Injury to the thoracic aorta following fatal blunt trauma : an autopsy study

Background: Transection of the thoracic aorta (TTA) remains a leading cause of death after blunt trauma. In this autopsy study, the natural history of this injury is reviewed. Patients and Methods: All blunt trauma deaths that occurred in the Milano urban area over a period of one year were collected. Autopsies were available in all cases. Incidence, mechanisms, anatomical locations of TTA, deaths due to TTA or coexisting injuries, and times of death were reviewed. Cause of death was established. Death was attributed to TTA if its abbreviated injury score was six (hemorrhage not confined to the mediastinum). Results: 199 cases of fatal blunt trauma were included, 72% of which were males; mean age 53 ± 21. A TTA was observed in 53 subjects (27%), with a significantly higher incidence between the ages of 45 and 64 years and after falls from height. The aorta was transected at the isthmus in 36% of cases. Victims with TTA had a higher pre-hospital mortality and more injuries to chest organs, the chest wall and pelvis. In victims with TTA, injury to the aorta was the cause of death in 58%. Only five patients with TTA survived more than 1 h, reaching the hospital alive; four of these died due to the rupture of a mediastinal hematoma during the first hours of in-hospital care. Conclusions: This study demonstrates that TTA is a frequent cause of immediate deaths among blunt trauma victims. Patients with risk factors for TTA who reach the hospital alive need to be promptly investigated with a contrast CT scan. Evidence of mediastinal hematoma is suggestive for possible rapid evolution.