Anatomic characteristics of aortic transection: centerline analysis to facilitate graft selection.

BACKGROUND: Traumatic transection of the thoracic aorta is a life-threatening complication that most commonly occurs after high-speed motor vehicle collisions. Although such injuries were previously treated with open surgical reconstruction, they are now more commonly being treated with endovascularly placed stent grafts. Unfortunately, most stent grafts are designed for treating aortic aneurysmal disease instead of traumatic injury. Further refinements in stent graft technology depend on a thorough anatomic understanding of the transection injury process.

METHODS: All patients with computed tomography (CT) evidence of blunt aortic injury (BAI) between 2006 and 2012 at a Level 1 trauma center were queried. Their initial CT scans were imported into the Intuition (Terarecon, Inc.) viewing program, and off-line centerline reconstruction was performed. Standard demographic data were collected in addition to anatomic characteristics, including aortic diameters and the relationship of the injury to the arch vessels.

RESULTS: Thirty-five patients were identified. Three patients were injured proximal to the left subclavian artery. The average length from the left subclavian artery to the proximal site of injury was 16.2 mm (range 2-31 mm). Most patients had >15 mm of landing zone beyond the left subclavian artery. The range of proximal diameters ranged from 17 to 32 mm, with an average aortic diameter of 23.9 mm. The average length of injured aortic segment was 27 mm.

CONCLUSIONS: In this contemporary series from a large trauma center, 91% of patients are anatomically able to be treated with a stent graft that does not require coverage of the left common carotid artery. Most patients have an aortic diameter that falls between 21 and 26 mm in diameter, as well as a short segment of injured artery. Centers interested in emergently treating aortic transections are able to do so while maintaining a limited stock of stent grafts that can be used to treat the majority of the population.