Outcomes of thoracic endovascular aortic repair in patients with concomitant blunt thoracic aortic injury and traumatic brain injury from the Aortic Trauma Foundation global registry

Thoracic aortic pseudoaneurysm: Inside its pathophysiology

OBJECTIVES

Our aim was to investigate pathophysiology of pseudoaneurysm of the thoracic aorta, an acute or chronic pathology, respectively, secondary to blunt thoracic trauma and aortitis, or complicating a deep penetrating aortic ulcer, intraparietal hematoma, aortic aneurysm, and even aortic graft, often with atherosclerosis as a common background.

METHODS

Given the relative rarity of this disease, an "inductive" retrospective method made it possible to retrieve clinical, radiological, and histopathological elements, which were mutually compared and validated through a "deductive" process of reinterpretation.

RESULTS

We have identified three main structural constituents of this disease: a cavity, a single blood entry port, communicating with the aortic lumen, and a pseudocapsule. It is often caused by a chronic degenerative pathology of the intima and medial layers of the aorta, typically involving elastic fibers and smooth muscle cells, with possible intermediate stages of deep aortic ulcer or intraparietal hematoma. Otherwise, the acute onset may be secondary to acute aortitis or aortic injury.

CONCLUSIONS

Today, thanks to the current angiographic tools represented by 3-D high resolution multidetector CT and MRI angiography, the diagnosis of thoracic aortic pseudoaneurysm is easier, as well as its surgical indications.

Using machine learning to predict outcomes of patients with blunt traumatic aortic injuries

BACKGROUND

The optimal management of blunt thoracic aortic injury (BTAI) remains controversial, with experienced centers offering therapy ranging from medical management to TEVAR. We investigated the utility of a machine learning (ML) algorithm to develop a prognostic model of risk factors on mortality in patients with BTAI.

METHODS

The Aortic Trauma Foundation registry was utilized to examine demographics, injury characteristics, management and outcomes of patients with BTAI. A STREAMLINE (A Simple, Transparent, End-To-End Automated Machine Learning Pipeline Facilitating Data Analysis and Algorithm Comparison) model as well as logistic regression (LR) analysis with imputation using chained equations was developed and compared.

RESULTS

From a total of 1018 patients in the registry, 702 patients were included in the final analysis. Of the 258 (37%) patients who were medically managed, 44 (17%) died during admission, 14 (5.4%) of which were aortic related deaths. Four hundred forty-four (63%) patients underwent TEVAR and 343 of which underwent TEVAR within 24 hours of admission. Among TEVAR patients, 39 (8.8%) patients died and 7 (1.6%) had aortic related deaths ( Table 1 ). Comparison of the STREAMLINE and LR model showed no significant difference in ROC curves and high AUCs of 0.869 (95% confidence interval, 0.813-0.925) and 0.840 (95% confidence interval, 0.779-0.900) respectively in predicting in-hospital mortality. Unexpectedly, however, the variables prioritized in each model differed between models. The top 3 variables identified from the LR model were similar to that from existing literature. The STREAMLINE model, however, prioritized location of the injury along the lesser curve, age and aortic injury grade.

CONCLUSION

Machine learning provides insight on prioritization of variables not typically identified in standard multivariable logistic regression. Further investigation and validation in other aortic injury cohorts are needed to delineate the utility of ML models.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Current expert-based opinions on endovascular treatment of blunt thoracic aortic injury: A state-of-the-art narrative review on indications, techniques, results, and challenges

INTRODUCTION

Blunt thoracic aortic injury (BTAI) represents one of the most devastating scenarios of vascular trauma which warrants prompt recognition with expedited management. Clinical manifestations of BTAI may not be straightforward to detect and may be misdiagnosed. Therefore, diagnosis of BTAI requires a high index of suspicion based on the mechanism of injury along with urgent transfer to centers with appropriate expertise and facilities.

