Manubrial Fracture with an Associated Innominate Artery Injury

Abstract

A 21-year-old man was a restrained front-seat passenger in a high-speed head-on motor vehicle crash. Initial chest radiograph showed an abnormal mediastinum (Fig 1); subsequent contrast-enhanced chest computed tomography (CT) angiography showed a mediastinal hematoma and innominate artery dissection (Fig 2). Sagittal reformatted images demonstrated a manubrial fracture immediately anterior to the vascular injury. Conventional angiography confirmed the innominate artery dissection and also showed an additional left common carotid artery origin injury not seen on CT (Fig 3). These injuries were confirmed and repaired at surgery. In blunt chest trauma, sternal fractures are uncommon, seen in 8%-10% of patients in 1 series 1 and 1.5%-4% of patients in another. 2 Risk factors for sternal fractures include seatbelt use in motor vehicle collisions and advanced age. Indeed, the incidence of sternal fractures has increased 3-fold since the standard use of across-the-shoulder belts. 2 Before widespread seatbelt use, sternal fractures were most often seen in motor vehicle accidents where the patient’s chest had direct contact with the steering wheel upon deceleration. In older patients, sternal fractures tend to be isolated injuries. Younger patients have a more elastic and pliable chest wall, so the energy of impact tends to be transmitted to the underlying soft tissues more readily. Thus, the energy required to fracture the