Prognostic implications of descending thoracic aorta dilation after surgery for aortic dissection

Background: The present study assessed whether descending thoracic aorta growth can be measured reliably by volumetric analysis using multi-detector row computed tomography (MDCT) and whether growth influences the need for future aortic interventions in survivors of acute type A aortic dissection. Methods: A total of 51 patients (58 +/- 11 years, 61% male) who underwent surgery for type A aortic dissection with >= 2 postoperative MDCT scans >= 5 months apart were included. Volumetric analysis of the descending thoracic aorta was performed with acceptable intraobserver variability. Growth of the complete, false and true lumen was estimated in ml/year and defined as slow growth (<= average growth) or fast growth (>average growth). Results: The complete lumen volume increased from 133 +/- 8 ml to 163 +/- 9 ml after 3.5 years follow-up (p < 0.001), with an average growth rate of 6.1 ml/year. The false lumen volume increased from 81 7 ml to 106 +/- 12 ml (p = 0.018) with an average growth rate of 2.8 ml/year. The true lumen changed only slightly from 59 +/- 4 ml to 65 +/- 8 ml (p = 0.205). Five-year freedom from descending thoracic aorta intervention was significantly lower in patients with above-average growth of the complete lumen (80 +/- 9%) compared to slow growth (100%; p = 0.003). Similar observations were made for the false lumen (fast: 74 +/- 12% vs. slow: 100%; p = 0.042). Conclusions: Increased growth of the false lumen of the descending thoracic aorta after type A aortic dissection was associated with a higher risk of secondary interventions. (C) 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.