Diagnosis and treatment of blunt thoracic aortic injuries: changing perspectives

The diagnosis and management of blunt thoracic aortic injuries has undergone many significant changes over the last decade. The present study compares clinical practices and results between an earlier prospective multicenter study by the American Association for the Surgery of Trauma completed in 1997 (AAST1) and a new similar study completed in 2007 (AAST2).

The AAST1 study included 274 patients from 50 participating centers over a period of 30 months. The AAST2 study included 193 patients from 18 centers, over a period of 26 months. The comparisons between the two studies included the method of definitive diagnosis of the aortic injury [computed tomography (CT) scan, aortography, transesophageal echocardiogram (TEE) or magnetic resonance imaging], the method of definitive aortic repair (open repair vs. endovascular repair, clamp and sew vs. bypass techniques), the time from injury to procedure (early vs. delayed repair), and outcomes (survival, procedure-related paraplegia, other complications).

There was a major shift of the method of definitive diagnosis of the aortic injury, from aortography in the AAST1 to CT scan in AAST2, and a nearly complete elimination of aortography and TEE in the AAST2 study. In the AAST2 study the diagnosis was made by CT scan in 93.3%, aortography in 8.3%, and TEE in 1.0% of patients when compared with 34.8%, 87.0%, and 11.9%, respectively, in the AAST1 study (p < 0.001). The mean time from injury to aortic repair increased from 16.5 hours in the AAST1 study to 54.6 hours in the AAST2 study (p < 0.001). In the AAST1 study, all patients were managed with open repair, whereas in the AAST2 study only 35.2% were managed with open repair and the remaining 64.8% were managed with endovascular stent-grafts. In the patients managed with open repair, the use of bypass techniques increased from 64.7% to 83.8%. The overall mortality, excluding patients in extremis, decreased significantly from 22.0% to 13.0% (p = 0.02). Also, the incidence of procedure-related paraplegia in patients with planned operation, decreased from 8.7% to 1.6% (p = 0.001). However, the incidence of early graft-related complications increased from 0.5% in the AAST1 to 18.4% in the AAST2 study.

Comparison between the two AAST studies in 1997 and 2007 showed a major shift in the diagnosis of the aortic injury, with the widespread use of CT scan and the almost complete elimination of aortography and TEE. The concept of delayed definitive repair has gained wide acceptance. Endovascular repair has replaced open repair to a great extent. These changes have resulted in a major reduction of mortality and procedure-related paraplegia but also a significant increase of early graft-related complications.