The causal relationship between thoracic aortic aneurysm and immune cells: a mendelian randomization study

One of the pathogenic causes of thoracic aortic aneurysm (TAA), a dangerous vascular condition that can cause aortic rupture, is autoimmune disorders. Currently, immune cell clustering is becoming more and more refined, and the specific immune cell phenotypes involved are yet unknown. Here, we want to clarify the causal link between TAA risk and 731 immune cell traits. There was a Mendelian randomization analysis (MR). We discovered that the presence of TAA led to an increase in CD45 on CD33- HLA-DR- myeloid cells, an increase in CD45 on natural killer cells, and a decrease in FSC-A on granulocytes after applying FDR correction. Our research also revealed a strong correlation between the incidence of TAA and an increase in immune cells with CD3 on CD39+ CD4+, and CD25 on IgD- CD27- phenotypes. Through genetic techniques, our research has shown the intimate relationship between immune cells and TAA, offering direction for future clinical investigations.

Narrative Review of Risk Assessment of Abdominal Aortic Aneurysm Rupture Based on Biomechanics-Related Morphology

CLINICAL IMPACT

Studies have shown that the biomechanical indicators based on multi-scale models are more effective in accurately assessing the rupture risk of AAA. To meet the need for clinical monitoring and rapid decision making, the typical morphological parameters associated with AAA rupture and their relationships with the mechanical environment have been summarized, which provide a reference for clinical preoperative risk assessment of AAA.

Right Sinus of Valsalva Aneurysm Rupturing into the Right Atrium and Dissecting into the Interventricular Septum

The right sinus of the Valsalva aneurysm (SVA) rupturing into the right atrium (RA) and dissecting into the interventricular septum (IVS) is rare. The disease can be definitively diagnosed using two-dimensional (2D) echocardiography and color Doppler ultrasonography. Real-time biplane imaging and three-dimensional (3D) echocardiography offer new perspectives for viewing and diagnosing this disease.

Temporal trends in mortality of aortic dissection and rupture in the UK, Japan, the USA and Canada

OBJECTIVE

Aortic dissection and aortic aneurysm rupture are aortic emergencies and their clinical outcomes have improved over the past two decades; however, whether this has translated into lower mortality across countries remains an open question. The purpose of this study was to compare mortality trends from aortic dissection and rupture between the UK, Japan, the USA and Canada.

METHODS

We analysed the WHO mortality database to determine trends in mortality from aortic dissection and rupture in four countries from 2000 to 2019. Age-standardised mortality rates per 100 000 persons were calculated, and annual percentage change was estimated using joinpoint regression.

RESULTS

Age-standardised mortality rates per 100 000 persons from aortic dissection and rupture in 2019 were 1.04 and 1.80 in the UK, 2.66 and 1.16 in Japan, 0.76 and 0.52 in the USA, and 0.67 and 0.81 in Canada, respectively. There was significantly decreasing trends in age-standardised mortality from aortic rupture in all four countries and decreasing trends in age-standardised mortality from aortic dissection in the UK over the study period. There was significantly increasing trends in mortality from aortic dissection in Japan over the study period. Joinpoint regression identified significant changes in the aortic dissection trends from decreasing to increasing in the USA from 2010 and Canada from 2012. In sensitivity analyses stratified by sex, similar trends were observed.

CONCLUSIONS

Trends in mortality from aortic rupture are decreasing; however, mortality from aortic dissection is increasing in Japan, the USA and Canada. Further study to explain these trends is warranted.

Animal Models, Pathogenesis, and Potential Treatment of Thoracic Aortic Aneurysm

Thoracic aortic aneurysm (TAA) has a prevalence of 0.16-0.34% and an incidence of 7.6 per 100,000 person-years, accounting for 1-2% of all deaths in Western countries. Currently, no effective pharmacological therapies have been identified to slow TAA development and prevent TAA rupture. Large TAAs are treated with open surgical repair and less invasive thoracic endovascular aortic repair, both of which have high perioperative mortality risk. Therefore, there is an urgent medical need to identify the cellular and molecular mechanisms underlying TAA development and rupture to develop new therapies. In this review, we summarize animal TAA models including recent developments in porcine and zebrafish models: porcine models can assess new therapeutic devices or intervention strategies in a large mammal and zebrafish models can employ large-scale small-molecule suppressor screening in microwells. The second part of the review covers current views of TAA pathogenesis, derived from recent studies using these animal models, with a focus on the roles of the transforming growth factor-beta (TGFβ) pathway and the vascular smooth muscle cell (VSMC)-elastin-contractile unit. The last part discusses TAA treatment options as they emerge from recent preclinical studies.

