Acute aortic syndromes: Role of multi-detector row CT

Women With Acute Aortic Dissection Have Higher Prehospital Mortality Than Men

Background

Acute aortic dissection (AAD) often leads to out-of-hospital cardiac arrest (OHCA) and death before hospital arrival.

Objectives

The purpose of this study was to investigate differences in AAD incidence by sex.

Methods

A population-based study in a city with 121,180 residents was conducted using postmortem computed tomography data to identify patients with AAD who died before hospital arrival in 2008-2020. The incidence rate ratio and odds ratio were estimated using Poisson regression and univariable logistic regression, respectively.

Results

A total of 266 patients with incident AAD were enrolled: 84 patients with OHCA, 137 women [n = 137], and 164 patients with type A AAD. The crude and age-adjusted incidence of AAD was 16.2 and 14.3/100,000 person-years, respectively. The incidence of AAD was comparable by sex (men, 16.7/100,000 person-years; women, 15.7/100,000 person-years; incidence rate ratio: 0.94; 95% CI: 0.74-1.20; P = 0.64). Compared with men with AAD, women with AAD were older (77 ± 11 years vs 70 ± 14 years; P < 0.001), and a higher proportion had type A AAD (76% vs 47%; P < 0.001). Women with AAD had higher prehospital mortality than men with AAD (37% vs 21%; P = 0.004; OR: 2.24; 95% CI: 1.30-3.87; P = 0.004). Among 1,373 patients with OHCA, the proportion of women with AAD was significantly higher than the proportion of men with AAD (11% vs 3.9%; P < 0.001; OR: 2.90; 95% CI: 1.86-4.53; P < 0.001). AAD was most common in women aged 60 to 69 years (16.4%).

Conclusions

Women had a higher incidence of AAD presenting as prehospital death than men.

CT findings of type A acute aortic dissection that did and did not result in prehospital death

The differences between the pathologies of cases of type A acute aortic dissection (AAD) that did and did not result in prehospital death (PHD) have not been fully elucidated.This study aimed to compare the CT findings and clarify the differences between the pathologies of such cases.Ninety four consecutive type A AAD patients between 2010 and 2020 were enrolled in this study. There were 47 males and 47 females (mean age: 69.0 ± 14.4 years). The patients were divided into those that did (n = 25, 27%) and did not (n = 69, 73%) suffer PHD. We retrospectively evaluated the CT or postmortem CT findings of each case and analyzed the relationships between clinical factors (CT findings and clinical characteristics) and PHD using logistic regression analysis.Bloody pericardial effusion (96% vs 35%, P < .0001), bloody pleural effusion (40% vs 1%, P < .0001), and mediastinal hematomas (88% vs 14%, P < .0001) were significantly more common in the PHD group than in the no PHD group.In the multivariate logistic regression analysis, bloody pericardial effusion and lung consolidation were found to be significant risk factors for PHD (odds ratio: 21.29 [95% confidence intervals {CI}: 1.19-248.29] and 13.72 [95% CI: 1.79-105.06], respectively; P = .014 and P  = .012, respectively). AD affecting the abdominal aorta was identified as a significant negative risk factor for PHD (odds ratio: 0.02 [95% CI: 0.01-0.65]; P = .0042).Most PHD due to type A AAD are associated with hemorrhaging. Bleeding into the pericardium and type A AAD confined to the thoracic aorta are significant risk factors for PHD. Secondary respiratory failure might contribute to PHD in such cases.

Population-based incidence and outcomes of acute aortic dissection in Japan

AIMS

The population-based incidence and outcomes of acute aortic dissection (AAD) are still unknown because some patients are already dead on arrival, and the accurate diagnosis of AAD is difficult due to the low autopsy rate. We performed a population-based review of all patients with AAD in a well-defined geographical area in Japan between 2016 and 2018.

