Abstract
An aorta is directly connected to a heart and a large artery. Therefore, aortic injury is severe trauma that leads to massive hemorrhage. For safety reasons to prevent the thoracic aortic injury in the traffic accident, it is essential to understand the mechanical properties of aorta. We conducted the internal pressure tests using thoracic aortas that were removed from fresh hogs slaughtered for meat packing. The fluid circulation system was developed and, specimens were inflated using three kinds of fluids (water, saline, and methylcellulose). The internal pressure, external diameter, and longitudinal elongation were measured, and their relationships were evaluated. Furthennore, the difference of mechanical properties between proximal and distal thoracic aorta was studied. We found that the external diameter and longitudinal elongation did not change in the range of approximately 200 to 600 mrnHg. Additionally, it was shown that the mechanical properties are affected by osmotic pressure and viscosity of the circulation fluid.