Characterization of multiple organ failure after ruptured abdominal aortic aneurysm repair

BACKGROUND

Multiple organ failure (MOF) is associated with poor outcomes and increased mortality in sepsis and trauma. There are limited data regarding MOF in patients after ruptured abdominal aortic aneurysm (rAAA) repair. We aimed to identify the contemporary prevalence and characteristics of patients with rAAA with MOF.

METHODS

We retrospectively reviewed patients with rAAA who underwent repair (2010-2020) at our multihospital institution. Patients who died within the first 2 days after repair were excluded. MOF was quantified by modified (excluding hepatic system) Denver, Sequential Organ Failure Assessment (SOFA) score, and Multiple Organ Dysfunction Score (MODS) for postoperative days 3 to 5 to determine the prevalence of MOF. MOF was defined as a Denver score of >3, dysfunction in two or more organ systems by SOFA score, or a MODS score of >8. Kaplan-Meier curves and log-rank testing were used to evaluate differences in 30-day mortality between multiple organ failure and patients without MOF. Logistic regression was used to assess predictors of MOF.

RESULTS

Of 370 patients with rAAA, 288 survived past two days (mean age, 73±10.1 years; 76.7% male; 44.1% open repair), and 143 had data for MOF calculation recorded. From postoperative days 3 to 5, 41 (14.24%) had MOF by Denver, 26 (9.03%) by SOFA, and 39 (13.54%) by MODS criteria. Among these scoring systems, pulmonary and neurological systems were impacted most commonly. Among patients with MOF, pulmonary derangement occurred in 65.9% (Denver), 57.7% (SOFA), and 56.4% (MODS). Similarly, neurological derangement occurred in 92.3% (SOFA) and 89.7% (MODS), but renal derangement occurred in 26.8% (Denver), 23.1% (SOFA), and 10.3% (MODS). MOF by all three scoring systems was associated with increased 30-day mortality (Denver: 11.3% vs 41.5% [P < .01]; DOFA: 12.6% vs 46.2% [P < .01]; MODS: 12.5% vs 35.9% [P < .01]), as was MOF by any criteria (10.8% vs 35.7 %; P < .01). Patients with MOF were more likely to have a higher body mass index (55.9±26.6 vs 49.0±15.0; P = .011) and to have had a preoperative stroke (17.9% vs 6.0%; P = .016). Patients with MOF were less likely to have undergone endovascular repair (30.4% vs 62.1%; P < .001). Endovascular repair was protective against MOF (any criteria) on multivariate analysis (odds ratio, 0.23; 95% confidence interval, 0.08-0.64; P = .019) after adjusting for age, gender, and presenting systolic blood pressure.

CONCLUSIONS

MOF occurred in only 9% to 14% of patients after rAAA repair, but was associated with a three-fold increase in mortality. Endovascular repair was associated with a reduced MOF incidence.

Computerized Differentiation of Growth Status for Abdominal Aortic Aneurysms: A Feasibility Study

Fast-growing abdominal aortic aneurysms (AAA) have a high rupture risk and poor outcomes if not promptly identified and treated. Our primary objective is to improve the differentiation of small AAAs' growth status (fast versus slow-growing) through a combination of patient health information, computational hemodynamics, geometric analysis, and artificial intelligence. 3D computed tomography angiography (CTA) data available for 70 patients diagnosed with AAAs with known growth status were used to conduct geometric and hemodynamic analyses. Differences among ten metrics (out of ninety metrics) were statistically significant discriminators between fast and slow-growing groups. Using a support vector machine (SVM) classifier, the area under receiving operating curve (AUROC) and total accuracy of our best predictive model for differentiation of AAAs' growth status were 0.86 and 77.50%, respectively. In summary, the proposed analytics has the potential to differentiate fast from slow-growing AAAs, helping guide resource allocation for the management of patients with AAAs.

