Advances in Imaging and Management Trends of Traumatic Aortic Injuries

Computed Tomography Angiography for Aortic Diseases

Aortic pathologies encompass a heterogeneous group of disorders, including acute aortic syndrome, traumatic aortic injury , aneurysm, aortitis, and atherosclerosis. The clinical manifestations of these disorders can be varied and non-specific, ranging from acute presentations in the emergency department to chronic incidental findings in an outpatient setting. Given the non-specific nature of their clinical presentations, the reliance on non-invasive imaging for screening, definitive diagnosis, therapeutic strategy planning, and post-intervention surveillance has become paramount. Commonly used imaging modalities include ultrasound, computed tomography (CT), and MR imaging. Among these modalities, computed tomography angiography (CTA) has emerged as a first-line imaging modality owing to its excellent anatomic detail, widespread availability, established imaging protocols, evidence-proven indications, and rapid acquisition time.

MR Angiography for Aortic Diseases

Aortic pathologic conditions represent diverse disorders, including aortic aneurysm, acute aortic syndrome, traumatic aortic injury, and atherosclerosis. Given the nonspecific clinical features, noninvasive imaging is critical in screening, diagnosis, management, and posttherapeutic surveillance. Of the commonly used imaging modalities, including ultrasound, computed tomography, and MR imaging, the final choice often depends on a combination of factors: acuity of clinical presentation, suspected underlying diagnosis, and institutional practice. Further research is needed to identify the potential clinical role and define appropriate use criteria for advanced MR applications such as four-dimenional flow to manage patients with aortic pathologic conditions.

Nationwide Analysis of Penetrating Thoracic Aortic Injury: Injury Patterns, Management, and Outcomes

INTRODUCTION

Penetrating thoracic aortic injuries (PTAI) represent a rare form of thoracic trauma. Unlike blunt thoracic aortic injuries (BTAI), only scarce data, included in small case series, are currently available for PTAI. The purpose of this study was to describe injury patterns, surgical management, and outcomes of patients with PTAI and compare to those with BTAI.

MATERIALS AND METHODS

A 9-y retrospective cohort study (2007-2015) was conducted using the National Trauma Data Bank. Patient demographics, injury profile, procedures performed, and patient outcomes were compared between the PTAI and BTAI group.

RESULTS

A total of 2714 patients with PTAI and 14,037 patients with BTAI were identified. Compared to BTAI, PTAI patients were younger (28 versus 42 y, P < 0.001), more often male (89.1% versus 71.7%, P < 0.001), and more likely to arrive without signs of life (27.6% versus 7.5%, P < 0.001). PTAI patients had less associated injuries, overall, compared to those with BTAI; however, were more likely to have injuries to the esophagus, diaphragm, and heart. Patients with PTAI were less likely to undergo endovascular (5.8% versus 30.5%, P < 0.001) or open surgical repair (3.0% versus 4.2%, P < 0.001) compared to BTAI. While the large majority of PTAI patients expired before their hospital arrival or in the emergency department, the in-hospital mortality rate among those who survivedemergency department stay was 43.1%.

CONCLUSIONS

Most patients with PTAI present to the hospital without any signs of life, and their overall mortality rate is extremely high. Only a small portion of PTAI patients who survived the initial resuscitation period underwent surgical interventions for thoracic aortic injuries. Further studies are still warranted to clarify the indications and types of surgical interventions for PTAI.

Minimal Aortic Injury Detected on Computed Tomography Angiography during Initial Trauma Imaging: Single Academic Level 1 Trauma Center Experience

BACKGROUND

 Minimal aortic injury (MAI), a subtype of acute traumatic aortic injury, is being increasingly recognized with better imaging techniques. Given conservative management, the role of follow-up imaging albeit important yet has to be defined.

METHODS

 All trauma chest computed tomography angiographies (CTAs) at our center between January 2012 and January 2019 were retrospectively reviewed for presence of MAI. MAIs were generally reimaged at 24 to 72 hours and then at a 7- and 30-day interval. Follow-up CTAs were reviewed for stability, progression, or resolution of MAI, along with assessment of injury severity scores (ISS) and concomitant injuries, respectively.

RESULTS

 A total of 17,569 chest CTAs were performed over this period. Incidence of MAI on the initial chest CTA was 113 (0.65%), with 105 patients receiving follow-up CTAs. The first, second, third, and fourth follow-up CTAs were performed at a median of 2, 10, 28, and 261 days, respectively. Forty five (42.9%), 22 (21%), 5 (4.8%), and 1 (1%) of the MAIs were resolved by first, second, third, and fourth follow-up CTAs. Altogether, 21 patients showed stability (mean ISS of 16.6), and 11 demonstrated improvement (mean ISS 25.8) of MAIs. Eight patients had no follow-up CTA (mean ISS 21). No progression to higher-grade injury was observed. Advancing age decreased the odds of MAI resolution on follow-up. A possible trend (p-value 0.22) between increasing ISS and time to resolution of MAIs was noted.

