Biomechanical analysis identifies the sinotubular junction as the weakest region of the healthy human ascending aorta, correlating with clinical observations of aortic dissection tear sites.
The finding of weakest region at the sinotubular junction along the longitudinal direction corroborates clinical observations of that region being commonly involved as the initial site of intimal tear in aortic dissections. Failure stretch ratios correlated to elastic modulus at each region. Furthermore, strong correlation was seen between STJ failure stresses and elastic modulus at physiological pressure along both circumferential and longitudinal directions. Correlating in-vivo aortic elastic modulus based on in-vivo imaging with experimentally determined elastic modulus at physiological pressure and failure stresses may potentially provide valuable information regarding aortic wall strength. Better understanding of aortic biomechanics in normal physiologic and aneurysmal pathologic states may aid in determining risk factors for predicting dissection in patient-specific fashion.
Xuan et al. (Sat,) studied this question.