Traumatic aortic rupture in the pediatric population. Role of plain film, CT and angiography in the diagnosis

Urgent and emergent pediatric cardiovascular imaging

The need for urgent or emergent cardiovascular imaging in children is rare when compared to adults. Patients may present from the neonatal period up to adolescence, and may require imaging for both traumatic and non-traumatic causes. In children, coronary pathology is rarely the cause of an emergency unlike in adults where it is the main cause. Radiology, including chest radiography and computed tomography in conjunction with echocardiography, often plays the most important role in the acute management of these patients. Magnetic resonance imaging can occasionally be useful and may be suitable in more subacute cases. Radiologists' knowledge of how to manage and interpret these acute conditions including knowing which imaging technique to use is fundamental to appropriate care. In this review, we will concentrate on the most common cardiovascular emergencies in the thoracic region, including thoracic traumatic and non-traumatic emergencies and pulmonary vascular emergencies, as well as acute clinical disorders as a consequence of primary and postoperative congenital heart disease. This review will cover situations where cardiovascular imaging may be acutely needed, and not strictly emergencies only. Imaging recommendations will be discussed according to the different clinical presentations and underlying pathology.

Traumatic Thoracic Aortic Injury in a Three-Year-Old Patient: A Case Report

Management of a traumatic ruptured aorta in the pediatric population is quite challenging. Options vary, with each having its own morbidity, and include open repair, endovascular stent grafts, and/or anti-impulse therapy. Although endovascular stenting is an emerging management modality in traumatic aortic injury in adults, open repair is still the gold standard in the pediatric population. In this case, we reported the survival of a three-year-old boy who underwent successful surgical repair with a Dacron graft and anastomosis after an acute traumatic thoracic aortic pseudoaneurysm with mediastinal hematoma.

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.

Interventional radiology for paediatric trauma

Paediatric interventional radiology plays a cornerstone role in the management of paediatric trauma. In the acute setting, interventional radiology techniques allow minimally invasive control of haemorrhage or re-establishment of blood flow. Percutaneous stenting and drainage can allow disruptions in urinary or biliary systems to heal without the need for further surgery. Interventional radiology techniques also have a significant role in treating delayed complications of trauma, including embolization of arterial pseudoaneurysms and pulmonary embolism prophylaxis in individuals immobilized due to the trauma or its operative treatment.

Paediatric chest trauma (part 2) — Hidden Injuries

Chest trauma is the second greatest cause of mortality from trauma, a leading cause of death in children over the age of one. Prompt diagnosis can be difficult as the underlying thoracic injuries are often disproportionately severe compared to the visible surface injury and symptoms may not appear for several hours. Diagnosis are easily underestimated, delayed or missed. This is the second of a 2 part article reviewing Paediatric chest trauma and its current management. The injuries are usefully classified into 6 lethal injuries that need excluding in the primary survey and 6 hidden injuries that must be considered in the secondary survey. The 6 lethal injuries are covered in the first part of this article along with biomechanics and mechanisms of injury. This article looks in depth at the 6 hidden injuries, along with a review of chest trauma in non-accidental injury.

Multi-detector computed tomography findings of atypical blunt traumatic aortic injuries: a pictorial review

Traumatic injuries to the aorta are a significant source of morbidity and mortality in trauma patients, which highlights the importance of rapid diagnosis and treatment. Multi-detector row computed tomography has become the primary imaging modality for the imaging assessment of the polytrauma patient because it is fast, noninvasive, and the data sets can be used to create tailored multi-planar reformatted images that optimally display the location and morphology of aortic trauma and its relationship to adjacent structures. Although the classic location of blunt injury to the aorta occurs just distal to the left subclavian artery, aortic injuries may occur at any location along the aorta and in any patient population. Radiologists should be prepared to evaluate these types of injuries in nontraditional planes that are tailored to each examination and to present the data to clinicians using commercially available 3D software for purposes of surgical planning. Here, we review in pictorial form atypical aortic injuries with emphasis on multi-planar reformations.

