Diagnosis of deep vein thrombosis

Venous thromboembolism: diagnosis and current anticoagulation strategies for deep vein thrombosis and pulmonary embolism

The diagnosis and treatment of venous thromboembolic events represents a significant source of medical spending, both domestically and worldwide. Advances in medical imaging and pharmacology continue to alter and improve established treatment paradigms. In this article, we discuss venous thromboembolism etiology, diagnosis, and rationale for current and future treatment strategies.

Comparison of four clinical prediction scores for the diagnosis of lower limb deep venous thrombosis in outpatients

PURPOSE

We compared three scores for the prediction of deep venous thrombosis with a new score designed specifically for outpatients.

METHODS

Patients referred for evaluation because of suspected deep venous thrombosis were examined by ultrasonography. Sensitivity and specificity were calculated for three clinical scores (Wells [nine components], Kahn [four components], and St. André [six components]). We developed a new score by multivariate analysis, and then compared this score with the others in a new sample.

RESULTS

Four hundred and forty-four outpatients were included in the first sample, of whom 126 (28%) had deep venous thrombosis. The Wells score was a better predictor of deep venous thrombosis than the Kahn and St. André scores. According to the Wells score, 73 patients had a high probability of deep venous thrombosis (of whom 51 [70%] actually had a thrombosis) and 178 had a low probability of deep venous thrombosis (of whom 19 [11%] had a thrombosis). A new score was developed as follows: male sex (+1), lower limb palsy or immobilization (+1), confinement to bed >3 days (+1), lower limb enlargement (+1), unilateral lower limb pain (+1), and other plausible diagnosis (-1). In a validation sample of 282 outpatients, this score identified 31 patients who had a high probability of deep venous thrombosis (score > or =3), of whom 18 (58%) had a thrombosis, and 70 patients who had a low probability (score < or =0), of whom 3 (4%) had a thrombosis. The Wells score and this ambulatory score had similar test operating characteristics in the validation sample.

CONCLUSION

Our new six-component score had similar diagnostic utility as the nine-component Wells score among outpatients being evaluated for deep venous thrombosis.

Body MR venography

MRV offers unique diagnostic possibilities for detection and characterization of venous disease. It allows evaluation of perivascular and vascular anatomy, evolution of thromboembolic events, and assessment of vascular flow. MRI is a diagnostic tool that can be tailored for a variety of clinical dilemmas, not only DVTs. Continued improvements in hardware and software will expand the role of MRV.

Emergency department D-dimer testing

Since the early 1980s, much attention has been paid to the development of a biochemical marker for venous thromboembolism. D-dimers are derivatives of fibrinolysis and recently have been touted as a means of screening for thromboemoblism. We review the physiologic, pathologic, and chemical bases for this new test, and outline the specific D-dimer assays currently available. We conclude with a discussion of the clinical utility of D-dimer in the evaluation of patients with venous thromboembolism.