Identification and characterization of new candidates for abdominal aortic aneurysm screening in patients outside of current accepted guidelines

BACKGROUND

Previous studies have identified groups of patients with abdominal aortic aneurysm (AAA) that fall outside of currently accepted screening guidelines. Population-based studies have found AAA screening would be cost-effective at a prevalence of 0.5% to 1.0%. The goal of this study was to determine the prevalence of AAA in patients that fall outside of the current screening guidelines. In addition, we analyzed outcomes of the groups with a prevalence of greater than 1%.

METHODS

Using the TriNetX Analytics Network, several patient cohorts were abstracted with a diagnosis of ruptured or unruptured AAA based on previously identified groups with a potentially high risk for AAA that fall outside of currently accepted screening guidelines. Groups were also stratified by sex. For groups found to have a prevalence of greater than 1%, the unruptured patients were further analyzed for long-term rates of rupture and included male ever-smokers aged 45 to 65, male never-smokers aged 65 to 75, male never-smokers aged greater than 75, and female ever-smokers aged 65 or greater. Long-term mortality, stroke, and myocardial infarction rates were compared in patients with treated and untreated AAA after propensity score matching.

RESULTS

We identified 148,279 patients across the four groups with a prevalence of AAA of greater than 1% with female ever-smokers aged 65 or older being the most prevalent (2.73%). In each of the four groups, the rate of AAA rupture increased every 5 years and all had rupture rates of greater than 1% at 10 years. Meanwhile, controls for each of these four subgroups without a previous AAA diagnosis had rupture rates between 0.090% and 0.013% at 10 years. Those who underwent repair of their AAA had decreased incidence of mortality, stroke, and myocardial infarction. Specifically, male ever-smokers aged 45 to 64 had a significant difference in incidence of mortality and myocardial infarction at 5 years and stroke at 1 and 5 years.

CONCLUSIONS

Our analysis suggests male ever-smokers aged 45 to 65, male never-smokers aged 65 to 75, male never-smokers aged greater than 75, and female ever-smokers aged 65 or greater have a more than 1% prevalence of AAA and, therefore, may benefit from screening. Outcomes were significantly worse compared with well-matched controls in these groups.

A ruptured thoracic aortic aneurysm and the difficulties of confirming syphilis

A 43-year-old woman died suddenly and was found at PM to have a ruptured thoracic aortic aneurysm. The endothelial surface of the aorta showed a 'tree-bark' appearance. Histology of the aneurysm wall showed a patchy, mainly perivascular, plasma cell infiltrate. Multiple spirochete-like organisms were identified on T. pallidum IHC. However, PM syphilis serology (screen including rapid plasma reagin (RPR) and T. pallidum particle agglutination (TPPA)) on femoral blood was negative. PCR testing on FFPE aortic wall tissue was negative. Further history revealed routine antenatal syphilis screening tests had been negative, no known history or risk of exposure to syphilis or other treponemes. This case raises the possibility of false negative syphilis testing. While acknowledged in RPR testing, with the modern testing regime using multiple methods, the rate of false negative results is now thought to be markedly reduced, and false positive results are a much greater problem in clinical medicine. The most common cause of false negative results is early in primary infection before an immune response has been mounted and in those patients that are immunocompromised. False negative results are also more often seen in tertiary syphilis, as in this case. Newer testing methods which include 16S rRNA sequencing have become available and early discussion with a microbiologist would be recommended. Strong macroscopic and microscopic suggestion of syphilis as the cause of the aneurysm makes it necessary to include the possibility of infection in the Post Mortem Report to Coroner as this will have implications for her sexual partners and children.

