The Role of Imaging in Aortic Dissection and Related Syndromes

Imaging and Surveillance of Chronic Aortic Dissection: Current Practice and Future Directions

Chronic aortic dissection is a complex disease with a heterogenous clinical course. Specialised imaging is necessary for the long-term surveillance of this disease to identify patients who meet the criteria for intervention, and to monitor surgically treated patients for complications. Whilst computed tomography and magnetic resonance imaging are the most widely utilised modalities, providing a high degree of anatomical detail and reproducible aortic measurements, they are not without significant limitations. These techniques cannot accurately predict patients that are at risk of late complications who may benefit from early intervention. Emerging techniques such as four-dimensional magnetic resonance imaging and computational fluid dynamics have identified multiple haemodynamic variables with potential prognostic value for identifying adverse events such as rupture, malperfusion, or aneurysmal degeneration, and may in the future become integrated into routine clinical practice. This review provides a detailed analysis of current diagnostic and surveillance imaging modalities in chronic aortic dissection and discusses future paradigms in aortic imaging to enable better prognostication and earlier intervention for high-risk patients.

Related factors affecting misdiagnosis of aortic dissection: a single-center retrospective study

Objective

Aortic dissection (AD) is a life-threatening cardiovascular emergency. Delayed diagnosis frequently leads to treatment delays, elevated mortality, and complications. This study investigates the factors contributing to the misdiagnosis of AD and proposes strategies for improving its early diagnosis.

Methods

A retrospective analysis of 801 patients with AD identified 219 cases for inclusion, which were split into a training set (131 cases) and a validation set (88 cases). A binary logistic regression model was used to identify factors influencing misdiagnosis, while a Nomogram prediction model was developed.

Results

The analysis revealed that factors such as the timing and suddenness of symptom onset, typical back pain, walk-in clinic visits, and laboratory results (D-dimer, fibrinogen, and white blood count) were significant in predicting misdiagnosis. The Nomogram model showed high predictive accuracy with an Area under the ROC curve (AUC) of 0.924 in the training set and 0.912 in the validation set, demonstrating good sensitivity and specificity.

Conclusion

The model offers potential for improving diagnostic accuracy and clinical outcomes in AD cases.

Thoracic Aortic Shape: A Data-Driven Scale Space Approach

The scale and resolution of anatomical features extracted from medical CT images are crucial for advancing clinical decision-making tools. While traditional metrics, such as maximum aortic diameter, have long been the standard for classifying aortic diseases, these one-dimensional measures often fall short in capturing the rich geometrical nuances available in progressively advancing imaging modalities. Recent advancements in computational methods and imaging have introduced more sophisticated geometric signatures, in particular scale-invariant measures of aortic shape. Among these, the normalized fluctuation in total integrated Gaussian curvature (δ K ~ ) over a surface mesh model of the aorta has emerged as a particularly promising metric. However, there exists a critical tradeoff between noise reduction and shape signal preservation within the scale space parameters - namely, smoothing intensity, meshing density, and partitioning size. Through a comprehensive analysis of over 1200 unique scale space constructions derived from a cohort of 185 aortic dissection patients, this work pinpoints optimal resolution scales at which shape variations are most strongly correlated with surgical outcomes. Importantly, these findings emphasize the pivotal role of a secondary discretization step, which consistently yield the most robust signal when scaled to approximately 1 cm. This approach enables the development of models that are not only clinically effective but also inherently resilient to biases introduced by patient population heterogeneity. By focusing on the appropriate intermediate scales for analysis, this study paves the way for more precise and reliable tools in medical imaging, ultimately contributing to improved patient outcomes in cardiovascular surgery.

From Cardiac Arrest to Survival: Managing Acute Type A Aortic Dissection With Emergent Surgery

Acute type A aortic dissection (AAD) is a life-threatening cardiovascular emergency with extremely high mortality, especially if complicated by cardiac arrest. Early diagnosis and prompt surgical intervention are essential for survival but pose major difficulties in unstable patients. We describe the clinical course of a 68-year-old man with out-of-hospital cardiac arrest due to AAD. Cardiopulmonary resuscitation was performed on-site and was in progress during transport. After achieving return of spontaneous circulation in the emergency department, emergency coronary angiography ruled out coronary artery disease and revealed aneurysmal dilation of the ascending aorta, severe aortic valve regurgitation, and an intimal flap consistent with dissection. The diagnosis of AAD from the aortic root to the iliac arteries, with pericardial and left pleural effusions, was confirmed by total-body computed tomography. Emergent surgical management included the replacement of the dissected ascending aorta with a 28 mm synthetic graft and replacement of the severely regurgitant aortic valve with a 21 mm bioprosthesis. The procedure was carried out with full circulatory arrest and axillary cannulation. The patient's postoperative course was complicated by coagulopathy and slow gradual neurological improvement, but ultimately, he had no evidence of ischemic or hemorrhagic brain injury. He was discharged in stable condition on the 15th postoperative day. Follow-up imaging showed stable chronic dissection of the descending aorta, as well as complete resolution of pleural and pericardial effusions. This case highlights the complexities of diagnosing and managing AAD in a patient presenting with cardiac arrest. It also demonstrates the importance of multidisciplinary collaboration, timely imaging, and advanced surgical techniques in overcoming the significant challenges associated with this critical condition.

Pitfalls of computed tomography angiography examination in veno-arterial extracorporeal membrane oxygenation patients: a case report of a patient with cardiac rupture

BACKGROUND

Veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO) is commonly used for patients with cardiac arrest, cardiogenic shock, or heart failure and is a life-saving technique. Computed tomography angiography (CTA) examination in patients on ECMO presents certain challenges. Due to the dual circulation characteristics of blood flow in ECMO patients, vascular imaging and interpretation can be difficult and may even present pitfalls.

CASE PRESENTATION

A 59-year-old male was admitted with a diagnosis of cardiogenic shock due to "sudden onset of chest discomfort for 6 hours and altered mental status for 4 hours". He underwent V-A ECMO treatment twice and had two aortic CTA examinations. The initial CTA mistakenly diagnosed an aortic dissection. Considering the dual circulation blood flow characteristic in ECMO patients, a second CTA was performed. Combined with echocardiography, the patient was accurately diagnosed with left ventricular rupture and underwent left ventricular rupture repair surgery. The patient was successfully weaned off ECMO, transferred out of the ICU, and eventually discharged in good condition.

CONCLUSION

The unique hemodynamics of V-A ECMO patients necessitate interpreting CTA examinations with an understanding of the dual circulation characteristic to avoid misdiagnosis.

