Outcomes of Routine Surveillance of Grade 1 Blunt Traumatic Aortic Injury.

Introduction: Blunt traumatic aortic injury (BTAI) can present with a wide range of severity from mild intimal injuries (grade 1) to rupture (grade 4). While there is consensus that patients with grade 3 and 4 injuries should undergo immediate thoracic endovascular aortic repair (TEVAR), the optimal treatment strategy for milder injuries is less clear due to the lack of data regarding the natural history of these injuries. Grade 1 injuries are typically treated with anti-impulse therapy and surveillance imaging. However, the efficacy of this approach remains unclear and therefore the aim of this study was to assess the outcomes of routine surveillance in grade 1 BTAI.

Methods: Electronic medical records of all patients who presented to our institution with BTAI between 1999 and 2024 were reviewed retrospectively. Initial CT scans were reviewed, and patients with grade 1 BTAI were included for further review. All initial follow-up studies were assessed and compared to the initial CT scan.

Results: A total of 542 patients were initially reviewed, of which 165 (18%) presented with grade 1 BTAI. Of these patients 162 (98%) were managed non-operatively whereas 3 (2%) underwent immediate surgical intervention for BTAI. Two patients in the early part of our series underwent diagnostic thoracic aortography without further intervention, and one patient underwent repair of a common carotid injury in addition to TEVAR due to multiple grade 1 injuries. Of these patients, 125 (77%) underwent repeat imaging at a median interval of 7 days (interquartile range 3 - 8 days). The initial surveillance imaging showed absence of injury or improvement in 67 patients (54%), stable grade 1 BTAI in 55 (43%), progression to grade 2 BTAI in 1 patient (0.8%), and progression to grade 3 BTAI in 2 patients (1.6%). The 3 patients who showed progression of BTAI on repeat CT underwent further assessment with thoracic aortography and/or intravascular ultrasound. The patient with progression to grade 2 injury underwent assessment with intravascular ultrasound which ruled out pseudoaneurysm formation, and no further intervention was performed. Of the 2 patients with progression to grade 3 injuries, 1 patient underwent thoracic aortography without further intervention as the injury appeared more consistent with grade 2, whereas the other patient underwent TEVAR.

Conclusion: In our series of patients with grade 1 BTAI who underwent non-operative management and surveillance imaging, the rate of progression of injury on CT was 2.4%. Only 1 patient (0.8%) ultimately underwent interval TEVAR. These findings suggest that the utility of serial imaging in mild BTAI is low in the setting of appropriate non-operative management.