Thrombolytic Therapy

Thrombolytic therapy is a treatment used to break up dangerous clots inside your blood vessels. Your physician injects clot-dissolving medications into a blood vessel. In most cases, the medication will flow through your bloodstream to the clot. In other cases, the surgeon will guide a long, thin tube called a catheter, through your blood vessels to the area of the clot. The catheter then delivers the medications or mechanically breaks up the clot.

Thrombolytic therapy is commonly used to treat clots in an artery of the lung, (P.E. or pulmonary embolism) deep vein thrombosis (DVT), your heart, a bypass graft, or dialysis access (fistula, graft, or central venous catheter) that has become blocked. Thrombolysis may be done as an emergency treatment under certain circumstances such as stroke, pulmonary embolism, or as a scheduled procedure for DVT or a blocked bypass graft.

Prior to receiving thrombolysis, your surgeon will review your prescription medications as well as any herbal or dietary supplements. Some of these substances have an effect on the blood’s clotting abilities. You may also require some blood tests to check if your blood is clotting properly. The tests you receive will depend upon the blood vessel that is blocked and your medical condition.

Your blood is normally a liquid that travels smoothly through your arteries and veins. Sometimes, however, blood components, called platelets, can form clumps and, together with other blood components, can cause the blood to gel. This process is called clotting or, more technically, coagulation. This is a normal process that protects you from excessive bleeding from even a minor injury. However, in certain circumstances blood clots can break off, travel through your blood stream, lodge in a blood vessel somewhere else in your body and obstruct normal blood flow. Blood clots in your heart or lungs, for example, can starve the organ and be life threatening.

What happens during thrombolytic therapy

In some hospitals, physicians perform thrombolytic therapy in the ICU, (Intensive Care Unit) but in others, thrombolysis may be performed in nursing units familiar with the treatment and potential complications. In either circumstance, your physicians and nurses will carefully watch your vital signs and be prepared for an emergency during the procedure, such as bleeding.

To deliver the thrombolytic therapy, your physician will make a small puncture over an artery or vein in your groin, your wrist, or your elbow. This place is called the access site. Before inserting the catheter through this puncture, the skin will be cleansed and numbed with a local anesthetic. Although you may be given some mild sedation, you will usually stay awake during the procedure.

Next, your physician will usually inject contrast through the catheter to map your blood vessels with angiography and to locate the clot. You may feel a warm sensation during the injection, which is normal. As the contrast flows through your blood vessels, x-rays are taken. The x-rays do not pass through the contrast, so pictures of your blood vessels appear on a screen indicating the location of the clot as well.

Once your physician locates the clot, depending on the particular circumstances, he or she may inject the thrombolytic drugs through the catheter. More commonly, your vascular surgeon will guide a longer catheter through your blood vessels to the vicinity of the clot and then inject the drugs near or into it. You will not feel the catheter as you have no nerve endings in your blood vessels.

Clot Busting Drugs

  • Streptokinase
  • Tissue plasminogen activator (t-PA)
  • Recombinant, or genetically engineered, ( a newer version of t-PA) and
  • TNK (Tenecteplase)

Your physician will periodically monitor the x-ray screen to see the clot breaking up. However, depending on the size and location of the clot, the drugs your physician chooses, and other factors, this process can take several hours. Sometimes, if you have a severe blockage, the treatment could last for several days. Once the clot has been dissolved or if it cannot be dissolved further, your physician will stop the medication. When the tests used to monitor your blood’s coagulation are in the satisfactory range, your physician will then remove the IV or the catheter, and press on the access site for 10-20 minutes to stop any bleeding. You will be asked to remain still for several hours afterwards to minimize the risk of bleeding.

Mechanical Thrombectomy is similar, except that small devices are attached to the catheter tip to remove the clot or even break it up physically. These devices include a suction cup, rotating device, high speed fluid jet, or special ultrasound devices. Mechanical thrombectomy can work faster than thrombolytic drugs in some cases, and in favorable circumstances the procedure may take as little as 30 minutes. In some situations, both mechanical and pharmacologic thrombolysis will be performed.

After thrombolytic therapy

Usually, you will stay in bed as you recover from thrombolytic therapy. During this time, your physician and staff closely watch you for any complications. You may receive fluids, antibiotics, or pain killers. Once any bleeding from your access site stops, your vital signs are normal, you may be discharged.

Before your discharge, your physician will give you instructions about everyday tasks. For example, you should not lift more than 10 pounds for a few days after your procedure. You should drink plenty of water to help flush the contrast dye out of your body.

If you received thrombolytic therapy in an emergency, you may receive additional care for your condition. For example, if you had a stroke, your physician may prescribe medications, a special diet, or physical therapy. If you had a heart attack, your physician may need to examine your heart to see if any other arteries are blocked. If you had a blocked bypass graft, you may need further treatment or anticoagulation to keep the bypass open.

Complications are not unusual with thrombolytic therapy, which is why it should be carried out under close supervision.

However, your physician can manage most of them, including:

  • Bleeding in the access site or elsewhere
  • Low blood pressure
  • Allergy to thrombolytic drugs

Thrombolytic therapy is not always successful. In up to 25 % of patients, the treatment is unable to break up the clot. This is especially true if the clot has been established for a long time. In another 12 out of every 100 patients, the clot or blockage will re-form in the blood vessel, especially if any underlying reason for the clot to form in the first place is not found and treated.

If you notice any unusual symptoms after or during your procedure, you should tell your physician immediately.

These symptoms may include

  • Arm or leg pain that lingers or gets worse
  • Fever
  • Shortness of breath
  • An arm or leg that turns blue, develops swelling, or feels cold
  • Problems around your access site, such as bleeding, swelling, pain, or numbness