Thromb Haemost 2014; 111(01): 10-13
DOI: 10.1160/TH13-07-0562
Clinical Focus
Schattauer GmbH

Mandatory contrast-enhanced venography to detect deep-vein thrombosis (DVT) in studies of DVT prophylaxis: upsides and downsides

Jack Hirsh
1   Department of Medicine, McMaster University, Hamilton, Ontario, Canada
,
Jeffrey S. Ginsberg
1   Department of Medicine, McMaster University, Hamilton, Ontario, Canada
,
Noel Chan
1   Department of Medicine, McMaster University, Hamilton, Ontario, Canada
,
Gordon Guyatt
1   Department of Medicine, McMaster University, Hamilton, Ontario, Canada
,
John W. Eikelboom
1   Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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Weitere Informationen

Publikationsverlauf

Received: 12. Juli 2013

Accepted after major revision: 30. August 2013

Publikationsdatum:
21. November 2017 (online)

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Summary

The introduction of venography into patient care was a major advance because it was the first accurate method for the diagnosis of DVT. Compression ultrasound has since become the preferred test for patients with suspected DVT because, unlike venography, it is simple, non-invasive and widely available. Venography has facilitated the development and approval of new anticoagulants and remains widely used as an efficacy outcome in trials of venous thromboembolism prevention. Most thrombi detected by screening venography are, however, small and unimportant for patients. In order to calculate the trade-off between an asymptomatic thrombus and a bleed we require an estimate of the number of asymptomatic thrombi that must be prevented to avoid a patient-important thrombus. A credible estimate of this ratio is not available. Therefore when used as a measure of efficacy in trials of thromboprophylaxis, venography has limitations for comparing the relative effects of alternative antithrombotic agents on outcomes important to patients.