Combined acute traumatic aortic injury and left main bronchus transection in a 5-year-old child

Blunt traumatic aortic and tracheobronchial injuries are extremely rare in children. We report a case of a 5 year old male who suffered both of these rare injuries (traumatic aortic rupture and left mainstem bronchus transaction). To our knowledge this combination of injuries has not been previously described in a child. CT with multiplanar images was critical for the detection of both injuries.

Imaging Evaluation of Pediatric Chest Trauma

Following a discussion of the various imaging manifestations of pediatric chest trauma by anatomic location, the authors discuss their diagnostic approach to the pediatric multitrauma patient with an emphasis on chest imaging.

Risk factors for blunt thoracic aortic injury in children

BACKGROUND/PURPOSE

Because blunt thoracic aortic injury is rare in children, a high index of suspicion is needed to identify this injury. The purpose of this study was to use a large national trauma database to define the risk factors for blunt thoracic aortic injury in children.

METHODS

Using the National Trauma Database, the authors compared patient demographics, mechanism of injury, and associated injuries between children sustaining blunt trauma with and without a thoracic aortic injury. Factors independently associated with this injury were identified using multivariate methods.

RESULTS

Among 26,940 children with a blunt mechanism of injury, 34 (0.1%) children sustained a thoracic aortic injury, 14 (41%) of whom died. Thoracic aortic injuries were independently associated with age, injury sustained as an occupant in a motor vehicle crash, and severe injuries (Abbreviated Injury Scale value of > or =3) involving the head, thorax (other than aorta), abdomen, and lower extremities.

CONCLUSIONS

Older children involved in a motor vehicle crash with severe head, torso, and lower extremity injuries are a group at high risk for injury to the thoracic aorta. These easily identifiable risk factors may facilitate more rapid identification of this rare and potentially fatal injury.

Management of traumatic rupture of the thoracic aorta in pediatric patients

BACKGROUND

Traumatic rupture of the thoracic aorta (TRA) in the pediatric population is uncommon. Management of TRA in general has evolved to include selective nonoperative and endovascular stent graft approaches, although operative repair remains the standard.

METHODS

We conducted a retrospective chart review of patients younger than 16 years of age admitted to a single institution between March 1985 and February 2002.

RESULTS

Of 160 patients admitted with TRA, 11 were younger than 16 (11.9 +/- 3.5) years of age. Concomitant injuries included closed head injury (5 patients) and acute lung injury (6 patients). All were started on beta-blockers when the diagnosis was suspected. Laparotomy was required in 3 patients and orthopedic procedures in 5 patients. Six underwent operative repair (two primary repairs), with no mortality. Cross-clamp time was 30.4 +/- 2.6 minutes. One patient (operated on without bypass) was partially paralyzed. Two patients were managed nonoperatively, 1 with an intimal arch injury, who on subsequent follow-up has demonstrated healing, and 1 who died of head injury. Three patients were managed by endovascular stent grafts, 2 who died of closed head injury and 1 who at 1-year follow-up has fully recovered. The endovascular stent grafts were placed through the femoral artery in 2 patients and through an iliac conduit in 1 patient. No patient died of rupture.

CONCLUSIONS

The approach to pediatric TRA should be identical to the adult, with early institution of beta-blockers. Depending on the clinical setting, a spectrum of options should be considered, including operation, non-operation, and endovascular stent graft, although the choice of the latter must be tempered by the lack of long-term follow-up data.

Pediatric thoracic trauma

Although thoracic injuries occur less frequently in children than adults, they remain a source of substantial morbidity and mortality. Disparate problems such as rib fractures, lung injury, hemothorax, pneumothorax, mediastinal injuries, and others may present in isolation or in combination with one another. Knowledge of the manner in which pediatric anatomy, physiology, and injury patterns change with age may expedite the evaluation of the pediatric chest after trauma. Differences in pulmonary functional residual capacity, blood volume, chest wall and spinal soft-tissue mobility, and cardiac function may translate into problems or benefits of important consequence. For example, although more predisposed to hypoxemia, young children may remain well compensated hemodynamically, despite significant blood loss. Rare injuries in children, such as cardiac and great vessel trauma, may remain undiagnosed precisely because of their scarcity and protean symptoms.

