[Venous Doppler ultrasonography. Methods, indications and limits]

The analysis of velocities by the Doppler effect has limited applications in venous pathology. There are, however, many potential advantages: the introduction of deep venous catheters, early diagnosis of venous thrombosis, studies of venous incompetence, right sided cardiopathies, follow-up of medical and surgical treatment (thrombolytics, venous thrombectomy, bypass surgery, vena cava clips). The results in a series of venous thrombosis are reported: the correlation between Doppler and phlebography was 86,5% in 110 investigations. Doppler sensitivity was 86% and specificity 91%. These results are compared to other reports. A 90% correlation was found with isotope venography in 32 cases in which the permeability of vena cava clips was studied. The sensitivity of doppler in the diagnosis of thrombosis of the clip was 75% and its specificity 100%. The main limitations were the lack of sensitivity in the diagnosis of distal thrombosis and incomplete occlusion (floating thrombi). As a complement to occlusive plethysmography and other non-invasive investigations, Doppler ultrasonography helps determine the indications for phlebography. It is useful in detecting high risk patients and is a sensitive, effective non-invasive method of surveillance in the postoperative period.