Hypothermic Circulatory Arrest in Adult Aortic Arch Surgery: A Review of Hypothermic Circulatory Arrest and its Anesthetic Implications

Diseases affecting the aortic arch often require surgical intervention. Hypothermic circulatory arrest (HCA) enables a safe approach during open aortic arch surgeries. Additionally, HCA provides neuroprotection by reducing cerebral metabolism and oxygen requirements. However, HCA comes with significant risks (eg, neurologic dysfunction, stroke, and coagulopathy), and the cardiac anesthesiologist must completely understand the surgical techniques, possible complications, and management strategies.

The contribution of matrix metalloproteinases and their inhibitors to the development, progression, and rupture of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) account for up to 8% of deaths in men aged 65 years and over and 2.2% of women. Patients with AAAs often have atherosclerosis, and intimal atherosclerosis is generally present in AAAs. Accordingly, AAAs are considered a form of atherosclerosis and are frequently referred to as atherosclerotic aneurysms. Pathological observations advocate inflammatory cell infiltration alongside adverse extracellular matrix degradation as key contributing factors to the formation of human atherosclerotic AAAs. Therefore, macrophage production of proteolytic enzymes is deemed responsible for the damaging loss of ECM proteins, especially elastin and fibrillar collagens, which characterise AAA progression and rupture. Matrix metalloproteinases (MMPs) and their regulation by tissue inhibitors metalloproteinases (TIMPs) can orchestrate not only ECM remodelling, but also moderate the proliferation, migration, and apoptosis of resident aortic cells, alongside the recruitment and subsequent behaviour of inflammatory cells. Accordingly, MMPs are thought to play a central regulatory role in the development, progression, and eventual rupture of abdominal aortic aneurysms (AAAs). Together, clinical and animal studies have shed light on the complex and often diverse effects MMPs and TIMPs impart during the development of AAAs. This dichotomy is underlined from evidence utilising broad-spectrum MMP inhibition in animal models and clinical trials which have failed to provide consistent protection from AAA progression, although more encouraging results have been observed through deployment of selective inhibitors. This review provides a summary of the supporting evidence connecting the contribution of individual MMPs to AAA development, progression, and eventual rupture. Topics discussed include structural, functional, and cell-specific diversity of MMP members; evidence from animal models of AAA and comparisons with findings in humans; the dual role of MMPs and the requirement to selectively target individual MMPs; and the advances in identifying aberrant MMP activity. As evidenced, our developing understanding of the multifaceted roles individual MMPs perform during the progression and rupture of AAAs, should motivate clinical trials assessing the therapeutic potential of selective MMP inhibitors, which could restrict AAA-related morbidity and mortality worldwide.

Hotspots and development frontiers of postoperative complications of AD: Bibliometric analysis - a review

The research on the postoperative complications of aortic dissection (AD) has received great attention from scholars all over the world, and the number of research articles in this field has consistently increased year after year. However, no bibliometric reports have been published yet to analyze the scientific output and the current situation in this field. The Bibliometrix R-package, VOSviewer, and CiteSpace software were used to conduct a bibliometric analysis of the hotspots and development frontiers of AD. A total of 1242 articles were retrieved. The USA, China, and Japan had the highest number of publications. The five keywords with the highest frequency were "analysis," "incidence," "acute type," "graft," and "risk factor." The results also indicated that the research in related fields had shifted from surgical treatment and utilizing experience to the evidence-based exploration of risk factors and the construction of prediction models to help better manage postoperative complications of AD. This is the first bibliometric analysis of global publications on the postoperative complications of AD. The current research hotspots focus on three areas: common postoperative complications of AD, exploration of the related risk factors, and management of complications. Future research could focus on identifying risk factors through meta-analysis and using a multicenter database for AD as well as building relevant models to predict the development of complications to better facilitate the clinical management of AD patients.

Extended Stanford Type-A Aortic Dissection with Multivessel Coronary and Peripheral Artery Involvement: An Autopsy Case Report

We report the case of a 64-year-old male who died suddenly short after his admission to hospital because of strong chest pain and before any clinical diagnosis was established. His medical history included coronary disease with coronary by-pass surgery at the age of 40 years old, uncontrolled hypertension, diabetes mellitus, and elevated levels of cholesterol. The autopsy revealed quite a rare case of Stanford A aortic dissection with extension to the common and internal carotid arteries; the subclavian, axillary, brachial, and radial arteries; three coronary arteries; the superior mesenteric artery; and the iliac arteries. There was no histological evidence of aortitis or connective tissue disease. The death did not result from the rupture of the aortic dissection, but from myocardial ischemia due to coronary occlusion in combination with hemodynamic disturbance from stress caused by the extended aortic dissection.

