Acute aortic syndrome: pathology and therapeutic strategies

Spontaneous Aortic Rupture: A Case Report

Introduction

Acute aortic syndrome (AAS) includes the disease processes of aortic dissection, penetrating atherosclerotic ulcer, and intramural hematoma. This case demonstrates an atypical presentation of the disease and offers approaches to potentially prevent missed diagnoses.

Case Report

An 87-year-old female with hypertension and Alzheimer's dementia presented to the emergency department with stable vital signs and a chief complaint of throat pain. Initial work-up was significant for ischemia on electrocardiogram and elevated troponin. Computed tomography of the soft tissue neck revealed evidence of a ruptured aorta.

Conclusion

Aortic rupture is a fatal complication of AAS. In an elderly patient with a history of hypertension, ischemic changes on electrocardiogram, and nonspecific pain, AAS should be on the emergency physician's differential even in the setting of a benign or limited history and exam.

The Dilemma in the Management of Thromboembolic Disease in the Setting of Concomitant Aortic Pseudoaneurysm

Ascending aortic pseudoaneurysm (AAP) is a rare and serious complication of cardiothoracic surgeries or blunt chest trauma. We present a patient with paroxysmal atrial fibrillation, acute right pontine stroke, and acute pulmonary embolism (PE) with an incidental AAP that precluded the use of anticoagulation and surgery. The case findings substantiate the need for a CT-based assessment of aortic pathology after coronary artery bypass grafting (CABG) in the asymptomatic patient to determine the most appropriate treatment modalities. However, the high cost of CT imaging and the potential radiation exposure challenge its routine use in high-risk patients.

Immunological therapeutics in acute aortic syndrome

Acute aortic syndrome is a group of interlinked conditions with common presenting symptoms, including aortic dissection, penetrating atherosclerotic ulcer, and intramural hematoma. Pharmacological management of acute aortic syndrome is a growing area, with key themes to address the underlying inflammatory pathways believed to be the cause. Research into interleukins, matrix metalloproteinases, and granulocyte macrophage colony-stimulating factor are just some of the many immunological properties being investigated and translated into medical therapies. Stem cell experiments may indicate further advances in the pathologies of acute aortic syndrome. The study of pharmacogenomics to improve treatment across different genomes is also a novel area outlined in this paper.

Acute type A aortic intramural hematoma and type A aortic dissection: correlation between the intimal tear features and pathogenesis

Background

To determine the prevalence, clinical and imaging features of intimal tear detected by ECG-gated multidetector computed tomography (MDCT) and confirmed by surgery in patients with acute type A intramural hematoma (ATAIMH) and acute type A aortic dissection (AAAD).

Methods

This retrospective study involved analysis of the intimal tear characteristics in 72 consecutive patients with ATAIMH and 209 with AAAD who were diagnosed by MDCT. The size and location of the intimal tear were measured and compared between these two groups of patients. The findings were also compared with those from 28 patients with ATAIMH who underwent surgical treatment to determine the intimal tear features as observed on CT angiography (CTA).

Results

Patients in the ATAIMH group were significantly older than those in the AAAD group (58.6±11.3 vs. 49.4±12.8 years, P<0.001), and females were predominant in the former category (ATAIMH vs. AAAD: 44.4% vs. 27.8%, P<0.01). Marfan syndrome and pregnancy were associated with most of the occurrences of AAAD. Sixty-four patients (88.9%) with ATAIMH were recognized as having intimal tear in the CTA images. The number of aortic segments in the ATAIMH patients was smaller than that in the AAAD patients (4.45±1.56 vs. 5.04±1.72 segments, P<0.01). The distribution of the intimal tear did not show any difference between the two groups. During the surgery, pericardial hemorrhage was observed in a higher proportion of patients in the ATAIMH than in the AAAD group (60.7% vs. 22.1%; P<0.01). In the former category, all of the intimal tears detected using CTA were confirmed during the operation, and the size was significantly larger than measured on the CTA images (6.95±5.12 vs. 19.59±6.51 mm, P<0.001). Six ATAIMH patients progressed to classical aortic dissection (AD) at surgery.

