Blood Clots & Thrombolysis
Coagulation is the process that allows blood to clot, thus preventing blood loss from a pierced or broken vein or artery. For blood to clot, the body needs blood cells called platelets and proteins known as clotting factors, all of which are normally present in the blood. The process also requires vitamin K, usually found in a healthy diet.
When a blood vessel is damaged, these substances combine to form a protective mesh which hardens over the cut to prevent leakage. There are two basic types of coagulation disorders, one in which the blood doesn't clot properly and one in which it clots too easily.
Hypocoagulation is the condition that occurs when the blood doesn't clot normally. If left untreated, the disorder may lead to hemorrhage, bleeding on the brain or gastrointestinal bleeding. Conditions that may prevent blood from clotting normally are:
- Thrombocytopenia, or low platelet count
- Genetic diseases like hemophilia or von Willebrand disease
- Blood, bone marrow or liver disease
- Certain medications, like blood thinners
- Vitamin K deficiency
- Eclampsia, a complication of pregnancy
Symptoms of hypocoagulation may include unexplained bleeding or bruising, excessive bleeding from a minor injury, numerous nosebleeds, bleeding gums or excessive menstrual bleeding.
Hypercoagulation or Thrombophilia
Hypercoagulation may result in the formation of blood clots that block blood vessels. Such clots may occur after long periods of inactivity, as during plane travel or after surgery. Risk factors for hypercoagulation include:
- Hereditary predisposition
- Certain medications, such as birth control pills
- Certain cancers, like pancreatic, prostate, or breast
Abnormal blood clots result in minor symptoms like varicose veins, but left untreated can cause dangerous complications such as phlebitis, deep vein thrombosis, pulmonary embolism or stroke.
Thrombolysis, also known as thrombolytic therapy, is a treatment used to dissolve abnormal blood clots. Blood clots, or thrombi, may form anywhere in the body. Most are small and dissolve on their own, but when such clots are large and block important blood vessels, they become dangerous.
More serious thrombi may form for a number of reasons, including infection, injury, surgery, atherosclerosis, diabetes and heart disease. When thrombolysis is administered within one to two hours of the diagnosis of a serious clot, the procedure can be effective and lifesaving, eliminating the need for more invasive surgery.
Thrombolysis is often employed as an emergency procedure to remove blood clots in the arteries feeding the heart or brain. Blood clots in these arteries are life-threatening and, if left untreated, can result in a heart attack or stroke. A blockage in a deep blood vessel in the limbs or pelvis can also be successfully treated with thrombolysis. Such a clot, called a deep vein thrombosis, can result in severe damage to tissue and even necessitate amputation. Another threat is that such a thrombus can break off and travel to the lungs, resulting in a pulmonary embolism.
Thrombolysis, by improving blood flow, prevents damage to tissues and organs which might otherwise be life-threatening. During the procedure, thrombolytic medications, commonly referred to as clot busters, are administered either through an injection into an intravenous line (IV) or through a catheter threaded directly to the site of the blockage. At times, the catheter is fitted with a special tip that can mechanically remove or break up the clot.