Blunt Chest Trauma Victims: Role of Intravascular Ultrasound and Transesophageal Echocardiography in Cases of Abnormal Thoracic Aortogram

Abstract

The objective of our study was to use transesophageal echocardiography (TEE) and intravascular ultrasonography (IVUS) to evaluate their role in interrogating abnormal or equivocal findings seen on thoracic aortography performed on blunt chest trauma patients. A prospective, nonblinded, observational, institutional review board-approved study of IVUS and TEE was conducted in acute blunt chest trauma victims with abnormal findings on thoracic aortograms. IVUS was performed with a 20-MHz catheter and TEE was performed with an omniplane probe. Abnormal aortographic findings were present in 10 men and 4 women (mean age, 40.5 years). All 14 patients were evaluated with IVUS and 13 with TEE. TEE was not performed on one patient because of time constraints. By IVUS, there were 11 true-positives, 2 true-negatives, and 1 equivocal (considered as false-negative), resulting in 91.7% sensitivity and 100% specificity. In the equivocal case, an intimal flap was missed by IVUS and by TEE, but was present at surgery. By TEE, there were six true-positives, two true-negatives, one false-positive, and four false-negatives, resulting in 60% sensitivity and 66.7% specificity. In the false-positive case, an avulsed intercostal artery without an intimal flap was found at surgery. The remaining three false-negative cases were a missed intimal flap, a missed intramural hematoma, and a missed intimal flap obscured by a mural hematoma. In our study, both IVUS and TEE were found to be diagnostic in the four equivocal aortograms. Three of the equivocal results were cases read as a prominent ductus diverticulum versus a pseudoaneurysm. Two were confirmed to be false lumen/pseudoaneurysm by both IVUS and TEE, whereas the other was confirmed to be a prominent ductus diverticulum by both of these modalities. In the fourth equivocal case, thoracic aortography showed an abnormal contour but no intimal flap located along the lesser curvature of the aorta at the junction of the arch and isthmus. No abnormalities were found by IVUS or TEE. This patient was followed clinically. A follow-up thoracic aortogram obtained 1 year later showed no aortic injury. When thoracic aortography yields an abnormal and especially equivocal findings, both IVUS and TEE are helpful in further sorting this out rather than subjecting the patient to a potentially unnecessary thoracotomy. In cases of aortic injury suspected at the lesser curvature of the arch-isthmic junction, TEE allowed better delineation because of multiplane imaging capability.