Abstract 3539: Long-term Predictors of the Aneurysmal Change of Descending Aorta in Patients with Aortic Dissection
Background: Long-term natural history of the distal aortic dissection (AD) and predictors of the late aneurysmal change have yet to be demonstrated.
Methods: Contrast-enhanced computed tomography (CT) was performed during the acute phase in 100 patients including 49 patients with type 3 AD and 51 with type 1 AD. All patients with type 1 AD received ascending aorta graft replacement. Clinical observation was conducted for 53±26 months, and CT was repeated after 31±27 months in 97 patients. Aorta diameters and false lumen diameters were measured in upper (UT), mid (MT) and lower descending thoracic (LT), and abdominal aorta (AA).
Results: Average rates of diameter dilatation in UT, MT, LT and AA were 0.19, 0.19, 0.17, and 0.09 mm/month, respectively. These rates were not different between type 1 and 3 AD. Aneurysmal change (diameter ≥ 60 mm) occurred in 14.4, 8.2, 4.1, and 3.1% of patients at UT, MT, LT and AA, respectively. Among 53 patients in whom CT was repeated after ≥ 2 years, aneurysmal change was developed in 15 patients (28%). The false lumen diameter at UT (p<0.005), aorta diameter at MT (p<0.05) in the acute phase CT and Marfan syndrome (p<0.05) were independent predictors of the late aneurysmal change by multiple logistic regression analysis. False lumen diameter at UT ≥ 22 mm in the initial CT predicted late aneurysmal change with sensitivity 100% and specificity 76%. The patients with initial false lumen diameter at UT ≥ 22 mm (n=42) showed higher event rate (aneurysmal change or death) than others (n=58) (Figure⇓).
Conclusion: UT is the major site of late aneurysmal change. A large false lumen diameter at UT in the initial CT portends late adverse outcome warranting early intervention.