatments.While the studies to date have been on small numbers of patients, “the new combination techniques seem to offer a significant advance in treating DVT,” says Suresh Vedantham, MD, an interventional radiologist at Washington University in St. Louis and one of the presenters. Vedantham also heads the DVT research committee on SIR’s venous taskforce.Approximately 10 years ago, interventional radiologists developed a nonsurgical procedure to treat DVT called catheter-directed thrombolysis (CDT). Performed under imaging guidance, the procedure delivers medications directly to the clot through a catheter inserted in the vein rather than through an IV in the arm.In the past few years, interventional radiologists have tried to improve the CDT so they could still use it to treat DVT but in less time and with fewer risks. They have since developed three new techniques, all of which combine the direct delivery of clot-busting drugs with devices that chew or dissolve the clot at the same time.
One technique is the Power Pulse Spray, which injects a diluted clot-dissolving drug to the area of the clot at high force. The advantage of the spray is that it delivers the drug to more surface area throughout the clot. It takes roughly a half-hour for the clot to partially dissolve, and then the vein is sprayed again with powerful saline jets. The jets create a vacuum that draws the thrombus into the catheter, where it is removed from the body.

The Power Pulse Spray technique is a new method of using the already existing AngioJet device, says Jacob Cynamon, MD, director of vascular and interventional radiology at the Montefiore Medical Center in the Bronx, N.Y. Cynamon reported on his experience with the method at the SIR meeting.

A second technique uses the Trellis-8 Peripheral Infusion System, which uses an inflated balloon placed on both sides of the clot to prevent pieces of it from traveling to other parts of the body. The physician feeds a wire “filament” through the clot. The wire begins to whip around, chewing the clot into pieces, which are aspirated into the catheter and removed from the body. The FDA recently approved the Trellis as a drug infusion catheter for vascular clots.
The third technique is the Helix Clot Buster Thrombectomy Device in which a miniature impeller is housed in the distal end. The impeller creates a recirculating vortex that breaks the thrombus into pieces that can be flushed from the body. The HELIX is FDA-approved for dialysis graft clots and is used off-label for DVT.

Balloon Angioplasty and Stenting
If a vein has been narrowed or damaged, it may be necessary for the interventional radiologist or other physician to perform balloon angioplasty, a procedure in which a catheter is placed in the vein under X-ray guidance to the site of the narrowing, and a balloon is inflated to press open the narrowed blood v essel. In many cases, a small mesh cylinder called a stent may be inserted through the catheter and left behind in the vein to keep it open.

Balloon Angioplasty: A catheter is directed into the blood vessel and a balloon is inflated to press open the narrowed wall

Treatments for Varicose Veins
Behavioral changes can help prevent the formation of varicose veins.

  • Cross the legs at the ankles instead of the knees when sitting
  • Avoid high heels, which limit the use of the calf muscles.
  • Avoid restrictive clothing which limit blood flow in the groin or calf.
  • Avoid prolonged sitting or standing.
  • Take breaks to elevate the legs or walk around to help move the blood along and prevent valve failure.

Existing varicose veins won’t get better without treatment. Treatment may consist of:

  • Rest.
  • Elevation of the leg.
  • External support such as elastic wraps or support hose. Elastic stockings are preferred over elastic bandages.
  • Laser treatment. A new laser treatment is being provided by interventional radiologists as an alternative to surgical treatments. The EndoVenous Laser Treatment uses a laser fiber to heat and seal the main vein that is causing the varicosity.
  • RF Energy. Radiofrequency (RF) energy is another new technique provided by interventional radiologists as an alternative to surgery. RF energy heats the problem vein from the inside, shrinking it. Nearby veins take over.
  • Sclerotherapy. In this treatment, a thin tube called a catheter is directed to the vein and a substance is injected that causes the veins to scar and close – rerouting the blood to healthier veins. The affected vein forms a knot of scar tissue that is absorbed by the body over time.
  • Phlebectomy. In this procedure, varicose veins are removed through a series of small holes in the skin under local anesthesia.
  • Vein stripping involves removal of a long vein through small incisions in the skin.
  • Endoscopic repair. This procedure is performed in advanced cases of vascular disease involving sores or ulcers on the legs. Surgeons insert an endoscopic camera into the varicose vein via small incisions to visualize and treat the defects.