METHODS

We provide an expert-based narrative review on endovascular treatment of BTAI highlighting indications, techniques, results, and challenges.

RESULTS

Multiple imaging modalities can be used including computed tomography angiography, transesophageal echocardiography, magnetic resonance imaging, and intravascular ultrasound. Whilst conservative pharmacological management can be a safe option in low-grade BTAI, thoracic endovascular aortic repair has become the gold-standard strategy in most cases, replacing open surgical repair. Nevertheless, it is important to account for patient demographics particularly age, severity of injury, choice of endograft including its type and size, and endovascular technique including landing zone and left subclavian artery revascularization.

CONCLUSIONS

Overall, TEVAR in BTAI has been shown to be an efficacious strategy with favorable early outcomes. In contrast, less is known on the long-term clinical outcomes of TEVAR in BTAI. Hence, despite the optimal early technical and clinical success rates, concerns remain about the need for long-term surveillance. The exact timing of follow-up and the integration of different modalities that can also investigate potential downstream cardiovascular effects remain hot topics for future research. Finally, industry should focus on developing more compliant endografts to improve the stiffness mismatch between the endograft and the aorta to optimize results.

A Systematic Review on Thoracic Endovascular Repair Outcomes in Blunt Thoracic Aortic Injuries

PURPOSE

Blunt thoracic aortic injury (BTAI) represents a potentially life-threatening condition and thoracic endovascular aortic repair (TEVAR) is recommended as the first-line treatment (Class I level of evidence C) by the current guidelines. The aim of this systematic review was to determine the perioperative and mid-term follow-up outcomes of patients with BTAI treated with TEVAR.

MATERIALS AND METHODS

We reviewed the English literature published between 2000 and 2022, via Ovid, using MEDLINE, EMBASE, and CENTRAL databases, until July 30, 2022. Observational studies and case series, with ≥5 patients, reporting on the perioperative and follow-up outcomes of patients who underwent TEVAR for BTAI were included. The Newcastle-Ottawa Scale was used to assess the risk of bias. Primary outcomes were technical success and 30-day mortality, cerebrovascular morbidity. Secondary outcomes were mortality and re-interventions during the mid-term follow-up.

RESULTS

From 5201 articles identified by the literature search, 35 eligible studies were included in this review. All studies had a retrospective study design. In total, 991 patients were included. The mean age was 34.5±16.5 years (range=16-89 years). Technical success was 98.0% (odds ratio [OR], 95% confidence interval [CI]=0.98, 0.99, p<0.001, I2=0%). Mortality at 30 days was 5.0% (OR, 95% CI=0.03, 0.06, p<0.001, I2=5.56%). Spinal cord ischemia occurred in 1.0% (OR, 95% CI=0.01, 0.02, p<0.001, I2=0%) and stroke rate was 2.0% (OR, 95% CI=0.01, 0.02, p<0.001, I2=0%). The available follow-up was estimated at 29 months (range=3-119 months) with mortality rate at 2.0% (OR, 95% CI=0.01, 0.02, p<0.001, I2=0%) and re-intervention rate at 1.0% (OR, 95% CI=0.01, 0.02, p<0.001, I2=10.5%).

CONCLUSION

Thoracic endovascular aortic repair showed high technical success and low early cerebrovascular morbidity and mortality rates. In the mid-term follow-up, the estimated mortality and re-intervention rates were also low. Furthermore, higher quality prospective studies are needed.

CLINICAL IMPACT

Thoracic endovascular aortic repair (TEVAR) is recommended as the first line treatement in patients with blunt thoracic aortic injuries (BTAI). This systematic review of 35 retrospective studies and 991 patients showed high technical success (98.0%) with an associated 30-day mortality at 5.0% and low spinal cord ischemia (1%) and stroke rates (2.0%). Mid-term mortality and re-intervention rates reassure the effectiveness of TEVAR in BTAI cases.

