Internal mammary artery injury, anterior mediastinal hematoma, and cardiac compromise after blunt chest trauma.

A rare case of blunt chest trauma resulting in internal mammary artery hemorrhage and cardiac tamponade is presented. Thoracotomy revealed anterior mediastinal hemorrhage but no pericardial hematoma. The significance of chest wall vessel hemorrhage as a cause of widened mediastinum is reiterated. The importance of accurate angiographic assessment and vigilant care of victims of blunt chest trauma who present with a widened mediastinum is emphasized.