Gender differences in the dissection properties of ascending thoracic aortic aneurysms

Abstract

OBJECTIVES Presentation, management and outcomes in the aortic dissection (AD) of ascending thoracic aortic aneurysm (ATAA) differ in gender and age. The purpose of this study is to investigate the dissection properties of male and female ATAAs. METHODS Peeling tests were performed to quantitatively determine the delamination strength and dissection energy of 41 fresh ATAA samples (22 males and 19 females) in relatively young (≤65 years) and elderly (>65 years) patients. The delamination strength of the ATAAs was further correlated with patient ages for males and females. The histological investigation was employed to characterize the dissected morphology. RESULTS For elderly patients, circumferential and longitudinal delamination strengths of the female ATAAs were statistically significantly lower than those of the males (circumferential: 31 ± 6 vs 42 ± 6 mN/mm, P < 0.01; longitudinal: 35 ± 7 vs 49 ± 10 mN/mm, P = 0.02). No significant differences were found in the delamination strength between males and females for relatively young patients. The circumferential and longitudinal delamination strengths were significantly decreased and strongly correlated with patient ages for females. However, these correlations were not present in males. Dissection routes propagated in the aortic media to create ruptured surfaces for all specimens. Peeling tests of the male ATAAs generate rougher surfaces than females. CONCLUSIONS There is a higher propensity of AD occurrence for the elderly females as compared to males with matched ages. Surgeons should be cognizant of the risk of AD onset later in life, especially in females.

Female Sex Is Not an Independent Risk Factor for Poor Prognosis of Patients with Acute Type A Aortic Dissection Undergoing Surgery

“…Increased arterial stifness in postmenopausal females could be partly ameliorated by estrogen replacement therapy [20,21]. Tong et al found that age-related decrease of the circumferential and longitudinal delamination strengths in elderly females with ascending aortic aneurysm was more prominent than that in elderly males (>65 years), which indicated that elderly females had a higher propensity for dissection occurrence compared with elderly males [22]. Similarly, GERAADA's study also confrmed a higher incidence of TAAD in females older than 75 years [4].…”

Aortic Dissection in Women

“…Older women tend to have stiffer aortas with exaggerated systolic pulse amplification, 7 which may adversely impact hemodynamics, location of intimal tear, and propagation of aortic dissection. The tissue architecture and mechanical properties of the aorta may differ between men and women, 8 predisposing the latter to partial or complete rupture. Indeed, bloodstained pleural effusions were observed more often in women in the present study.…”