Milk Fat Globule Epidermal Growth Factor VIII Fragment Medin in Age-Associated Arterial Adverse Remodeling and Arterial Disease

Medin, a small 50-amino acid peptide, is an internal cleaved product from the second discoidin domain of milk fat globule epidermal growth factor VIII (MFG-E8) protein. Medin has been reported as the most common amylogenic protein in the upper part of the arterial system, including aortic, temporal, and cerebral arterial walls in the elderly. Medin has a high affinity to elastic fibers and is closely associated with arterial degenerative inflammation, elastic fiber fragmentation, calcification, and amyloidosis. In vitro, treating with the medin peptide promotes the inflammatory phenotypic shift of both endothelial cells and vascular smooth muscle cells. In vitro, ex vivo, and in vivo studies demonstrate that medin enhances the abundance of reactive oxygen species and reactive nitrogen species produced by both endothelial cells and vascular smooth muscle cells and promotes vascular endothelial dysfunction and arterial stiffening. Immunostaining and immunoblotting analyses of human samples indicate that the levels of medin are increased in the pathogenesis of aortic aneurysm/dissection, temporal arteritis, and cerebrovascular dementia. Thus, medin peptide could be targeted as a biomarker diagnostic tool or as a potential molecular approach to curbing the arterial degenerative inflammatory remodeling that accompanies aging and disease.

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.

Single Cell RNA Sequencing Reveals the Pathogenesis of Aortic Dissection Caused by Hypertension and Marfan Syndrome

Aortic dissection (AD) is mainly caused by hypertension and Marfan syndrome. However, it is unclear whether the cellular components and functions are different between the two causes. A total of 11 aortic samples were collected for single-cell RNA analysis and 20 clusters were disclosed, including VSMCs, fibroblasts, endothelial cells, T cells, B cells, monocytes, macrophages, mast cells, and neutrophils components. There were differences in cell subclusters and function between hypertension and Marfan patients. The cells also had different differentiations. Cellchat identified cell ligand–receptor interactions that were associated with hypertension and Marfan-induced AD involving SMC, fibroblast, mo-macrophages, and T-cell subsets. This study revealed the heterogeneity of cellular components and gene changes in hypertension and Marfan-induced AD. Through functional analysis and the changes in intercellular communication, the possible mechanisms of different causes of AD were explained from a new perspective, so we can better understand the occurrence and development of diseases.

Fatal association of COVID‐19 and acute type A aortic dissection

Type A aortic dissection is a catastrophic event that requires prompt diagnosis and intervention to save the patient. It seems that type A aortic dissection in COVID‐19 patients has increased severity, and even with immediate diagnosis, it has a high mortality.

A Cascaded Deep Learning Framework for Detecting Aortic Dissection Using Non-contrast Enhanced Computed Tomography

Aortic dissection (AD) is a rare but potentially fatal disease with high mortality. The aim of this study is to synthesize contrast enhanced computed tomography (CE-CT) images from non-contrast CT (NCE-CT) images for detecting aortic dissection. In this paper, a cascaded deep learning framework containing a 3D segmentation network and a synthetic network was proposed and evaluated. A 3D segmentation network was firstly used to segment aorta from NCE-CT images and CE-CT images. A conditional generative adversarial network (CGAN) was subsequently employed to map the NCE-CT images to the CE-CT images non-linearly for the region of aorta. The results of the experiment suggest that the cascaded deep learning framework can be used for detecting the AD and outperforms CGAN alone.

Bariatric surgery is associated with reduced admission for aortic dissection: a nationwide case-control analysis

BACKGROUND

Aortic dissection (AD) is an uncommon but life-threatening condition associated with high morbidity and mortality. Hypertension (HTN) and hyperlipidemia (HLD) are common modifiable risk factors.

OBJECTIVES

Since bariatric surgery is associated with remission of obesity-related co-morbidities, we hypothesize that surgical weight loss might be protective against this feared aortic pathology.

SETTING

A cross-sectional analysis was performed using the National Inpatient Sample database from 2010 to 2015.

METHODS

The treatment group included bariatric patients and the control group patients with obesity (body mass index [BMI] ≥ 35kg/m²) without previous bariatric surgery. Analyzed covariates included demographics, co-morbidities, aortic diseases, and AD. A multivariate logistic regression analysis (MLRA) was performed to assess the odds of admission for AD in both groups.

RESULTS

A total of 2,300,845 patients were identified (2,004,804 controls and 296,041 cases). The mean (SEM) age was 54.4 (.05) versus 51.9 (.05) years, for the control and treatment groups, respectively (P < .0001). Bariatric patients posed a significantly lower prevalence of type 2 diabetes (T2D), HTN, HLD, aortic aneurysm, and bicuspid aortic valve (P < .0001) than control subjects. In the control group, 1411 individuals (.070%) had AD, whereas only 94 patients (.032%) in the bariatric surgery group had such diagnosis (P < .0001). The MLRA showed that non-bariatric obese patients had a significantly higher likelihood of suffering from AD (OR = 1.8 [95%CI 1.44-2.29] P < .0001). Considering different age groups, bariatric surgery was found to be less associated with admission for AD for individuals below and above 40 years of age (OR = 2.95 [95%CI 1.09-7.99] P = .0345) and (OR = 1.75 [95%CI 1.38-2.22] P < .0001), respectively.

CONCLUSIONS

Bariatric surgery could be a protective factor against aortic dissection and should be considered in patients with obesity and risk factors for this cardiovascular complication.