Development and Validation of a Risk Prediction Tool for In-hospital Mortality After Thoracic Endovascular Repair in Patients with Blunt Thoracic Aortic Injury Using the Aortic Trauma Foundation Registry

BACKGROUND

The objective of our present effort was to use an international blunt thoracic aortic injury (BTAI) registry to create a prediction model identifying important preoperative and intraoperative factors associated with postoperative mortality, and to develop and validate a simple risk prediction tool that could assist with patient selection and risk stratification in this patient population.

METHODS

For the purpose of the present study, all patients undergoing thoracic endovascular aortic repair (TEVAR) for BTAI and registered in the Aortic Trauma Foundation (ATF) database from January 2016 as of June 2022 were identified. Patients undergoing medical management or open repair were excluded. The primary outcome was binary in-hospital all-cause mortality. Two predictive models were generated: a preoperative model (i.e. only including variables before TEVAR or intention-to-treat) and a full model (i.e. also including variables after TEVAR or per-protocol).

RESULTS

Out of a total of 944 cases included in the ATF registry until June 2022, 448 underwent TEVAR and were included in the study population. TEVAR for BTAI was associated with an 8.5% in-hospital all-cause mortality in the ATF dataset. These study subjects were subsequently divided using 3:1 random sampling in a derivation cohort (336; 75.0%) and a validation cohort (112; 25.0%). The median age was 38 years, and the majority of patients were male (350; 78%). A total of 38 variables were included in the final analysis. Of these, 17 variables were considered in the preoperative model, 9 variables were integrated in the full model, and 12 variables were excluded owing to either extremely low variance or strong correlation with other variables. The calibration graphs showed how both models from the ATF dataset tended to underestimate risk, mainly in intermediate-risk cases. The discriminative capacity was moderate in all models; the best performing model was the full model from the ATF dataset, as evident from both the Receiver Operating Characteristic curve (Area Under the Curve 0.84; 95% CI 0.74-0.91) and from the density graph.

CONCLUSIONS

In this study, we developed and validated a contemporary risk prediction model, which incorporates several preoperative and postoperative variables and is strongly predictive of early mortality. While this model can reasonably predict in-hospital all-cause mortality, thereby assisting physicians with risk-stratification as well as inform patients and their caregivers, its intrinsic limitations must be taken into account and it should only be considered an adjunctive tool that may complement clinical judgment and shared decision-making.

Early Versus Delayed Thoracic Endovascular Aortic Repair for Blunt Traumatic Aortic Injury: A Systematic Review and Meta-Analysis

Blunt aortic injury is the second most prevalent cause of patient fatalities post-trauma, closely following head injuries as the leading cause. In recent years, thoracic endovascular aortic repair (TEVAR) has evidently improved survival rates and reduced complications in patients suffering from blunt traumatic aortic injury (BTAI) in comparison to open surgery and non-operative management. It is difficult to characterize the appropriate criteria for the timing of TEVAR, whether early or delayed for BTAI, considering the discrepancies related to timing. Electronic databases, including PubMed, Scopus, the Cochrane Central Register of Controlled Trials (CENTRAL), and Embase, were searched through April 2023. The primary outcomes were short-term mortality and hospital and intensive care unit (ICU) stays. Time to TEVAR, acute respiratory distress syndrome, sepsis, deep vein thrombosis, delayed stroke, and renal failure were also evaluated. We included a total of seven studies, comprising 4177 patients who met the inclusion criteria. Short-term mortality was significantly higher in the early TEVAR group (RR: 1.86; 95% confidence interval (CI); (1.26-2.74); p<0.001; I2=33%). In contrast, the ICU length of stay was significantly shorter in the early group (mean difference: -2.82 days; 95% CI; (-4.09 - -1.56); p<0.0001; I2=55%). There was no significant difference between both groups in the presenting profile or postoperative complications. Patients undergoing delayed TEVAR had markedly lower mortality rates but a longer ICU stay. The need for future studies with more robust designs is imperative to investigate the factors influencing the timing of repair and the associated outcomes.