METHODS AND RESULTS

Data of all patients with AAD at Miyazaki Prefectural Nobeoka Hospital (MPNH), which performs medical care for 120 000 residents, were collected retrospectively. The emergency medical service is dedicated to the transfer of all patients in this area to the MPNH. For all patients who were dead on arrival, the diagnosis of AAD was made by autopsy imaging (AI) using computed tomography. The age-adjusted incidence and mortality per 100 000 population were calculated using the Japanese population distribution model in 2015. The total incidence of AAD was 79 (type A: 64.5%, n = 51). Of those, 60.8% (31/51) of patients with type A and 21.4% (6/28) with type B were dead on arrival and diagnosed by AI. The 30-day mortality rates were 74.5% (38/51) in type A and 25.0% (7/28) in type B. The age-adjusted incidence and mortality of AAD per 100 000 inhabitants were 17.6 (type A: 11.3, type B: 6.2) and 9.9 (type A: 8.4, type B: 1.5), respectively.

CONCLUSIONS

The population-based survey of AAD showed that the age-adjusted incidence of AAD was two-fold higher than in previous reports, and the actual mortality rates were markedly higher due to the high incidence of dead-on-arrival.

Incidence and characteristics of acute aortic dissection in patients with out-of-hospital cardiopulmonary arrest evaluated by non-contrast computed tomography

Background

The exact epidemiology of acute aortic dissection, including cases of out-of-hospital cardiopulmonary arrest, is unclear. We aimed to investigate the incidence and characteristics of acute aortic dissection in patients with out-of-hospital cardiopulmonary arrest transferred to our institution and validate the related factors to out-of-hospital cardiopulmonary arrest in Stanford type A acute aortic dissection.

Methods

We retrospectively reviewed the acute-phase computed tomography data of patients with out-of-hospital cardiopulmonary arrest who visited our hospital between 1 January 2015 and 31 December 2017.

Results

Among 1011 consecutive patients with out-of-hospital cardiopulmonary arrest, excluding those aged 17 years and younger and exogenous out-of-hospital cardiopulmonary arrest, such as suicide and trauma, 934 underwent computed tomography examination and 71 (7.6%) were diagnosed with acute aortic dissection: 66 with Stanford type A and five with type B acute aortic dissection (out-of-hospital cardiopulmonary arrest group). Seventy-five patients without out-of-hospital cardiopulmonary arrest with Stanford type A acute aortic dissection visited our institution during the same period (non-out-of-hospital cardiopulmonary arrest group). Age, incidence of massive bloody pericardial effusion and massive intrathoracic haemorrhage were significantly higher in the out-of-hospital cardiopulmonary arrest than in the non-out-of-hospital cardiopulmonary arrest group (78 ± 8 years, 72.7% and 24.2% vs. 70 ± 13 years, 26.7% and 1.3%, respectively; all P &lt; 0.01). These variables were independently related to out-of-hospital cardiopulmonary arrest.

Conclusions

There may be more patients with acute aortic dissection with out-of-hospital cardiopulmonary arrest than previously thought. Aortic rupture into the pericardial space or thoracic cavity is the major cause of out-of-hospital cardiopulmonary arrest in these cases. Non-contrast computed tomography can be used to diagnose acute aortic dissection in patients with out-of-hospital cardiopulmonary arrest. Our study is one of a few to evaluate the real circumstances surrounding acute aortic dissection and its epidemiology.

Three-dimensional Visualization of Aortic Arch Morphology via Rearrangement of Non-enhanced Thoracic CT Images

Objective

The objective of this study was to evaluate the reproducibility of three-dimensional (3D) images of the aortic arch reconstructed using a novel image processing algorithm for non-enhanced computed tomography (CT) images of the cervicothorax and abdomen obtained before emergency endovascular surgery.

Case Presentations

In all, 46 patients who underwent acute mechanical thrombectomy between January and December 2018 were examined. The anatomical variations of the aortic arch were reproduced in all cases; however, the reproduction of the carotid arteries was difficult.

Conclusion

Our novel 3D analysis system enables obtaining information on the aortic arch easily from plain CT data that may be useful in acute endovascular treatment.

The Role of Dual-Source Computed Tomography Angiography in Evaluating the Aortic Arch Vessels in Acute Type A Aortic Dissection: A Retrospective Study of 42 Patients

Background

This study aimed to investigate the role of dual-source computed tomography angiography (DSCTA) to evaluate the anatomy of the aortic arch vessels in patients with acute Type A aortic dissection (AD).