Post-operative computed tomography imaging evaluation of ascending aorta surgery

Ascending thoracic aorta disease is often a life-threatening condition. Aortic aneurysm and aortic dissection are the most frequent ascending aorta diseases requiring surgical intervention. Surgical repair techniques of the ascending aorta are various; they include reconstruction of the ascending aorta by using a graft with or without a prosthetic valve, reconstruction with a composite artificial graft or using a biological graft, and reconstruction of the ascending aorta with a composite graft preserving the native valve and arch repair. The radiologist plays a key role in the identification of post-operative complications; differentiation from normal postoperative findings is fundamental. Our aim is to discuss the main diseases affecting the ascending aorta requiring surgery and the different techniques used to treat them. We also discuss the normal computed tomography (CT) imaging findings and after-surgery complications.

Aortic aneurysms and dissections: Unmet needs from physicians and engineers perspectives

The treatment of aortic disease is complex, requiring cardiothoracic and vascular surgeons to make pre-, post- and intraoperative decisions directly influencing patient survival and well-being. Despite tremendous advancement in vascular surgery and endovascular techniques in the last two decades, along with the abundance of research in the field, many unmet needs and unanswered questions remain. Tight collaboration between engineers and physicians is a keystone in translating new tools, techniques, and devices into practice. Here, we have gathered our perspective, as physicians and engineers, in several pressing issues associated with the diagnosis and treatment of aortic aneurysms and dissection, referring to the current knowledge and practice, signifying unmet needs as well as future directions.

Prevalence of Intracranial Aneurysm in Patients With Aortic Disease in Korea: A Nationwide Population-Based Study

Background Patients with aortic disease (AD) might have a higher prevalence of intracranial aneurysm (IA). The present study evaluated the prevalence of IA in patients with AD and identified potential risk factors of IA using nationwide representative cohort sample data. Methods and Results We defined AD as both aortic dissections and aortic aneurysms. This study used a nationwide representative cohort sample from the Korea National Health Insurance Service-National Sample Cohort database from 1.1million patients. Using χ² or Fisher's exact tests, the prevalence of the IA in patients with AD and potential risk factors for their concurrence were analyzed. The prevalence of IA in patients with AD was 6.8% (155/2285). The adjusted odds ratios (OR) for having concurrent IA in patients with AD was 3.809 (95% CI, 3.191-4.546; P<0.01). Patients with AD and hypertension were >19 times more likely to be affected by IA (adjusted OR, 18.679; 95% CI, 16.555-21.076; P<0.01). Patients with AD and diabetes mellitus, old age (>60 years), and male sex were >4, 3, and 2 times more likely to be affected by IA, respectively (adjusted OR, 4.291, 3.469, and 1.983, respectively; 95% CI, 3.914-4.704, 3.152-3.878, and 1.779-2.112, respectively). Subgroup analysis with socioeconomic status or disability revealed that the prevalence of IA was significantly higher in all groups. Conclusions In the current population-based study, the prevalence of IA in patients with AD was quadrupled compared with that in the general population. Early IA screening might be considered among patients with AD for appropriate management.

Non-A non-B aortic dissection: A literature review

Non-A non-B aortic dissections are an infrequent occurrence and represent a small proportion of aortic dissections. Treating this life-threatening medical emergency often requires surgeons to undertake some one of the most challenging surgical or endovascular cases in medicine. This literature review aims to define and classify non-A non-B dissections, describe their epidemiology as well as their pathology. This review also aims to discuss the range of surgical techniques employed in their treatment and management and to investigate the patient outcomes associated with each technique.

Contained aortic rupture in a term pregnant patient during the COVID-19 pandemic

Aortic dissection and rupture is a rare occurrence in pregnant and postpartum patients. This case discusses the presentation and diagnosis of a patient with an acute contained thoracic aortic aneurysm rupture at 38 weeks of gestation, after presenting with throat pain and syncope during the COVID-19 pandemic. The patient underwent emergent caesarean delivery for non-reassuring fetal heart tracing, following which continued syncope workup revealed an aortic aneurysm and pericardial effusion. Diagnosis in this case was finalised with multimodality imaging, including transthoracic echocardiogram, and the patient underwent surgical aortic repair.

Predictive Factors of Operative Need in Medically Managed Type B Aortic Dissections

BACKGROUND

Aneurysmal degeneration of medically managed type B aortic dissection (TBAD) can be a life-threatening condition. Preventive thoracic endovascular aorta repair (TEVAR) in patients at risk could potentially be beneficial. The aim of this study was to examine the predictors for late aneurysmal dilatation after TBAD.

METHODS

A retrospective study was conducted on 82 patients with medically managed acute TBAD for a minimum of 14 days. Relevant demographic, biochemical, and radiographic variables at presentation were studied. The aortic dissection risk calculator tool developed by Sailer et al., predicting the risk of adverse events after aortic dissection based on demographic and radiographic variables at presentation, was tested retrospectively.

RESULTS

With a median follow-up of 36 months (range 13-68), 25 (30.5%) patients underwent surgery (92% TEVAR). A larger initial aortic and false lumen diameter as well as a greater distal extension of the dissection was associated with higher need for surgery (respectively, P = 0.003, P = 0.004, and P = 0.001). We observed higher growth rates of maximum aortic diameter in patients with a greater distal extension of the dissection, larger false lumen diameters and false lumen outflow, and entry tears located at the inner aortic arch (respectively, P = 0.001, P = 0.005, P = 0.001 and P = 0.014). No significant correlations could be found for the risks provided by the calculator tool.

