Deep venous thrombosis (DVT) and Thrombophlebitis
A clot in the veins is called a deep venous thrombosis (DVT) when it is in the deep veins within the muscle and superficial thrombophlebitis when it is in the veins outside the muscle just under the skin surface. Both types of clots generally occur in the veins of the leg, but about 10-15% occur in veins of the arms or elsewhere (neck, pelvis, chest wall).
Superficial thrombophlebitis can occur after a blood draw or IV. It is also not unusual to get clots in a cluster of large varicose veins. In general, superficial thrombophlebitis is not dangerous, just painful until it resolves. Sometimes, a thrombophlebitis can leave behind a darkened area on the skin (hyperpigmentation). Rarely, more serious complications can occur, like infection in the clot (septic thrombophlebitis) or extension of clot into the deep veins.
A superficial thrombophlebitis will feel like a hard, tender lump in the vein, or like a rope underneath the skin surface. Often the skin over the top of the vein is red and inflamed. Fever or shaking skills indicates infection.
Typically the treatment is anti-inflammatory medication like ibuprofen, moderate activity, and warm compresses. Referral to a vascular specialist is often advised to discuss treatment of the varicose veins to prevent future similar episodes. For more on treatment of varicose veins, click here.
DVT is a more worrisome problem because clots in the deep vein system can dislodge and travel through the veins to the heart and lungs, causing a pulmonary embolism (PE). Although only a small number of DVT result in PE, PE is fatal in 30-40% of cases. DVT can also cause permanent damage to the valves in the leg veins, resulting in deep venous insufficiency (DVI), or pooling of blood in the legs. DVI leads to edema (swelling), discoloration of the skin in the lower leg, and leg discomfort (aching, throbbing, tightness or a feeling of engorgement). A third of people with DVT will develop chronic venous stasis disease (CVSD), skin damage which can lead to skin infection and ulcers.
DVT usually are manifest as deep, persistent pain in the calf muscle or thigh muscle. People often describe it as like a Charley horse. Sudden onset of chest pain or shortness of breath may be a sign of a pulmonary embolus.
Most DVT result from periods of inactivity, when the calf muscle is not moving and the blood in the veins of the legs is stagnant. Examples of this are long plane rides or car rides, surgical procedures or periods of time when the leg is in a cast or is immobilized. Other predisposing factors for DVT include: active smoking, use of birth control or other hormonal replacement, extreme dehydration, obesity, and pregnancy. Some people with DVT have an inherited or acquired tendency to clot the blood, something we call a hypercoagulable state. In some cases when there is a strong family history of clotting problems or when the DVT is unprovoked (no other risk factors), we may recommend a hypercoagulable state evaluation (a series of specialized blood tests) and referral to a hematologist. DVTs are also associated with cancer and cancer treatment. A certain percentage of people with DVT have an occult (not yet detected) malignancy. For this reason, we remind all people with DVT to consider routine cancer screening exams (mammography, colonoscopy, prostate exam).
Blood thinners are a mainstay in treatment for DVT. Warfarin (coumadin) is the most widely used oral medication for this purpose, but the medication may take several days to reach an appropriate level in the bloodstream. Usually, patients are started on a medication given by injection (Lovenox or Enoxaparin) which acts immediately, until the warfarin reaches full effect. Blood tests called protime (PT) and INR must be checked periodically in order to ensure that the warfarin level is appropriate. The level may vary dependent on diet, exercise, and other medications. Other oral anticoagulants are being studied currently to be used as alternatives to warfarin.
Some people with DVT may be good candidates for clot thrombolysis, a procedure to remove clot surgically.
Inferior vena cava (IVC) filter placement
An IVC filter may be discussed if you have a deep venous thrombosis (DVT) in the leg. The primary concern for DVT is risk of pulmonary embolus (PE), clot traveling from the leg to the heart and lungs. In many cases, PE can be fatal. Standard of care for treatment of DVT is anticoagulation with warfarin, but if you cannot take blood thinners because of bleeding problems, recent surgery or head trauma, or if you have new or worsening clot while on blood thinners, your physician may advise placement of an IVC filter.
