Minimal aortic injury,increasingly diagnosed,and still potentially difficult to manage: A case report

Abstract

A 50-year-old man fell 4 m, sustaining multiple fractures involving the pelvis and chest. There was no previous medical history or family history of note. Computerized tomography showed a small filling defect in the ascending aorta, as well as multiple rib and pelvic fractures. Due to the minimal nature of the aortic injury, he was managed conservatively. Repeat CT scans at 1 month and 3 months showed complete resolution of the lesion. We discuss the case and the phenomenon of “minimal aortic injury.”

Background

Blunt chest trauma is a leading cause of death, most commonly due to exsanguination from major vessel injury, delayed pulmonary complications, and severe brain injury. It is a relatively common occurrence in civilian practice, with many patients dying before receiving medical attention. ¹ Improved survival is partly due to the advancements in diagnostic imaging, grading systems, management options, multidisciplinary teams, and follow-up protocols in patients with minimal aortic injuries. ²

Minimal aortic injuries (MAI) account for 10%–28% of aortic injuries ³ and are more often picked up due to the use of high-resolution vascular imaging post-trauma, and are defined as small (less than 10 mm) intimal flaps or thrombus with no or minimal periaortic hematoma. ⁴ MAI is now defined as a sub-centimeter round, triangular, or linear aortic filling defect attached to an aortic wall, representing a small intimal flap or thrombus. ³ Small intramural hematoma without external aortic contour deformity is also included in the MAI spectrum. ³ Patients with minimal aortic injuries (limited to intimal tears and aortic hematomas) are usually managed medically with repeat imaging directing further treatment modalities. ²

Case presentation

A 50-year-old male construction worker was brought to the Emergency department following a fall from a 4 m height, with his main complaints being pain in the hip and chest. There was no previous medical history or family history of note. All his vital signs were stable, and the only abnormal signs were some external bruising on the left chest and lower abdominal wall. He then underwent a pan-computerized tomogram (CT) as part of his trauma workup. The CT scan of his chest showed a small left pneumothorax with non-displaced fractures of the fourth and fifth ribs on the left side. He had a small filling defect in the ascending aorta on the posterior wall, but there were no significant peri aortic findings, such as hematoma (Figure 1, left and center images). The pelvis had multiple fractures, with a right sacral alar non-displaced comminuted fracture, a right posterior superior iliac spine non-displaced fracture, right superior and inferior pubic bone minimally displaced fractures, and a left posterior iliac body non-displaced fracture. In view of the aortic findings a 2D transthoracic echo was performed which revealed normal left ventricular function, a competent aortic valve, no pericardial effusion, and the visualized ascending aorta had no flaps or masses visible.

Figure 1.

Computerized tomography (CT) shows a small filling defect in the ascending aorta (left and center). Repeat CT at 1 month showed resolution of the lesion (right).

The aortic injury was designated as minor, and so he was managed conservatively with tight blood pressure control (maximum systolic pressure 110 mmHg) and beta-blockade. None of his bony fractures required surgical management.

Diagnostic assessment

The following day a relook ECG-gated CT aortogram was performed, showing no change in the mass in the proximal ascending aorta with no evidence of any external aortic wall abnormality. The decision was to continue with the conservative management. The orthopedic team managed his pelvic injuries conservatively and he was discharged 1 week later. Three weeks later, a repeat ECG-gated CT aortogram showed complete resolution of the aortic findings (Figure 1, right image). The patient made a full recovery from all his injuries and was discharged from follow-up 3 months later following a further CT aortogram (normal findings).

Discussion

This patient presented following blunt trauma to the chest and abdomen, and the CT aortogram revealed minimal aortic injury. The mainstay of management is recognizing and treating other serious injuries and observing the serial imaging studies of the aortic injury. ³ Surgical intervention is rarely required and may be contraindicated due to other injuries such as severe head or pelvic injuries (which would not allow full anticoagulation). For minimal aortic injuries, medical management is safer than open repair. ⁵ This patient was stable with no extra-aortic changes and absence of pericardial effusion, so a decision was made for conservative management, with subsequent imaging revealing that it was not an artifact, that it had not progressed, and then it subsequently resolved.

The management of these MAI lesions is usually conservative^4,6,7 with follow-up CT in 48 h and later after 4 weeks. ³ Indications for surgery are based on the subsequent evolution of these lesions based on imaging or clinical status.^4–7

Conclusions

Minimal aortic injuries are increasingly picked up on “pan” imaging post-trauma. The decision on whether to operate on these lesions may seem to be difficult to make, but data support that the majority of these can be managed conservatively. This case report is a reminder that these lesions will be picked up more frequently and medical management may be an entirely appropriate treatment plan.