**10. Conclusions / open questions**

About 5% of all thromboses are expected to occur in the deep veins of the upper extremities. Besides effort-related thromboses, most patients with arm vein thrombosis have typical risk factors, like central venous catheters or malignancies. Typical clinical syndromes include edema and localized pain, whereas other patients are asymptomatic or present with complex syndromes. Today, diagnosis will most often be performed by ultrasound; in some cases additional testing (e.g. computed tomography scanning, magnetic resonance imaging) will be necessary. The most important complications are recurrent thrombosis, pulmonary embolism and post-thrombotic syndrome. Treatment should be initiated without delay and consist in most cases of standard anticoagulation treatment with heparins followed by a vitamin K antagonist for at least 3 months. In selected cases, invasive therapeutic regimes including catheter-guided thrombolysis and surgical procedures may be applied. Routine prevention of catheter-related thrombosis or embolic complications by anticoagulants in prophylactic doses or implantation of superior vena cava filters is not recommended. Compared to deep vein thrombosis of the lower extremities, deep vein thrombosis of the arm veins has been studied much less intensely. For example, the optimal duration of anticoagulant therapy and the value of compression therapy are not precisely known for arm vein thromboses. Therefore, many of the current recommendation are in fact extrapolations from data on deep leg vein thrombosis. Specific studies are needed to better understand the pathogenesis of deep vein thrombosis of the arms and to improve diagnostic and therapeutic strategies.
