Thoracic endovascular aortic repair for traumatic aortic injuries: insight from literature and practical recommendations

INTRODUCTION

Thoracic endovascular aortic repair (TEVAR) for treatment of blunt traumatic aortic injuries (BTAIs) is nowadays the gold standard technique in adult patients, replacing gradually the use of open repair (OR). Although randomized controlled trials will never be performed comparing TEVAR to OR for BTAIs management, trauma and vascular societies guidelines today primarily recommend the former for BTAI patients with a suitable anatomy. The aim of this review was to describe past and recent data published in literature regarding pros and cons of TEVAR treatment in BTAI, and to analyze some debated issues and future perspectives.

EVIDENCE ACQUISITION

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Scale for the Assessment of Narrative Review Articles (SANRA) were used to obtain and describe selected articles on TEVAR in BTAI.

EVIDENCE SYNTHESIS

Young (<50 years) men were the most operated population. The use of TEVAR increased over the years, with a progressive reduction in mortality and overall postoperative complication rates when compared with OR. Lack of information remains about the percentage of urgent cases.

CONCLUSIONS

TEVAR is considered nowadays the treatment of choice in BTAI patients. In case of aortic rupture (grade IV) the treatment is mandatory, while intimal tear (grade I) and intramural hematoma (grade II) can be safely managed with no operative management (NOM). Debate is still ongoing on grade III (pseudoaneurysms). Unfortunately, several aspects remain not yet clarified, including disease classification, type and grade to treat, timing (urgent versus elective), priority of vascular injuries in polytrauma patients, and TEVAR use in pediatrics and young patients.

Deceleration thoracic aortic ruptures in trauma center level I areas: a 6-year retrospective study

OBJECTIVES

This retrospective study aimed to analyze the trend of mortality due to thoracic aortic ruptures caused by deceleration injuries that occurred within the catchment area of Hradec Kralove University Hospital.

MATERIALS AND METHODS

The study sample comprised 175 patients who had sustained thoracic aortic ruptures caused by deceleration injuries and were transported to Hradec Kralove University Hospital in 2009-2014. The small proportion of patients enrolled in this retrospective study were diagnosed and treated at the emergency department (ED). However, the overwhelming majority of the sample comprised of patients who died at the accident scene and later underwent an autopsy at the Institute of Forensic Medicine in our hospital.

RESULTS

Of 175 patients, 150 underwent an autopsy. Of these, 139 individuals (79%) died at the incident scene, and 11 (6%) were transported to the ED and later died of their injuries. A total of 36 patients were admitted to the hospital; 29 were admitted primary (11 later died), and 7 were transferred. No deaths occurred in the group of secondary admissions. Thus, 31% of all patients hospitalized died following transport to the hospital. Of 175 patients, 15% (or 69% of all hospitalized patients) survived their injuries. Among patients who died as a result of thoracic aortic injury, no unexpected deaths were recorded (i.e., no deaths among patients with survival probability more than 50% = PS > 0.5).

CONCLUSION

Our results suggested that the lethality of thoracic aortic injuries might be minimized by transporting triage-positive patients directly to trauma centers. Accurate diagnoses and treatments were supported by admission chest X-rays, a massive transfusion protocol, and particularly, CT angiography, which is not routinely included in primary surveys. An additional prognostic parameter was clinical collaboration between an experienced trauma surgeon, an interventional radiologist, and a vascular or thoracic surgeon.

Call for a new classification system and treatment strategy in blunt aortic injury

OBJECTIVE

The current Society for Vascular Surgery (SVS) classification scheme for blunt aortic injury (BAI) is descriptive but does not guide therapy. We propose a simplified classification scheme based on our robust experience with BAI that is descriptive and guides therapy.

METHODS

Patients presenting with BAI between January 1999 and September 2014 were identified from our institution's trauma registry. We divided patients into eras by time. Era 1: before the first United States Food and Drug Administration (FDA)-approved thoracic endovascular aortic repair (TEVAR) device (1999-2005); era 2: FDA-approved TEVAR devices (2005-2010); and era 3: FDA-approved BAI-specific devices (2010-present). Baseline demographic information, Injury Severity Score, hospital details, and survival were collected and compared. Our classification scheme was minimal aortic injury, SVS grade 1 and 2; moderate aortic injury, SVS grade 3; and severe aortic injury, SVS grade 4.

RESULTS

We identified 226 patients with a diagnosis of BAI: 75 patients in era 1, 84 in era 2, and 67 in era 3. Mean Injury Severity Score was 39.5 (range, 16-75). The BAI-related in-hospital mortality was significantly higher before endovascular introduction in era 1 (14.6% vs 4.8%; P = .03), but was not significantly different between eras 2 and 3 or before and after BAI-specific devices were introduced (P = .43). Of 146 patients (64.6%) who underwent aortic intervention, 91 underwent endovascular repair, and 55 underwent open repair. All but nine patients (94%) had a moderate or severe injury. Survival across all three eras of patients undergoing operative intervention was 80.2%. Survival in eras 2 and 3 was higher than in era 1 (86.4% vs 73.8%) but was not significant (P = .38). Of 47 patients in eras 2 and 3 with minimal aortic injury, 45 (96%) were managed nonoperatively, with no BAI-related deaths. After 2007, follow-up imaging was obtained in 38 patients (80%) with minimal aortic injury, and progression was not observed. Computed tomography scans showed the injury in 13 patients appeared stable, 19 had complete resolution (50%), and 6 had a decreasing size of injury.

