Diagnosis of deep vein thrombosis

A wide range of clinical symptoms and signs are observed with venous thrombosis. Nonetheless, clinical diagnosis has been found to be unreliable and accurate diagnostic methods must be used before potent therapy such as anticoagulation is instituted, since the complications of treatment themselves can be life-threatening. Phlebography is still the basic reference for evaluation of deep venous disease. While it is felt to be the most accurate, there are still limitations relative to difficulty in separating acute from chronic disease, and in obtaining adequate contrast in certain veins such as calf muscles and in the larger intraabdominal veins. Moreover, it is an uncomfortable invasive test, not without complications of its own. The 125I-fibrinogen uptake test is an excellent test for screening for forming thrombi. The sensitivity of this test is high, particularly in the detection of small calf vein thrombi. The primary drawbacks of this technique are that it is falsely positive in cases where there has been bleeding, inflammation, gross edema, arthritis, or leg ulceration. It is not accurate above mid-thigh because of the high blood flow at the level of the groin and pelvis. Radioactive labeled plasmin which will adhere to the surface of recently formed thrombi can also be used for diagnosis. The limitations are a very short half-life of the radioactive label so that repeated investigation of a patient cannot be performed unless new injections are given. The diagnostic accuracy is comparable to that of radioactive labeled fibrinogen and has the same advantages and disadvantages. Plethysmographic techniques have been used with various modifications.(ABSTRACT TRUNCATED AT 250 WORDS)