ACR Appropriateness Criteria(®) blunt chest trauma--suspected aortic injury

Traumatic aortic injury from pellet gun: A case report

Acute traumatic aortic injuries are of the most lethal sequelae of penetrating thoracic injuries and require rapid detection and management. The American College of Radiology currently recommends the use of noncontrast CT, followed by computed tomography angiography (CTA) as the first-line imaging modalities when traumatic aortic injury is suspected. Direct signs of aortic injury on CTA include pseudoaneurysm, focal contour abnormality, intimal flap, intramural hematoma, an abrupt change in aortic caliber, and contrast extravasation. Aortic pseudoaneurysms are most often caused by blunt or penetrating trauma that results in damage to the vessel wall, turbulent blood flow, and formation of a surrounding hematoma contained by a wall of products from the clotting cascade. This wall is weaker than those of a true aneurysm and will ultimately rupture over time if not repaired. Traumatic aortic pseudoaneurysms are preferably treated by thoracic endovascular aortic repair using a prosthetic stent graft. Here, we present a 44-yearold female with a history of homelessness, polysubstance use disorder, and HIV who presented to the emergency department after being found down. She reported being shot by a pellet gun, and physical examination revealed a penetrating left-sided chest wound that appeared to be several days old. A STAT CTA was obtained and revealed a hemopneumothorax and possible thoracic aortic pseudoaneurysm. A left-sided chest tube was placed and the patient underwent thoracic endovascular aortic repair through right femoral arterial access and tolerated the procedure well. The patient was placed on daily aspirin postoperatively and discharged on post-op day 5.

Acute traumatic injury of the aorta: presentation, diagnosis, and treatment

Despite advances in detection and treatment, acute traumatic aortic injury (ATAI) is associated with high rates of morbidity and mortality. Both physical and hemodynamic forces have been postulated as mechanisms of aortic injury during a traumatic event. For patients who survive the initial injury, rapid detection is critical for diagnosis and procedural planning, which requires a thorough knowledge of both its clinical presentation and the available diagnostic imaging modalities. Radiography, computed tomography (CT), and magnetic resonance imaging (MRI) can each have a role in the diagnosis of ATAI. After stabilization of the patient, the management of ATAI is guided by the severity of injury. Appropriately selected patients with low grade injuries may be managed non-operatively. When treatment is required, there are both open surgical and endovascular options. In current practice, endovascular approaches with stent-graft placement are preferred due to their high clinical success and low rates of complications. Complications from endograft placement can include: endoleak, endograft collapse, infection, endograft failure, and endograft migration. Open surgical repair is now reserved for patients with unfavorable anatomy for endovascular therapies. This review provides a comprehensive overview of ATAI including its epidemiology and demographics, mechanisms of injury, clinical and radiographic diagnosis, treatment options, and post-therapeutic follow-up.

[Diagnostics and treatment of traumatic aortic injuries]

Hintergrund

Traumatische Aortenverletzungen (TAV) sind seltene Folgen von stumpfen Traumata, die eine hohe Mortalität und Morbidität aufweisen. Die schnelle und akkurate Diagnostik sowie die Wahl der korrekten Therapie sind für das Patientenüberleben elementar.

Fragestellung

Bestimmung des aktuellen Standards der Abklärung von TAV im akuten Trauma-Setting und Evaluation der aktuellen Leitlinien zur Therapie.

Material und Methode

Eine Literaturrecherche wurde durchgeführt, mit der Suche nach Publikationen, die die Abklärung und Diagnostik der TAV beschreiben. Außerdem wurden Leitlinien für die Behandlung und Nachsorge von TAV zusammengefasst.

Ergebnisse

In der Literatur wird trotz geringer Spezifität eine konventionelle Thoraxröntgenaufnahme als Initialdiagnostik genannt. Es sollte primär, als Modalität der Wahl, zur Diagnostik und zur Therapiestratifizierung eine Computertomographie (CT) aufgrund der hohen Sensitivität und Spezifität nachfolgen. In allen Leitlinien ist die thorakale endovaskuläre Aortenrekonstruktion („thoracic endovascular aortic repair“, TEVAR) die Therapie der Wahl bei höhergradigen TAV (Grade II–IV) und hat die offene Chirurgie in dem meisten Fällen abgelöst.

Schlussfolgerung

Nach einer kurzfristig erfolgten CT-Diagnostik und Einteilung wird die TEVAR der offenen Chirurgie bei therapiebedürftigen TAV vorgezogen.

