Distal deep vein thrombosis: is there a way out of this dark forest?

Isolated distal deep vein thrombosis (IDDVT) represents a common manifestation of venous thromboembolism (VTE), accounting for up to 50% of cases involving lower-extremity deep vein thrombosis (DVT). In contrast to proximal DVT, IDDVT exhibits a higher association with transient risk factors and less frequently occurs spontaneously. IDDVT generally entails a substantially lower risk of proximal extension, pulmonary embolism, post-thrombotic syndrome, and recurrence compared to proximal DVT. Nevertheless, specific patient subgroups, including those with active cancer, prior VTE, unprovoked IDDVT, and involvement of more than one vein, demonstrate a noteworthy recurrence risk. Unlike proximal DVT, the optimal therapeutic management of IDDVT remains uncertain. In clinical practice, the predominant approach for managing IDDVT involves anticoagulation rather than ultrasound imaging surveillance, due to a significant reduction in the risk of proximal extension and recurrence. Conversely, serial imaging is typically preferred for individuals without risk factors for extension or at high risk for bleeding. Finally, anticoagulant duration relies on the different risk of VTE recurrence within the specific patient subgroups considered. This review offers an updated overview of the epidemiology, risk factors, and natural history of IDDVT, emphasizing therapeutic management in accordance with current guideline recommendations and the latest evidence, trying to provide a way out of this dark forest.