A Rare Case of Aortic Arch Penetrating Stab Wound Masked and Occluded by Mediastinal Hematoma: A Case Report and Literature Review.

Background:Penetrating injuries to the aortic arch are extremely rare and are associated with a very high prehospital mortality rate. Most patients succumb to massive hemorrhage even before reaching definitive care. In hemodynamically stable patients such injuries may be radiologically silent posing significant diagnostic and therapeutic challenges. Mediastinal hematoma can occasionally tamponade bleeding obscuring radiologic evidence of vascular injury, and delaying intervention.Case Report:An 18-year-old male presented to the emergency department after sustaining a penetrating stab wound over the suprasternal notch. He was hemodynamically stable with no external bleeding or signs of respiratory compromise. Initial investigations including transthoracic echocardiography and noncontrast computed tomography (CT) showed no evidence of major vascular injury however a retrosternal hematoma and mediastinal widening was evident. Surgical exploration via median sternotomy was done which revealed a full-thickness tear at the superior aspect of the aortic arch. This tear was seen to be involving the origins of the innominate and left common carotid arteries. The hematoma had effectively tamponaded the lesion thereby masking active bleeding. Cardiopulmonarybypass was instituted to provide optimal visualization. The tear was successfully repaired and the patient had an uneventful recovery.Conclusion:A high index of suspicion is essential in cases of penetrating chest injuries. Early surgical exploration should be strongly considered when clinical presentation and mechanism of injury raise concern for major vascular trauma regardless of reassuring imaging findings.