[Distal deep-venous thrombosis: diagnostic and therapeutic issues]

Compression ultrasonography is the reference test for the diagnosis of distal deep venous thrombosis of lower limbs. However, the ways it is performed and the related treatments are very heterogeneous between various countries.

In USA, Canada and Netherlands, compression ultrasonography is restricted to proximal limbs considering that this test is inadequate to explore the distal veins. The strategy consisting of a clinical approach, including the clinical probability and/or a follow-up ultrasonography has demonstrated its efficacy and safety (extension rate to proximal veins of 1.2% at three months and absence of fatal pulmonary embolism). In France, Italy and Spain, lower limb ultrasonography testing includes the examination of calf veins in a so called "complete testing". This procedure leads to the diagnosis of a large number of distal deep venous thrombosis (45-56%) among the 14 to 36% of deep vein thrombosis diagnosed in the setting of clinical suspicion. Recent diagnosis strategy studies have shown that both strategies are effective, but the complete ultrasound strategy doubles the number of anticoagulation treatments. Justification of inappropriate anticoagulation is not evident owing to the relatively low risk of proximal venous-thrombosis extension, the rate of severe hemorrhagic events at three months and the cost excess.

Prospective comparative clinical trials are necessary in distal-venous thrombosis and ongoing Cactus study addresses this therapeutic dilemma.