MCQ Surgery Answer 12

The Correct Answer is C

Aortic injury is one of the deadliest injuries and often is difficult to diagnose. It is being seen with increasing frequency in motor vehicle accidents due to the increase in traveling speed over the years. Of the trauma victims with an aortic injury who survive the accident to be transported to the hospital, about 70% will survive if the diagnosis is made promptly and intervention is available without delay.

The majority of aortic ruptures occur in the descending aorta (80-90%) just distal to the origin of the left subclavian artery. Even though only 9-10% of aortic ruptures occur in the ascending aorta, they are identified as a lethal injury 70-80% of the time. Blunt force injury to the chest can cause a "shearing" force to the aorta due to sudden deceleration. Lacerations to the aorta from this shearing force can be small, or may cause a complete fracture of the aorta. The patient who has suffered blunt chest or thoracic trauma must be considered to have an undiagnosed aortic injury until fully evaluated at the trauma center.

Upon initial examination the patient may present with upper extremity hypertension and pulse discrepancies. Femoral pulses will probably be absent.

Chest radiographs typically show:

• Widened mediastinum
• Displacement of the left mainstem bronchus
• Aortic knob distortions
  

If a nasogastric tube has been inserted, a displacement of the esophagus may also be visualized.

Thoracic CAT scans and aortography are useful in diagnosis of this phenomenon, but often the patient is too unstable to tolerate these procedures. Once the diagnosis is confirmed, the patient will need immediate surgical repair of the aortic laceration. If it is believed that the patient will not survive long enough to reach the operating suite, emergency thoracotomy is necessary in the emergency department.

Category: Surgery MCQs