Conclusions

Patients with ATAIMH have a high prevalence of intimal tear, which is significantly smaller than that measured in patients with classic AAAD. Just like AD, ATAIMH may also be triggered by intimal tear. Hence, timely surgical repair is needed.

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.

Aortogastric Fistula Due to a Penetrating Atherosclerotic Aortic Ulcer

Penetrating aortic ulcer (PAU) is an atherosclerotic lesion with ulceration that penetrates the internal elastic lamina of the aortic wall. PAUs are classified as a category of acute aortic syndrome and have a reported rupture rate of up to 38%. To our knowledge, there is no prior published report of a PAU causing an aortogastric fistula. With the goal of raising awareness of this potentially catastrophic complication, we present herein a case of a PAU that ruptured into the gastric fundus, resulting in massive bleeding. The diagnosis was confirmed by computed tomography angiography, and thoracic endovascular aortic repair was used to control bleeding. Unfortunately, the patient did not survive the severe hypovolemic shock.

Defining acute aortic syndrome after trauma: Are Abbreviated Injury Scale codes a useful surrogate descriptor?

BACKGROUND

The severity and location of injuries resulting from vehicular collisions are normally recorded in Abbreviated Injury Scale (AIS) code; we propose a system to link AIS code to a description of acute aortic syndrome (AAS), thus allowing the hypothesis that aortic injury is progressive with collision kinematics to be tested.

METHODS

Standard AIS codes were matched with a clinical description of AAS. A total of 199 collisions that resulted in aortic injury were extracted from a national automotive collision database and the outcomes mapped onto AAS descriptions. The severity of aortic injury (AIS severity score) and stage of AAS progression were compared with collision kinematics and occupant demographics. Post hoc power analyses were used to estimate maximum effect size.

RESULTS

The general demographic distribution of the sample represented that of the UK population in regard to sex and age. No significant relationship was observed between estimated test speed, collision direction, occupant location or seat belt use and clinical progression of aortic injury (once initiated). Power analysis confirmed that a suitable sample size was used to observe a medium effect in most of the cases. Similarly, no association was observed between injury severity and collision kinematics.

CONCLUSION

There is sufficient information on AIS severity and location codes to map onto the clinical AAS spectrum. It was not possible, with this data set, to consider the influence of collision kinematics on aortic injury initiation. However, it was demonstrated that after initiation, further progression along the AAS pathway was not influenced by collision kinematics. This might be because the injury is not progressive, because the vehicle kinematics studied do not fully represent the kinematics of the occupants, or because an unknown factor, such as stage of cardiac cycle, dominates.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level IV.

Endovascular management of acute aortic syndromes

The term "acute aortic syndrome" (AAS) refers to a spectrum of life-threatening thoracic aortic pathologies including intramural hematoma, penetrating atherosclerotic ulcer, and aortic dissection. Clinically, patients often present with characteristic aortic pain. AAS often leads to aortic rupture. Therefore, recognition of this condition, its prompt diagnosis, and timely treatment is crucial to obtain clinical success and improved overall survival. The management of AAS, however, remains a therapeutic challenge. Endovascular strategies have gained wide acceptance and now represent a minimally invasive alternative to traditional open surgery. Several studies have shown endovascular repair of varying thoracic aortic pathologies to be technically feasible with fewer complications than open surgery. In this review, the authors discuss AAS pathology and its management, with particular attention to the current role of endovascular aortic repair and its treatment.

Outcomes before and after initiation of an acute aortic treatment center

BACKGROUND

Acute aortic syndromes remain life-threatening. Time is of the essence, as mortality rises with increasing time after the acute episode. The aim of this report is to show changes in practice and outcomes after the establishment of an acute aortic treatment center (AATC) to expedite the care of acute aortic syndromes in a major metropolitan area with the belief that "door to intervention time under 90 minutes" reduces mortality and morbidity from acute aortic disease.

