Thoracic Aortic Dilation after Endovascular Repair of Blunt Traumatic Aortic Injury

Background: Thoracic endovascular aneurysm repair (TEVAR) has become the current standard of care for emergent treatment of traumatic blunt thoracic aortic injuries (BTAI). Although aortic dilation (AD) of the infrarenal neck after EVAR for aortic aneurysms has been studied, changes in aortic diameter after TEVAR for BTAI is not well understood. This study aims to characterize changes in thoracic aortic diameter after stent-graft placement in the setting of nonaneurysmal traumatic aortic injury. Methods: A single-center, retrospective review was performed involving patients presenting with BTAI treated with TEVAR. Only patients with at least 12 months follow-up were included. Aortic diameter, defined as the outer-to-outer diameter on 3D center-line imaging, was measured at six locations along the proximal and mid thoracic aorta. The first postoperative CT (<= 1 month) served as a baseline from which interval measurements were compared. Results: Twenty patients with BTAI treated from 2011 to 2017 had adequate imaging available for review and were included in this study cohort. Median follow-up time was 46.8 (12-80, range) months. At the latest follow-up, AD occurred at all measured locations within the endograft, starting from the proximal graft edge (0.62 +/- 0.69 mm, P = 0.027) to the distal graft edge (1.21 +/- 1.28 mm, P = 0.003). AD was most pronounced in the distal graft segment 2 cm proximal to the distal graft edge, with a mean AD of 1.32 +/- 1.59 mm (+5.3%, P 0.001). At this location, AD was found to increase in a linear manner with an estimated rate of 0.67 +/- 0.20 mm/year (P = 0.006). The native aorta proximal and distal to the endograft was not found to significantly dilate during follow-up (P = 0.280-0.897). Seventy percent of the patients were found to have AD 5%. The amount of AD was not found to be associated with either graft oversizing (P = 0.151) or age (P = 0.340). There were no cases of graft migration, erosion, or endoleak. Conclusions: AD is a common benign finding after TEVAR for BTAI. AD is most pronounced at the near the distal end of the stent graft. In late-term follow-up, there are no known associated complications related to AD.