Predictive biomechanical analysis of ascending aortic aneurysm rupture potential.
Aortic aneurysm is a leading cause of death in adults, often taking lives without any premonitory signs or symptoms. Adverse clinical outcomes of aortic aneurysm are preventable by elective surgical repair; however, identifying at-risk individuals is difficult. The objective of this study was to perform a predictive biomechanical analysis of ascending aortic aneurysm (AsAA) tissue to assess rupture risk on a patient-specific level. AsAA tissues, obtained intra-operatively from 50 patients, were subjected to biaxial mechanical and uniaxial failure tests to obtain their passive elastic mechanical properties. A novel analytical method was developed to predict the AsAA pressure-diameter response as well as the aortic wall yield and failure responses. Our results indicated that the mean predicted AsAA diameter at rupture was 5.6 ± 0.7 cm, and the associated blood pressure to induce rupture was 579.4 ± 214.8 mmHg. Statistical analysis showed significant positive correlation between aneurysm tissue compliance and predicted risk of rupture, where patients with a pressure-strain modulus ≥100 kPa may be nearly twice as likely to experience rupture than patients with more compliant aortic tissue. The mechanical analysis of pre-dissection patient tissue properties established in this study could predict the "future" onset of yielding and rupture in AsAA patients. The analysis results implicate decreased tissue compliance as a risk factor for AsAA rupture. The presented methods may serve as a basis for the development of a pre-operative planning tool for AsAA evaluation, a tool currently unavailable.
Tissue Mechanics Laboratory, Biomedical Engineering Program and Mechanical Engineering Department, University of Connecticut, Storrs, CT 06269, United States.
Caitlin
C
Martin
Wei
W
Sun
Thuy
T
Pham
John
J
Elefteriades
D001014:Aortic Aneurysm / Q000503:physiopathology*; D001019:Aortic Rupture / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D001794:Blood Pressure; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged
Ascending aortic aneurysm; Bicuspid aortic valve; Bovine aortic arch; Rupture potential