Is there any difference in aortic wall quality between patients with aortic stenosis and those with regurgitation?

OBJECTIVES The interaction between aortic valve (AV) and aortic wall pathology is currently unclear. No intraoperative examination or investigation is able to predict postoperative dissection or aneurysm formation in patients operated on for primary AV pathology. The aim of the present study was therefore to evaluate the mechanical and histological properties of the aortic wall in patients operated on for aortic stenosis (AS) or regurgitation (AR). METHODS The aortic walls of 229 patients (age 67.5 ± 11.0 years) operated on for AS (n = 135, Group 1) or AR (n = 94, Group 2) were subjected to mechanical stress testing and postoperative histological examination. Ascending aortic diameter was ≥50 mm in 46/229 patients and 40-49 mm in 52/229 patients. RESULTS AR was associated with an increased tendency to aortic media disruption (P < 0.001) and with media degeneration (P < 0.001) compared with AS patients. The incidence of aortic aneurysm (≥50 mm) was increased in AR patients (35 in AR and 11 in AS, P < 0.01). The aortic wall cohesion was better in patients with an aortic diameter of <40 mm compared with those with moderate dilatation of 40-49 mm (P = 0.009) or an aortic aneurysm (P = 0.002). CONCLUSIONS Our study proves that patients presenting for AV replacement with AR have a poorer quality of the ascending aorta despite a superior thickness compared with patients with AS. In addition, patients with a slightly dilated aorta (40-49 mm) have a poorer cohesion of the aortic wall than those with normal aortic dimensions.