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

ABSTRACT

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.