Type B Aortic Dissection CTA Collection with True and False Lumen Expert Annotations for the Development of AI-based Algorithms

Aortic dissections (ADs) are serious conditions of the main artery of the human body, where a tear in the inner layer of the aortic wall leads to the formation of a new blood flow channel, named false lumen. ADs affecting the aorta distally to the left subclavian artery are classified as a Stanford type B aortic dissection (type B AD). This is linked to substantial morbidity and mortality, however, the course of the disease for the individual case is often unpredictable. Computed tomography angiography (CTA) is the gold standard for the diagnosis of type B AD. To advance the tools available for the analysis of CTA scans, we provide a CTA collection of 40 type B AD cases from clinical routine with corresponding expert segmentations of the true and false lumina. Segmented CTA scans might aid clinicians in decision making, especially if it is possible to fully automate the process. Therefore, the data collection is meant to be used to develop, train and test algorithms.

Diagnostic Ultrasound: On-Site Diagnosis of Type B Aortic Dissection During Cataract Surgery

We report a case of aortic dissection occurring during cataract surgery under local anesthesia, which was diagnosed on-site by point-of-care ultrasound. Intimal flaps were detected in the abdominal aorta, whereas the parasternal view showed no abnormalities in the aortic root or left ventricular function. According to these ultrasound findings, a Stanford type B aortic dissection was more likely than a type A aortic dissection, and imminent death was unlikely. Therefore, we decided to resume and complete the surgery. Subsequent computed tomography (CT) confirmed the point-of-care diagnosis. The patient was transferred to a tertiary hospital for medical treatment.

Image quality, contrast enhancement and radiation dose of electrocardiograph- versus non-electrocardiograph-triggered computed tomography angiography of the aorta

INTRODUCTION

Computed tomography angiography of the aorta (CTAA) is the modality of choice for investigating aortic disease. Our aim was to evaluate the image quality, contrast enhancement and radiation dose of electrocardiograph (ECG)-triggered and non-ECG-triggered CTAA on a 256-slice single-source CT scanner. This allows the requesting clinician and the radiologist to balance radiation risk and image quality.

METHODS

We retrospectively assessed the data of 126 patients who had undergone CTAA on a single-source CT scanner using ECG-triggered (group 1, n = 77) or non-ECG-triggered (group 2, n = 49) protocols. Radiation doses were compared. Qualitative (4-point scale) and quantitative image quality assessments were performed.

RESULTS

The mean volume CT dose index, dose length product and effective dose in group 1 were 12.4 ± 1.9 mGy, 765.8 ± 112.4 mGy cm and 13.0 ± 1.9 mSv, respectively. These were significantly higher compared to group 2 values (9.1 ± 2.6 mGy, 624.1 ± 174.8 mGy cm and 10.6 ± 3.0 mSv, respectively) ( P < 0.001). Qualitative assessment showed the image quality at the aortic root-proximal ascending aorta was significantly higher in group 1 (median 3) than in group 2 (median 2, P < 0.001). Quantitative assessment showed significantly better mean arterial attenuation, signal-to-noise ratio and contrast-to-noise ratio in ECG-triggered CTAA compared to non-ECG-triggered CTAA.

CONCLUSION

ECG-triggered CTAA in a single-source scanner has superior image quality and vessel attenuation of aortic root/ascending aorta, but a higher radiation dose of approximately 23%. Its use should be considered specifically when assessing aortic root/ascending aorta pathology.

Comparison between transthoracic echocardiography and transoesophageal echocardiography in the diagnosis of acute aortic dissection from an emergency perspective. A systematic review and meta-analysis

Background

Acute aortic dissection (AAD) is a life-threatening medical condition with high early fatality. Therefore, a prompt and precise diagnosis, which can be achieved through invasive and non-invasive techniques is vital. Echocardiography, unlike MRI and CT, is accessible in emergency units and bedside-compatible. The recommended echocardiographic techniques for AAD are transthoracic and transoesophageal echocardiography (TTE and TOE). Therefore, our review compares their diagnostic roles in AAD.

Methods

Studies relevant to our topic were attained through a database search and manual scrutiny of references lists of articles obtained from the electronic databases. The Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2) has been used for quality assessment. All quantitative analyses were performed using either STATA 16 or Comprehensive Meta-Analyst software.

Results

The search strategy yielded 1,798 articles, of which only 11 were eligible for inclusion. Our subgroup analysis showed that conventional TTE had a sensitivity and specificity of 85.35% and 84.51% for the diagnosis of Stanford type A AAD and was 45.89% sensitive and 87.05% specific for the diagnosis of type B AAD. However, the subgroup analysis shows that contrast-enhancement of TTE results in a sensitivity and specificity of 93.30% and 97.60% for diagnosis of type A AAD, and 83.60% and 94.50% for diagnosis of type B AAD, respectively. On the other hand, conventional TOE was 93.64% sensitive and 95.50% specific for the diagnosis of type A AAD, 99.80% sensitive and 99.87% specific for the diagnosis of type B AAD. Moreover, our analyses show that TTE has pooled false negative and positive rates of 28.6% and 18.6%, while TOE has shown false negative and positive rates of 2.4% and 4.3%, respectively.

Conclusion

TOE is the more favorable diagnostic tool for AAD diagnosis than TTE. However, it cannot be used as a stand-alone diagnostic tool since misdiagnosis cases are being reported. Contrast-enhanced TTE can also diagnose AAD since it provides similar results to conventional TOE.

Fast Approximate Quantification of Endovascular Stent Graft Displacement Forces in the Bovine Aortic Arch Variant

PURPOSE

Displacement forces (DFs) identify hostile landing zones for stent graft deployment in thoracic endovascular aortic repair (TEVAR). However, their use in TEVAR planning is hampered by the need for time-expensive computational fluid dynamics (CFD). We propose a novel fast-approximate computation of DFs merely exploiting aortic arch anatomy, as derived from the computed tomography (CT) and a measure of central aortic pressure.

MATERIALS AND METHODS

We tested the fast-approximate approach against CFD gold-standard in 34 subjects with the "bovine" aortic arch variant. For each dataset, a 3-dimensional (3D) model of the aortic arch lumen was reconstructed from computed tomography angiography and CFD then employed to compute DFs within the aortic proximal landing zones. To quantify fast-approximate DFs, the wall shear stress contribution to the DF was neglected and blood pressure space-distribution was averaged on the entire aortic wall to reliably approximate the patient-specific central blood pressure. Also, DF values were normalized on the corresponding proximal landing zone area to obtain the equivalent surface traction (EST).

RESULTS

Fast-approximate approach consistently reflected (r2=0.99, p<0.0001) the DF pattern obtained by CFD, with a -1.1% and 0.7° bias in DFs magnitude and orientation, respectively. The normalized EST progressively increased (p<0.0001) from zone 0 to zone 3 regardless of the type of arch, with proximal landing zone 3 showing significantly greater forces than zone 2 (p<0.0001). Upon DF normalization to the corresponding aortic surface, fast-approximate EST was decoupled in blood pressure and a dimensionless shape vector (S) reflecting aortic arch morphology. S showed a zone-specific pattern of orientation and proved a valid biomechanical blueprint of DF impact on the thoracic aortic wall.

