Vascular laboratory and deep venous thrombosis: impact on management.

Two hundred and twenty-nine patients with the diagnosis of deep venous thrombosis admitted to the hospital prior and subsequent to the development of our vascular laboratory were reviewed. The institution of a clinical vascular laboratory improved the accuracy of diagnosis of deep venous thrombosis. The percentage of patients undergoing venography increased from 34 to 110 (31%) to 70 of 119 (59%), documenting an increased demand by the clinician for objective confirmation of the clinical diagnosis of deep venous thrombosis. Fifty-five patients had both phlebography and vascular laboratory examination. Twenty-seven of these had phlebograms along with pulse volume recordings of maximum venous outflow with Doppler ultrasound. The overall accuracy was 71.4%, with false positives in 22.2% (6 patients) and false negatives in 7.4% (2 patients). Phleborheography and phlebography were done in 28 patients. The overall accuracy of phleborheographic examination was 89.3%. The false positive rate was 3.6% (1 patient) and the false negative rate was 7.1% (2 patients).