33 Sewall Street, Portland, Maine 04102 207.956.6650



Deep vein thrombosis ("DVT" or clots in the veins) is a very common problem in the United States with approximately 1 million new cases diagnosed each year. Risk factors for DVT include:

  • recent trauma
  • major surgery
  • cancer
  • use of oral contraceptives
  • immobilization
  • obesity
  • smoking
  • history of previous clotting problems in the patient or patient's family


Deep venous thrombosis is a chronic disease. There is a 25-50% risk of developing post-thrombotic syndrome (PTS) at some point after the first DVT. The clinical manifestations of PTS, which include chronic limb swelling, pain, heaviness/fatigue, itching, skin changes and/or skin ulceration. PTS is caused by damage to the veins and vein valves by the clot.

The physical limitations of patients with PTS are comparable to those of patients with other severe chronic medical conditions – many patients are disabled, unable to work, and/or unable to perform household duties. As a result, PTS causes major impairment of quality of life.

Treatment Options

Standard medical therapy for proximal DVT patients consists of the use of anticoagulant drugs. This form of therapy is highly effective in preventing pulmonary embolism (PE). However, anticoagulant drugs do not actively eliminate thrombus. As a consequence, PTS occurs frequently (25-50%) in anticoagulated DVT patients.

Catheter-directed thrombolysis (CDT) refers to thrombus removal by administration of a "Clot-Busting" drug directly into the clot via a device/catheter which is embedded within the thrombus using imaging guidance. It is an added therapy to anticoagulation.

CDT is a minimally-invasive procedure that is performed with the patient under conscious sedation. NO surgery is involved. There is no cutting or stitches. After the patient is sedated and local anesthetic is applied, a tiny needle is inserted into a vein in the lower leg. Under x-ray guidance, a catheter is placed into the clot. Using a combination of clot-busting drugs and devices designed to break up clots and remove them, CDT provides RAPID clot removal in >80% of patients.

Typically, within 48 hours, patients experience significant relief of pain and swelling in the affected limb because the clot has been removed from their veins. In addition, the damage to the veins and valves is prevented which is expected to then prevent the risk of developing PTS down the road.

Our physicians have the most experience with DVT “clot-busting” therapy in the entire State of Maine. We provide complete pre-procedural inpatient and outpatient evaluation along with longitudinal post-procedure outpatient follow-up care. Due to our expertise in this field and our interest in furthering knowledge about DVT, we are also helping run a NIH-sponsored clinical trial using this clot-busting technique.

Thrombolysis Thrombolysis

A tiny catheter is entered into the clot and delivers a “clot-busting” drug directly into the clot. The catheter then breaks up the clot with highly pressurized fluid and sucks it out of the patient.


What is CDT (catheter-directed thrombolysis)?

It is a non-surgical treatment that directly removes clot from the blood vessel by using a combination of a clot-busting drug and mechanical devices.

Under moderate sedation and local anesthetic, a tiny needle is inserted into the vein near the blood clot and through this tiny hole, a catheter is entered under x-ray and ultrasound guidance to remove the clot. The devices we use for this procedure are approved by the FDA for this indication.

Why should I have CDT (catheter-directed thrombolysis) over conventional anticoagulation (blood-thinning)?

At this time the standard of care for DVT is anticoagulation. Recent studies have suggested, however, that CDT offers earlier relief of pain and swelling and can prevent the long-term complications of DVT better than blood-thinning alone.

What are the risks of CDT?

In appropriately selected patients, there is a low risk of bleeding from the clot-busting drug. In experienced hands, it is a safe procedure and highly effective.

What is the recovery time after CDT?

Because CDT is a non-surgical treatment, there are no scalpels or stitches. Patients are instructed to lie in bed for 2 hours after the procedure and take it easy for 1 day.

Who performs CDT and how much experience do you have with this treatment?

There are other physician groups that are learning to perform CDT but there is absolutely no question that Vascular & Interventional Physicians of Spectrum have the most extensive experience for CDT in the entire state. Patients from all over the state are referred to us for their DVT care.

Due to our extensive experience with DVT, we are the only group in the state that have been asked to help lead a NIH study involving CDT in the treatment of DVT patients.

How do I learn more about CDT?

Talk to your physician and they can arrange a consultation with us by calling our office at (207) 956-6650.

Technology Updated

Did You Know? We treat varicose veins and spider veins? Varicose veins are swollen veins which protrude in a rope-like manner under the skin. Normal veins, by virtue of one-way valves, channel blood against gravity up the leg and back to the heart. When a valve becomes defective, it allows blood flow to leak back down the leg resulting in congestion and swelling of the vein. This is a medical condition called Venous Insufficiency.
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