In vivo evaluation of aorta remodeling in ascending aortic aneurysm：effect of size and sex

WANG Feng; LIN Bin; FENG De-guang; CHENG Zhao-yun; WANG Jia-xiang; XU Cheng-yang; XIE Zhou-liang

Abstract：Objective To evaluate the effect of size of ascending aortic aneurysm and sex on remodeling and me -chanical characteristics of aorta .Methods 67 patients with ascending aortic aneurysm undergoing selective surgery and 90 control patients with normal aortas undergoing coronary artery bypass grafting were selected .According to aneurysm di-ameter, 67 patients were further divided into 4 subgroups, <4 cm (n=11), 4-5 cm (n=9), 5-6 cm (n=31) and>6 cm (n=16).Aortic distensibility (Dist), wall stress (WS) and incremental elastic modulus (Einc) were measured in all patients .Results Mean end-systolic diameter was significantly shorter than end -diastolic diameter in the aneuris-mal and control groups and all 4 subgroups (P<0.05), which was more evident in men than in women (P<0.05).Aor-tic distensibility was reduced in both male and female groups (P<0.05).Wall stress increased with increaseing aortic di-ameter, comparing the 4 aneurysmal subgroups and the control group .Incremental elastic modulus was elevated in the an-eurismal group than in the control group ( P<0.05 ) , showing an increasing trend with increasing diameter of aneurysm (P<0.05).Conclusion There may be differences between male and female in the remodeling and biomechanical char-acteristics of the aorta , where aortic diameter and aortic wall stress were less in female .When aortic diameter is greater than 5 cm, remodeling occurs in a geometrical change in morphology .When aortic diameter is greater than 6 cm, aortic wall thickness decreases more evidently , giving rise to a rapid increase in the occurrence of acute vascular events , e.g. aortic dissection formation or rupture .