Risk factors predictive of unfavorable distal aortic remodeling after surgical repair of type A thoracic aortic dissection.

BACKGROUND

One-third of the patients successfully treated for acute type A aortic dissection (AAD) require re-intervention secondary to the distal aortic disease progression. The aim of this study is to identify clinical and morphologic risk factors in the pre and postoperative AAD patients with respect to unfavorable aortic remodeling, reoperations and poor long term outcomes.

METHODS

One hundred and twenty-three consecutive patients who survived proximal AAD surgery were reviewed at a single institution. The medical charts and computed tomography (CT) studies of these patients were reviewed from 2005 to 2014. The short axis area of the true lumen (TL), false lumen (FL) and the total cross-sectional area were measured from reconstructed images using centerline technique at the largest segment each of the aortic arch (AA), descending thoracic aorta (TA), aorta proximal to the celiac artery (CA), and the abdominal aorta (AbA). Survival and time to first reoperation were analyzed with Kaplan Meier and Cox proportional-hazards models. Factors associated with radiologic change were evaluated using multiple linear regression models. A significant change was defined as >10% change (cm2) from the baseline CTA.

RESULTS

At least one sequential CT scan was available for 62 (50%) of the 123 patients (40 male, 22 female; average age, 59.1±13.5 years). Mean interval (baseline and the comparison CT scan) was 779 days. In general, the TA and FL increased in size over the study period. Multivariate analysis showed that age >60 years and smoking were significantly associated with an increase in TL over time, while coronary artery disease (CAD) and chronic obstructive pulmonary disease (COPD) were associated with decrease TL (P=0.03). Hyperlipidemia and CAD were associated with an increase in FL size., while pre-existing aortic aneurysm, coronary surgery and hemodialysis were significant risk factors for reoperations (P=0.029). Age >60 (P=0.01), COPD (P=0.002), and male gender (P=0.02) were also associated with an increase in total area, signifying distal aneurysmal progression.

CONCLUSIONS

Patient risk factors predict unfavorable long-term morphologic outcomes in the remaining aorta after AAD surgical repair. These factors can be used as markers to identify patients who may benefit from closer surveillance and possibly earlier endovascular intervention to the distal thoracic aorta.