Material/Methods

A retrospective clinical study included 42 patients with acute Type A AD who underwent DSCTA and were treated in our hospital between January 2018 and December 2018. The findings were compared with a control group of 45 healthy individuals with hypertension and without aortic arch lesions.

Results

The diagnostic accuracy of DSCTA in patients with acute Type A AD was almost 100%. The innominate artery was most frequently affected. The mean DSCTA imaging measurements for the root of the innominate artery, the left common carotid artery, and the left subclavian artery, in the coronal plane of the aortic arch, were 17.7±3.7 mm, 17.7±3.7 mm, and 12.9±3.1 mm, respectively. The angles formed by the origin of the three aortic arch branches vessels and the aortic arch were 70.5±10.2°, 58.5±15.5°, and 90.2±22.7°, respectively. In the transverse plane of the aortic arch, the mean angles were 110.5±22.3°, 100.3±15.2°, and 95.4±10.6°, respectively. These DSCTA imaging findings were significantly different in the patient group compared with the control group.

Conclusions

DCTA demonstrated that patients with Type A AD showed anatomic differences in the aortic arch vessels. These findings may help surgeons to develop treatment strategies and select the most appropriate vascular grafts and stents.

Computed Tomography Imaging Findings of Acute Aortic Pathologies

Acute aortic syndromes (AAS) encompass a spectrum of life-threatening conditions characterized by acute aortic pain. AAS include acute aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, and aneurysm rupture. The prognosis of AAS is clearly related to prompt diagnosis and appropriate management. The different types of AAS cannot be reliably differentiated solely based on clinical presentation since the clinical features are indistinguishable. Multidetector-row computed tomography (MDCT) with electrocardiographic gating (ECG-gated MDCT) has been used in the acute emergency setting as a powerful clinical tool, which enables rapid and specific diagnosis of aortic pathologies. ECG-gated MDCT significantly reduces motion artifact and avoids potential pitfalls in the diagnosis of AAS. The aim of this review is to evaluate the role of MDCT imaging in the assessment of AAS and to discuss the differentiation of this spectrum of aortic diseases with reference to the key imaging findings.

Impact of 24-hour specialist coverage and an on-site CT scanner on the timely diagnosis of acute aortic dissection

INTRODUCTION

Acute aortic dissection (AAD) is a rare and potentially fatal condition that has been known to be missed in diagnoses. Our primary objective was to determine if the availability of 24-hour emergency department (ED) specialist coverage and an on-site computed tomography (CT) scanner reduced the rate of missed diagnoses of AAD.

METHODS

We selected records of patients diagnosed with dissection of the aorta from a hospital's discharge database and death register in the period of January 1998 to December 2014. AAD was defined as missed if imaging to diagnose AAD or a cardiology/cardiothoracic surgical consultation was not obtained in the ED. We compared the rates of missed diagnosis before and after the availability of 24-hour ED specialist coverage and an on-site CT scanner in the ED.

RESULTS

Among 145 patients, 42 (29.0%) had a missed diagnosis. The proportion of missed AAD was lower in the post-implementation period compared to the pre-implementation period (20.0% vs. 37.3%, odds ratio [OR] 0.42, 95% confidence interval [CI] 0.20‒0.89; p = 0.023). After adjusting for confounders, the difference remained significant (OR 0.31, 95% CI 0.14‒0.70; p = 0.005). In the post-implementation period, concurrent signs of congestive cardiac failure (OR 33.51, 95% CI 1.42‒789.20; p = 0.024) and absence of a widened mediastinum on chest radiography (OR 11.52, 95% CI 1.37‒96.80; p = 0.029) were independent predictors of missed diagnoses.

CONCLUSION

The availability of 24-hour ED specialist coverage and an on-site CT scanner improved the diagnosis of AAD in our study.