CONCLUSIONS

Our experience confirms that BAI-related mortality for patients who survive to presentation is now 5%. From our findings during the past 15 years, we propose simplification of the SVS grading criteria of BAI into minimal, moderate, and severe based on treatment differences among the three groups. Minimal aortic injury can be successfully managed nonoperatively without mandatory follow-up imaging. Moderate aortic injury can be managed semielectively with TEVAR, and severe aortic injury, requires emergency TEVAR.

Acute traumatic aortic injury: practical considerations for the diagnostic radiologist

The diagnosis of acute traumatic aortic injury (ATAI) relies heavily on accurate and efficient imaging interpretation, thereby making the radiologist integral to the care of patients in whom these life-threatening lesions are suspected. Typically, this evaluation begins with the initial trauma radiograph, in which findings suggestive of mediastinal hematoma or ATAI can be detected. Definitive diagnosis of ATAI is made with the current gold standard, computed tomography, wherein indirect and direct signs of ATAI provide the means for sensitive and specific diagnosis. Although the diagnosis of ATAI on computed tomography can be straightforward, technical and anatomic pitfalls can complicate interpretation and must be understood. Once the diagnosis is made, the radiologist needs to provide a meaningful report that includes an appropriate description of the lesion location and characteristics. The purpose of this article is to review the key aspects of the imaging evaluation of ATAI with a focus on factors that affect the management of these patients.

Outcomes of Traumatic Aortic Injury in a Primary Open Surgical Approach Paradigm

Background:

Multiple classifications can be used to define the magnitude of aortic injury. The Vancouver Classification (VC) is a new and simplified computed tomography-based Blunt Aortic Injury (BAI) grading system correlating with clinical outcomes.

Objectives:

The objectives of this study are: 1) to describe the severity of aortic injury in a center with a predominantly surgical approach to BAI; 2) to correlate the severity of aortic trauma to hospital survival rate and rate of adverse events according to the type of interventions performed during the hospital stay; and 3) to evaluate VC.

Patients and Methods:

All patients referring to the Sacre-Coeur Hospital of Montreal between August 1998 and April 2011 for management of BAI were studied. Two radiologists reviewed all CT scan images individually and classified the aortic injuries using VC.

Results:

Among the 112 patients presenting with BAI, 39 cases had local CT scans available for reconstruction. Seven patients were identified as suffering from grade I injuries (flap or thrombus of less than 1 cm), 6 from grade II injuries (flap or thrombus of more than 1 cm), and 26 from grade III injuries (pseudoaneurysm). Among the patients with grade I injuries, 57% were treated surgically and 43% medically with a survival rate of 100%. Among the patients with grade II injuries (67% treated surgically and 33% treated medically) survival was also 100%. Among patients with grade III injuries (85% treated surgically, 7% had Thoracic Endovascular Aortic Repair (TEVAR) and 8% treated medically) survival was 95%, 95% and 50%, respectively. There were no significant differences between groups as to clinical outcome. Inter-rater reliability was 0.81.

Conclusions:

VC is easy to use and has low inter-observer variability. Low grades of injury were associated with low mortality related to medical treatment.

MDCT distinguishing features of focal aortic projections (FAP) in acute clinical settings

Focal aortic projections (FAP) are protrusion images of the contrast medium (focal contour irregularity, breaks in the intimal contour, outward lumen bulging or localized blood-filled outpouching) projecting beyond the aortic lumen in the aortic wall and are commonly seen on multidetector computed tomography (MDCT) scans of the chest and abdomen. FAP include several common and uncommon etiologies, which can be demonstrated both in the native aorta, mainly in acute aortic syndromes, and in the post-surgical aorta or after endovascular therapy. They are also found in some types of post-traumatic injuries and in impending rupture of the aneurysms. The expanding, routine use of millimetric or submillimetric collimation of current state-of-the-art MDCT scanners (16 rows and higher) all the time allows the identification and characterization of these small ulcer-like lesions or irregularities in the entire aorta, as either an incidental or expected finding, and provides detailed three-dimensional pictures of these pathologic findings. In this pictorial review, we illustrate the possible significance of FAP and the discriminating MDCT features that help to distinguish among different types of aortic protrusions and their possible evolution. Awareness of some related and distinctive radiologic features in FAP may improve our understanding of aortic diseases, provide further insight into the pathophysiology and natural history, and guide the appropriate management of these lesions.

