LAUSR

Objective: This study investigated the growth and behavior of the ascending aorta in patients with descending thoracic aortic disease. Methods: We examined 200 patients with descending thoracic aortic disease including acute type B dissection (n = 95), chronic type B dissection (n = 38), intramural hematoma (n = 23), and thoracoabdominal aortic aneurysms (n = 44). Images from computed tomography and magnetic resonance imaging were evaluated after three‐dimensional reconstruction to examine the growth rate in those with >1 year of imaging follow‐up (n = 108). Survival data were derived from all 200 patients in this study. Results: Average proximal aortic dimensions at the index image were relatively small, measuring 3.65 ± 0.51 cm in the root, 3.67 ± 0.48 cm in the ascending aorta, and 3.50 ± 0.44 cm in the proximal arch. Average growth rate was low for the aortic root, ascending aorta, and proximal arch at 0.36 ± 0.64 mm/y, 0.26 ± 0.44 mm/y, and 0.25 ± 0.44 mm/y, respectively. There was no difference in baseline proximal aortic dimensions and growth rate between the four subgroups. An index aortic diameter ≥4.1 cm grew faster than those <4.1 cm at the ascending aorta (P = .028) and proximal arch (P = .019). There was no difference in aortic growth rates at the aortic root (P = .887). After the index scan, five patients underwent six ascending aortic replacement procedures, leading to a 3% ascending aortic intervention rate. Overall median life expectancy was 86.15 years. Conclusions: Native ascending aortic growth in patients with descending thoracic aortic disease is slow. We suggest regular follow‐up for index ascending aorta ≥4.1 cm because of its larger initial size and more rapid growth.