Experimental Insight into the Hemodynamics and Perfusion of Radiological Contrast in Patent and Non-patent Aortic Dissection Models

PURPOSE

In a curved vessel such as the aortic arch, the velocity profile closer to the aortic root is normally skewed towards the inner curvature wall, while further downstream along the curve, the velocity profile becomes skewed towards the outer wall. In an aortic dissection (AD) disease, blood velocities in the true lumen (TL) and false lumen (FL) are hypothesized to depend on the proximity of the entry tear to the root of aortic arch. Faster velocity in the FL can lead to higher hemodynamic loading, and pose tearing risk. Furthermore, the luminal velocities control the perfusion rate of radiological contrast media during diagnostic imaging. The objective in this study is to investigate the effect of AD disease morphology and configuration on the blood velocity field in the TL and FL, and on the relative perfusion of radiological enhancement agents through the dissection.

METHODS

Eight in vitro models were studied, including patent and non-patent FL configurations. Particle image velocimetry (PIV) was used to quantify the AD velocity field, while laser-induced fluorescence (LIF) was implemented to visualize dynamical flow phenomena and to quantify the perfusion of injected dye, in mimicry of contrast-enhanced computed tomography (CT).

RESULTS

The location of the proximal entry tear along the aortic arch in a patent FL had a dramatic impact on whether the blood velocity was higher in the TL or FL. The luminal velocities were dependent on the entry/reentry tear size combination, with the smaller tear (whether distal or proximal) setting the upper limit on the maximal flow velocity in the FL. Upon merging near the distal reentry tear, the TL/FL velocity differential gave rise to the roll up and shedding of shear layer vortices that convected downstream in close proximity to the wall of the non-dissected aorta. In a non-patent FL, the flow velocity was practically null with all the blood passing through the TL. LIF imaging showed much slower perfusion of contrast dye in the FL compared to the TL. In a patent FL, however, dye had a comparable perfusion rate appearing around the same time as in the TL.

CONCLUSIONS

Blood velocities in the TL and FL were highly sensitive to the exact dissection configuration. Geometric case A1R, which had its proximal entry tear located further downstream along the aortic arch, and had its entry and reentry tears sufficiently sized, exhibited the highest FL flow velocity among the tested models, and it was also higher than in the TL, which suggest that this configuration had elevated hemodynamic loading and risk for tearing. In contrast-enhanced diagnostic imaging, a time-delayed acquisition protocol is recommended to improve the detection of suspected cases with a non-patent FL.

Role of PET/CT in the Evaluation of Aortic Disease

Positron emission tomography (PET) /computed tomography (CT) has been established as a standard imaging modality in the evaluation of malignancy. Although PET/CT has played a major role in the management of oncology patients, its clinical use has also increased for various disorders other than malignancy. Growing evidence shows that PET/CT images have many advantages in aortic disease as well. This review article addresses the potential role of PET/CT in diseases involving the aorta, emphasizing its usefulness with regard to acute thoracic aortic syndromes, aortic aneurysm, atherosclerotic lesions, aortitis and aortic tumors.

Computed Tomography Angiographic Assessment of Acute Chest Pain

Acute chest pain is a leading cause of Emergency Department visits. Computed tomography angiography plays a vital diagnostic role in such cases, but there are several common challenges associated with the imaging of acute chest pain, which, if unrecognized, can lead to an inconclusive or incorrect diagnosis. These imaging challenges fall broadly into 3 categories: (1) image acquisition, (2) image interpretation (including physiological and pathologic mimics), and (3) result communication. The aims of this review are to describe and illustrate the most common challenges in the imaging of acute chest pain and to provide solutions that will facilitate accurate diagnosis of the causes of acute chest pain in the emergency setting.

Combined CT angiography of the aorta and craniocervical artery: a new imaging protocol for assessment of acute type A aortic dissection

Background

To investigate the feasibility of combined computed tomography angiography (CTA) of the aorta and craniocervical artery in acute type A aortic dissection (ATAAD) and the value of incremental craniocervical information.

Methods

Combined CTA of head, neck and aorta was performed in patients with suspected aortic dissection and 243 ATAAD patients were analyzed. The image quality and radiation dose were assessed. Valuable craniocervical CTA findings were determined for further surgical analysis.

