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The incidence of penetrating trauma to the brachiocephalic artery and aortic arch is not known, because most patients die of hemorrhage before they receive adequate treatment. Furthermore, when torrential hemorrhage from penetrating trauma is present, the anatomy of the thoracic vasculature can present a challenge for gaining adequate exposure, achieving vascular control, and performing proper repair. We describe the case of a patient with a gunshot wound to the anterior chest; he was placed under cardiopulmonary bypass and deep hypothermic circulatory arrest while we performed a patch repair of the proximal brachiocephalic artery and aortic arch.
The incidence of penetrating trauma to the brachiocephalic artery and aortic arch is not known. Most patients die of hemorrhage due to their injuries before adequate treatment can be administered.1 Discrete clinical signs in a patient who survives such an injury can include evidence of external or internal hemorrhage, bruit, distal pulse deficit, neurologic deficit, and shock.1–3 The anatomy of the thoracic vasculature can present a challenge for gaining adequate exposure, achieving vascular control, and performing proper repair. We describe our treatment of a patient who sustained a gunshot wound to the anterior chest, which required patch repair of the proximal brachiocephalic artery and aortic arch.
In March 2006, a 17-year-old obese male was brought to the emergency department after he had been shot with a low-caliber weapon. The bullet had entered at the right anterior axillary line, inferior to the clavicle, and there was no exit wound. On presentation, the patient had a heart rate of 117 beats/min, a blood pressure of 110/70 mmHg, and a blood oxygen saturation of 99% on room air. Pericardial sonography was negative for effusion. On physical examination, the patient was morbidly obese. His score on the Glasgow Coma Scale was 13, and he had equal bilateral breath sounds. A chest radiograph obtained in the emergency room showed a widened mediastinum, and a computed tomographic scan of the chest showed extravasation of contrast material near the origin of the brachiocephalic artery (Fig. 1).
The patient was taken to the operating room immediately, where a median sternotomy was performed. A large, expanding hematoma with active venous and arterial bleeding was found. Abundant mediastinal and thymic fat made exposure exceedingly difficult. Moreover, control of bleeding from within the pericardium without disturbing the hematoma was not possible. The brachiocephalic vein was quickly ligated and divided, but arterial bleeding remained profuse. The patient began to show signs of hemodynamic instability. Arterial bleeding was temporarily controlled with direct pressure by use of 1 hand. At this point, precise location of the arterial injury was impossible; however, the amount and central location of the bleeding led to a high suspicion of aortic arch involvement.
Since temporary control of bleeding was being maintained with heavy, direct pressure on the mediastinal fat and underlying structures, we cannulated the left common femoral artery with a 20F William Harvey arterial perfusion cannula (C.R. Bard; Santa Ana, Calif) and the right atrium with a 32F 2-stage cannula. The patient was given heparin (400 U/kg) intravenously. He was placed on cardiopulmonary bypass (CPB) and cooled to a nasopharyngeal temperature of 18 °C. The heart was allowed to fibrillate, and a left ventricular vent was placed in the right superior pulmonary vein. At 18 °C, CPB was stopped, and the thoracic vasculature was exposed. The injury was identified as a 2 × 2-cm circular defect, occupying 45% of the circumference of the brachiocephalic vessel at the junction of the brachiocephalic artery and the aortic arch. The injury was repaired with a 2 × 2-cm patch of bovine pericardium and running 4-0 Prolene suture. The duration of deep hypothermic circulatory arrest (DHCA) was 23 minutes. A thorough exploration revealed no other intrathoracic injuries.
The patient's postoperative course was unremarkable, and he was discharged from the hospital on the 9th postoperative day. At 1-year follow-up, he was symptom-free with excellent exercise tolerance and no residual effects.
Injuries to the great vessels can provide therapeutic challenges.1,4,5 Clinical signs of such injuries include external or internal hemorrhage, bruit, distal pulse deficit, neurologic deficit, and shock.1 Most patients who survive to receive medical attention have few external changes that would enable physicians to identify the magnitude of the injury. Diagnosis is generally made when an arteriogram or computed tomogram shows a contained pseudoaneurysm or an extravasation of contrast material.1,3,5
Appropriate exposure and vascular control in the chest can be problematic when there is active torrential hemorrhage from penetrating trauma.1 Median sternotomy offers excellent exposure of the brachiocephalic artery, and the safety of the incision makes it the preferred approach for brachiocephalic artery and aortic arch injuries.1
The use of CPB and DHCA for injuries to the great vessels or to the aortic arch is controversial. Most reported cases of surgery for great-vessel injuries have been performed without CPB.1,3,4 Because patients who sustain thoracic vascular trauma may have associated injuries, some surgeons hesitate to use CPB with systemic heparinization. However, in selected cases, such as ours, CPB with DHCA enables optimal exposure for precise repair, and it is well tolerated by the patient.4,5 Poor exposure is more likely to lead to inaccurate surgical repairs, which can cause further damage. Safe periods of DHCA at a nasopharyngeal temperature of 18 °C extend to 30 minutes in nearly 100% of patients and to 45 minutes in 70% of patients.6
In our patient, the proximal nature of the injury necessitated control of the substantial arterial bleeding with digital compression of the mediastinal tissues. Precise location of the injury, after sternotomy, was impossible. Cannulation of the femoral artery and right atrium and institution of CPB were easily achieved while 1 surgeon maintained pressure on the injury. The use of DHCA enabled rapid exposure and accurate repair of the brachiocephalic artery and aortic arch injury. Patch repair with bovine pericardium was easier than graft interposition because of the unique position of the injury at the junction of the brachiocephalic artery and the aortic arch.
Penetrating thoracic vascular injuries can produce dramatic challenges. Institution of CPB and DHCA in selected cases of great-vessel and aortic arch trauma can provide superior exposure and enable accurate repair of these vital structures. Cardiopulmonary bypass and DHCA are valuable in these settings if arrest times are kept within well-documented limits.6
Address for reprints: Christopher Mutrie, MD, 938 Rock Springs Ct., Atlanta, GA 30306 E-mail: ude.yrome@eirtumc