Type:
Educational Exhibit
Keywords:
Arteries / Aorta, Emergency, Interventional vascular, CT, CT-Angiography, Conventional radiography, Contrast agent-intravenous, Normal variants, Education and training, Trauma, Dissection
Authors:
I. Vasvary1, M. Meissnitzer2, T. Meissnitzer3, R. Gottardi4, K. Hergan2, R. Forstner2; 1Mondsee, AU/AT, 2Salzburg/AT, 3Mariapfarr/AT, 4Vienna/AT
DOI:
10.1594/ecr2013/C-1933
Background
Blunt aortic injury is a severe and life-threatening concern which is most commonly associated with deceleration or crush injury.
It is the second most common cause of death in blunt trauma patients,
most often in high velocity MVC (motor vehicle collisions).
Only about 10-20% of the patients reach the emergency departement livelily whereas hemodynamically unstable patients have a 2% chance of survival.
So fast an accurate diagnosis is vital.
Anatomy:
The thoracic aorta is divided into 4 parts (max.
diameter in cm )
- aortic root (4 cm)
- ascending aorta (3,7 cm)
- aortic arch (2,7 cm)
- descending aorta (2,9 cm)
The most immobile parts are the root and the attachment of the ligamentum arteriosum – a non-functional vestige of the ductus arteriosus Botalli – attached on the pulmonary trunk and the aortic arch,
just distal to the origin of the left subclavian artery.
Trauma mechanism:
The mechanism of aortic injury is based on a combination of forces such as shearing,
streching and torsion,
the waterhammer effect (sudden elevation of intraluminal blood pressure through deceleration) and the osseous pinch (entrapment of the aorta between the sternum and the vertebral column).
90% of the aortic injuries occur at the attachment of the ligamentum arteriosum,
5% at the ascending aorta including the aortic root.
Lesions of the aortic wall range from small intimal flaps,
medial tears and pseudoaneurysms (adventitia remains intact) to complete ruptures of the aortic wall with mediastinal hemorrhage.