[Endovascular Treatment of a Ruptured Mediastinal Bronchial Artery Aneurysm]

Case 1:A 73-year-old man was transported to our hospital for evaluation of sudden onset of chest pain, back pain, and dyspnea. We initially misdiagnosed him with advanced esophageal cancer accompanied by mediastinal metastasis;however, subsequent multi-detector row computed tomography (MDR-CT) confirmed the diagnosis. We performed coil embolization of a bronchial artery aneurysm and thoracic endovascular aortic repair( TEVAR) to seal the root of the bronchial artery. Case 2:An 81-year-old woman with a one-week history of fever and cervical pain was diagnosed with a ruptured infected thoracic aneurysm. She underwent the same treatment as described in Case 1. Physicians should consider it as a differential diagnosis of mediastinal hematoma.

A quarter of a century biomechanical rupture risk assessment of abdominal aortic aneurysms. Achievements, clinical relevance, and ongoing developments

Abdominal aortic aneurysm (AAA) disease, the local enlargement of the infrarenal aorta, is a serious condition that causes many deaths, especially in men exceeding 65 years of age. Over the past quarter of a century, computational biomechanical models have been developed towards the assessment of AAA risk of rupture, technology that is now on the verge of being integrated within the clinical decision-making process. The modeling of AAA requires a holistic understanding of the clinical problem, in order to set appropriate modeling assumptions and to draw sound conclusions from the simulation results. In this article we summarize and critically discuss the proposed modeling approaches and report the outcome of clinical validation studies for a number of biomechanics-based rupture risk indices. Whilst most of the aspects concerning computational mechanics have already been settled, it is the exploration of the failure properties of the AAA wall and the acquisition of robust input data for simulations that has the greatest potential for the further improvement of this technology.

Socioeconomic disparities in abdominal aortic aneurysm repair rates and survival

BACKGROUND

Abdominal aortic aneurysm (AAA) is more prevalent in socioeconomically disadvantaged areas. This study investigated socioeconomic disparities in AAA repair rates and survival.

METHODS

The study used ecological and cohort study designs, from 31 672 census areas in England (April 2006 to March 2018), the Index of Multiple Deprivation 2010 as the area-level deprivation indicator, and Poisson, logistic and Cox regression.

RESULTS

Some 77 606 patients (83.4 per cent men) in four age categories (55-64, 65-74, 75-84, 85 or more years) were admitted with AAA from a population aged at least 55 years of 14.7 million. Elective open and endovascular repair rates were 41 (95 per cent c.i. 23 to 61) and 60 (36 to 89) per cent higher respectively among men aged 55-64 years in the most versus least deprived areas by quintile. This differences diminished and appeared to reverse with increasing age, with 26 (-1 to 45) and 25 (13 to 35) per cent lower rates respectively in men aged 85 years or more in the most deprived areas. Men admitted from more deprived areas were more likely to die in hospital without aneurysm repair. Among those who had aneurysm repair, this was more likely to be for a ruptured aneurysm than among men from less deprived areas. For intact aneurysm repair, they were relatively more likely to have this during an emergency admission. The mortality rate after repair was higher for men from more deprived areas, although the hazard diminished with age. Patterns were unclear for women.

CONCLUSION

There were clear socioeconomic disparities in operation rates, mode of presentation, and outcome for AAA surgery. Policies are needed to address these disparities.

