Blunt injury of the ascending aorta and aortic arch: repair with hypothermic circulatory arrest

Transection of the origin of the innominate artery: A rare sequela of blunt traumatic chest trauma

Blunt traumatic transection of the innominate artery is rare. We describe a case of a 36-year-old male who presented to our Emergency & Trauma Center after being struck by a motor vehicle at high speed. Computerised Tomography (CT) scanning after the patient was stabilised facilitated the prompt diagnosis of the injury. The patient underwent open repair by midline sternotomy, with debranching of the innominate artery, using hypothermic circulatory arrest as a neuroprotective measure. The patient was successfully extubated on post-operative day 3, without neurological deficit. We provide our experience as an option for treating any patient that presents with such an injury.

Blunt injury of the innominate artery and left innominate vein

Injuries to the branches of the aortic arch are rare and may be caused by blunt, penetrating, blast or iatrogenic trauma. Innominate vascular injury is a rare entity, particularly in blunt trauma. It is estimated that 71% of patients with innominate injuries die before arrival at the hospital. We report here a successfully managed case of a combined blunt trauma of the innominate artery and transection of the left innominate vein after blunt injury to the chest.

[Innominate artery war injury]

AIM

A case is reported of successfully surgically treated explosive war injury to the innominate artery.

CASE REPORT

A 26-year-old soldier was injured in combat by a fragment of mortar shell. In the field hospital, the wound gauze packing was applied, followed by orotracheal intubation and thoracic drainage. The soldier was admitted to MMA six hours later. Physical examination, on admission, revealed huge swelling of the neck, the absence of pulse in the right arm and the right common carotid artery. Chest x-ray revealed hemopneumothorax of the right side and the foreign metal body in the projection of the right sternoclavicular joint. Due to the suspicion of large vessel injury, a median sternotomy was immediately performed. Surgery revealed disrupted bifurcation of the right innominate artery, so the ligation was performed. Aortography was performed postoperatively, followed by the reconstruction of innominate bifurcation with synthetic grafts. Control aortography showed good graft patency, and the patient was discharged from the hospital in good general condition with palpable pulses and mild anisocoria as a sole neurological sequela.

CONCLUSION

A rare and life-threatening injury was successfully managed, mainly due to the rational treatment carried out in the field hospital that helped the injured to survive and arrive to the institution capable of performing the most sophisticated diagnostic and therapeutic procedures.

Hypothermia-Induced Coagulopathy during Hemorrhagic Shock

A porcine model of hemorrhagic shock was used to study the effect of hypothermia on hemodynamic, metabolic, and coagulation parameters. The model was designed to simulate the events of severe blunt injury with hemorrhage occurring initially, to a systolic blood pressure of 30 mm Hg, followed by simultaneous hemorrhage and crystalloid volume replacement, followed by cessation of hemorrhage and blood replacement. Half of the animals were rendered hypothermic by external application of ice, and half remained normothermic. There was seven pigs in each group. Two deaths occurred in each during the hemorrhage phase. The hypothermic pigs demonstrated larger reduction in cardiac output than normothermic pigs. Volume replacement in the normothermic group restored cardiac output to baseline values. In the hypothermic group, cardiac output remained depressed despite volume replacement. Prothrombin times and partial thromboplastin times showed significantly more prolongation in the hypothermic group. Furthermore, this was not corrected by replacement of shed blood in the hypothermic group, as was seen in the normothermic group. We conclude that when shock and hypothermia occur together, their deleterious effect on hemodynamic and coagulation parameters are additive. The effects of hypothermia persist despite the arrest of hemorrhage and volume replacement. Thus, it is necessary to aggressively address both shock and hypothermia when they occur simultaneously.