Disaster-associated venous thromboembolism countermeasures in Japan: Insights from past major earthquakes

Japan experiences more than 1000 perceptible earthquakes annually, including major events such as the 2011 Great East Japan Earthquake and the 1995 Great Hanshin-Awaji Earthquake. These events lead to a documented increase in cardiovascular events, particularly venous thromboembolism (VTE), including pulmonary embolism and deep vein thrombosis (DVT). Disaster-associated VTE is influenced by Virchow's triad: hemodynamic stasis, hypercoagulability, and endothelial injury. The incidence of DVT after earthquakes ranges from 10% to 30%, often developing 1 to 2 weeks post disaster. Early interventions in evacuation shelters to prevent venous stasis and hypercoagulability are critical. Left untreated, DVT can progress to pulmonary embolism, which may be fatal; however, most cases are preventable through timely intervention and improved shelter environments. Various organizations, including the Disaster Medical Assistance Team, the Japan Medical Association Team, and local institutions, contribute to disaster medical responses. In 2016, the Disaster Countermeasure Committee was established by the Japanese Society of Phlebology to lead VTE prevention efforts, including DVT screening, compression stocking distribution, public awareness campaigns, and promoting cardboard beds to enhance shelter conditions. In preparation for future large-scale disasters, it is vital to share evidence-based knowledge with health care professionals and the public to decrease the burden of disaster-associated VTE.