Unusual site venous thromboembolism (VTE) refers to thrombosis occurring in venous districts outside the veins of the lower extremities and the pulmonary arteries, and includes splanchnic vein thrombosis (SVT), cerebral vein thrombosis (CVT), retinal vein thrombosis, ovarian vein thrombosis, and renal vein thrombosis. The use of the novel direct oral anticoagulants (DOAC), thrombin or factor Xa-inhibitors (such as dabigatran, apixaban, edoxaban, rivaroxaban), in patients with unusual VTE in clinical practice is increasing. Through an international multicentre prospective registry, the investigators aim to evaluate the rationale for the use of the DOAC for the treatment of unusual site VTE and to assess the safety and effectiveness of this approach in real life clinical practice.

Inclusion Criteria:

• Objective diagnosis of venous thrombosis not involving the upper limbs, lower limbs and pulmonary arteries
• Treatment with one of the DOAC (e.g. apixaban, dabigatran, edoxaban, rivaroxaban)

Exclusion Criteria:

• Enrolment in interventional studies evaluating the DOAC for the treatment of unusual site VTE

All consecutive patients who fulfill the inclusion/exclusion criteria at the participating thrombosis centers will be eligible