Long Term Stent Graft Durability and Aortic Remodelling after Thoracic Endovascular Aortic Repair for Blunt Traumatic Aortic Injury.

OBJECTIVE: The aim of this study was to assess long term stent graft durability after thoracic endovascular aortic repair (TEVAR) for blunt traumatic aortic injury (BTAI). Secondary objectives were to evaluate aortic remodelling, to explore anatomic predictors of adverse imaging findings, and to assess imaging modalities and frequency of post-treatment surveillance. METHODS: This was a retrospective, multicentre, imaging based observational study of patients treated with TEVAR for BTAI (2001 - 2021) at four tertiary centres in Sweden. Patients surviving > 1 year were eligible. Inclusion required at least three computed tomography (CT) scans (pre-treatment, early post-treatment, and > 1 year after TEVAR). All CT scans were re-analysed at a single core facility using a pre-defined protocol. TEVAR related adverse findings included endoleak, graft infolding, fracture, collapse, thrombosis, or aneurysm formation. The report was structured according to the STROBE protocol for observational studies. RESULTS: Of 95 treated patients, 43 met the imaging follow up criteria. Most patients were male (86%), median age 42.1 years; ESVS grade II injury predominated (53%). Median follow up was 9.4 years (interquartile range 2.8, 12.7), with a median imaging frequency of 0.7 examinations/year. Adverse imaging findings occurred in nine patients (21%). Aortic dimensions increased significantly over time. From the early post-operative imaging to last follow up, the mean diameter increased by 4.7% (p < .001) at the level of the left subclavian artery, and in the descending aorta 2 cm distal to the stent graft the median diameter increased by 8.3% (p < .001). Aortic length increased in the ascending aorta by 9.5% (p = .037), in the arch by 8.4% (p = .028), and in the descending segment by 2.0% (p = .006). No anatomic variable predicted adverse imaging findings, but bird beak occurred in more than half of the patients and proved to be a dynamic phenomenon, capable of both appearing de novo and spontaneously regressing during follow up. CONCLUSION: In patients surviving the early phase, TEVAR for BTAI demonstrated durable outcome up to 10 years, with low risk of failure in patients with 2 years of uneventful initial follow up. However, progressive aortic remodelling persisted, with significant increases of both aortic diameters and lengths despite the relatively young age of the cohort, underlining the need for continued lifelong surveillance.