CONCLUSIONS

The initial maximum aortic diameter of TBAD is a key predictor for aortic growth. Furthermore, the distal extension of the dissection also seems to play an important role in late aneurysmal degeneration. However, we were not able to confirm the added value of the risk calculator tool in our study group.

Iatrogenic Aortic Dissection Associated With Cardiac Surgery: A Narrative Review

Iatrogenic aortic dissection (iAD) is a relatively rare but a life-threatening complication associated with cardiac surgery. All members of the team caring for cardiac surgical patients (surgeons, perfusionists, and anesthesiologists) must be familiar with this complication to minimize its incidence and improve outcome. The present narrative review focuses on iAD occurring intraoperatively and during the early postoperative period (within 1 month) of cardiac surgery. The review also addresses iAD that occurs late (beyond 1 month) after cardiac surgery and iAD associated with other procedures. iAD occurs in about 0.06% of cases when the ascending aorta is the site of arterial cannulation, in about 0.6% when the femoral or iliac arteries are used, and in about 0.5% when the axillary or subclavian arteries are used. Mortality is estimated to be 30% but is more than double if not recognized until the postoperative period. Site of origin of dissection is most commonly the arterial inflow cannula (∼33%). Other common sites are the aortic cross-clamp or partial occlusion clamp (∼29%) and the proximal saphenous vein anastomosis site (14%). Sixty percent of cases occur during coronary artery bypass graft (CABG) surgery and 17% during aortic valve surgery with or without CABG. iAD may be somewhat less common in off-pump versus on-pump CABG but is still not very rare. Risk factors, presentation, diagnosis, and management are reviewed in detail as is the key role of the use of echocardiography in the early diagnosis of iAD and for guiding its management.

Aortic dissection in four cats: clinicopathological correlations

Aortic dissection (AD) is characterized by bleeding within the aortic wall or a tear in the intimal layer of the aortic wall, resulting in the passage of blood from the aortic lumen into the tunica media. In cases of AD, a floating, intimal flap in the aortic lumen divides the lumen into a true portion, with flow present, and a false portion, with no flow. We describe a series of 4 cats with AD of the ascending aorta and moderate aortic insufficiency. Three cats had an acute onset of clinical signs with pericardial effusion and cardiac tamponade, whereas one cat showed a chronic onset without pericardial effusion. Detailed gross and histopathological characterization is available for two cats, which revealed the typical features of AD. One cat also showed connective tissue abnormalities, microscopically resembling Marfan-like syndrome. Concomitant detection of hypertrophic cardiomyopathy in 2 cats represents a novel finding in the veterinary literature. Feline AD is generally associated with systemic hypertension. In all the cats of this case series, blood pressure was normal at presentation, although systemic hypertension before the acute dissection cannot be ruled out. In humans, hypotension is more common with AD of the ascending aorta, so the anatomical location could also play a role in cats. Hypertrophic cardiomyopathy in cats could have been a potential trigger of AD through shear stress. Transthoracic echocardiography, as herein demonstrated, can be considered as a rapid, non-invasive and useful method for the diagnosis of dissection at the level of the ascending aorta.

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.

Aortic Dissection in a Pregnant Patient without Other Risk Factors

Background. An aortic dissection is a life-threatening condition in which the intima of the artery tears causing separation of the intima and media. Pregnancy places women at a significantly increased risk of common vascular events including venous thromboembolism, myocardial infarction, and stroke, while also increasing the risk of rarer vascular events such as aortic dissection and aortic rupture. Case. A 30-year-old previously healthy multiparous woman presenting at 36 weeks of pregnancy with a Type A aortic dissection. She underwent a combined emergent cesarean delivery followed by repair of her aortic root. Conclusions. Aortic dissection should be high on the differential for pregnant patients presenting with the characteristic complaints and physical exam findings given the high mortality rate associated with this vascular event. Teaching Points. (1) This report reviews the characteristic presentation, risk factors, and physical exam findings in a patient with an aortic dissection. (2) The report includes treatment options for pregnant patients based on the classification of the dissection.

Oxygenation impairment in patients with acute aortic dissection is associated with disorders of coagulation and fibrinolysis: a prospective observational study

Background

Stanford type-A acute aortic dissection (AAD) is typically accompanied by oxygenation impairment before surgery. In addition, inflammation, coagulation and fibrinolysis also impair blood oxygenation. However, our understanding of the concentration of these factors in bronchoalveolar lavage fluid (BALF) has not been reported. The objective of the study was to investigate the impact of preoperative acute lung injury (ALI) on postoperative oxygenation impairment and to explore the effect of coagulation and fibrinolysis in blood and BALF.

Methods

This investigation utilized a prospective observational study design, which was registered at www.clinicaltrials.gov (identifier NCT01894334). The study included 53 patients undergoing surgery for Stanford type-A AAD at an academic hospital in China between October 2013 and July 2014. Preoperative ALI was identified according to the oxygenation index calculated by the PaO₂/FiO₂ ratio. The subjects were divided into the ALI group (oxygenation index ≤300 mmHg) or the control group (oxygenation index >300 mmHg). The primary outcome was patient oxygenation index, while secondary outcomes were concentrations of tissue factor (TF), tissue factor pathway inhibitor (TFPI), and plasminogen activator inhibitor-1 (PAI-1) in serum and BALF.