CONCLUSION

Requiring only a few seconds and quantifying clinically relevant biomechanical parameters of proximal landing zones for arch TEVAR, our method suits the real preoperative decision-making process. It paves the way toward analyzing large population of patients and hence to define threshold values for a future patient-specific preoperative TEVAR planning.

Common Cardiovascular Diseases in Women

Cardiovascular disease is a leading cause of death for women in the United States. This article encompasses the epidemiology/etiology, clinical presentation, diagnostic assessment, management, and prognosis of some common cardiovascular disorders seen in women with a special focus on pregnancy.

The Silent Threat: A Case of Iatrogenic Asymptomatic Aortic Dissection Post Coronary Artery Bypass Grafting

Asymptomatic aortic dissection (AD) is a rare but potentially life-threatening complication that can occur following coronary artery bypass graft (CABG) surgery. While CABG is a well-established surgical procedure for managing multivessel coronary artery disease, it can inadvertently predispose patients to the development of AD, especially in those with pre-existing aortic pathology. The pathophysiology underlying AD after CABG is multifactorial, with factors, such as atherosclerosis, manipulation of the aorta during surgery, and hemodynamic stress, playing significant roles. Notably, the absence of symptoms poses a diagnostic challenge, as patients may remain unaware of the underlying condition until a catastrophic event occurs. Therefore, a high index of suspicion and vigilant postoperative monitoring are crucial in identifying asymptomatic AD. Diagnostic modalities including imaging techniques, such as computed tomography angiography (CTA), magnetic resonance imaging (MRI), and echocardiography, play pivotal roles in confirming the diagnosis and determining the extent of the dissection. Prompt surgical intervention is generally recommended in symptomatic patients or those with evidence of impending complications. We hereby present a case report of a patient who presented with asymptomatic AD post CABG surgery and discuss the pathophysiology, presentation, diagnostic workup, and treatment options.

Risk factors for early death after surgery in patients with acute Stanford type A aortic dissection: A systematic review and meta-analysis

BACKGROUND

There are many risk factors related to early death after surgery among patients with acute Stanford type A aortic dissection (ATAAD) that have been analyzed in previous studies, but no evidence-based study has been conducted to confirm these risk factors.

AIMS

The aims of this study were to investigate risk factors for early death after surgery in patients with ATAAD via systematic review and meta-analysis and assess evidence-based strategies for preventing adverse events.

METHODS

The protocol for this study was prospectively registered with PROSPERO (CRD 42022332772). The authors systematically searched PubMed, Ovid, Scopus, Web of Science and Cochrane Library following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines from database construction to May 2021. Studies that met the selection criteria were determined by two independent researchers, and the odds ratios (ORs) and 95% confidence intervals (95% CIs) were reported for the risk factors and were pooled using Stata 15.0.

RESULTS

A total of 23 studies including 5510 patients met the inclusion criteria, and 10 risk factors were analyzed in this meta-analysis. The preoperative risk factors for early death after surgery in patients with ATAAD were age [(OR: 1.03, 95% CI (1.01, 1.06)], male sex [(OR: 1.43, 95% CI (1.06, 1.92)], shock [(OR: 1.91, 95% CI (1.06, 3.45)], malperfusion [(OR: 3.45, 95% CI (2.24, 5.31)] and cardiac tamponade [(OR: 3.89, 95% CI (1.17, 12.98)].

CONCLUSION

Patients with ATAAD who have an older age, male sex, shock, malperfusion and cardiac tamponade have a higher risk for early death after surgery. However, more highly homogenous studies are needed to demonstrate these results. Clinical staff should pay more attention to these factors and take individual actions to reduce mortality after surgery in patients with ATAAD.

ADAMTS-7 deficiency attenuates thoracic aortic aneurysm and dissection in mice

Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening cardiovascular disease with severe extracellular matrix (ECM) remodeling that lacks efficient early stage diagnosis and nonsurgical therapy. A disintegrin and metalloproteinase with thrombospondin motif 7 (ADAMTS-7) is recognized as a novel locus for human coronary artery atherosclerosis. Previous work by us and others showed that ADAMTS-7 promoted atherosclerosis, postinjury neointima formation, and vascular calcification. However, whether ADAMTS-7 is involved in TAAD pathogenesis is unknown. We aimed to explore the alterations in ADAMTS-7 expression in human and mouse TAAD, and investigate the role of ADAMTS-7 in TAAD formation. A case-control study of TAAD patients (N = 86) and healthy participants (N = 88) was performed. The plasma ADAMTS-7 levels were markedly increased in TAAD patients within 24 h and peaked in 7 days. A TAAD mouse model was induced with 0.5% β-aminopropionitrile (BAPN) in drinking water. ELISA analysis of mouse plasma, Western blotting, and immunohistochemical staining of aorta showed an increase in ADAMTS-7 in the early stage of TAAD. Moreover, ADAMTS-7-deficient mice exhibited significantly attenuated TAAD formation and TAAD rupture-related mortality in both male and female mice, which was accompanied by reduced artery dilation and inhibited elastin degradation. ADAMTS-7 deficiency caused repressed inflammatory response and complement system activation during TAAD formation. An increase in plasma ADAMTS-7 is a novel biomarker for human TAAD. ADAMTS-7 deficiency attenuates BAPN-induced murine TAAD. ADAMTS-7 is a potential novel target for TAAD diagnosis and therapy. KEY MESSAGES: A case-control study revealed increased plasma ADAMTS-7 is a risk factor for TAAD. ADAMTS-7 was elevated in plasma and aorta at early stage of mouse TAAD. ADAMTS-7 knockout attenuated mouse TAAD formation and mortality in both sexes.

The Role of Multimodality Imaging Approach in Acute Aortic Syndromes: Diagnosis, Complications, and Clinical Management

Acute aortic syndromes are life-threatening conditions with high morbidity and mortality. The principal pathological feature is acute wall damage with possible evolution towards aortic rupture. Accurate and timely diagnosis is mandatory to avoid catastrophic consequences. Indeed, misdiagnosis with other conditions mimicking acute aortic syndromes is associated with premature death. In this view, cardiovascular imaging is necessary for the correct diagnosis and management. Echocardiography, computed tomography, magnetic resonance imaging, and aortography allow for diagnosis, guarantee immediate treatment, and detect associated complications. Multimodality imaging is essential in the diagnostic work-up to confirm or rule out acute aortic syndromes. The aim of this review is to highlight the contemporary evidence on the role of single cardiovascular imaging techniques and multimodality imaging in the diagnosis and management of acute aortic syndromes.

