Arterial and venous thrombolysis and stenting

Catheter-directed thrombolysis (CDT) procedure

Catheter-directed thrombolysis (CDT) is performed by interventional radiologists with image guidance. The purpose is to help rapidly clear blood clot from a vein or artery and restore blood flow.

This procedure, performed in a hospital's interventional radiology suite, is designed to rapidly break up the clot, restore blood flow within the vein and potentially preserve valve function to minimize the risk of post-thrombotic syndrome. The interventional radiologist inserts a catheter into the popliteal (located behind the knee) or other leg vein and threads it into the vein containing the clot using imaging guidance. The catheter tip is placed into the clot and a "clot-busting" drug is infused directly to the thrombus (clot). The fresher the clot, the faster it dissolves - one to two days. Any narrowing in the vein that might lead to future clot formation can be identified by venography, an imaging study of the veins, and treated by the interventional radiologist with a balloon angioplasty or stent placement.

In patients in whom this is not appropriate and blood thinners are not medically appropriate, an interventional radiologist can insert a vena cava filter, a small device that functions like a catcher's mitt to capture blood clots but allow normal liquid blood to pass.

CDT is helpful in the following situations

Deep venous thrombosis (DVT) is a blood clot that occurs in veins. Frequently they involve veins of the legs and can lead to leg swelling and pain. If a DVT is not appropriately addressed it can progress to form further clots or migrate to the lungs and is referred to as a pulmonary emboli (PE). PE's can be life threatening.

Effort thrombosis (Paget-Schroetter syndrome) is a condition in which blood clot blocks the flow of blood from an arm to the heart. This is commonly associated with children that are athletic and perform activities of their arms such as swimmers, weight lifters, right handed baseball or softball players. This can lead to debilitating arm swelling restricting physical activities.

Thrombosis (blood clot) can also develop in arteries. This can then lead to decrease blood flow to an organ or limb. If there is not adequate blood flow to an organ or limb this can lead to risk of organ or limb loss if the blood flow is not adequately restored.

CDT procedure

The procedure is performed in the interventional radiology suite with image guidance. Your child will be sedated to ensure comfort for the procedure. A small catheter (plastic tube) is placed into the region of the blood clot. Through the catheter x-ray dye will be injected to determine the extent of the blood clot. Special medication called thromblytic agents (“clot busting” medication) will be infused through the catheter into the blood clot. A special catheter can also be used to help remove the clot by a suction mechanism. Following clot removal or clearance an angioplasty balloon may be used to help dilate the vessel if there is a narrowing to facilitate continued good blood flow. If needed a stent may be placed to help keep the blood vessel open for blood flow.

Occasionally, if the blood clot cannot be removed adequately your child may need to have the catheter left in place overnight while the thromblytic agent continues to infuse to help further clear residual clot. Frequently, sedation or anesthesia will be used to help facilitate the successful completion of the procedure. This helps to minimize anxiety for the child and decrease risk of complications as a result of movement during the procedure.

The procedure typically requires 1-3 hours and may also require overnight infusion of blood “clot busting” medication.

Benefits of CDT treatment

• Helps restore blood flow through the occluded vessel and relieve symptoms
• Preserve blood flow to organ
• Performed procedure through a skin puncture, which is minimally invasive

Risks of CDT treatment

Any procedure where the skin is penetrated carries a potential risk of infection. The chance of developing an infection that requires added antibiotic treatment appears to be less than one in 1,000.

Rarely, significant bleeding may occur as result of the thrombolytic agents (blood clot busting medication). However, there is a small risk of:

• Bleeding into brain
• Bleeding from puncture sites (such as IV's)
• Bleeding from intestine
• Bruising

Pain level after treatment

Your child may have some soreness at the site of prior clot or catheter insertion particularly if a bruise (hematoma) develops. Typically this can be well controlled with ibuprofen or Tylenol. Upon removal of the catheter and recovery from sedation your child can resume normal activities.

Additional Resources

• Society of Interventional Radiology