Deep Vein Thrombosis / Blood Clots

Overview
Why Do Blood Clots Happen?
Venous Outflow Obstruction
Diagnosing DVT / Blood Clots
Treating DVT / Blood Clots

Overview

Approximately 2 million patients per year are diagnosed with a blood clot in the legs, a condition known as deep vein thrombosis, or DVT. These patients are typically placed on blood thinners for months or years. Sometimes an inferior vena cava (IVC) filter is placed so the clot doesn’t travel to the lungs and cause bigger problems. But what happens to the clot? Does it dissolve?

Blood-thinning medications do not dissolve the clot. Blood-thinning medications attempt to keep the clot from growing and even dislodging and traveling to the lungs. It’s actually the human body that very slowly over time sends different cells to attach to the blood clot to dissolve it or break it up.

This can take a very long time and often the clot is so large that the body cannot dissolve it. If that is the case, the body will try to separate from the clot and the clot will then become part of the vein wall and calcify. For many patients this can cause extended lifelong effects that usually don’t show up until years later.

All patients with new clots should be evaluated for having the clot removed or dissolved as soon as possible to prevent later complications such as post-thrombotic syndrome (PTS) and venous ulcers.

Even patients who had a blood clot months or years ago and who have developed symptoms of chronic venous insufficiency (CVI) such as pain, swelling, heaviness, skin discoloration, or leg ulceration are candidates for treatment to clean out any clot still left over, restore the normal flow of blood in the veins, and relieve symptoms.

Today’s advanced technology allows doctors to remove blood clots right after they occur and restore normal blood flow in the leg to relieve the patient’s symptoms. The procedure is performed in a physician’s office without hospitalization and the patient goes home the same day with improvement in their symptoms.

Why Do Blood Clots Happen?

Blood that tends to clot too much is referred to as a hypercoagulable state or thrombophilia, which increases the risk for blood clots to develop in the arteries and veins.

The human body has various complex compounds circulating in the blood (such as red blood cells and platelets) to make sure blood clots don’t form randomly but do form when they are needed. For example, you don’t want blood clots in your leg veins but you do want your blood to clot if you accidently cut your finger.

If the cause of excessive blood clotting lies in the body’s anticoagulation pathway (the complex chemicals that interact to make sure we are not randomly clotting), doctors can test for many of the chemicals and offer preventive treatment.

The problem can also be an anatomic abnormality. For example: If a busy highway narrows from 5 lanes to 2 lanes, you will see too many cars in one area, which causes congestion. A similar situation can happen in the human body. If a vein is narrowed downstream and blood cannot flow like it should, a blood clot can develop.

The result of congestion increases venous blood pressure, which causes symptoms known as venous outflow obstruction.

Venous Outflow Obstruction

Venous outflow obstruction is a narrowing of a vein that results in an inability of blood to exit the leg and go back to the heart. When blood is not able to leave the legs in a normal flow, pressure builds up before the narrowing and symptoms occur down in the lower leg.

This is similar to a kitchen sink that’s clogged up: The water in the sink may flow out the drain slowly if the problem is not that bad, but once it’s completely clogged, the water will not be able to drain from the kitchen sink and it will then overflow.

When this happens in the human body, the consequences can be life-threatening. The red blood cells that carry oxygen cannot leave the leg and end up dying, which can result in blood clots and increased venous pressures because blood continues to be delivered to the legs via the arteries (similar to a faucet being on). As a result, patients experience symptoms of CVI and can develop lower leg skin discolorations and venous ulcers.

Vein obstructions come in many varieties and can be due to:

A new or old blood clot (stenosis)
Compression from an outside source, such as an artery [May-Thurner Syndrome], a tumor, another organ, or fat in individuals with increased pelvic fat
Webs
Trabeculae
Previous radiation

Diagnosis and treatment for vein obstruction is normally covered by Medicare and private insurance companies.

Diagnosing DVT / Blood Clots

To identify this type of vein disorder, physicians at The Vein Center at Water’s Edge Dermatology use leading-edge technology known as intravascular ultrasound (IVUS). By using a very tiny catheter containing an ultrasound at the tip of it, our vein specialists can image the vein from the inside and identify any obstruction. After identifying an obstruction, our physicians can fix the problem with several techniques, among them angioplasty and stenting.

This video shows an example of a stenosis discovered using IVUS. Although this video demonstrates an artery (chosen for quality of video demonstration), the same technology is available to evaluate the venous system of the legs, pelvis, and abdomen.

Treating DVT / Blood Clots

If an abnormality of the vein is identified using IVUS, the treatment is angioplasty (opening up the diseased vein with a pressure balloon) and placement of a vein stent. This video demonstrates both procedures and the use of IVUS.