Results

The mean dose-length product (DLP) was 314.11±29.31 mGy.cm. The image quality of craniocervical arteries were 100% diagnostic. Intimal flap involving carotid arteries was detected in 47% of patients, and significant stenosis of true lumen was observed in 60% of common carotid arteries (CCAs). Hypodensity and hypoplasia/occlusion of carotid arteries were also detected and apprised surgeons. The tortuosity of carotid artery was found in 90.9% of patients. Bilateral antegrade selective cerebral perfusion (ASCP) was performed in 21.1% of aortic arch surgery based on 7 hemodynamic variation types of the circle of Willis (CW) determined by cranial CTA information.

Conclusions

A combined CTA of head, neck and aorta is feasible with low radiation dose and diagnostic image quality. Incremental information on craniocervical pathology and anatomy may be useful for surgery repair of ATAAD.

Leaking abdominal aortic aneurysm mimicking ureteric colic: So rare but so real in Middle East

Aortic aneurysms are very rare in Middle East unlike Europe and America. Therefore, this pathology is very likely to be missed in acute presentation to the Emergency Medicine Department. We present a case of leaking abdominal aortic aneurysm mimicking right ureteric colic, which was missed in the initial assessment.

Preoperative evaluation value of aortic arch lesions by multidetector computed tomography angiography in type A aortic dissection

The purpose of this study was to preoperatively evaluate the value of aortic arch lesions by multidetector computed tomography (MDCT) angiography in type A aortic dissection (AD).From January 2013 to December 2015, we enrolled 42 patients with type A AD who underwent MDCT angiography in our hospital. The institutional database of patients was retrospectively reviewed to identify MDCT angiography examinations for type A AD. Surgical corrections were conducted in all patients to confirm diagnostic accuracy.In this study, the diagnostic accuracy of MDCT angiography was 100% in all 42 patients. The intimal tear site locations that were identified in patients included the ascending aorta (n = 25), aortic arch (n = 12), and all other sites (n = 5). Compared with the control group, there were significant differences in the aortic arch anatomy among the cases. Regarding the distance between the left common carotid and left subclavian arteries, compared with the control group, most cases with type A AD had a significant variation.MDCT angiography plays an important role in detecting aortic arch lesions of type A AD, especially in determining the location of the intimal entry site and change of branch blood vessels. Surgeons can formulate an appropriate operating plan, according to the preoperative MDCT diagnosis information.

Prevalence of Type A Acute Aortic Dissection in Patients With Out-Of-Hospital Cardiopulmonary Arrest

Postmortem computed tomography (PMCT) has been recently reported to be useful for detecting causes of death in the emergency department. In this study, the incidence and causes of death of type A acute aortic dissection (AAD) were investigated in patients who experienced out-of-hospital cardiopulmonary arrest (OHCPA) using PMCT. PMCT or enhanced computed tomography was performed in 311 of 528 consecutive patients experiencing OHCPA. A total of 23 (7%) of 311 patients were diagnosed with type A AAD based on clinical courses and CT findings. Eighteen consecutive patients who did not experience OHCPA were diagnosed with type A AAD during the same period. Pre-hospital death was observed in 21 (51%) of 41 patients with type A AAD. Bloody pericardial effusion was observed more frequently in patients who experienced OHCPA with type A AAD than in those who did not experience OHCPA with type A AAD (91% vs 28%, respectively; p <0.05). In conclusion, the incidence of type A AAD was common (7%) in patients who experienced OHCPA, with a high rate of pre-hospital death. Aortic rupture to the intrapericardial space was considered the major cause of death in patients who experienced OHCPA with type A AAD.

CT-angiography protocol with low dose radiation and low volume contrast medium for non-cardiac chest pain

AIM

To evaluate the diagnostic quality of a new multiple detector-row computed tomography angiography (MDCT-A) protocol using low dose radiation and low volume contrast medium techniques for evaluation of non-cardiac chest pain.

METHODS

Forty-five consecutive patients with clinically suspected noncardiac chest pain and requiring contrast-enhanced chest computed tomography (CT) were examined. The patients were assigned to the protocol, with 80 kilovolt (peak) (kV[p]) and 150 effective milliampere-second (eff mA-s). In our study group, 40 mL of low osmolar contrast material was administered at 3.0 mL/s.

