Blunt Aortic Injury

• Caused by high acceleration/deceleration
• e.g. MVA, MCA, ped vs. auto

• CXR
• Suspicion if:
• widened mediastinum (although only present in 2/3 of cases)
• Indistinct aortic knob (21%)
• ¼ of cases have normal CXRs
Associated injuries





• Closed head – 39%
• Closed head w/ bleed – 22%
• Rib fxs – 68%
• Lung contusion – 42%
• Pelvic fx – 34%
• Femur fx – 25%
• Tibial fx – 25%
• Facial fx – 25%
• Liver – 25%
• Spleen – 13%


Diagnosis
• Gold standard historically aortography

• Newer evidence supports use of CT angiogram
• Very sensitive
• But more false positives

• Advantages of CT over aortography:

• 1) easier, faster, less invasive, less expensive
• 2) pts likely to get CTs for other injuries
• 3) reconstructions can be made
• 4) CT may be better at dx # & extent of injuries
CT angio
• One prospective study evaluated 8000+ CTs for blunt torso trauma over 4 years

• 494 had mediastinal hematoma, or aortic injury, or both on CT
• 71 dx w/ aortic injury
• MVA 92%, ped vs. auto 4%, MCA 3%
• 71% male
• Incidence in MVA – 1.2%

• Sensitivity 100%, Specificity 83%, Positive Predictive Valve 50%
• Aortogram: 92%, 99%, 97%

• Therefore only need aortogram if CT is positive or indeterminate
• this decreased # of aortograms by 66%


Areas most-likely injured
• Where aorta is fixed
• Isthmus – 86%
• Arch – 7%
• Diaphragm – 7%
• Ascending – 1%



CT findings
• Intimal flap
• Minor – 39%
• Moderate – 30%
• Severe – 30%
• Pseudoaneurysm
• Absent – 12%
• Small – 20%
• Medium – 13%
• Large – 55%


Comparison of survivors to non-survivors
• Age
• 36 vs. 47 (p value=0.02)
• Injury severity score
• 31 vs. 39 (p value=0.01)
• Glascow coma scale
• 14 vs. 8 (p value=0.0001)


Treatment
• Immediate operative repair
• Delayed operative repair after medically optimized
• Medical management alone

Operative repair
• Immediate repair if hemodynamically unstable
• Delayed repair if hemodynamically stable & pt has other major injuries
• closed head injury, lung injury, abd injury, etc.
• Close f/u to determine if clinically significant

Medical management
• Use of anti-hypertensives first described at MGH
• Successful in mgt of dissecting aortic aneurysms -> reducing shearing forces
• Goal: maintain MAP of 80, HR < 80
• Beta blockers
• labetalol, esmolol
• Vasodilators if BP not controllable w/ B blockers alone
• Nitroprusside
• One study showed 0/71 ruptures w/ early dx and rx


Endovascular vs. Open repair?
• In one study EV repair had decreased mortality, morbidity & ICU length of stay compared to open repair
• Mortality 0% vs. 17%
• Paraplegia 0% vs. 16%
• Recurrent laryngeal nerve injury 0% vs. 8%