Targeting endothelial tight junctions to predict and protect thoracic aortic aneurysm and dissection

AIMS

Whether changes in endothelial tight junctions (TJs) lead to the formation of thoracic aortic aneurysm and dissection (TAAD) and serve as an early indicator and therapeutic target remains elusive.

METHODS AND RESULTS

Single-cell RNA sequencing analysis showed aberrant endothelial TJ expressions in the thoracic aortas of patients with TAAD. In a β-aminopropionitrile (BAPN)-induced TAAD mouse model, endothelial TJ function was disrupted in the thoracic aortas at an early stage (5 and 10 days) as observed by a vascular permeability assay, while the intercellular distribution of crucial TJ components was significantly decreased by en face staining. For the non-invasive detection of endothelial TJ function, two dextrans of molecular weights 4 and 70 kDa were conjugated with the magnetic resonance imaging (MRI) contrast agent Gd-DOTA to synthesize FITC-dextran-DOTA-Gd and rhodamine B-dextran-DOTA-Gd. MRI images showed that both probes accumulated in the thoracic aortas of the BAPN-fed mice. Particularly, the mice with increased accumulated signals from 5 to 10 days developed TAAD at 14 days, whereas the mice with similar signals between the two time points did not. Furthermore, the protease-activated receptor 2 inhibitor AT-1001, which seals TJs, alleviated the BAPN-induced impairment of endothelial TJ function and expression and subsequently reduced TAAD incidence. Notably, endothelial-targeted ZO-1 conditional knockout increased TAAD incidence. Mechanistically, vascular inflammation and edema were observed in the thoracic aortas of the BAPN-fed mice, whereas these phenomena were attenuated by AT-1001.

CONCLUSION

The disruption of endothelial TJ function is an early event prior to TAAD formation, herein serving as a potential indicator and a promising target for TAAD.

Prognostic value of interleukin-33, sST2, myeloperoxidase, and matrix metalloproteinase-9 in acute aortic dissection

Background and purpose

Acute aortic dissection (AAD) is a life-threatening cardiovascular emergency. Both neutrophil granzyme and interleukin (IL)-33/ST2 systems have proven to be effective diagnostic markers for AAD. This study aimed to investigate the relationship between plasma IL-33, soluble suppression of tumorigenesis-2 (sST2), myeloperoxidase (MPO), and matrix metalloproteinase (MMP)-9 levels at admission and all-cause mortality in patients with AAD.

Methods

A total of 155 patients with AAD were enrolled from the Prospective Evaluation of Acute Chest Pain (PEACP) study. Plasma concentrations of IL-33, sST2, and MMP-9 were measured using an enzyme-linked immunosorbent assay, and MPO was detected using a chemiluminescence immunoassay. Aortic anatomical parameters were measured using CT radiography. The primary endpoint was all-cause mortality rate.

Results

The median age of the patients was 55 years, and 96 (61.9%) were diagnosed with type A-AAD. After adjusting for confounding factors, the highest tertiles of IL-33, sST2, MPO, and MMP-9 had hazard risks of 0.870 (95% CI: 0.412-1.836, P = 0.714), 3.769 (95% CI: 1.504-9.446, P = 0.005), 4.689 (95% CI: 1.985-11.076, P < 0.001), and 4.748 (95% CI: 1.763-12.784, P = 0.002), respectively, compared to the lowest tertile. Pearson's correlation analysis revealed a significant correlation between these markers (P < 0.001). Moreover, sST2, MPO, and MMP-9 levels had a significant positive correlation with aortic diameter and pseudolumen area (P < 0.001).

Conclusion

The biomarkers sST2, MPO, and MMP-9 were independently associated with mortality in patients with AAD. The significant correlation between these biomarkers suggests a pathogenic role for the IL-33/ST2/neutrophil granzyme system in patients with AAD.

The Echocardiographic Evaluation of Aortic Aneurysm

PURPOSE OF REVIEW

Aortic aneurysm is the second most common aortic disease associated with significant morbidity and mortality. We summarize the role of echocardiography in the evaluation of aortic aneurysms in assessing the different etiologies, associated complications, and the role in serial follow-up. In addition, we discuss the limitations of echocardiographic evaluation and the role of multimodality imaging.

RECENT FINDINGS

Echocardiographic tools such as 2D/3D and Doppler imaging have helped improve the quality of aortic evaluation in acute and long-term follow-up. Moreover, multimodality imaging (CT and MR angiography) has advanced the field of aortic imaging. Echocardiography is an essential and critical tool for the evaluation of normal aorta and various aortic pathologies. It provides valuable information with its diverse modalities such as TTE and TEE. Echocardiography along with complimentary multimodality imaging is critical to identify the acute aortic syndromes and other associated complications of aortic aneurysms, and in long-term follow-up.

Ethnic Disparities in CT Aortography Use for Diagnosing Acute Aortic Syndrome

Purpose

To determine whether CT aortography was performed in proportion to patient risk for acute aortic syndrome (AAS) and incidence of AAS for different ethnic groups.

Materials and Methods

All atraumatic thoracic aorta CT aortographic examinations performed in adults (age > 15 years) suspected of having AAS between January 2009 and December 2019 at Auckland City Hospital (New Zealand) were included. Patients were risk stratified using the aortic dissection detection risk score (ADD-RS). The primary outcomes were the ratio of CT aortography rates to rates of positive CT aortographic examinations and the incidence of AAS. Population census data were used to determine age-standardized incidence of AAS in the emergency department (ED).

Results

In total, 1646 CT aortographic examinations were performed in 1543 patients (mean age, 62 years ± 16 [SD]; 877 male patients). Māori (34% [68 of 203]) and Pacific Islanders (35% [80 of 229]) were more likely to be at high risk of AAS (ADD-RS > 1) compared with patients from other ethnic groups (25% [308 of 1214]); in the ED catchment population, age-standardized AAS incidence was significantly higher in Māori (6.9 per 100 000 person-years [95% CI: 4.3, 10.4]) and Pacific Islanders (5.3 [95% CI: 3.4, 7.8]) than in other ethnic groups (2.3 [95% CI: 1.8, 2.8]). Despite this higher incidence, disproportionately fewer CT aortographic examinations were requested in the ED for Māori (9.2 CT aortographic examinations per AAS diagnosis) and Pacific Islanders (9.2 CT aortographic examinations per AAS diagnosis) compared with other ethnic groups (13.8 CT aortographic examinations per AAS diagnosis).

Conclusion

Māori and Pacific Islanders were at disproportionately higher risk of AAS but had fewer requested CT aortographic examinations compared with other ethnic groups. This increased risk of AAS in Pacific Islander and indigenous Māori patients should be considered by clinicians when investigating AAS.Keywords: Ethnicity, Māori, Pacific Islander, Aortic Dissection Detection Risk Score, Acute Aortic Syndrome, Aortic Dissection, CT Angiography Supplemental material is available for this article. © RSNA, 2022.