CONCLUSION

 In our series of acute traumatic MAIs diagnosed on CTA imaging, there was no progression of injuries with conservative management, questioning the necessity of sequential follow-up imaging.

Current updates in acute traumatic aortic injury: radiologic diagnosis and management

Acute traumatic aortic injuries, which have substantial lethal outcomes at the time of admission, are fatal in 80% to 90% of cases. These injuries are relatively rare and have nonspecific clinical presentations. Radiologists and emergency physicians need to identify the radiological signs of acute traumatic aortic injury and differentiate them from common imaging errors to ensure accurate diagnosis and determine appropriate management protocols. In combination with image-guided interventions, advances in cross-sectional imaging have enabled nonsurgical management of acute traumatic aortic injuries. Timely and precise diagnoses of these injuries following prompt treatment are essential as up to 90% of patients presenting at the hospital can undergo early repair.

Tension Hemothorax in Aortic Rupture: A Case Report

Background: The standard ATLS protocol calls for chest drain insertion in patients with hemothorax before performing further diagnostic steps. However, if trauma-induced thoracic aortic rupture is the underlying cause, such drainage can lead to massive bleeding and death of the patient. Case report: This report describes a case of a polytrauma patient (car accident), aged 21, with symmetrical chest and decreased breath sounds dorsally on the left. An urgent CT scan revealed subadventitial Grade III thoracic aortic transection with mediastinal hematoma, a massive left-sided hemothorax with mediastinal shift to the right, and other injuries. Stent-graft implantation with subsequent left hemithorax drainage was urgently performed, during which the patient became increasingly unstable from the circulatory point of view. This traumatic hemorrhagic shock was successfully managed at the ICU. Conclusion: Although hemothorax is a serious condition requiring rapid treatment, the knowledge of its origin is of utmost importance; performing chest drainage without bleeding control can lead to circulatory instability and death of the patient. Hence, where aortic injury can be suspected based on the mechanism of the injury, it is beneficial to perform spiral CT angiography for accurate diagnosis first and, in cases of aortic injury, to control the bleeding prior to drainage.

Factors Affecting Radiation Dose in Computed Tomography Angiograms for Pulmonary Embolism: A Retrospective Cohort Study

Objectives

Computed tomography pulmonary angiogram (CTPA) is one of the most commonly ordered and frequently overused tests. The purpose of this study was to evaluate the mean radiation dose to patients getting CTPA and to identify factors that are associated with higher dose.

Material and Methods

This institutionally approved retrospective study included all patients who had a CTPA to rule out acute pulmonary embolism between 2016 and 2018 in a tertiary care center. Patient data (age, sex, body mass index [BMI], and patient location), CT scanner type, image reconstruction methodology, and radiation dose parameters (dose-length product [DLP]) were recorded. Effective dose estimates were obtained by multiplying DLP by conversion coefficient (0.014 mSv•mGy^-1•cm^-1). Multivariate logistic regression analysis was performed to determine the factors affecting the radiation dose.

Results

There were 2342 patients (1099 men and 1243 women) with a mean age of 58.1 years (range 0.2-104.4 years) and BMI of 31.3 kg/m² (range 12-91.5 kg/m²). The mean effective radiation dose was 5.512 mSv (median - 4.27 mSv; range 0.1-43.0 mSv). Patient factors, including BMI >25 kg/m², male sex, age >18 years, and intensive care unit (ICU) location, were associated with significantly higher dose (P < 0.05). CT scanning using third generation dual-source scanner with model-based iterative reconstruction (IR) had significantly lower dose (mean: 4.90 mSv) versus single-source (64-slice) scanner with filtered back projection (mean: 9.29 mSv, P < 0.001).

Conclusion

Patients with high BMI and ICU referrals are associated with high CT radiation dose. They are most likely to benefit by scanning on newer generation scanner using advance model-based IR techniques.

Imaging of the aortic root on high-pitch non-gated and ECG-gated CT: awareness is the key!

The aortic pathologies are well recognized on imaging. However, conventionally cardiac and proximal aortic abnormalities were only seen on dedicated cardiac or aortic studies due to need for ECG gating. Advances in CT technology have allowed motionless imaging of the chest and abdomen, leading to an increased visualization of cardiac and aortic root diseases on non-ECG-gated imaging. The advances are mostly driven by high pitch due to faster gantry rotation and table speed. The high-pitch scans are being increasingly used for variety of clinical indications because the images are free of motion artifact (both breathing and pulsation) as well as decreased radiation dose. Recognition of aortic root pathologies may be challenging due to lack of familiarity of radiologists with disease spectrum and their imaging appearance. It is important to recognize some of these conditions as early diagnosis and intervention is key to improving prognosis. We present a comprehensive review of proximal aortic anatomy, pathologies commonly seen at the aortic root, and their imaging appearances to familiarize radiologists with the diseases of this location.