Results

The incidence of preoperative ALI for Stanford type-A AAD patients was 41.5%. Stanford type-A AAD patients with preoperative ALI had a lower postoperative oxygenation index (104.6±31.7 vs. 248.7±48.0 mmHg, P<0.001), higher concentrations of TF in serum and BALF (F=133.67, P<0.001; F=68.14, P<0.001), higher concentrations of TFPI in serum and BALF (F=31.98, P<0.001; F=45.58, P<0.001), and higher concentrations of PAI-1 in serum and BALF (F=213.88, P<0.001; F=107.95, P<0.001) when compared with those without preoperative ALI. Type-A AAD patients also showed a greater loss of blood (1,524±458 vs. 1,175±327 mL, P=0.040), longer mechanical ventilation time in the ICU (27.24±8.37 vs. 17.33±7.36 h, P<0.001), longer total stay in the ICU (42.27±10.85 vs. 33.45±9.05 h, P=0.002), and longer total hospital stay (17.77±5.00 vs. 13.48±3.97 days, P=0.001). Multivariate linear regression analysis indicated that preoperative PAI-1 in BALF, and TF in both serum and BALF were significantly associated with preoperative oxygenation impairment in patients with Stanford type-A AAD.

Conclusions

Preoperative ALI caused more serious postoperative oxygenation impairment for Stanford type-A AAD, and coagulation and fibrinolysis appear to play critical roles in this process. Preoperative PAI-1 in BALF and TF in both serum and BALF were significant factors related to the occurrence of preoperative oxygenation impairment for Stanford type-A AAD.

Post-Transcriptional Control of Tropoelastin in Aortic Smooth Muscle Cells Affects Aortic Dissection Onset

Aortic dissection (AD) is a catastrophic disease with high mortality and morbidity, characterized with fragmentation of elastin and loss of smooth muscle cells. Although AD has been largely attributable to polymorphisms defect in the elastin-coding gene, tropoelastin (TE), other undermined factors also appear to play roles in AD onset. Here, we investigated the effects of post-transcriptional control of TE by microRNAs (miRNAs) on elastin levels in aortic smooth muscle cells (ASMC). We found that miR-144-3p is a miRNA that targets TE mRNA in both human and mouse. Bioinformatics analyses and dual luciferase reporter assay showed that miR-144-3p inhibited protein translation of TE, through binding to the 3'-UTR of the TE mRNA. Interestingly, higher miR-144-3p levels and lower TE were detected in the ASMC obtained from AD patients, compared to those from non-AD controls. In a mouse model for human AD, infusion of adeno-associated viruses (serotype 6) carrying antisense for miR-144-3p (as-miR-144-3p) under CAG promoter significantly reduced the incidence and severity of AD, seemingly through enhancement of TE levels in ASMC. Thus, our data suggest an essential role of miR-144-3p on the pathogenesis of AD.

Long-term efficacy of endovascular vs open surgical repair for complicated type-B aortic dissection: a single-center retrospective study and meta-analysis

This study aimed to evaluate the long-term survival and risk factors of traditional open surgical repair (OSR) vs thoracic endovascular aneurysm repair (TEVAR) for complicated type-B aortic dissection (TBAD). A total of 118 inpatients (45 OSR vs 73 TEVAR) with TBAD were enrolled from January 2004 to January 2015. Kaplan-Meier curves and Cox proportional hazards analysis were performed to identify the long-term survival rate and independent predictors of survival, respectively. Meta-analysis was used to further explore the long-term efficacy of OSR and TEVAR in the eight included studies using Review Manager 5.2 software. An overall 10-year survival rate of 41.9% was found, and it was similar in the two groups (56.7% OSR vs 26.1% TEVAR; log-rank P=0.953). The risk factors of long-term survival were refractory hypertension (OR=11.1; 95%CI=1.428-86.372; P=0.021] and preoperative aortic diameter >55 mm (OR=4.5; 95%CI=1.842-11.346; P=0.001). Long-term survival rate did not differ significantly between OSR and TEVAR (hazard ratio=0.87; 95%CI=0.52-1.47; P=0.61). Compared with OSR, TEVAR did not show long-term advantages for patients with TBAD. Refractory hypertension and total aortic diameter >55 mm can be used to predict the long-term survival of TBAD in the Chinese Han population.

Putative pathophysiological mechanisms in recurrent hemicrania from aortic dissection: a case report

Background

Transient or permanent neurological symptoms occur in 17–40% of patients with aortic dissection. They can distract from or even mask the underlying life-threatening condition.