Putative computed tomography scan-negative type A dissection

Objectives

Computed tomography angiography (CTA) is the imaging modality most frequently used to diagnosis type A aortic dissection for chest pain with a high degree of sensitivity and specificity. False negative and positive errors in diagnosis are infrequent. Despite initial negative imaging studies for dissection, surgeons must consider early operation in patients with recent onset chest pain in the presence of an ascending aortic aneurysm.

Methods

We report 4 cases (2004-2021) of patients with a mean age of 51.25 years (male:female = 3:1) who presented with chest pain. Two had a history of syncope. On computed tomography angiography, all had an ascending aortic aneurysm and no dissection flap. Three had thickening of the ascending aorta and 1 had a chronic type B dissection. On echocardiography, aortic regurgitation was moderate-severe in 2 patients, 2 had a pericardial effusion, and none had a definitive dissection flap. All were operated on because of the surgeon's concern for the association of chest pain and an ascending aortic aneurysm. The Institutional Review Board at George Washington University Committee on Human Research has determined that the research is exempt from review under Department of Health and Human Services regulatory category 4 (#FWA00005945). The project as described in the application may proceed without further oversight by the Office of Human Resources on September 9, 2022.

Results

The diagnosis of type A aortic dissection was made at operation (3 on median sternotomy and 1 after aortotomy). All patients did well. One patient who had peripheral cannulation (no malperfusion) and severe coagulopathy developed a compartment syndrome and postoperatively required a below-knee amputation.

Conclusions

Surgeons must maintain a high index of suspicion for aortic dissection when patients present with chest pain and are found to have an ascending aortic aneurysm even in the absence of initial, classic features of dissection on computed tomography angiography. Improvements in imaging techniques and analysis are required.

Use of Point-of-Care Ultrasound for Early Identification of Acute Aortic Root Dissection

Point-of-care ultrasound (POCUS) is becoming a frequently utilized imaging tool in the emergency department (ED) as it can aid in early diagnosis of many pathologies. This is a case report of a 55-year-old male who presented to the emergency department by ambulance for sudden onset chest pain followed by a syncopal episode. Point-of-care echocardiogram revealed a large pericardial effusion with a significantly dilated aortic root, concerning for aortic dissection. Patient was emergently taken for a computed tomography (CT) scan, which was only remarkable for an ascending thoracic aortic aneurysm but failed to show an aortic dissection flap. On repeat POCUS, a dissection intimal flap, large pericardial effusion with tamponade physiology, and aortic regurgitation were identified and later confirmed on transesophageal echocardiogram. This case report details a rare pathology that was correctly identified on initial POCUS before it was seen on CT scan.

Current Understanding of Aortic Dissection

The aorta is the largest artery in the body, delivering oxygenated blood from the left ventricle to all organs. Dissection of the aorta is a lethal condition caused by a tear in the intimal layer of the aorta, followed by blood loss within the aortic wall and separation of the layers to full dissection. The aorta can be affected by a wide range of causes including acute conditions such as trauma and mechanical damage; and genetic conditions such as arterial hypertension, dyslipidaemia, and connective tissue disorders; all increasing the risk of dissection. Both rapid diagnostic recognition and advanced multidisciplinary treatment are critical in managing aortic dissection patients. The treatment depends on the severity and location of the dissection. Open surgical repair is the gold standard of treatment for dissections located to the proximal part of the aorta and the arch, while endovascular interventions are recommended for most distal or type B aortic dissections. In this review article, we examine the epidemiology, pathophysiology, contemporary diagnoses, and management of aortic dissection.

Trends in computed tomography aortography and acute aortic syndrome in an emergency department within Aotearoa New Zealand

OBJECTIVE

Acute aortic syndrome (AAS) comprises a triad of life-threatening aortic conditions that are difficult to diagnose because of their non-specific clinical presentations. Contrast-enhanced computed tomography aortography (CTA) has a high sensitivity and specificity for these conditions. However, under- and over-investigation of patients with suspected AAS using CTA carries significant risk. The aim of the present study was to evaluate the diagnostic imaging practices of CTA use for patients presenting to an ED with suspected AAS.

METHODS

All atraumatic thoracic CTAs performed on patients aged ≥15 years old with suspected AAS who presented to Auckland City Hospital between 2009 and 2019 were included. Outcomes of interest were the annual ED and population incidences of AAS, and the rate of CTAs performed.

RESULTS

A total of 1646 CTAs were included. There were 135 (8.2%) cases of at least one AAS diagnosis and 220 (13.4%) cases where an alternative diagnosis was made. The population-adjusted number of AAS diagnoses remained relatively stable over the study period, with a mean annual AAS incidence of 19.6 (95% confidence interval 9.9-33.7) per 100 000 patients, and 3.2 (95% confidence interval 1.6-5.4) per 100 000 population. The number of ED presentations increased during the study period, along with the population-adjusted rate of CTAs performed, from approximately 150 per 100 000 patients (2009) to 350 per 100 000 patients (2019).

CONCLUSIONS

Thoracic CTA use for investigating suspected AAS in our ED has recently increased. However, the annual incidence of AAS did not increase over the same period, but was higher than reported in overseas institutions.

Endovascular Repair of the Thoracic Aorta Combined with Drug Therapy in Acute Uncomplicated Type B Aortic Dissection

Objective

This study was to evaluate the clinical efficacy of thoracic endovascular aortic repair (TEVAR) combined with Best Medical Therapy (BMT) in acute uncomplicated type B aortic dissection (TBAD).

Methods

Using the random method, 90 patients admitted to our hospital between January 2018 and January 2020 with acute uncomplicated TBAD were randomly divided into a control group and a study group, with 45 cases in each of the groups. The effectiveness of BMT combined with TEVAR treatment was compared.

Results

The incidence of recent adverse reactions did not differ significantly between the two groups. Compared to the control group, the 1-year survival rate and 2-year survival rate of patients in the study group were considerably higher. In order to examine the relationship between survival and time, the Kaplan-Meier curve was used. Both groups reached the median survival time after 24 months of follow-up. The expected survival time of the study group was longer than that of the control group. False lumen thrombosis or absence of thrombus was significantly more prevalent in the study group than in the control group.

Conclusion

For patients with acute uncomplicated TBAD, BMT combined with TEVAR can significantly improve the long-term survival rate and increase the expected survival time.

Trends in mortality from aortic dissection analyzed from the World Health Organization Mortality Database from 2000 to 2017

BACKGROUND

We assessed trends in aortic dissection (AD) death rates in 23 countries from 2000 to 2017.