METHODS

A database of patients admitted with acute aortic disease (Type A and B aortic dissections, acute thoraco-abdominal aortic aneurysms, acute and ruptured abdominal aortic aneurysms) for 1 year prior to initiation (2007) and 1 year after initiation of the pathway (AATC) in 2008 was developed. Comorbidities were scored according to Society of Vascular Surgery criteria. Anatomic and functional outcomes were determined and categorized by Society of Vascular Surgery reporting criteria. Multivariate analysis was performed for categorical outcomes and Cox proportional hazard analyses for time-dependent outcomes.

RESULTS

Six hundred twenty-one patients reported with aortic disease to the cardiovascular services; 306 patients were considered to have acute disease. When compared with the year before the AATC was instituted, there was a 30% increase in the total number of admissions and a 25% increase in acute pathology after setting up the AATC (P = .02). There was a two-fold increase in thoracic aortic dissections admitted to the service. Initiation of the treatment pathway resulted in a highly significant 64% reduction in time to definitive therapy (526 ± 557 vs 187 ± 258 minutes, mean ± SD pre-AATC vs AATC; P = .0001). Comorbidity scores were equivalent between the two cohorts. Despite the increase in acuity, mortality (4% vs 6%) and morbidity (41% vs 45%) rates were unchanged, and there was a significant decrease in intensive care unit length of stay (5 vs 4 days, pre-AATC cohort vs the AATC cohort), but total hospital length of stay (11 vs 10 days) was unchanged. There was no correlation between deaths within 30 days and length of stay in the intensive care unit.

CONCLUSION

Establishment of a multidisciplinary AATC pathway was associated with a 30% increase in volume, 64% reduction in time to definitive treatment, improved throughput with reduced intensive care unit time, and maintained clinical efficacy despite an increase in acute admissions. These results suggest the concept be further evaluated.

[CT and MR imaging follow-up of medically treated acute aortic syndrome]

The follow-up of medically treated acute aortic syndromes relies on CT and MR imaging. Comparison with prior examinations is essential. For aortic dissections, progressive enlargement of the false lumen, visceral hypoperfusion, and extension should be excluded. Mural hematomas and ulcers also undergo close follow-up to detect progression and recanalization. It is important to be familiar with the risk factors of disease progression for medically treated acute aortic syndromes and their management. It is also important to be familiar with the imaging features of disease progression. Acute aortic syndromes managed medically should undergo routine follow-up with CT or MR because these lesions may evolve silently over time and present with complications.

Sudden death due to spontaneous rupture in splenic artery atypical dissection with features of vasculitis: case report and review of the literature

A case of sudden death in a 45-year-old man due to splenic artery dissection and rupture diagnosed at a medico-legal autopsy is described. The examination of the splenic artery revealed macroscopically the features of a ruptured intramural haematoma (no intimal tear, no lumen dilation) and histologically the characteristics of a lymphoplasmacytic vasculitis of the vasa vasorum associated with fibrinoid degeneration. The patient died at home after having been discharged from hospital where he had presented for modest abdominal pain with no evidence of the true nature of the disease found using echography. The Authors discuss the literature relative to splenic artery dissection (13 cases of which only one diagnosed in vivo), the present case being the only one due to vasculitis of the vasa vasorum and the forensic implications (autopsy was ordered to examine the causes of death, to verify whether diagnosis could have been reached during hospitalization with consequences on the outcome and if a hypothesis of malpractice could be prospected).

Comprehensive evaluation of CT pulmonary angiography for patients suspected of having pulmonary embolism

Recently, CT pulmonary angiography (CTPA), especially performed with multi-detector row CT, has become a key imaging modality for pulmonary embolism. However, CTPA that was performed under clinical suspicion of pulmonary embolism has been shown to lead to high prevalence of alternative diagnosis, up to 25.4%. A comprehensive evaluation of pulmonary and extrapulmonary abnormalities including cardiovascular lesions is critical in proper diagnosis and patient care. Radiologists should be familiar with the comprehensive interpretation of CTPA to facilitate differential diagnosis and further treatment decision.

