Identification of unique characteristics and the management of blunt traumatic aortic injuries occurring at unusual locations in the descending thoracic aorta

Background: The usual location of thoracic blunt traumatic aortic injury (BTAI) is just distal to the left subclavian artery; however, injuries can also be found in other locations in the descending thoracic aorta (DTA). Methods: This is a single-institution, retrospective study, using 74 consecutive BTAI in the DTA. The patients were separated into two groups based on the location of the injury. The proximal group included injuries within 5 cm of the left subclavian artery, whereas the distal group included injuries in the rest of the DTA. A total of 27 factors were compared. Results: Between 2010 and July 2017, we identified 14 of 74 patients (19%) with BTAI in the distal zone. Females were 9 of the 14 (64%) in the distal zone group, whereas females were 16 of 60 (27%) in the proximal zone group (P < .012). Thoracic spine fractures occurred in 7 of the 14 patients (50%) with injuries at the distal zone, whereas they occurred in 12 of the 60 patients (20%) in the proximal zone group (P < .038). Eleven of the 14 distal zone injuries (79%) were grade 1 or 2 compared with 15 of 60 injuries (25%) at the proximal zone (P = .016). Only 2 of the 14 injuries (14%) in the distal zone required an endovascular repair as opposed to 39 of 60 (65%) in the proximal zone (P < .001). The mean hospital duration of stay in patients with BTAI at the distal zone was 8.5 days compared with 20.3 days for patients in the proximal zone group (P < .004). Mortality occurred in 5 of 14 patients (36%) in the distal zone group compared with 5 of 60 patients (8%) in the proximal zone group (P = .017). The odds of mortality from an injury in the distal zone were almost 6-fold greater than the odds of mortality from an injury in the proximal zone (odds ratio, 5.9; 95% confidence interval, 1.2-31.8). No mortalities were related to the BTAI itself. The association of location with mortality remained significant even after adjusting for other significant factors like Injury Severity Score and patient age. Patients who died from injuries in the distal zone had a shorter duration of stay (5 days vs 20 days; P = .0002). Conclusions: BTAI in the distal zone of DTA are associated with unique characteristics. They are (1) more frequently associated with thoracic spine fractures, (2) more common in women, (3) tend to be lower grade, (4) less likely to require intervention, and (5) seem to have a higher mortality owing to other associated traumatic injuries.