METHODS

We extracted AD mortality data for countries with high usability data from the World Health Organization (WHO) Mortality Database and from the Center for Disease Control (CDC) WONDER Database for the United States of America (USA). Age Standardized Death Rates (ASDRs) per 100,000 population were computed. Trends were assessed by locally weighted scatter plot smoother (LOWESS) regression.

RESULTS

Between 2000 and 2017, ASDRs from AD decreased in Australia, Belgium, Croatia, Denmark, France, Italy, New Zealand, Norway, Sweden, the United Kingdom, and the USA for both sexes. Increasing AD mortality was observed in Austria, Czech Republic, Germany, Hungary, Israel, and Japan for both sexes. The largest absolute increases in ASDR were in Japan for men (+1.59) and women (+1.11). The largest percentage decreases were in Norway for men (-0.91) and in New Zealand (-0.6) for women. In 2017, the highest mortality rates were in Japan for both sexes (3.22 and 2.09, respectively). The lowest ASDR was in Kyrgyzstan for both sexes (0.16 and 0.10, respectively). ASDRs for AD in 2017 were higher for men than women in all countries included. Spain had the greatest difference between the gender's mortality rates with a 2.71-fold higher mortality average rate in men.

CONCLUSION

We identified an overall decrease in AD mortality in most included countries, while an increase was noted in other countries including Israel and Japan.

Recent Advances in Intelligent Wearable Medical Devices Integrating Biosensing and Drug Delivery

The primary roles of precision medicine are to perform real-time examination, administer on-demand medication, and apply instruments continuously. However, most current therapeutic systems implement these processes separately, leading to treatment interruption and limited recovery in patients. Personalized healthcare and smart medical treatment have greatly promoted research on and development of biosensing and drug-delivery integrated systems, with intelligent wearable medical devices (IWMDs) as typical systems, which have received increasing attention because of their non-invasive and customizable nature. Here, the latest progress in research on IWMDs is reviewed, including their mechanisms of integrating biosensing and on-demand drug delivery. The current challenges and future development directions of IWMDs are also discussed.

Acute aortic dissection in a young man with bilateral Covid-19 pneumonia: A suggestive case report at Computed Tomography Angiography

Acute Aortic Dissection (AAD) is one of the most common lifethreatening diseases that affects the aortic vessel. An its immediate and accurate diagnosis is crucial to initiate the appropriate treatment.

The Covid-19 Coronavirus infectious pandemic started since December 2019 and was declared a pandemic by the World Health Organization in March 2020. It caused mainly bilateral interstitial pneumonia, up to causing a severe respiratory failure for the patients, and other complications.

Now, we describe the case of a young man that was admitted to our hospital and was found positive for the Coronavirus disease 2019 (Covid-19). While we were performing Computed Tomography (CT) scan of the chest, we had suspected the concomitant presence of an aortic dissection, which was then immediately confirmed by Computed Tomography Angiography (CTA) study, that we had performed to complete the baseline CT scan.

The impact of dissection membrane motility on mid-term aortic remodelling after thoracic endovascular repair

OBJECTIVES

The aim of this study was to assess preoperative dissection flap motility and to evaluate its impact on the aortic remodelling and the development of distal stent-induced new entry after thoracic endovascular aneurysm repair (TEVAR)/frozen elephant trunk (FET).

METHODS

Patients with primary or residual type B dissections were included in a retrospective study with transoesophageal echocardiography analysis of the preoperative dissection flap motility assessed by the true lumen (TL) strain. Three-dimensional computing tomography centreline reconstructions before TEVAR/FET and during the follow-up were conducted to measure aortic remodelling: false lumen thrombosis, TL expansion and aortic diameters at 10 and 20 cm downstream the left subclavian artery, at the coeliac trunk and in the infrarenal aorta. All continuous variables are reported as median with first and third quartiles.

RESULTS

Fifty-six consecutive patients were treated with TEVAR (n = 45) or FET (n = 11) in the acute (n = 16), subacute (n = 16) and chronic (n = 24) dissection phase. At a median follow-up of 6 (3-12) months, they showed a favourable TL expansion in the descending aorta, significantly higher in the acute [+9 mm (5-12); P < 0.001] and subacute groups [+5 mm (3-8); P = 0.039] than in the chronic group [+2 mm (0-5)]. The dissection flap motility parameter TL strain was superior in the acute (P = 0.006) and subacute (P = 0.035) groups in comparison to the chronic group. The motile flap [TL strain >22.5% (median)] was associated with a higher TL expansion rate in the thoracic aorta (P = 0.009) and a comparable distal stent-induced new entry incidence (overall: 16%) in comparison to the immobile flap (P = 0.89).

CONCLUSIONS

The intraoperative assessment and the inclusion of the dissection flap motility parameters in the decision-making during TEVAR/FET may refine the distal endograft sizing for an improved remodelling of the TL.

A mixed method approach to understanding the impact of COVID-19 on patients with or at risk for aortic dissection

Aortic dissection (AD) is a life-threatening rare disease that occurs as a spontaneous tear in the wall of the aorta. Survivors of AD go on to have a chronic disease process that requires lifelong follow-up and management. Although the COVID-19 pandemic has strained health systems and impacted practice in the United States, the effects of these impacts on people living with or at risk for AD is not well understood. This mixed methods project examined the experiences of people in the AD community during the COVID-19 pandemic between March and October 2020. Results reveal that the AD community lacked clear guidance on the role aortic health status plays in COVID-19 risk and experienced significant disruptions in aortic healthcare. At the same time, the new expansion in access to medical care with telehealth conferred unforeseen benefits in the form of reduced barriers for access to specialized aortic health care.

Analysis of imaging characteristics of blunt traumatic aortic dissection: an 8-year experience

BACKGROUND

Traumatic aortic dissection (TAD) has a low incidence but extremely high mortality. It always presents atypical clinical manifestations that are easily missed or misdiagnosed. This study mainly aims to describe the imaging characteristics and management of TAD patients.

METHODS

A retrospective analysis of 27 blunt TAD patients was performed between 2013 and 2020. Demographic features, imaging characteristics, and management were analyzed.

RESULTS

Twenty-seven patients with type B aortic dissection (age 56.04±16.07 years, 20 men) were included. Aortic intimal tears were mostly initiated from the aortic isthmus. The sizes of the proximal intimal tears in the greater curvature were larger than those in the lesser curvature (1.78±0.56 cm vs. 1.24±0.52 cm, P=0.031). Compared with those in the control group, the maximum diameters of the aortic arch, thoracic aorta, and abdominal aorta in the TAD patients were all significantly widened (all P<0.050). Multivariate logistic regression analysis showed that the maximum diameter of the thoracic aorta was an independent risk factor for TAD, with a predictive value with an area under the receiver operating characteristic curve (AUC) of 0.673. Finally, 26 patients successfully underwent delayed thoracic endovascular aortic repair (TEVAR), and the remaining one patient was treated conservatively. No progression of aortic dissection or death occurred during the six-month follow-up period.

