Long-term predictors of descending aorta aneurismal change in patients with aorta dissections

Abstract

Conclusion: Aneurysmal dilatation as a late manifestation of aortic dissection is most likely to take place in the upper thoracic aorta. Aneurysmal dilatation of the upper thoracic aorta is predicted by a large false lumen diameter on the initial computed tomography (CT) scan. Summary: After acute aortic dissection, late aneurysmal dilatation of the aorta is a significant complication. The authors sought to demonstrate the long-term natural history of descending aorta dilatation after acute aortic dissection. They also sought to identify early predictors of late aneurysmal change in the dissected aorta. Contrast-enhanced CT scans for acute aortic dissection were performed in 100 patients. There were 51 patients with DeBakey type 1 dissections and 49 patients with DeBakey type 3 dissections. The patients with type 1 dissections underwent ascending aortic surgery ≤24 hours of diagnosis. Clinical follow-up was for 53 ± 26 months, and CT scans were repeated at a mean of 31 ± 27 months. Aortic dilatation to >60 mm occurred in 14.4% of the upper thoracic descending aortas, 8.2% of the middle descending thoracic aortas, 4.1% in the lower descending thoracic aortas, and in 3.1% of the abdominal aortas. A repeat CT scan was done in 53 patients >2 years after the initial dissection. On the basis of these scans, rates of aortic enlargement per year at the upper, middle, and lower thoracic, and abdominal aorta levels were 3.43 ± 3.66, 3.21 ± 2.70, 2.62 ± 2.19, and 1.93 ± 3.66 mm, respectively (P < .01). Aneurysms developed in 28%. Predictors of late aneurysmal change included the initial false lumen diameter of the upper thoracic aorta, aortic diameter in the middle thoracic aorta, and Marfan syndrome. A ≥22-mm initial false lumen diameter of the upper thoracic aorta predicted late aneurysmal degeneration with a sensitivity of 100% and a specificity of 76%. The 42 patients with initial upper thoracic aorta false lumen diameters ≥22 mm also had a higher rate of the combination of aneurysm formation and death (P < .001). Comment: The study suggests patients with acute aortic dissection with large false lumens of their upper thoracic aorta may be ones where prophylactic stent grafting might be beneficial. A European trial that has either just begun, or will begin soon, is investigating the impact of stent grafting on uncomplicated acute type 3 aortic dissections, the ADSORB (Acute Dissection Stenting or Best Medical Treatment study). Results of this trial will, hopefully, help determine the optimal role of stent grafting for acute aortic dissection.