Blunt Aortic / Inferior Vena Cava Injury: Are We Consistently Providing the Same Level of Care?

Major vascular traumatic injuries have a higher pre-hospital and in-hospital mortality rate. The different mechanisms of injury and anatomy of the aorta and inferior vena cava (IVC) make the management a constant challenge to surgeons and clinicians. Blunt traumatic aortic injury (BTAI) can occur at the thoracic or abdominal level, each of which possesses different considerations. Blunt traumatic inferior vena cava injury (BTIVCI) also has important diagnostic challenges since the lesion may not be as evident in the IVC as compared to the aorta, possibly due to lower caval pressures or the ability to self-tamponade from adjacent structures. Endovascular management has significantly increased in the past years, and despite an improvement in mortality, the approach to aortic and IVC injuries is not well standardized. Diagnostic imaging helps to classify the extent of the lesions and guide towards the best therapeutic options for each case. Conservative management, in some cases, has shown to reduce mortality, and close follow-up has proven good outcomes. Future research will provide more evidence to determine the best approach to BTAI and BTIVCI for better long-term outcomes. This article aims to provide an updated review of the current literature regarding diagnosis, classification, and management of BTAI and BTIVCI.

National Trends of Thoracic Endovascular Aortic Repair versus Open Thoracic Aortic Repair in Pediatric Blunt Thoracic Aortic Injury

BACKGROUND

Blunt thoracic aortic injury (BTAI) occurs in <1% of all trauma admissions. Thoracic endovascular aortic repair (TEVAR) has become the preferred treatment modality in adult patients with BTAI, but its use in pediatrics is currently not supported by device manufacturers and lacks United States Food and Drug Administration approval. We hypothesized that there would also be an increased use of TEVAR in the pediatric population, thus conferring a lower risk of mortality compared with open thoracic aortic repair (OTAR).

METHODS

The National Trauma Data Bank (2007-2015) was queried for patients ≤17 years with BTAI. The primary outcomes were the incidences of TEVAR and OTAR. Secondary outcome was risk of mortality in those undergoing intervention. A multivariable logistic regression model was used to determine the risk of mortality in OTAR versus TEVAR.

RESULTS

We identified 650 pediatric BTAI patients with 159 (24.5%) undergoing intervention. Of these, 124 underwent TEVAR (78.0%) and 35 (22.0%) underwent OTAR. The rate of TEVAR steadily increased from 2007 to 2015 (15.4% vs. 27.1%, P < 0.001). Patients receiving OTAR and TEVAR had a similar injury severity score and rate of hypotension on admission (P > 0.05). Compared with OTAR, TEVAR patients had a higher rate of any traumatic brain injury (TBI) (63.7% vs. 37.1%, P = 0.005) and shorter hospital and intensive care unit length of stay (LOS) (16.4 vs. 21.4 days, P = 0.02; 10.1 vs. 12.2 days, P = 0.01). TEVAR and OTAR, even when stratified by ≤14 years and 15-17 years, had no difference in risk for mortality (odds ratio 1.20, confidence interval 0.29-5.01, P = 0.80).

CONCLUSIONS

The rate of TEVAR in pediatric BTAI nearly doubled from 2007 to 2015. Compared with OTAR, TEVAR was associated with a shorter hospital LOS despite a higher rate of TBI. There was no difference in risk for mortality between TEVAR and OTAR. Longitudinal studies to determine the long-term efficacy and complication rates, including reintervention, development of endoleak, and/or need for further operations, are needed as this technology is being rapidly adopted for pediatric trauma patients.

Evolution of conservative treatment of acute traumatic aortic injuries: lights and shadows

OBJECTIVES

The objective of this study is to compare early and long-term results in terms of survival and aortic complications for traumatic aortic injuries depending on the initial management strategy.

METHODS

From January 1980 to January 2017, 101 patients with aortic injuries were divided into 3 groups according to management strategy at admission: 60 patients, conservative management; 26 patients, open surgery and 15 patients, endovascular repair. The groups were similar in terms of gender and trauma severity scores.

RESULTS

All but 1 aortic-related complications and aortic-related mortality occurred in the conservative group (11.6% conservative vs 2.4% in both surgical and endovascular groups, P = 0.091). Total follow-up was 1109.27 patient-years. Survival in the conservative, surgical and endovascular group was 71.7%, 80.8% and 79.4% at 1 year, 68.2%, 80.8% and 79.4% at 5 years and 63.9%, 72.7% and 79.4% at 10 years, respectively (log-rank = 0.218). The rate of aortic-related complications was 58.3% in the conservative cohort. Cox regression identified the following risk factors for aortic-related complications: aortic injuries grade >I [odds ratio (OR), 3.05; P = 0.021], Trauma Injury Severity Score >50% (OR 1.21; P = 0.042) and the decade of treatment (OR 0.49; P = 0.011).

