Atypical profile of aortic injury associated with blunt trauma in the metropolitan area of Japan

BACKGROUND: Aortic injury caused by blunt trauma is a critical medical condition that requires extraordinary caution in the treatment. It is often caused by direct hit and high-speed deceleration in motor vehicle accidents. We reviewed and analysed the cases of aortic injury that referred to our institution located in the midst of the metropolitan area of Tokyo, Japan. METHODS: We retrospectively reviewed the blunt trauma cases transferred to Tokyo Medical and Dental University Hospital in the past 10 years. All cases with aortic injury were analyzed regardless of the AIS scores. Results: Between 2007 and 2017, a total of 3500 blunt trauma cases were transferred. Nineteen cases showed aortic injuries associated with blunt trauma (Age: 63.5±15.6 y.o.; 15 males). Thirteen patients were injured by fall, four patients were senior pedestrians hit by cars, one was injured while riding a motor bike, and one was hit by a train. A total of 11 cases presented a cardiopulmonary arrest on arrival; 8 severe aortic injuries, 1 cardiac rupture; and 2 multiple injuries. Eight cases were alive on arrival; 3 Stanford type A aortic dissections, 3 Stanford type B aortic dissections, and 2 aortic ruptures. Two cases of Stanford type A dissection underwent emergency repairs, whereas all 3 type B dissections went on a good course with conservative treatment. CONCLUSIONS: Aortic injury caused by blunt trauma seems to be rare in a metropolitan area in Japan. In addition, the leading cause in our cases was fall, which might be a rare cause of aortic injuries in the other countries. Our observation might be a manifestation of population aging.