Biomechanical characterization of internal layer subfailure in blunt arterialinjury.
Stemper,BD; Yoganandan,N; Sinson,GP; Gennarelli,TA; Stineman,MR; Pintar,FA
Abstract Blunt carotid artery injuries occur in 0.3% of blunt injured patients and maylead to devastating neurological consequences. However, arterial mechanics leading to internallayer subfailure have not been quantified. Twenty-two human carotid artery segments and 18 porcinethoracic aorta segments were opened to expose the intimal side and longitudinally distracted tofailure. Porcine aortas were a geometrically accurate model of human carotid arteries. Internallayer subfailures were identified using videography and correlated with mechanical data.Ninety-three percent (93%) of vessels demonstrated subfailure prior to catastrophic failure. Allsubfailures occurred on the intimal surface. Initial subfailure occurred at 79% of the stress and85% of the strain to catastrophic failure in younger porcine specimens, compared to 44% and 60%,respectively, in older human specimens. In most cases, multiple subfailures occurred prior tocatastrophic failure. Due to limitations in human specimen quality (age, priorstorage), young andfresh porcine aorta specimens are likely a more accurate model of clinical blunt carotid arteryinjuries. Present results indicate that vessels are acutely capable of maintaining physiologicfunction following initial subfailure. Delayed symptomatology commonly associated with bluntarterial injuries is explained by this mechanics-based and experimentally quantified onset ofsubcatastrophic failure.
Keywords Carotid Artery Injuries; Endothelium, Vascular; Models, Cardiovascular;Thoracic Arteries
Annals of Biomedical Engineering
0090-6964, Volume 35, Issue 2, 2007, Pages 3-291
