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

Diagnosis

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%

CT angio

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 <>

Medical management

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%