Deep venous thrombosis and thrombophilia: indications for testing and clinical implications.

In the past 3 decades, numerous biological abnormalities linked with deep venous thrombosis have been described. Among the different possibilities, it is crucial to order tests that can modify the therapeutic attitude towards the patient and/or his family. A combined clinical and laboratory approach taking into account the history of the patient and his family, the prevalence of the defects, and also the accuracy of the tests should allow tailoring a laboratory testing program to each patient. It is essential to keep in mind that the more difficult task is not to perform the tests but to consider who will benefit from testing both for prevention and therapy of venous thromboembolism. This article provides answers to some of these issues. These answers should, however, be considered as tentative and provisional because new findings and study results will certainly modify them in the near future.