Case presentation

We present the case of a young Caucasian man who consulted for recurrent episodes of stereotyped right-sided sudden-onset severe headache. Upon questioning, he also reported a dull chest pain. Clinical examination and brain magnetic resonance imaging were unremarkable. The concomitant presence of chest pain made us consider aortic dissection. Contrast-enhanced cervico-thoraco-abdominal computerized tomography revealed type A aortic dissection. The patient underwent surgical replacement of the ascending aorta and reported no further episode of headache thereafter. Differential diagnosis of headache in this case includes paroxysmal hemicrania, cluster headache, migraine, trigeminal neuralgia and short lasting unilateral neuralgiform headache with conjunctival injection and tearing. Failure to match diagnostic criteria for any of these primary headache disorders and the resolution of pain episodes following surgery led us to postulate that these new-onset hemicrania episodes were symptomatic of aortic dissection. We hypothesize that aortic wall ischemia could have activated the trigeminovascular system and thereby caused hemicranial pain. Such an effect might be mediated by two different pathways that can be referred to as anatomical and humoral. The humoral hypothesis would posit that ischemia results in synthesis of pro-inflammatory mediators released from the aortic wall into the blood stream, such that they reach the central nervous system and directly stimulate specific receptors. The anatomical hypothesis would imply that pain signals generated by nociceptors in the aortic wall are transferred to the trigeminal ganglion via the cardiac plexus, the first cervical ganglion and the internal carotid nerve such that pain perception is referred to related cranio-cervical dermatomes.

Conclusion

In cases of isolated headache that does not match key diagnostic criteria for a primary headache entity; a thorough review of systems should be performed to look for symptoms that may indicate symptomatic headache from potentially life-threatening conditions. Neurologists should consider aortic dissection in patients presenting with acute headache and chest pain. Further clinical or experimental studies are required to refute or validate the pathophysiological hypothesis discussed here.

The Role of CTA, MRA, and Sonography in Aortic Dissection

Aortic dissection is an emergent condition requiring rapid diagnosis and immediate treatment. Patients with aortic dissection typically present with complaints of a sudden onset of severe abdominal and back pain. Patients with a suspected dissection may undergo a variety of imaging tests such as computed tomography angiography, sonography, and/or magnetic resonance angiography. The role of these diagnostic imaging modalities for aortic dissection is examined in detail in this literature review. These imaging modalities are compared and contrasted by reviewing their advantages, disadvantages, and overall effectiveness for aortic dissection.

Detection of aortic wall instability with the new dissectometer: Correlation with histological findings

OBJECTIVES

Although risk stratification for aortic dissection or rupture based on aortic diameter is quite suboptimal, alternative methods for the assessment of the aortic wall stability are rare. We assessed the mechanical properties of the aortic wall by a new custom-made device mimicking transversal aortic wall shear stress during open heart surgery in comparison with histological examination.

MATERIAL AND METHODS

One-hundred and five aortic walls were tested by the 'dissectometer' (seven different measured and two calculated values) as well as histological examination was performed.

RESULTS

Histological examination classified the aortic wall as normal in 54 (51.4%) patients and pathologic in 51 (48.6%) patients. Six out of nine parameters assessed by the dissectometer showed a significant correlation to histological findings. Using ROC-analysis, the most reliable parameter (P9) showed a sensitivity of 93.3% and a specificity of 80.4% with an area under the curve of 0.89 when using a cut-off value of 3.4. In the logistic regression analysis, P9 was an independent predictor for aortic wall instability (OR 28.983, 95% CI 11.507-72.993, p < 0.0001).

CONCLUSION

The dissectometer is suitable for discriminating between stable and unstable aortic walls with a good correlation to histological examination holding promise for direct and quick intraoperative identification of aortic walls at risk for dissection.

Aortic Dissection and Sudden Unexpected Deaths: A Retrospective Study of 31 Forensic Autopsy Cases

Acute aortic dissection (AAD) is the most common cause of sudden unexpected death related to aortic diseases. A retrospective study of 31 sudden unexpected deaths caused by AAD was conducted at Xi'an Jiaotong University Forensic Center from 2001 to 2012. We summarized the forensic characteristics of AAD and assessed the clinically diagnostic accuracy of AAD. The characteristics of sudden unexpected death due to AAD were male predominant (male: female=6.7:1), relatively young with the mean age of 44, and predominance of type A dissection (77.4%). Cardiac tamponade was the most frequent cause of sudden death (87.1%). Of the 31 cases, 26 (83.9%) patients were not recognized clinically and were misdiagnosed with acute myocardial infarction, coronary artery disease, cholecystitis, acute gastroenteritis, renal/urinary lithiasis, or acute pancreatitis. In summary, AAD can be difficult to recognize, diagnosis is therefore sometimes delayed or missed. The medicolegal death investigation can help physicians have a better understanding of AAD.

A Description of the Prehospital Phase of Aortic Dissection in Terms of Early Suspicion and Treatment

Purpose

Aortic dissection is difficult to detect in the early phase due to a variety of symptoms. This report describes the prehospital setting of aortic dissection in terms of symptoms, treatment, and suspicion by the Emergency Medical Service (EMS) staff.

Basic Procedures

All patients in the Municipality of Gothenburg, Sweden, who, in 2010 and 2011, had a hospital discharge diagnosis of aortic dissection (international classification of disease (ICD) I 71,0) were included. The exclusion criteria were: age < 18 years of age and having a planned operation. This was a retrospective, descriptive study based on patient records. In the statistical analyses, Fisher's exact test and the Mann-Whitney U test were used for analyses of dichotomous and continuous/ordered variables.

