Comparative value of tests for the diagnosis of venous thrombosis

Abstract

The clinical diagnosis of venous thrombosis lacks sensitivity and specificity. Venography is recognized as the diagnostic reference standard but is invasive and associated with patient morbidity.125I‐fibrinogen leg scanning is sensitive to calf vein thrombosis but is relatively insensitive to femoral vein thrombosis and does not detect iliac vein thrombosis. This test is most useful as a screening test in high‐risk medical and surgical patients. The test may be falsely positive at the site of hematoma, and because of this, it has serious limitations in patients undergoing knee and hip surgery. Leg scanning also has limitations when used to diagnose patients with suspected venous thrombosis because it may take up to 72 hours to obtain a positive result. Impedance plethysmography (IPG), a noninvasive technique, is sensitive and specific for thrombosis involving the popliteal, femoral, and iliac veins. Combined with125Ifibrinogen leg scanning, this test has considerable potential as a screening test in patients undergoing hip surgery. The combined use of IPG and leg scanning has also been shown to be highly accurate for the diagnosis of clinically suspected venous thrombosis, and this approach offers a less invasive alternative to venography in these patients. The Doppler ultrasound flowmeter, like the IPG, is sensitive to popliteal and more proximal vein thrombosis but is relatively insensitive to calf vein thrombosis. The interpretation of the results of this test is more subjective and much more dependent upon the expertise of the examiner than is the IPG. A number of other techniques, including image scanning, and themography, are under investigation but require further evaluation before they can be recommended in the management of patients with venous thromboembolism.

Changes in Coagulation and Fibrinolysis after Total Hip Replacement and Their Relations with Deep Vein Thrombosis

“…According to several workers, the increase of varied coagulation factors, the anomalies of the electrophoretic mobility of AT III and the presence of fibrin monomers could be related to an 'in vivo' activation of the coag ulation mechanisms [1,2], A prolongation of euglobulin lysis time, an increase in the FDP levels and the pres ence of plasmin-antiplasmin complexes were found in our series. Some of our findings point to a decrease in fibrinolytic activity and are similar to those found by other au thors [36][37][38].…”

“…The increase in FDP and the presence of plasmin-antiplasmin complexes would indicate an activation of the fibrino lytic mechanism [23,39,40], In view of our findings, we can conclude that an activation of the coagulation mecha nism and a decrease in fibrinolytic activity follow upon total hip replacement in a signif icant percentage of cases. These findings could, for some authors [ 1,2,4,6], constitute the biological demonstration of a hypercoag ulability state. Still, no relationship could be established between such a state and the de velopment of DVT.…”

“…Several changes in hemostatic mechanisms would take place in such a state [1][2][3][4]. Nev ertheless, the existence of a prethrombotic state remains an unresolved enigma [5,6], Alterations in one or more components of the hemostatic mechanism involving the co agulation system, its inhibitors and the fibri nolytic system have been detected after ma jor surgical procedures [7,8], Most studies carried out have used only a limited number of hemostatic tests.…”

Study of Platelet Function in Patients with Sickle Cell Anemia during Steady State and Vaso-Occlusive Crisis

“…Platelet factor 4 (PF4) and (l-thromboglobulin ((1TG) are secreted during the platelet release reaction in vitro [14][15][16] and their plasma levels may pro vide an index of platelet activation in vivo [16,17]. Accord ingly, we measured the plasma levels of PF4 and [1TG in both steady state and vaso-occlusive crisis in order to de termine whether in vivo platelet activation could be dem onstrated.…”

Mechanisms of perioperative cerebral infarction.

“…27 -39 Microcirculatory impairment due to increased viscosity could enhance, if not directly initiate, cerebral ischemia. 27 However, in vitro laboratory abnormalities have not been reliable predictors of perioperative arterial or venous thrombosis, 26 - 36 and correlation of laboratory indices of a prothrombotic state and postoperative stroke has not yet been attempted.…”