A killer at large: acute aortic dissection

Acute aortic dissection is one of the most fatal acute cardiovascular disorders that has challenged physicians and surgeons for decades. This article provides an up-to-date overview of the aetiology, pathophysiology, diagnosis and treatment of this condition.

Article Commentary: Managing Dissections of the Thoracic Aorta

Thoracic aortic dissection is associated with substantial morbidity and mortality, and it requires timely and accurate diagnosis and treatment. Long-term antihypertensive therapy remains critical for the treatment of this disease. Surgical intervention, although still a formidable undertaking, has evolved to better address both acute and chronic dissection, and the results have improved. Basic and clinical research, as well as technological advances, have increased our understanding of this challenging disease state.

Managing dissections of the thoracic aorta

Thoracic aortic dissection is associated with substantial morbidity and mortality, and it requires timely and accurate diagnosis and treatment. Long-term antihypertensive therapy remains critical for the treatment of this disease. Surgical intervention, although still a formidable undertaking, has evolved to better address both acute and chronic dissection, and the results have improved. Basic and clinical research, as well as technological advances, have increased our understanding of this challenging disease state.

Acute intramural hematoma of the aorta as a cause of positive FDG PET/CT

Type A acute intramural hematoma (IMH) of the ascending aorta is defined as hemorrhage in the aortic wall in the absence of intimal disruption. Proximity to the adventitia may explain the higher incidence of rupture in IMH. We present a case of IMH, diagnosed by the presence of linear intense uptake of FDG on PET/CT, in a 70-year-old woman undergoing staging for colorectal cancer. There is no current role for FDG-PET in the diagnosis of IMH. This case demonstrates that incidental focal FDG activity in the wall of the aorta may indicate the life-threatening diagnosis of IMH.

Endovascular Treatment of Traumatic Thoracic Aortic Transection—Role of Timing: A Case Report

Clinical management of traumatic thoracic aortic transection gains importance because of controversial approaches regarding diagnosis, treatment choices, and the timing of treatment modalities. We report on an emergency endovascular stent graft implacement for a patient with acute traumatic thoracic aortic transection and discuss the role of timing for this kind of procedure.

Small vessel avulsion and acute aortic syndrome: a putative aetiology for initiation and propagation of blunt traumatic aortic injury at the isthmus

Based on literature, clinical observation and the analysis of material properties of the aorta, we hypothesize that the aortic isthmus is intrinsically susceptible to blunt trauma because it has a higher density of tributary vessels than other elements of the aortic tree, the avulsion of which during trauma, is a contributory factor in the development of an acute aortic syndrome resulting from intra-mural haematoma, localized dissection and ultimately rupture. This hypothesis provides putative explanations for several aspects of the injury profile including: localized peri-isthmus injuries, inside out injury profiles and the concept of initiation versus propagation of blunt traumatic aortic injury.

[Diverticulum of the ductus arteriosus. Cause of traumatic aortic ruptures?]

INTRODUCTION

According to angiographic studies 9-26% of all adult aortae show a ductus arteriosus diverticulum (DAD), i.e. an indention of the aortic wall at the insertion of the obliterated ductus arteriosus. This region is predisposed for traumatic aortic rupture. Up to now fixation at the transition from aorta transversa to fixed aorta descendens is regarded as cause. It is unclear whether ductus diverticulum favours traumatic aortic rupture.

MATERIAL AND METHODS

A total of 143 thoracic aortas (female symbol:37; male symbol:106, 17-91 years) were scanned histomorphologically for DAD. Calcification was quantified by CT multislice volume scan.

RESULTS

A DAD was detected in 44% of macroscopically non-calcified and slightly calcified aortic specimens. Histologically, autochthonal elastic and collagenous fibres of the media were disrupted. CT in macroscopically non-calcified aortas proved isolated calcification in 78%.

DISCUSSION

The incidence of 44% DAD-higher than in angiographic studies-can be explained by the method (histopathology), allowing diagnosis of diverticula down to microm. These morphological alterations are to be seen, at least in part, as a causative factor for the predilection to traumatic aortic ruptures.