Are isolated distal deep-vein thromboses clinically significant?

The authors consider isolated distal deep-vein thrombosis (DVT) to be significant and recommend treating isolated symptomatic distal DVT in the same way as proximal lower-limb DVT. There is no guidance for the treatment of asymptomatic isolated distal DVT; however, certain triggers could be used to guide therapy. Our policy is as follows: all patients with distal DVT (asymptomatic and symptomatic) are given graduated compression stockings and early ambulation. We use anticoagulant therapy to treat asymptomatic distal DVT greater than 10 cm in length, or more proximal ones that are near the confluence of the venous trifurcation that forms the popliteal vein. Those patients with asymptomatic thrombi of 5–10 cm and with ongoing risk factors for propagation, for example immobilization or malignancy, generally receive treatment. We generally do not anticoagulate asymptomatic soleal vein and other small isolated distal DVT. We empirically watch untreated patients more closely, with repeat compression ultrasound...