Main findings

Of 92 patients, 78% were transported to the hospital by the EMS. The most common symptom was pain (94%). Pain was intensive or very intensive in 89% of patients, with no significant difference in relation to the use of the EMS. Only 47% of those using the EMS were given pain relief with narcotic analgesics. Only 12% were free from pain on admission to the hospital. A suspicion of aortic dissection was reported by the EMS staff in only 17% of cases. The most common preliminary diagnosis at the dispatch center (31%) and by EMS clinicians (52%) was chest pain or angina pectoris. In all, 79% of patients were discharged alive from the hospital (75% of those that used the EMS and 95% of those that did not).

Conclusion

Among patients who were hospitalized due to aortic dissection in Gothenburg, 78% used the EMS. Despite severe pain in the majority of patients, fewer than half received narcotic analgesics, and only 12% were free from pain on admission to the hospital. In fewer than one-in-five patients was a suspicion of aortic dissection reported by the EMS staff.

AxelssonC, KarlssonT, PandeK, WigertzK, ÖrtenwallP, NordanstigJ, HerlitzJ. A description of the prehospital phase of aortic dissection in terms of early suspicion and treatment. Prehosp Disaster Med. 2015;30(2):1-8.

Exacerbation of intracranial aneurysm and aortic dissection in hypertensive rat treated with the prostaglandin F-receptor antagonist AS604872

Intracranial aneurysm (IA) and aortic dissection are both complications of hypertension and characterized by degeneration of the media. Given the involvement of prostaglandin F2α and its receptor, FP, in extracellular matrix remodeling in a mouse model of pulmonary fibrosis, here we induced hypertension and IA in rats by salt loading and hemi-lateral ligation of renal and carotid arteries and examined effects of a selective FP antagonist, AS604872, on these vascular events. AS604872 significantly accelerated degeneration of the media in both cerebral artery and aorta as evidenced by thinning of the media and disruption of the elastic lamina and promoted IA and aortic dissection. Notably, AS604872 induced expression of pro-inflammatory genes such as E-selectin in lesions and significantly enhanced macrophage infiltration. Suppression of surface expression of E-selectin with cimetidine prevented macrophage infiltration and aortic dissection. Thus, AS604872 exacerbates vascular inflammation in hypertensive rats and facilitates IA and aortic dissection. These results demonstrate that both IA and aortic dissection are caused by chronic inflammation of the arterial wall, which is worsened by AS604872, cautioning that other FP antagonists may share such deleterious actions in vascular homeostasis and suggesting that AS604872 can be used to make models of these vascular diseases with extensive degeneration.

Acute aortic dissection caused by Clostridium septicum aortitis

Clostridium septicum aortitis is a rare cause of aortic dissection. So far, only 28 cases have been described in literature before. Most of these cases occurred in elderly patients and an association to colonic neoplasms and/or atherosclerosis has been witnessed frequently. Here we report the case of a 32-year-old man with fatal aortic dissection due to aortic infection with C. septicum. Beside a case of a 22-year-old man who died of aortic dissection due to C. septicum aortitis this is the second case of C. septicum aortitis in a young individual with no signs of colonic neoplasms or atherosclerosis.

A sneeze: an unusual trigger for aortic dissection

We describe a rare case of type B thoracic aortic dissection resulting from a forceful sneeze in a 57-year-old man. The presenting clinical features were not typical and consisted of pleuritic chest pain and breathlessness following a forceful sneeze. There was no haemodynamic compromise. The diagnosis was made incidentally when he underwent a CT pulmonary angiography as part of pulmonary embolism work-up.

Decreased expression of fibulin-4 in aortic wall of aortic dissection

In this research, we will examine the expression of Fibulin-4 in aortic wall to find out its role in aortic dissection development. The samples of aortic wall were obtained from 10 patients operated for acute ascending aortic dissection and five patients for chronic ascending aortic dissection. Another 15 pieces of samples from patients who had coronary artery bypass were as controls. The aortic samples were stained with aldehyde magenta dyeing to evaluate the arrangement of elastic fibers. The Fibulin-4 protein and mRNA expression were both determined by Western blot and realtime quantitative polymerase chain reaction. Compared with the control group, both in acute and chronic ascending aortic dissection, elastic fiber fragments increased and the expression of fibulin-4 protein significantly decreased ( P = 0.045 < 0.05). The level of fibulin-4 mRNA decreased in acute ascending aortic dissection ( P = 0.034 < 0.05), while it increased in chronic ascending aortic dissection ( P = 0.004 < 0.05). The increased amounts of elastic fiber fragments were negatively correlated with the expression of fibulin-4 mRNA in acute ascending aortic dissection. In conclusion, in aortic wall of ascending aortic dissection, the expression of fibulin-4 protein decreased and the expression of fibulin-4 mRNA was abnormal. Fibulin-4 may play an important role in the pathogenesis of aortic dissection.