Chest Radiographs of Limited Utility in the Diagnosis of Blunt Traumatic Aortic Laceration

BACKGROUND

The radiographic diagnosis of blunt traumatic aortic laceration (BTAL) remains problematic. We reviewed our experience with chest radiographic signs of BTAL at a single trauma center.

METHODS

The chest radiographs of 188 consecutive blunt trauma patients with suspected BTAL who underwent portable chest radiography and aortography were retrospectively reviewed by a thoracic radiologist. The presence or absence of 15 radiographic findings were recorded, and the sensitivity and specificity of individual radiographic signs and combinations of signs were determined.

RESULTS

There were 10 patients with BTAL. Although three signs showed greater than 90% sensitivity for BTAL, these signs showed low specificity, and no significant improvement in overall accuracy was achieved by combining radiographic findings.

CONCLUSION

The experience at our institution suggests that chest radiographs have limited utility in the accurate diagnosis of blunt traumatic aortic laceration. Cross-sectional imaging techniques will likely become the preferred imaging procedures for evaluating patients with suspected BTAL.

Current concepts on imaging of thoracic vascular abnormalities

Pediatric thoracic vascular abnormalities include many anatomic variants and pathologic conditions. Although some vascular variants are inconsequential and are discovered incidentally on imaging studies, several anomalies have profound effects on the airway and pulmonary parenchyma. Imaging plays a key role in evaluating the chest and its vasculature. The chest radiograph is usually the first screening study performed during the course of evaluation for a vascular abnormality. Cross-sectional imaging with CT and magnetic resonance imaging provides precise anatomic information and has in most cases replaced invasive diagnostic angiographic procedures. We describe common thoracic vascular abnormalities that occur in children and the imaging techniques currently used in their evaluation.

Guidelines for the diagnosis and management of blunt aortic injury: an EAST Practice Management Guidelines Work Group

In summary, BAI is a lethal result of severe blunt trauma. It should be considered in all patients who sustained injury by a deceleration or acceleration mechanism, especially in the face of physical or radiographic findings suggestive of mediastinal injury. Angiography remains the "gold standard" for diagnosis, although CT scanning is taking more of a role, especially for screening. Diagnosis should be followed by prompt surgical repair using some method of distal perfusion to minimize renal and spinal cord ischemia. If prompt repair is not feasible because of other injuries or comorbidities, medical control of blood pressure is warranted in the interim.

A retrospective review of the role of transesophageal echocardiography in aortic and cardiac trauma in a level I Pediatric Trauma Center

This study examined the role of transesophageal echocardiography in blunt aortic and cardiac trauma in a Pediatric Level I Trauma Center. In a > 5-year retrospective review, we identified 10 children with blunt cardiac (n = 4; tricuspid valve in two; mitral valve in one; aortic valve in one) and aortic (n = 6; aortic rupture in five, subintimal flap in one) trauma. Diagnosis of the cardiac injuries was made with transthoracic echocardiography, with transesophageal echocardiography providing additional anatomic detail and postoperative assessment in three of four children who required surgical intervention. Diagnosis of the aortic injuries was made with transesophageal echocardiography in five of six patients; one patient underwent aortography before transfer. Transesophageal echocardiography also identified depressed myocardial function in one child and aided in surgical management of the five aortic ruptures. In blunt chest trauma, transesophageal echocardiography provides accurate evaluation of cardiovascular structure and function and guides operative repair.

Traumatic thoracic aortic rupture in the pediatric patient

BACKGROUND

Traumatic thoracic aortic rupture is a rare injury in the pediatric patient. Experiences with thoracic aortic rupture in patients less than 17 years of age are needed to help identify factors that can influence injury occurrence, diagnosis, management, and outcome.

