Chapter 10: Thoracic Arch and Proximal Great Vessels

INTRODUCTION

The incidence of blunt and penetrating injury to the ascending aorta, aortic arch, and proximal great vessels is not precisely known. This is understandable since most victims succumb to these injuries prior to arriving at the hospital. In one autopsy study all victims of a penetrating injury to the aorta and arch vessels died at the scene and over one-half had another lethal thoracic injury.¹ Another large autopsy study found that hemorrhage was the leading cause of death following penetrating trauma and aortic injury was a principal cause.²

Although there is a moderate body of literature about great vessel trauma and blunt descending aortic injury, few studies specifically address trauma to the ascending aorta, aortic arch, and proximal great vessels. Not surprisingly these are typically case reports and small case series. However, when taken in aggregate they supply several important observations. Mortality varies widely, from less than 10% to over 90%. Mortality with ascending aorta, arch, and arch branches is higher with penetrating trauma and injury to the proximal great vessels. The most commonly injured arch vessel is the brachiocephalic artery. Notably, a high percentage of these patients with a penetrating mechanism present with hemodynamic instability or in extremis.^3–13 The anatomic complexity and lethality of these injuries is evidenced by a report stating that only prevention will improve survival in patients with this injury pattern.¹⁴

Historically these injuries were managed with an open surgical repair. The choice of incision, techniques of the repair, and the need for cardiopulmonary bypass was based on the location and severity of the injury. Recently there has been a dramatic shift from open to endovascular repair of aortic injuries and a growing experience treating selective aortic arch and proximal great vessel injuries with endovascular stenting. The transition from an open to an endovascular approach is highlighted by the use of endovascular stent grafts for atherosclerotic disease and by their use as the definitive treatment of blunt descending thoracic aortic injury. Endovascular techniques have revolutionized the care of high-risk patients with atherosclerotic disease of the descending thoracic and infra-renal aorta.^15,16 Dramatic, innovative improvements in stent-graft design and delivery systems have made it possible to treat a greater array of anatomy and pathologies.¹⁷ Despite these advances, open surgical repair remains the current gold standard for aortic arch aneurysms.^18,19 Although significant advances in cerebral protection have improved neurologic outcomes, mortality is approximately 11% for open arch repair.²⁰ The concept of using endovascular stent grafts to treat ascending aorta and aortic arch pathology has been contemplated and current research shows encouraging results.

Over the past two decades there also has been a remarkable transition from open repair to endovascular stent grafting for blunt injuries of the descending aorta. Two studies from the Association for the Surgery of Trauma in 1997 and 2008 demonstrate this dramatic shift from open to catheter-based therapy, with statistically ...