Blunt thoracic aortic injuries: CT characterisation and treatment outcomes of minor injury

OBJECTIVES

Computed tomography (CT)-defined anatomical differentiation of minor and major blunt traumatic aortic injuries (TAIs) was applied to determine injury grade and management/outcomes in minor TAIs, and if the presence of peri-aortic mediastinal haematoma (MH) correlated with TAI grade.

METHODS

Admission chest CT of blunt TAI cases during 2005-2011 were reviewed by consensus and categorised as major or minor. Minor was defined as pseudoaneurysm <10 % normal aortic lumen, intimal flap or contour abnormality. Presence/absence of MH was determined. Clinical management/outcome was ascertained from medical records.

RESULTS

Of 115 TAIs, 42 were minor (33 with MH, 9 without). Among the 73 with major TAI, 3 had no MH. Twenty-six (62 %) minor TAI patients were managed medically, 12 (29 %) percutaneous stent-grafts, 2 (5 %) died of non-aortic causes and 2 (5 %) underwent surgery. Of 26 managed without intervention, none developed complications from TAI at last clinical or CT follow-up. The relationship between presence/absence of peri-aortic MH and grade of TAI was statistically significant.

CONCLUSIONS

More than a third of multi-detector (MD) CT-diagnosed TAIs were minor. Minor TAIs treated medically were stable at last follow-up, suggesting this is a reasonable initial management approach. Absence of MH cannot be relied upon to exclude minor TAI, indicating the need for careful direct aortic inspection.

KEY POINTS

• MDCT can differentiate minor from major blunt traumatic aortic injuries. • About one-third of MDCT-diagnosed blunt traumatic aortic injuries are minor. • Minor aortic injuries are not necessarily accompanied by mediastinal haemorrhage. • MDCT diagnosis of minor aortic injury supports application of medical management.

Mid- and long-term results of endovascular treatment in thoracic aorta blunt trauma

Study Aim. Evaluation of results in blunt injury of the thoracic aorta (BAI) endovascular treatment. Materials and Methods. Sixteen patients were treated for BAI. Thirteen patients had associated polytrauma, 4 of these had a serious hypotensive status and 4 had an hemothorax. In the remaining 3, two had a post-traumatic false aneurysm of the isthmus and 1 had a segmental dissection. In those 13 patients a periaortic hematoma was associated to hemothorax in 4. All patients were submitted to an endovascular treatment, in two cases the subclavian artery ostium was intentionally covered. Results. One patient died for disseminated intravascular coagulation. No paraplegia was recorded. No ischemic complications were observed. A type I endoleak was treated by an adjunctive cuff. During the followup (1–9 years) 3 patients were lost. A good patency and no endoleaks were observed in all cases. One infolding and 1 migration of the endografts were corrected by an adjunctive cuff. Conclusion. The medium and long term results of the endovascular treatment of BAI are encouraging with a low incidence rate of mortality and complications. More suitable endo-suite and endografts could be a crucial point for the further improvement of these results.

Vancouver simplified grading system with computed tomographic angiography for blunt aortic injury

OBJECTIVE

Delineation of blunt aortic injury by computed tomographic angiography guides management of this potentially fatal injury. Two existing grading systems are problematic to apply and not linked to outcomes. A simplified computed tomographic angiography-based grading system, linked to clinical outcomes, was developed, and feasibility and reliability were evaluated.

METHODS

Retrospective review was performed of all blunt aortic injury cases presenting to a single provincial quaternary referral center designated for blunt aortic injury management between 2001 and 2009. Management, associated injuries, hospital survival, and cause of death were determined. Initial computed tomographic angiography was reviewed, and injuries were graded according to the new Vancouver simplified grading system by 2 study authors. Three additional trauma radiologists then graded the aortic injuries with the 2 existing systems and the simplified system. Interrater reliability was determined.

RESULTS

Forty-eight patients were identified. Two had minimal aortic injury (grade I), 7 had an intimal flap larger than 1 cm (grade II), 32 had traumatic pseudoaneurysm (grade III), 6 had active contrast extravasation (grade IV), and 1 could not be rated. Survivals were 100%, 90%, and 33% for grades I and II, III, and IV, respectively. Of grade III injuries, 14% were medically managed, 68% repaired endovascularly, and 18% repaired with open surgery. Interrater correlation was best with the simplified score, with only 0.5% of cases unable to be classified.

CONCLUSIONS

The Vancouver simplified blunt aortic injury grading system is easy to use and correlates with clinical outcomes. Prospective external validation is required.

Advanced trauma life support, 8th edition, the evidence for change

The American College of Surgeons Committee on Trauma's Advanced Trauma Life Support Course is currently taught in 50 countries. The 8th edition has been revised following broad input by the International ATLS subcommittee. Graded levels of evidence were used to evaluate and approve changes to the course content. New materials related to principles of disaster management have been added. ATLS is a common language teaching one safe way of initial trauma assessment and management.