CONCLUSIONS

Minimal aortic injuries seem to be an amenable target for medical management, but patients remain at risk of developing aortic-related complications. Close, long-term imaging surveillance is mandatory to detect such complications at an early stage.

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.

Endovascular Management of Acute Traumatic Aortic Injury

Acute traumatic injury of the thoracic aorta is a highly lethal condition, with many afflicted patients expiring before hospital arrival. While previously these conditions were managed with open surgery, endovascular repair has rapidly evolved and is now considered the standard of care for certain patterns of aortic injury at centers with appropriate expertise. The development of newer branched devices has allowed these techniques to be utilized further and further proximally into the aorta. Through minimally invasive techniques, many aortic injuries can now be treated percutaneously with shorter recovery time and less perioperative complications.

Non-penetrating traumatic injuries of the aortic arch

Background In severely injured trauma patients, non-penetrating aortic arch injuries (NAAI) have a remarkable incidence and mortality. Both diagnostics and therapy of NAAI recently underwent significant changes. Purpose To assess mortality, morbidity, and the risk factors associated with NAAI in severely injured patients (Injury Severity Score [ISS] ≥16) under the light of recent technical and procedural advances in trauma care. Material and Methods A total of 230 consecutive trauma patients with ISS ≥16 admitted to our level-I trauma center during a 24-month period, were prospectively included and underwent standardized whole-body computed tomography (CT) in a 2 × 128-detector-row scanner. Incidence, mortality, patient and trauma characteristics, and concomitant injuries were recorded for patients with NAAI. Localization of NAAI was described referring to Mitchell and Ishimaru; severity was graded according to the proposal of Heneghan et al. Results Thirteen of 230 patients had a NAAI, yielding an incidence of 5.6%. Mean age and ISS was not elevated in NAAI (44.4 ± 14.8 years, ISS = 38 ± 12.4). Mortality was 23.1%. One patient had severe neurologic sequelae from a stroke; all surviving patients had to undergo (transient) anticoagulant therapy. Trauma mechanism was of high kinetic energy in all cases. Concomitant injuries were predominantly thoracic (rib fractures = 76.9%, thoracic spine fracture = 38.5%). Conclusion Whenever an individual possibly encountered a deceleration-acceleration trauma mechanism, a high level of suspicion for NAAI should be maintained. It remains to be determined whether recent advances in mortality are due to changes in trauma care or due to improved vehicle and road safety.

Post-traumatic acute thoracic aortic injury (TAI)-a single center experience

Background

We assess the effectiveness and our experience in emergency thoracic endovascular aortic repair (TEVAR) in patients with post-traumatic acute thoracic aortic injury (TAI) and associated multiorgan trauma. TAI is a life-threatening condition. It usually results from a sudden deceleration caused by vehicle accident, a fall or some other misfortune. Techniques of endovascular aortic repair have become promising methods to treat emergent TAI.

Methods

Since 2007, 114 patients with thoracic aorta pathologies have been treated by TEVAR. Our study involved 15 (incl. 14 men) of them (13%) who underwent stent graft implantation for post-traumatic either aortic rupture or pseudoaneurysm. The procedural access was limited to small skin incision in one groin and percutaneous puncture of the contralateral femoral artery. We evaluated technical success, early and long-term mortality, complication rate of procedure and throughout clinical and instrumental follow-up.

Results

Technical success rate was 100%. All patients survived the endovascular interventions. No additional procedures or conversions to open surgery were necessary. After the operation, none of the patients had symptoms of stroke or spinal cord ischemia (SCI). No serious stent-graft-related adverse events such as endoleak, infection or migration were noted during follow-up period that ranged from 6 to 108 months.

Conclusions

In our department, techniques of TEVAR with stentgraft implantation have become methods of choice in treatment of traumatic TAIs since they have enabled to minimize operational risk, particularly in unstable multitrauma patients in severe clinical status. TEVAR for TAI performed in emergency settings provide favorable long-term results.

Blunt Cerebrovascular Injuries: Advances in Screening, Imaging, and Management Trends

Blunt cerebrovascular injury is a relatively uncommon but sometimes life-threatening injury, particularly in patients presenting with ischemic symptoms in that vascular territory. The decision to pursue vascular imaging (generally CT angiography) is based on clinical and imaging findings. Several grading scales or screening criteria have been developed to guide the decision to pursue vascular imaging, as well as to recommend different treatment options for various injuries. The data supporting many of these guidelines and options are limited however. The purpose of this article is to review and compare these scales and criteria and the data supporting clinical efficacy and to make recommendations for future research in this area.