The clinical characteristics and surgical treatment for delayed blunt thoracic aortic injury-a case series

BACKGROUND

Delayed thoracic aortic injury (DTAI) induced by left closed rib fractures (RFs) is a clinically rare blunt injury to the thoracic aorta with an insidious onset. DTAI is very prone to missed diagnosis due to the unreliability of using the initial post-injury computed tomography (CT) scan to explicitly detect any signs of an aortic injury, potentially leading to a fatal hemorrhage. Timely diagnosis and treatment are therefore key to preventing such deadly complications. With that said, not all cases of left RFs lead to delayed aortic injuries, so how can surgeons tell which cases are to be culled and focused on? Also, what kinds of treatment should be administered upon detection?

METHODS

A retrospective analysis was performed on the clinical data of DTAI cases induced by left closed RF that were admitted to our Hospital from June 2015 through June 2020. Injuries to the aortic tunica adventitia or the elastic layer were intraoperatively confirmed. CT scan findings, locations and numbers of RFs, as well as the choices of surgical procedure were reviewed postoperatively. In addition, a literature review was conducted to analyze characteristics shared by similar cases.

RESULTS

This study included 7 patients treated by our hospital and 8 reported in the literature. The broken ends of RFs causing aortic wall injury (including the tunica adventitia) were all found in the medial to the lateral erector spinae. All patients in our hospital received internal fixation for RFs and thoracoscopic removal of free bone fragments (if any). Concomitant injuries were managed either by simultaneous or staged surgery.

CONCLUSIONS

For multiple left RFs with the broken ends located in the inside of the lateral erector spinae, the number of fractured ribs ≥4 and a smaller number of fractured ribs with multiple fractures in a single rib are important factors for DTAI. Active surgical intervention is recommended for patients with these important factors. The specific intervention is tailored to each patient's particular needs to eliminate the risk of developing life-threatening thoracic aortic injury (TAI) and rupture.

Delayed Endovascular Repair With Procedural Anticoagulation: A Safe Strategy for Blunt Aortic Injury

BACKGROUND

Blunt aortic injury (BAI) and traumatic brain injury (TBI) are the leading causes of death after blunt trauma. The purposes of this study were to identify predictors of mortality for BAI and to examine the impact of procedural heparinization during thoracic endovascular aortic repair (TEVAR) on neurologic outcomes in patients with BAI/TBI.

METHODS

Patients with BAI were identified over an 8 year period. Age, gender, severity of injury and shock, time to TEVAR, morbidity, and mortality were recorded and compared. Multivariable logistic regression (MLR) was performed to determine independent predictors of mortality. Youden's index determined optimal time to TEVAR.

RESULTS

A total of 129 patients were identified. The majority (74%) were male with a median age and injury severity score (ISS) of 40 years and 29, respectively. Of these, 26 (20%) had a concomitant TBI. Patients with BAI/TBI had higher injury burden at presentation (ISS 37 vs. 29, P = 0.002; Glasgow Coma Scale [GCS] 6 vs. 15, P < 0.0001), underwent fewer TEVAR procedures (31 vs. 53%, P = 0.039), and suffered increased mortality (39 vs. 16%, P = 0.009). All TEVARs had procedural anticoagulation, including patients with TBI, without change in neurologic function. The optimal time to TEVAR was 14.8 hr. Mortality increased in TEVAR patients before 14.8 hr (8.7 vs. 0%, P = 0.210). MLR identified TEVAR as the only modifiable factor that reduced mortality (odds ratio 0.11; 95% confidence interval 0.03-0.45, P = 0.002).

CONCLUSIONS

TEVAR use was identified as the only modifiable predictor of reduced mortality in patients with BAI. Delayed TEVAR with the use of procedural heparin provides a safe option regardless of TBI with improved survival and no difference in discharge neurologic function.