CONCLUSIONS

In blunt trauma, the aortic isthmus is the most common site of proximal intimal tears. An accurate diagnosis of TAD requires an overall consideration of medical history and imaging characteristics. Delayed TEVAR might be an effective therapeutic option for TAD.

Cross-Entropy Learning for Aortic Pathology Classification of Artificial Multi-Sensor Impedance Cardiography Signals

An aortic dissection, a particular aortic pathology, occurs when blood pushes through a tear between the layers of the aorta and forms a so-called false lumen. Aortic dissection has a low incidence compared to other diseases, but a relatively high mortality that increases with disease progression. An early identification and treatment increases patients’ chances of survival. State-of-the-art medical imaging techniques have several disadvantages; therefore, we propose the detection of aortic dissections through their signatures in impedance cardiography signals. These signatures arise due to pathological blood flow characteristics and a blood conductivity that strongly depends on the flow field, i.e., the proposed method is, in principle, applicable to any aortic pathology that changes the blood flow characteristics. For the signal classification, we trained a convolutional neural network (CNN) with artificial impedance cardiography data based on a simulation model for a healthy virtual patient and a virtual patient with an aortic dissection. The network architecture was tailored to a multi-sensor, multi-channel time-series classification with a categorical cross-entropy loss function as the training objective. The trained network typically yielded a specificity of (93.9±0.1)% and a sensitivity of (97.5±0.1)%. A study of the accuracy as a function of the size of an aortic dissection yielded better results for a small false lumen with larger noise, which emphasizes the question of the feasibility of detecting aortic dissections in an early state.

Application value of preoperative dual-source computed tomography in assessing the rupture site of thoracic aortic dissection

Objective

To investigate the application value of dual-source computed tomography (DSCT) in preoperative assessment the rupture site of an thoracic aortic dissection (TAD).

Methods

A retrospective analysis of preoperative DSCT, multislice computed tomography (MSCT), and transthoracic echocardiography (TTE) results of 150 patients with suspected TAD in our hospital was conducted, and the intraoperative findings or interventional treatment results were used as the diagnostic gold standard.

Results

Of all 150 suspected TAD patients, 123 patients were confirmed to have TAD. The rupture site of TAD was in the ascending aorta in 46 patients, in the aortic arch in 13 patients, and in the descending aorta in 64 patients. The sensitivity of DSCT, MSCT, and TTE for locating the rupture site of the TAD was 100%, 93.5%, and 89.5%, respectively, and the specificity was 100%, 88.9%, and 81.5%. The differences were statistically significant. The distance between the actual rupture site and the one diagnosed by DSCT, MSCT, and TTE was 1.9 ± 1.2 mm, 5.1 ± 2.7 mm, and 7.8 ± 3.5 mm, respectively; the latter two were significantly worse than DSCT. The size of the rupture site diagnosed by DSCT, MSCT, and TTE was 1.5 ± 0.8 cm, 1.7 ± 0.9 cm, and 1.9 ± 1.0 cm, respectively. The size of the rupture site diagnosed by DSCT was not significantly different from the actual size of 1.4 ± 0.7 cm, while those by MSCT and TTE were.

Conclusion

DSCT has high sensitivity and specificity in diagnosing the rupture site of TAD and can clearly locate the rupture site. It can be a preferred imaging method for TAD.

Echocardiography in the intensive care unit: An essential tool for diagnosis, monitoring and guiding clinical decision-making

In the last years, new trends on patient diagnosis for admission in cardiac intensive care unit (CICU) have been observed, shifting from acute myocardial infarction or acute heart failure to non-cardiac diseases such as sepsis, acute respiratory failure or acute kidney injury. Moreover, thanks to the advances in scientific knowledge and higher availability, there has been increasing use of positive pressure mechanical ventilation which has its implications on the heart. Therefore, there is a growing need for Cardiac intensivists to quickly, noninvasively and repeatedly evaluate various hemodynamic conditions and the response to therapy. Transthoracic critical care echocardiography (CCE) currently represents an essential tool in CICU, as it is used to evaluate biventricular function and complications following acute coronary syndromes, identify the mechanisms of circulatory failure, acute valvular pathologies, tailoring and titrating intravenous treatment or mechanical circulatory support. This could be completed with trans-esophageal echocardiography (TOE), advanced echocardiography and lung ultrasound to provide a thorough evaluation and monitoring of CICU patients. However, CCE could sometimes be challenging as the acquisition of good-quality images is limited by mechanical ventilation, suboptimal patient position or recent surgery with drains on the chest. Moreover, there are some technical caveats that one should bear in mind while performing CCE in order to optimize its use and avoid misleading findings. The aim of this review is to highlight the key role of CCE, providing an updated overview of its main applications and possible pitfalls in order to facilitate its use in CICU for clinical decision-making.

Acute Aortic Syndromes

Acute aortic syndromes, classified into aortic dissection, intramural hematoma, and penetrating aortic ulcer, are associated with high early mortality for which early diagnosis and management are crucial to optimize outcomes. Patients often present with nonspecific clinical symptoms and signs; therefore, it is important for providers to maintain a high index of suspicion for acute aortic syndromes. Electrocardiogram-gated computed tomographic angiography of the chest, abdomen, and pelvis is currently the most practical imaging modality for diagnosis and identification of complications. Evolution in surgical techniques and the development of aortic endografts have improved patient outcomes, but randomized trials are still needed.

Management of acute aortic syndromes from initial presentation to definitive treatment

BACKGROUND

Acute aortic syndromes comprise a spectrum of diseases including aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcers. Early diagnosis, rapid intervention, and multidisciplinary team care are vital to efficiently manage time-sensitive aortic emergencies, mobilize appropriate resources, and optimize clinical outcomes.

OBJECTIVE

This comprehensive review outlines the multidisciplinary team approach from initial presentation to definitive interventional treatment and post-operative care.

DISCUSSION

Acute aortic syndromes can be life-threatening and require prompt diagnosis and aggressive initiation of blood pressure and pain control to prevent subsequent complications. Early time to diagnosis and intervention are associated with improved outcomes.

CONCLUSIONS

A multidisciplinary team can help promptly diagnose and manage aortic syndromes.

Three Cases of Emergency Department Medical Malpractice Involving "Consultations": How Is Liability Legally Determined?

This article presents three successfully litigated medical malpractice cases involving emergency physicians and consultants. We discuss the respective case medical diagnoses, as well as established legal principles that determine in a court proceeding which provider will be liable. Specifically, we explain the legal principles of “patient physician relationship” and “affirmative act.”

