[Prevalence of clinically silent pulmonary embolism in deep venous thrombosis of the legs].

BACKGROUND

Thromboembolic venous disease is a possible lethal condition which is very often present in clinical practice. The aim of this study was to evaluate the prevalence of clinically occult pulmonary embolism (PE) in a group of patients with recent proximal deep venous thrombosis (DVT), and the relationship between prevalence of PE and DVT extension, echographic features of the thrombi, anticoagulant therapy administered.

MATERIALS AND METHODS

The study enrolled 93 patients with DVT of the proximal lower extremities, without clinical symptoms and signs of PE. All patients were submitted to echo color-Doppler and ventilation-perfusion lung scan. The results were analysed by a score system for the echographic scan and by a series of probability criteria, as recommended by the PIOPED investigators, for the lung scan.

RESULTS

All patients were recognised to suffer from proximal DVT. High probability lung scans for PE were found in 43 subjects (46.2%), intermediate probability in 14 (15%), low probability in 7 (7.7%), very low-normal in 29 (31.1%). The prevalence of PE failed to show any significant difference with respect to DVT extension, ultrasonographic features of the thrombi and anticoagulant therapy administered.

CONCLUSIONS

The results obtained show a high prevalence of asymptomatic PE in patients with DVT, and suggest the need of an extensive use of lung scan in this kind of patients, and the utility of an early detection of DVT, in order to establish an intense antithrombotic therapy, irrespective of the extension of the thrombus with US.