The vena cava is the large central vein that takes blood back to your heart. It is formed by the confluence of the right and left iliac veins, which run through the pelvis from the groin to the level of the umbilicus. An IVC filter acts as a trap or sieve to capture blood clot that wants to travel from the legs to the heart. It looks like the wire frame of a tiny umbrella. Placement of the IVC filter is a minimally invasive procedure which generally takes less than 30 minutes and is done through a needle-stick incision. The vein at the base of your neck or in your groin is accessed with a needle, and then a sheath (tube) is guided over a wire into the vena cava. The filter is collapsed into the sheath, guided into position under continuous x-ray (fluoroscopy), and then deployed. You cannot feel the IVC filter in your abdomen and it will not cause the scanners in the airport to ring. Almost all IVC filters are nonferromagnetic, and are safe for MRI. As with any implant, it is important you carry a card with you that identifies what type of filter you have, its location, and when it was put in.
Most IVC filters are temporary, meaning they can potentially be removed if no longer needed. For instance, sometimes a filter is placed just prior to a DVT thrombolysis procedure (see below), and it is no longer needed after the clot is removed. Removing an IVC filter involves introducing a needle into the vein at the base of your neck, and through this vein, guiding a wire and sheath into the vena cava. Through the sheath, a tiny lasso called a snare is advanced into the vena cava and used to capture a small hook at the top end of the filter. The filter is then collapsed into the sheath and removed. This can be done as an outpatient procedure under a light sedative. The procedure can take 10-30 minutes. Nationwide, we only retrieve 50-75% of all temporary filters that are put in. Sometimes the filter is filled with clot, sometimes it is slightly tilted and the top hook is not exposed, or sometimes it is too embedded in the surrounding tissues to be removed safely. Our chances of removing the filter are greater the shorter the time that the filter has been in place. After a filter has been in place 3 months, our chances of removing it decrease significantly. Leaving a filter in and not being on blood thinners is associated with a small risk of development of clot in the filter which can lead to bilateral leg swelling.
Deep venous thrombosis (DVT) thrombolysis
DVT thrombolysis may be considered for a clot in the deep veins in the thigh and pelvis (iliofemoral DVT). This treatment is a minimally invasive surgery to dissolve and remove the clot percutaneously. It is performed by first placing an IVC filter (see above), then introducing a small tube (catheter) into the popliteal vein behind the knee through a 2mm incision. The catheter is guided up the vein through the clot. A variety of techniques can be used to remove the clot. Most commonly, we use a Trellis device. This device has a catheter with balloons at its tip and in its mid shaft. Between the balloons, the catheter is perforated with tiny holes. The catheter is advanced through the clot, and the balloons are inflated proximal and distal to the clot, to isolate a segment of clotted vein. A solution that dissolves clot (tissue plasminogen activator, or TPA) is instilled through the side holes of the catheter and then an oscillating wire is inserted through the catheter to disperse the solution through the clot. The dissolved clot is then aspirated out of the vein. Another device we commonly use is Angiojet, and uses a jet spray and suction catheter to break up and remove clot. The procedure is done under light sedation or a general anesthetic and typically takes about 2 hours. Afterwards, patients are continued on warfarin for a period of time while the vein is healing.
Thrombolysis is contraindicated for patients with advanced age, bleeding problems, recent surgery, or head trauma. It is not effective on older clots. We do not generally recommend treating clots that are over 6 weeks old because the likelihood of significantly impacting clot burden is low.
The standard of care for DVT remains anticoagulation with warfarin. The main reasons to consider DVT thrombolysis are to decrease leg pain and swelling and to preserve valve function in the deep veins. We believe that a successful early thrombolysis is associated with lower risk of developing post phlebitic syndrome (chronic leg swelling and skin changes).