Minimal Aortic Injury: Mechanisms, Imaging Manifestations, Natural History, and Management

Over the last 2 decades, increased depiction of minimal aortic injury (MAI) in the evaluation of patients who have sustained trauma has mirrored the increased utilization and improved resolution of multidetector CT. MAI represents a mild form of blunt traumatic aortic injury (BTAI) that usually resolves or stabilizes with pharmacologic management. The traditional imaging manifestation of MAI is a subcentimeter round, triangular, or linear aortic filling defect attached to an aortic wall, representing a small intimal flap or thrombus consistent with grade I injury according to the Society for Vascular Surgery (SVS). Small intramural hematoma (SVS grade II injury) without external aortic contour deformity is included in the MAI spectrum in several BTAI classifications on the basis of its favorable outcome. Although higher SVS grades of injury generally call for endovascular repair, there is growing literature supporting conservative management for small pseudoaneurysms (SVS grade III) and large intimal flaps (>1 cm, unclassified by the SVS), hinting toward possible future inclusion of these entities in the MAI spectrum. Injury progression of MAI is rare, with endovascular aortic repair reserved for these patients as well as patients for whom medical treatment cannot be implemented. No consensus on the predetermined frequency and duration of multidetector CT follow-up exists, but it is common practice to perform a repeat CT examination shortly after the initial diagnosis. The authors review the evolving definition, pathophysiology, and natural history of MAI, present the primary and secondary imaging findings and diagnostic pitfalls, and discuss the current management options for MAI. Online DICOM image stacks are available for this article. ^©RSNA, 2020.

Cross-sectional imaging of thoracic traumatic aortic injury

Aortic injury remains a major contributor to morbidity and mortality from acute thoracic trauma. While such injuries were once nearly uniformly fatal, the advent of cross-sectional imaging in recent years has facilitated rapid diagnosis and triage, greatly improving outcomes. In fact, cross-sectional imaging is now the diagnostic test of choice for traumatic aortic injury (TAI), specifically computed tomography angiography (CTA) in the acute setting and CTA or magnetic resonance angiography (MRA) in follow-up. In this review, we present an up-to-date discussion of acute traumatic thoracic aortic injury with a focus on optimal and emerging CT/MR techniques, imaging findings of TAI, and potential pitfalls.

Do patients with blunt thoracic aortic injury present to hospital with unstable vital signs? A systematic review and meta-analysis

BACKGROUND

Blunt thoracic aortic injury (BTAI) is an uncommon diagnosis, usually developing as a consequence of high-impact acceleration-deceleration mechanisms. Timely diagnosis may enable early resuscitation and reduction of shear forces, essential to prevent worsening of the injury prior to definitive management. Death is commonly due to haemorrhagic shock, but clinical features may be absent until sudden and massive haemorrhage.

OBJECTIVES

The aim of this systematic review was to determine the proportion of patients with BTAI who present with unstable vital signs.

METHODS

Manuscripts were identified through a search of MEDLINE, EMBASE and the Cochrane Library databases, focusing on subject headings and keywords related to the aorta and trauma. Mechanisms of injury, haemodynamic status and mortality from the included manuscripts were reviewed. Meta-analysis of presenting haemodynamic status among a select group of similar papers was conducted.

RESULTS

Nineteen studies were included, with five selected for meta-analysis. Most reported cases of BTAI (80.0%-100%) were caused by road traffic incidents, with mortality consistently higher among initially unstable patients. There was statistically significant heterogeneity among the included studies (P<0.01). The pooled proportion of patients with haemodynamic instability in the setting of BTAI was 48.8% (95% CI 8.3 to 89.4).

CONCLUSIONS

Normal vital signs do not rule out aortic injury. A high degree of clinical suspicion and liberal use of imaging is necessary to prevent missed or delayed diagnoses.

A case of blunt thoracic aortic injury requiring ECMO for acute malperfusion before TEVAR

BACKGROUND

Blunt thoracic aortic injury (BTAI) is associated with a high mortality rate and the paradigm of treating patients with BTAI currently favours thoracic endovascular aneurysm repair (TEVAR) if possible. In BTAI, lethal malperfusion caused by a pseudoaneurysm has rarely been reported. We present the first report of a successful case in which a pseudoaneurysm causing the infrequent occurrence of lethal malperfusion and subsequent acute severe ischaemia in the distal portion of the thoracic descending aorta was overcome by veno-arterial extracorporeal membrane oxygenation (VA ECMO) as a bridging therapy until the initiation of TEVAR.

