Travelers' Thrombosis

Long-haul flights are associated with about a threefold increased risk of venous thrombosis, which corresponds to about 1 in 4500 long-haul passengers in absolute terms. Increasing duration of the flight and making several flights in a short time frame lead to higher risks. Several high-risk groups are known (i.e., tall, short, and obese people, people with a genetic predisposition, oral contraceptive users, and patients with cancer or who underwent recent surgery, as well as people with a history of venous thrombosis). Prevention can generally be limited to encouraging exercise and discouraging behavior that will restrict movement. There is a need for studies into the efficacy and safety of preventative measures in high-risk individuals. Until such data are available, patients perceived to be at high risk may benefit from a short period (1–3 days) of low molecular weight heparin (LMWH) therapy starting 6–12 hours before the flight.