Late post-AVR progression of bicuspid aortopathy: link to hemodynamics

Background and aim of the study The ascending aortic dilatation may progress after aortic valve replacement (AVR) in bicuspid aortic valve (BAV) patients. Our aim was to evaluate rheological flow patterns and histological characteristics of the aneurysmal aorta in BAV patients at the time of reoperative aortic surgery. Materials and Methods 13 patients (mean age: 42 +/- 9 years, 10 (77%) male) with significant progression of proximal aortopathy after isolated AVR surgery for BAV disease (i.e., 16.7 +/- 8.1 years post-AVR) were identified by cardiac phase-contrast cine magnetic resonance imaging (MRI) in our hospital. A total of nine patients (69%) underwent redo aortic surgery. Based on the MRI data, the aortic area of the maximal flow-induced stress (jet sample) and the opposite site (control sample) were identified and corresponding samples were collected intraoperatively. Histological sum-score values [i.e. aortic wall changes were graded based on a summation of seven histological criteria (each scored from 0 to 3)] were compared between these samples. Results Mean proximal aortic diameter at MRI follow-up was 55 +/- 6 mm (range 47-66mm). Preoperative cardiac MRI demonstrated eccentric systolic flow pattern directed towards right-lateral/right posterior wall of the proximal aorta in 9/13 (69%) patients. Histological sum-score values were significantly higher in the jet sample vs control sample (i.e., 8.3 +/- 3.8 vs 5.6 +/- 2.4, respectively, p = 0.04). Conclusions Hemodynamic factors may still be involved in the late progression of bicuspid aortopathy even after isolated AVR surgery for BAV disease.