A combined diagnostic approach to venous thromboembolism was applied in 162 patients with suggestive symptoms or findings using Doppler ultrasound, impedance outflow testing, and radionuclide phlebography with simultaneous lung scanning. The diagnostic accuracy of Doppler ultrasound and impedance outflow testing was 82.9% and 70.9% when each was used independently. Combination of the two techniques increased the diagnostic accuracy to 95%. Radionuclide studies revealed a high incidence of multicentric thrombi, particularly in patients with abnormal perfusion lung scans (56.3% vs 23.2%).
Radionuclide phlebography was also helpful in detecting nonocclusive thrombi by localized increase of radioactivity. Of the 162 patients, 45 had symptoms but showed normal results on noninvasive testing and so were not treated. Follow-up to two years has shown no venous thrombosis or pulmonary embolization in any of them. Only four patients in the series required surgical interruption of the vena cava.
Yao JST, Henkin RE, Bergan JJ. Venous Thromboembolic DiseaseEvaluation of New Methodology in Treatment. Arch Surg. 1974;109(5):664-670. doi:10.1001/archsurg.1974.01360050058014