Step-by-step aortic clamping technique for safe retrieval of the elephant trunk

Staged repair of the aortic arch and downstream aorta using the elephant trunk technique is widely accepted for extensive aortic disease. However, elephant trunk retrieval is challenging in patients with unclampable descending aorta caused by extreme aneurysmal dilation or surrounding tissue adhesion. Here, we introduce a new elephant trunk retrieval technique using the step-by-step aortic clamping in descending aortic replacement of dissecting aortic aneurysm. This technique is a safe and feasible method of elephant trunk retrieval that consists of staged clamping and intraoperative ultrasound assessment of blood flow in the aorta.

Transthoracic Echocardiography: Beginner's Guide with Emphasis on Blind Spots as Identified with CT and MRI

Transthoracic echocardiography (TTE) is the primary initial imaging modality in cardiac imaging. Advantages include portability, safety, availability, and ability to assess the morphology and physiology of the heart in a noninvasive manner. Because of this, many patients who undergo advanced imaging with CT or MRI will have undergone prior TTE, particularly when cardiac CT angiography or cardiac MRI is performed. In the modern era, the increasing interconnectivity of picture archiving and communication systems (PACS) has made these images more available for comparison. Therefore, radiologists who interpret chest imaging studies should have a basic understanding of TTE, including its strengths and limitations, to make accurate comparisons and assist in rendering a diagnosis or avoiding a misdiagnosis. The authors present the standard TTE views along with multiplanar reformatted CT images for correlation. This is followed by examples of limitations of TTE, focusing on potential blind spots, which have been placed in seven categories on the basis of the structures involved: (a) pericardium (thickening, calcification, effusions, cysts, masses), (b) aorta (dissection, intramural hematoma, penetrating atherosclerotic ulcer), (c) left ventricular apex (infarcts, aneurysms, thrombus, apical hypertrophic cardiomyopathy), (d) cardiac valves (complications of native and prosthetic valves), (e) left atrial appendage (thrombus), (f) coronary arteries (origins, calcifications, fistulas, aneurysms), and (g) extracardiac structures (primary and metastatic masses). Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article . ^©RSNA, 2021.

Computed Tomography Angiography Assessment of Acute Aortic Syndromes: Classification, Differentiating Imaging Features, and Imaging Interpretation Pitfalls

An acute aortic syndrome (AAS) is an important life-threatening condition that requires early detection and management. Acute intramural hematoma (IMH), aortic dissection (AD) and penetrating atherosclerotic ulcer (PAU) are included in AAS. ADs can be classified using the well-known Stanford or DeBakey classification systems. However, these classification systems omit description of arch dissections, anatomic variants, and morphologic features that impact outcome. The Society for Vascular Surgery and Society of Thoracic Surgeons (SVS-STS) have recently introduced a classification system that classifies ADs according to the location of the entry tear (primary intimomedial tear, PIT) and the proximal and distal extent of involvement, but does not include description of all morphologic features that may have diagnostic and prognostic significance. This review describes these classification systems for ADs and other AAS entities as well as their limitations. Typical computed tomography angiography (CTA) imaging appearance and differentiating features of ADs, limited intimal tears (LITs), IMHs, intramural blood pools (IBPs), ulcer-like projections (ULPs), and PAUs will be discussed. Furthermore, this review highlights common imaging interpretation pitfalls, what should be included in a comprehensive CTA report, and provides a brief overview of current management options.

Aortic Intimo-intimal Intussusception: A Pooled Analysis of Published Reports

AIM

Aortic intimo-intimal intussusception (AoII) is a rare manifestation of aortic dissection with high mortality. This study aimed to obtain a comprehensive understanding of AoII.

METHODS

Three databases (PubMed, Scopus, Embase) were searched with predefined search terms ["intimal intussusception", "aortic intussusception", "(circumferential) AND (intimal dissection)" and "(circumferential) AND (aortic dissection)"]. Demographics, clinical manifestations, imaging methods, therapies, and follow-up data were recorded and analyzed.

RESULTS

The literature search finally identified 81 papers comprising 87 patients (Mean age: 53.7 ± 14.9 years old; male: n = 63). According to morphologic criteria (orientation of AoII intimal flap), patients were divided into three groups: antegrade (n = 37), retrograde (n = 49) and bidirectional (n = 1) orientation. The most frequent symptoms in antegrade group were chest pain (62.2%), syncope (27%), and unconsciousness (21.6%), while in retrograde group, they were chest pain (71.4%), dyspnea (20.4%), and back pain (16.3%). Regarding applied imaging modalities, 67.5% of patients in antegrade group were diagnosed with≥2 methods, comparing with 87.7% in retrograde group. A total of 21 patients (24.1%) with AoII finally died, among which 13.8% (12/87) died before surgery.

CONCLUSION

AoII is a rare form of aortic dissection with high mortality. Antegrade orientation of the intima flap was more accompanied with neurological disorders and asymmetric blood pressure, while retrograde orientation mostly manifested with aortic regurgitation. Application of multiple imaging examinations may detect this rare entity in time.

Early Detection of Aortic Degeneration in a Mouse Model of Sporadic Aortic Aneurysm and Dissection Using Nanoparticle Contrast-Enhanced Computed Tomography

[Figure: see text].

Aortic Dissection and Other Acute Aortic Syndromes: Diagnostic Imaging Findings from Acute to Chronic Longitudinal Progression

Acute aortic dissection is the prototype of acute aortic syndromes (AASs), which include intramural hematoma, limited intimal tear, penetrating atherosclerotic ulcer, traumatic or iatrogenic aortic dissection, and leaking or ruptured aortic aneurysm. The manifestation is usually sudden and catastrophic with acutely severe tearing chest or back pain. However, clinical symptoms do not allow distinction between AAS types and other acute pathologic conditions. Diagnostic imaging is essential to rapidly confirm and accurately diagnose the type, magnitude, and complications of AASs. CT fast acquisition of volumetric datasets has become instrumental in diagnosis, surveillance, and intervention planning. Most critical findings affecting initial intervention and prognosis are obtained at CT, including involvement of the ascending aorta, primary intimal tear location, rupture, malperfusion, size and patency of the false lumen, complexity and extent of the dissection, maximum caliber of the aorta, and progression or postintervention complications. Involvement of the ascending aorta-Stanford type A-has the most rapid lethal complications and requires surgical intervention to affect its morbidity and mortality. Lesions not involving the ascending aorta-Stanford type B-have a lesser rate of complications in the acute phase. During the acute to longitudinal progression, various specific and nonspecific imaging findings are encountered, including pleural and pericardial effusions, fluid collections, progression including aortic enlargement, and postoperative changes that can be discerned at CT. A systematic analysis algorithm is proposed for CT of the entire aorta throughout the continuum of AASs into the chronic and posttreated disease state, which synthesizes and communicates salient findings to all care providers. Online supplemental material is available for this article. ^©RSNA, 2021.