Retrosternal Hemomediastinum Caused by Internal Mammary Artery Injury: A Case Report and Review of the Literature

We describe a 35-year-old multi-trauma patient who had a high-grade liver laceration with extensive retrosternal hemomediastinum. Extrapericardial tamponade secondary to the fracture of the sternum was followed by the instantaneous surgical evacuation of the hematoma. Computed tomography (CT) angiography helped diagnose this uncommon entity of blunt trauma-induced internal mammary artery bleeding. Despite a large amount of blood accumulation in the retrosternal space after a period of time, it may have been misdiagnosed as pericardiac hemorrhage before operation due to its rarity and the physician’s lack of experience for this kind of problem. To prevent such disastrous injuries from being unnoticed and thus unattended, consideration should be given to possible injuries to the internal mammary artery and early detection using CT of the anterior mediastinal hematoma that is associated with a fracture of the sternum is important. This can also avoid misdiagnosis and ensure prompt surgical or angiographic intervention.