Whole blood agglutination D-dimer test for the diagnosis of deep vein thrombosis.

Deep vein thrombosis (DVT) is a clinical syndrome the clinical diagnosis of which is unreliable and objective tests often require specialized testing facilities. The authors examined the diagnostic accuracy of the whole blood agglutination D-dimer (SimpliRED) test in this condition. Patients who presented with acute onset of leg swelling were included in the study. Whole blood agglutination D-dimer test was performed upon admission and followed by the gold standard test, contrast venography. Forty three patients had venography proven DVT and proximal occlusion was found in 31 of them. The sensitivity and specificity of the test for DVT were 88.4 per cent and 53 per cent respectively while the positive predictive value (PPV) and the negative predictive value (NPV) were 82.6 per cent and 64.3 per cent. Interestingly, when focusing the diagnosis on proximal DVT, the sensitivity and NPV rose to 100 per cent, whereas, the specificity and PPV remained unchanged (48.3 and 67.4%). In conclusion, whole blood agglutination D-dimer test (SimpliRED) was sensitive but not specific for DVT diagnosis. Moreover, when focusing the diagnosis on proximal DVT, the test had excellent sensitivity and NPV. This test, therefore, can be an effective screening tool for the high embolic risk proximal DVT.

Radionuclide venography in the diagnosis of deep vein thrombosis of the lower extremities: a comparison to contrast venography.

Radionuclide venography (RNV) and contrast venography (CV) were compared in 72 limbs of 59 patients being clinically suspected of deep vein thrombosis (DVT) of the lower extremities. The criteria of positive RNV for DVT regarding flow pattern abnormality included (1) nonfilling or nonvisualization of a deep vein, (2) interruption of the flow, (3) irregular or asymmetric filling of a deep vein, and (4) presence of abnormal collateral vessels. The overall accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio (LR+) were 90 per cent, 88 per cent, 96 per cent, 98 per cent, 79 per cent, and 20.8 respectively. These figures are even higher when we focused on the major veins of the thigh and pelvis. They were 97 per cent, 95 per cent, 98 per cent, 98 per cent, 95 per cent, and 61 respectively. The results indicate that radionuclide venography, while technically simple, is a reliable test for detection of DVT particularly of the major veins of the lower extremities. Combined radionuclide venography and perfusion lung scan can also be performed in the same setting if Tc99m-MAA is used. Contrast venography which is an invasive procedure, should be reserved for questionable cases of those with suspected isolated calf vein thrombosis.