CASE PRESENTATION

An adult woman was transferred to our emergency room after injuries sustained by falling from height. Her vital signs were unstable on admission. CT examination revealed the multiple injuries: traumatic subarachnoid haemorrhage, severe unstable pelvic fracture, and a grade III injury of the thoracic aorta. We made the decision to perform TEVAR after external fixation and transcatheter arterial embolization (TAE) for the pelvic injury. During preparations for TEVAR, her lower limbs rapidly felt cold, and her blood lactate level and serum potassium rapidly increased. By the clinical data and ultrasonography and lower extremity Doppler, we diagnosed severe ischaemia in distal portion of the descending aorta caused by a pseudoaneurysm proximal to the descending thoracic aorta. Because we still had not prepared for TEVAR, we immediately started VA ECMO until TEVAR could begin. After the initiation of VA ECMO, her lactate and potassium levels could be controlled. Under VA ECMO support, she underwent TEVAR. After inpatient rehabilitation, she was discharged home without neurologic sequelae.

CONCLUSIONS

VA ECMO could be an important, less-invasive treatment as a bridging therapy for acute severe malperfusion syndrome until TEVAR is initiated for BTAI.

Emergency Computed Tomography Angiogram of the Chest, Abdomen, and Pelvis

In the setting of blunt trauma, the rapid assessment of internal injuries is essential to prevent potentially fatal outcomes. Computed tomography is a useful diagnostic tool for both screening and diagnosis. In addition to trauma, acute chest syndromes often warrant emergent computed tomographic angiography, looking for etiologies such as aortic aneurysms or complications of aortic aneurysms, or both, pulmonary emboli, as well as other acute vascular process like aortic dissection and Takayasu aortitis. With continued improvements in diagnostic imaging, computed tomographic angiography of the chest, abdominal and pelvis proves to be an effective modality to image the aorta and other major vascular structures.

Toward Reduction of Post-Hospital Admission Death Rate Caused by Acute Traumatic Aortic Tear

BACKGROUND

Terminology and classifications are the vehicles by which pathologic conditions are identified and understood. It is critically important for the patient admitted with suspected blunt thoracic aortic injury that admitting physicians have a thorough knowledge of acute traumatic aortic tear and its natural history.

OBJECTIVES

The objectives of this review were as follows: (1) to introduce a pathology-based terminology and classification of acute traumatic aortic injuries that unambiguously defines each, and (2) to emphasize the clinical relevance of acute traumatic tear to post-hospital admission deaths in blunt thoracoabdominally injured patients.

METHODS

This is a literature review of 32 refereed articles pertaining to acute traumatic thoracic aortic injury published from 1957 to the present.

RESULTS

The terminology used to describe aortic injury is inconsistent. Several terms are often loosely interchanged: tear, laceration, transection, and rupture. Furthermore, classifications of aortic injuries have been proposed based on microscopic or gross pathologic or computed tomography scan results. While microscopically-based classifications have little or no clinical application, a classification based on gross pathology provides information useful for aortic injury prognosis and management.

CONCLUSION

Reduction of post-hospital death caused by acute aortic tear requires knowledge and understanding of the pathology of acute traumatic aortic tear and its natural history. Such understanding of pathology of acute traumatic aortic tear and its natural history is enhanced by terminology that defines the aortic injury. Therefore, we present our proposed terminology and classification of acute traumatic injuries.

[Imaging of blunt chest trauma]

CLINICAL/METHODOLOGICAL ISSUE

Blunt chest trauma is associated with high morbidity and mortality. Consequently, all patients should be evaluated radiologically after blunt chest trauma to allow timely and appropriate treatment.

STANDARD RADIOLOGICAL METHODS

Conventional chest radiographs and computed tomography (CT) are proven modalities with which to evaluate patients after blunt chest trauma.

METHODOLOGICAL INNOVATIONS

Over the last several years extended focused assessment with sonography for trauma (eFAST) has gained increasing importance for the initial assessment of seriously injured patients.

PRACTICAL RECOMMENDATIONS

In the acute phase of severely injured patients eFAST examinations are helpful to exclude pneumothorax, hemothorax and hemopericardium. Chest radiographs may also be used to diagnose a pneumothorax or hemothorax; however, the sensitivity is limited and CT is the diagnostic modality of choice to evaluate severely injured patients.