Treatments for Phlebitis
Thrombophlebitis in the superficial veins is generally treated at home with periods of rest with the leg elevated, pain relievers such as aspirin and, if needed, antibiotics. Warm compresses may ease the inflammation and elastic stockings may be prescribed.
Deep vein thrombophlebitis is treated with anticoagulants (drugs that prevent the blood from clotting) or with thrombolysis, a procedure in which clot busting drugs are infused to the site of a blood clot. This procedure usually is performed by an interventional radiologist.

Treatments for Venous Stasis Disease
Over time, untreated DVT or other conditions may damage a valve in the vein so that it does not close completely. When this occurs, blood flows back into the vein below the valve and collects in the lower leg veins. Pooling of blood in these lower leg veins may cause swelling and tissue damage and lead to painful sores or ulcers. This condition is known as venous stasis disease.
Fortunately, prompt treatment of DVT or other vein disease can prevent complications such as pulmonary embolism and venous stasis disease.

Treatments for Pulmonary Embolism
Pulmonary Embolism is a common event, especially in hospitalized patients. It is estimated that more than 600,000 new cases of pulmonary embolism occur in the United States each year and 200,000 people die of the disorder.

Treatment options include:

  • Anticoagulation. Blood thinners are prescribed to prevent the clot from growing or new clots from forming while the body dissolves the existing clot on its own.
  • Vena cava filters are devices that are placed in some patients when there is a possibility of recurrent blood clots, or emboli, or in patients with chronic pulmonary disease to prevent further damage to the blood vessels of the lungs. Vena cava filters usually are placed by physician specialists called interventional radiologists who perform procedures without surgery by guiding catheters and other small instruments through the blood vessels under X-ray guidance.
  • Thrombolytic therapy is another interventional radiology technique in which clot busting drugs are fed (infused) through a catheter directly to the site of the blood clot in the lung.
  • Percutaneous thrombectomy. In this procedure, a catheter is sent to the site of the clot under X-ray guidance and a device is used to break up the clot into small pieces that are easily absorbed by the body.

IVC Filter – Minimally Invasive Surgical Solutions and Inferior Vena Cava Treatment

What is an IVC filter?
IVC stands for inferior vena cava, a major blood vessel that returns blood from the lower body to the heart. An IVC filter is a small piece of metal that can be put into the inferior vena cava to prevent blood clots in the legs from going up to the lungs.

A blood clot in the leg is called a deep vein thrombosis (DVT). If the clot goes to the lung, it is called a pulmonary embolus (PE). A large PE can be lethal.

Why does an IVC filter If you have a DVT, you’ll probably need to take blood-thinning medicine to prevent the clot from moving. Some people are unable to take blood thinners because of bleeding problems. Others may have tried blood thinners, but the medicine may not have worked properly. These people may need a temporary or permanent IVC filter to prevent blood clots from going to the lungs.

There are several types of IVC filters that are used today. The Greenfield filter is one of the most familiar names. Some of these filters are permanent; others are temporary and can be removed easily.

How is an IVC filter placed?
An IVC filter is placed by a doctor known as an interventional radiologist. It’s a minor surgical procedure. Since you are sedated for the operation, you won’t remember anything. A needle goes into a vein in your neck or groin to put a catheter into your blood vessel. The catheter is carefully positioned so the IVC filter can be inserted. By using an x-ray, the doctor can see the filter and move it to the right place.

How long does the procedure take?
The procedure usually takes less than an hour. Most people go home within a day or two if there aren’t any major problems.

What are the risks?
The procedure is considered low risk, so major problems are rare. Bleeding and infection are possible at the incision. The risk of injury to other organs is very small. Other risks, including death, are very rare.