Aortic Remodeling and Clinical Outcomes in Type B Aortic Dissection According to the Timing of Thoracic Endovascular Aortic Repair

The objective of the study was to investigate aortic remodeling and clinical outcomes after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (AD) according to timing of the procedure.A total of 87 patients with type B AD who underwent TEVAR at 2 centers were included in this retrospective analysis. Patients were divided into acute/subacute (≤6 weeks, n = 35), early chronic (6 weeks to 1 year, n = 20), and late chronic (1 year, n = 32) groups according to the timing of TEVAR after symptom onset. Changes in aorta dimensions on serial computed tomography angiograms and clinical outcomes were evaluated.AD complications were the most common indication for TEVAR in the acute/subacute group, whereas aortic expansion was the main reason in the early and late chronic groups. Maximum total aorta diameter (46.6 ± 10.6 vs. 54.8 ± 9.8 vs. 56.7 ± 10.1 mm, P 0.001) and false lumen diameter (30.9 ± 11.0 vs. 35.2 ± 12.0 vs. 39.9 ± 13.4 mm, P = 0.013) were smaller in the acute/subacute group than in the early and late chronic groups. At 1-year follow-up, maximum total aorta diameter was decreased in the acute/subacute and early chronic groups and increased in the late chronic group (-4.3 ± 9.3 vs. -5.2 ± 6.9 vs. 2.5 ± 4.6 mm, P 0.001). Survival free from the major adverse aortic event (death, aortic rupture, or reintervention) at 5 years after TEVAR was lowest in the late chronic group (92.6% vs. 88.2% vs. 73.1%, P = 0.033) but not significantly different between the acute/subacute and early chronic groups (P = 0.680).TEVAR in the acute/subacute and early chronic phases of type B AD resulted in similar aortic remodeling and clinical outcomes, which were more favorable than those with TEVAR performed during late chronic AD. This finding suggests 1 year after the onset of type B AD symptoms as the upper time threshold for TEVAR to achieve optimal aortic remodeling and safety.