METHODS

Between July 1989 and December 1995, 6 children were treated operatively for thoracic aortic rupture from blunt trauma at a level I pediatric trauma center. The average age was 13.2 years (range, 8 to 16 years). There were 4 females and 2 males. There were 5 motor vehicle accidents and 1 bicycle accident. Aortic injury was suspected based on the mechanism of injury and abnormal chest roentgenogram results, and was confirmed by aortography (3 cases) or chest computed tomography (2) and transesophageal echocardiography (3). Life-threatening central nervous system or gastrointestinal injuries were evaluated or treated first. Operative repair of the thoracic aorta was performed by cardiopulmonary bypass (2 patients) and clamp and sew technique (4).

RESULTS

Aortic ruptures were complete transections at the ligamentum arteriosum in 5 of 6 (83%); the other case was a cervical arch pseudoaneurysm. Associated injuries included pulmonary contusion (100%), pelvic/long bone fractures (50%), visceral laceration/perforation (50%), central nervous system (33%), paraplegia (17%), and myocardial contusion (17%). There were no rib fractures. Four of 5 patients (80%) were not wearing seat belts, and 2 of these were ejected. The average time from injury to the operating room was 17.6 hours (range, 5 to 48 hours); the time from diagnosis to the operating room exceeded 5 hours with aortography and was less than 3 hours with chest computed tomography and transesophageal echocardiography. Each diagnostic modality accurately identified an aortic injury. The average time for cardiopulmonary bypass and for clamp and sew was 52 minutes (range, 49 to 55 minutes) and 34 minutes (range, 16 to 45 minutes), respectively. One patient with preoperative paraplegia regained partial function; there were no other patients with paraplegia. There were no deaths. All patients are alive 2 months to 7 years after repair.

CONCLUSIONS

The multiply injured child with severe blunt trauma and an abnormal chest roentgenogram requires a search for aortic injury. We believe the most effective algorithm to follow for the diagnosis of traumatic thoracic aortic rupture in the child involves selective performance of chest computed tomography and transesophageal echocardiography. Our experience suggests that the mechanism of injury, the duration to diagnosis of an aortic injury, and failure to use seat belts may contribute to morbidity. A high index of suspicion and a systematic approach to the diagnosis and to the management strategy for injuries to the thoracic aorta can contribute to a good outcome in those few children who survive the injury.

Selected topics in chest trauma

Trauma is the leading cause of death of young adults in the United States, and chest trauma is one of the leading causes of trauma-related fatalities. This article presents an approach to the radiological evaluation and diagnosis of pneumothorax, pneumomediastinum, traumatic aortic rupture, and thoracic spine injuries. Also discussed is the radiological assessment of vascular catheters, endotracheal tubes, and thoracostomy tubes.

CT of blunt chest trauma in children

While trauma is still the leading cause of death in the pediatric age range, it is surprising how little the CT appearances of pediatric chest injury have been investigated in the literature. We have reviewed the CT findings of blunt chest trauma in 44 children for whom chest CT examinations were requested to investigate the extent of intrathoracic injury. We noted a propensity for pulmonary contusions to be located posteriorly or posteromedially, and for them to be anatomically nonsegmental and crescentic in shape. This is possibly attributable to the relatively compliant anterior chest wall in children. The CT appearances of other major thoracic injuries are described, including pulmonary lacerations, pneumothoraces, malpositioned chest tubes, mediastinal hematomas, aortic injury, tracheobronchial injury, hemopericardium, and spinal injuries with paraspinal fluid collections. Children demonstrating findings incidental to the actual injury yet important to the subsequent therapy are also presented. We conclude that, in the event of clinically significant blunt chest trauma, the single supine chest examination in the trauma room is insufficient to adequately identify the extent of intrathoracic injury. With the exception of concern for aortic injury for which aortography is indicated, a dynamically enhanced CT scan of the thorax should be performed as clinically significant findings may result in altered therapy.