Aortic dissection presenting primarily as acute spinal cord damage: a case report and literature review

Acute aortic dissection is a rare, life-threatening condition. Clinical manifestations generally include the acute onset of severe chest or back pain. Aortic dissection presenting with signs and symptoms of acute spinal cord damage is the most severe complication and is particularly rare. This paper reports a case of aortic dissection in a 50-year-old man with a 10-year history of hypertension manifesting as acute spinal cord damage (bilateral lower extremity weakness and loss of all types of sensation), acute skeletal muscle ischaemic necrosis with increased levels of creatine kinase, and acute kidney failure with increased levels of serum creatinine and decreased glomerular filtration rate. The patient refused surgical treatment. His clinical condition progressively worsened and he died 3 days later. This case indicates the importance of considering aortic dissection in patients presenting with acute spinal cord damage, acute skeletal muscle necrosis or acute kidney failure, which may allow early diagnosis and reduce the mortality rate.

CT Diagnosis of a Thoracic Aort Aneurysm with Type B Aortic Dissection Clinically Misdiagnosed as Acute Pulmonary Embolism

A 54-year-old man was admitted to the emergency department, presenting with an acute onset of chest pain and severe respiratory distress symptoms. He was medicated with intravenous analgesia and antihypertensive drugs. The patient was subjected to a chest X-ray which revealed a prominent widening of the mediastinum and pleural effusion on the left side. In laboratory tests-d-dimer level was highly elevated. The patient was clinically interpreted as having an acute pulmonary embolism and referred to the radiology clinic to perform a computed tomography (CT) examination. Contrast-enhanced CT demonstrated that there was no abnormality related to the pulmonary vasculature, but a huge thoracic aorta aneurysm measuring 11 × 8.1 × 7.7 cm in diameter was detected. Accompanying the aneurysm, an intimal flap was also present in the proximal descending thoracic aorta, distal to the origin of the left subclavian artery and extending into the bifurcation level. The patient was therefore diagnosed as having a type B aortic dissection as well. Once these serious conditions were detected, he was immediately transferred to a cardiovascular thoracic surgery hospital for endovascular repairment operation.

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.

[Low arterial pressure on admission as a predictor of mortality in operated patients with type A aortic dissection]

BACKGROUND/AIM

Hypertension is a known predictor of proximal aortic dissection, but it is not commonly present in these patients on presentation. The associations between ascending aorta with left ventricular hypertrophy, cardiovascular risk factors and coronary atherosclerosis, and outcome of these patients are not fully elucidated.

METHODS

This retrospective study included 55 consecutive patients with acute type A aortic dissection treated surgically in our institution during the last 2 years. The diagnosis was based on imaging studies. Diameter of ascending aorta was measured with echocardiography.

RESULTS

The mean age of the patients was 55.4 +/- 12.19 years, and 72.7% were men. A history of arterial hypertension was present in 76.4% of the patients. Maximal ascending aorta diameter was 4.09 +/- 0.59 cm, while patients with frank aneurysm accounted for 5.5%. Systolic blood pressure on admission was < 150 mmHg in 58.2% of the patients. Diastolic blood pressure on admission was < 90 mmHg in 54.5% of the patients. Mean arterial pressure on admission was 104.9 +/- 24.6 mmHg. No correlations were demonstrated between maximal ascending aorta diameter and diameter of the left ventricular wall, any obtained risk factor and with coronary artery atherosclerosis (p > 0.05). After six months 11 (20%) patients died, while intrahospital mortality was 72%. According to logistic regression analysis which included traditional risk factors, echo parameters, coronary artery disease and logistic euro scor, mean arterial blood pressure was the independent predictor of a six-month mortality [RR 0.956; CI (0.918-0.994);p = 0.024].

CONCLUSION

In our population the acute type A aortic dissection occurred rarely in the setting of frank ascending aortic aneurysms > 5.0 cm. The majority of patients had a history of arterial hypertension. A history of arterial hypertension was not associated with maximal ascending aorta diameter. Mean arterial blood pressure was the independent predictor of a six-months mortality.

Recommendations for haemodynamic and neurological monitoring in repair of acute type a aortic dissection

During treatment of acute type A aortic dissection there is potential for both pre- and intra-operative malperfusion. There are a number of monitoring strategies that may allow for earlier detection of potentially catastrophic malperfusion (particularly cerebral malperfusion) phenomena available for the anaesthetist and surgeon. This review article sets out to discuss the benefits of the current standard monitoring techniques available as well as desirable/experimental techniques which may serve as adjuncts in the monitoring of these complex patients.

The value of intravascular phased-array imaging in endovascular treatment of thoracic aortic pathology

BACKGROUND

Careful pre-, intra- and postoperative diagnostics in endovascular treatment of thoracic aortic pathology is crucial for a favourable outcome. Computer tomography (CT) and digitally subtracted angiography (DSA) do not always provide sufficient diagnostic information.

PURPOSE

To report our primary experiences of using intraluminal phased-array imaging (IPAI) as an additive tool for diagnostics and endovascular treatment of thoracic aortic pathology.

MATERIAL AND METHODS

Eleven patients, nine men and two women (mean age 60, range 45) were examined intraoperatively with IPAI in stentgraft procedures of thoracic aortic pathology.

RESULTS

IPAI could detect and visualize the entries and re-entries in the intima. Aortic branch vessels could be visualized for patency both during and immediately after stentgraft deployment. It was also possible to detect ceased blood flow in the false lumen or aneurysmal sac after stentgraft deployment.

CONCLUSION

IPAI is a helpful tool for diagnostics and for guiding stentgraft placing in the treatment of thoracic aortic pathology.