RESULTS

In the study group, four patients with pulmonary embolism, four with pleural effusion, two with ascending aortic aneurysm and eight patients with pneumonic consolidation were detected. The mean attenuation of the pulmonary truncus and ascendant aortic locations was considered 264±44 and 249±51 HU, respectively. The mean effective radiation dose was 0.83 mSv for MDCT-A.

CONCLUSIONS

Pulmonary artery and the aorta scanning simultaneously was significantly reduced radiation exposure with the mentioned dose saving technique. Additionally, injection of low volume (40 cc) contrast material may reduce the risk of contrast induced nephropathy, therefore, facilitate the diagnostic approach. This technique can be applied to all cases and particularly patients at high risk of contrast induced nephropathy due to its similar diagnostic quality with a low dose and high levels of arteriovenous enhancement simultaneously.

Acute aortic syndrome: CT findings

Acute aortic syndrome (AAS) is a constellation of potentially life-threatening acute aortic diseases. The spectrum includes penetrating atherosclerotic ulcer, intramural haematoma, dissection, and unstable thoracic aneurysm. AAS cannot be reliably diagnosed clinically and multidetector computed tomography (MDCT) has revolutionized the diagnosis and management of this group of conditions in the acute setting due to its availability, speed, and accuracy. The purpose of this review is to illustrate key MDCT findings of AAS. Imaging techniques, radiological findings, and common pitfalls are also discussed.

Diagnostic errors in the evaluation of nontraumatic aortic emergencies

Nontraumatic aortic emergencies (NTAE) are a complex and dynamic group of serious, potentially fatal conditions affecting the aorta. These entities most often present in the emergency department setting, and include aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, as well as aortic rupture and impending rupture. The radiologist plays a critical role in prompt diagnosis and evaluation since presenting signs and symptoms are often nonspecific. This article focuses on the potential sources of error in the imaging evaluation of patients presenting with NTAE.

Acute aortic dissection in the ED: risk factors and predictors for missed diagnosis

OBJECTIVE

This study aims to explore the risk factors and predictors involved in the missed diagnosis of acute aortic dissection (AAD) among patients in the emergency medicine department (EMD).

METHODS

This is a single-center retrospective chart review conducted over a 10-year period (January 1998 to December 2008). Records with a diagnosis of "dissection of aorta" (International Classification of Diseases, Ninth Revision code 441.0) from the hospital discharge database and hospital death register were selected. Acute aortic dissection was defined as missed if diagnostic imaging to diagnose AAD or cardiothoracic surgeon consult was not elicited while in the EMD. We compared the history, clinical findings, and investigations between patients who had the diagnosis of AAD missed in the EMD and those who did not.

RESULTS

A total of 68 patients were included in the analysis during the study period, of which 38.2% had a missed diagnosis. There was 63.2% of type A AAD by Stanford classification. Neither age, sex, nor a history of hypertension were significant risk factors for missed diagnosis of AAD. The likelihood of missed diagnosis was significantly higher in the absence of a pulse deficit (odds ratio, 35.76; 95% confidence interval, 3.70-345.34) and absence of widened mediastinum on chest radiography (odds ratio, 33.16; 95% confidence interval, 5.74-191.49).

CONCLUSION

Well-known risk factors for AAD such as age, male sex, and hypertension were not risk factors for missed diagnosis for AAD presenting in the EMD. The absence of pulse deficit or widened mediastinum does not exclude the diagnosis of AAD.

MDCT in diagnosing acute aortic syndromes: reviewing common and less common CT findings

Nontraumatic acute thoracic aortic syndromes (AAS) describe a spectrum of life-threatening aortic pathologies with significant implications on diagnosis, therapy and management. In this context, multidetector computed tomography (MDCT) is the gold standard due to its intrinsic diagnostic value; its performance approaches 100% sensitivity and specificity, and it is accepted as a first-line modality for suspected acute aortic disease. MDCT allows early recognition and characterisation of acute aortic syndromes as well as the presence of any associated complications - findings that are essential for optimising treatment and improving clinical outcomes. Although classic CT findings have long been known, other unusual signs are continually reported in the medical literature. We reviewed the classic and less common CT findings, correlating them with pathophysiology, timing and management options, to achieve a definite and timely diagnostic and therapeutic definition.