[When to suspect pulmonary embolism in a patient with deep venous thrombosis?]

The approach to take in trying to establish or disprove a diagnosis of pulmonary embolism in the presence of deep vein thrombosis is the subject of some controversy nowadays. Systematic perfusion lung scan can be proposed, given the mediocre specificity of the clinical symptoms of embolism or the high frequency of asymptomatic pulmonary embolism. This strategy, however, is not validated in terms of cost-efficacy. In practical terms, favourable evolution and the low rate of recurrent embolism observed with a well executed anticoagulant treatment pleads against systematic scintigraphy. Because of its moderate sensitivity, systematic echocardiography probably should not be an element of the assessment of asymptomatic pulmonary embolism. The advent of spiral CT scan in the management of such patients could however make it necessary to reconsider this position, by allowing complete venous and pulmonary examination in thrombo-embolic disease.