Blunt Aortic Injury
N Engl J Med 2008;359:1708-16.
- Sudden increase in intra-abdominal pressure may explain the association between blunt aortic injury and diaphragmatic rupture.
- "Water-hammer" effect: simultaneous occlusion of the aorta and a sudden elevation in blood pressure
- "Osseous pinch" effect: entrapment of the aorta between the anterior chest wall and the vertebral column.
- The absence of the following signs on CXR were valuable to exclude the diagnosis of aortic injury:
- loss of the aortico-pulmonary window
- abnormality of the aortic arch
- rightward tracheal shift
- widening of the left para-spinal line without associated fracture
- Between 7.3% and 44% of patients with blunt aortic injury may have a normal mediastinum on CXR.
- Helical CT of the thorax is now the diagnostic test of choice (sensitivity 100%).
- Minimal Aortic Injury was defined as an intimalflap of less than 1 cm with no or minimal peri-aortic hematoma, 50% of minimal aortic injuries that were followed up had developed pseudo-aneurysms by 8 weeks after injury.
- If the injury is associated with significant thrombus, peri-aortic hematoma, lumen encroachment, or pseudo-aneurysm, it is our practice to proceed with endograft coverage.
- Advantages of the veno-arterial bypass include the ability to cool the patient, which potentially enhances spinal-cord protection.
- No physiological burden
- In brain injury, the device can be deployed with the head of the bed elevated
- Not require single-lung ventilation
- Minimal or no heparin
- No need for a bypass of any kind
- No cause of paraplegia
Technical Limitations to Endografting
- Injuries that occur adjacent to a sharp bend in the aorta may result in poor apposition of the covered stent to the aortic wall.
- Lesions adjacent to the left subclavian artery.
- Coverage of the left subclavian artery can result in ischemia of the upper extremity or territory perfused by the left vertebral artery.