MR Elastography of Abdominal Aortic Aneurysms: Relationship to Aneurysm Events

Background Abdominal aortic aneurysm (AAA) diameter remains the standard clinical parameter to predict growth and rupture. Studies suggest that using solely AAA diameter for risk stratification is insufficient. Purpose To evaluate the use of aortic MR elastography (MRE)-derived AAA stiffness and stiffness ratio at baseline to identify the potential for future aneurysm rupture or need for surgical repair. Materials and Methods Between August 2013 and March 2019, 72 participants with AAA and 56 healthy participants were enrolled in this prospective study. MRE examinations were performed to estimate AAA stiffness and the stiffness ratio between AAA and its adjacent remote normal aorta. Two Cox proportional hazards models were used to assess AAA stiffness and stiffness ratio for predicting aneurysmal events (subsequent repair, rupture, or diameter >5.0 cm). Log-rank tests were performed to determine a critical stiffness ratio suggesting high-risk AAAs. Baseline AAA stiffness and stiffness ratio were studied using Wilcoxon rank-sum tests between participants with and without aneurysmal events. Spearman correlation was used to investigate the relationship between stiffness and other potential imaging markers. Results Seventy-two participants with AAA (mean age, 71 years ± 9 [SD]; 56 men and 16 women) and 56 healthy participants (mean age, 42 years ± 16; 27 men and 29 women) were evaluated. In healthy participants, aortic stiffness positively correlated with age (ρ = 0.44; P < .001). AAA stiffness (event group [n = 21], 50.3 kPa ± 26.5 [SD]; no-event group [n = 21], 86.9 kPa ± 52.6; P = .01) and the stiffness ratio (event group, 0.7 ± 0.4; no-event group, 2.0 ± 1.4; P < .001) were lower in the event group than the no-event group at a mean follow-up of 449 days. AAA stiffness did not correlate with diameter in the event group (ρ = -0.06; P = .68) or the no-event group (ρ = -0.13; P = .32). AAA stiffness was inversely correlated with intraluminal thrombus area (ρ = -0.50; P = .01). Conclusion Lower abdominal aortic aneurysm stiffness and stiffness ratio measured with use of MR elastography was associated with aneurysmal events at a 15-month follow-up. © RSNA, 2022 See also the editorial by Sakuma in this issue.

[Endovascular aneurysm repair (EVAR) : Update D]

BACKGROUND

Abdominal aortic aneurysms can either be treated by open surgery or endovascular repair. In both cases, prostheses are implanted to prevent potentially lethal aortic ruptures.

OBJECTIVES

Studies seeking to identify the optimal treatment came to diverging conclusions. The goal of this article is to shed light on the discussion of which treatment option is to be preferred.

MATERIALS AND METHODS

This article summarizes the relevant studies on elective and emergency abdominal aortic aneurysm repair. The presented studies are discussed, and results are interpreted and compared.

RESULTS

While most studies indicate lower short-term mortality rates in endovascular aneurysm repair (EVAR), mortality rates converged in multiple trials and even showed a lower mortality rate for open repair in mid-term analyses. Most recent studies indicate long-term equivalence in terms of mortality and a higher rate of secondary interventions in EVAR patients.

CONCLUSIONS

The current body of literature indicates no real advantage of one therapy over another. The choice of therapy should depend on anatomic, clinical, and logistic criteria.

Guidelines on the management of abdominal aortic aneurysms: updates from the Italian Society of Vascular and Endovascular Surgery (SICVE)

The objective of these Guidelines was to revise and update the previous 2016 Italian Guidelines on Abdominal Aortic Aneurysm Disease, in accordance with the National Guidelines System (SNLG), to guide every practitioner toward the most correct management pathway for this pathology. The methodology applied in this update was the GRADE-SIGN version methodology, following the instructions of the AGREE quality of reporting checklist as well. The first methodological step was the formulation of clinical questions structured according to the PICO (Population, Intervention, Comparison, Outcome) model according to which the Recommendations were issued. Then, systematic reviews of the Literature were carried out for each PICO question or for homogeneous groups of questions, followed by the selection of the articles and the assessment of the methodological quality for each of them using qualitative checklists. Finally, a Considered Judgment form was filled in for each clinical question, in which the features of the evidence as a whole are assessed to establish the transition from the level of evidence to the direction and strength of the recommendations. These guidelines outline the correct management of patients with abdominal aortic aneurysm in terms of screening and surveillance. Medical management and indication for surgery are discussed, as well as preoperative assessment regarding patients' background and surgical risk evaluation. Once the indication for surgery has been established, the options for traditional open and endovascular surgery are described and compared, focusing specifically on patients with ruptured abdominal aortic aneurysms as well. Finally, indications for early and late postoperative follow-up are explained. The most recent evidence in the Literature has been able to confirm and possibly modify the previous recommendations updating them, likewise to propose new recommendations on prospectively relevant topics.

On stress in abdominal aortic aneurysm: Linear versus non-linear analysis and aneurysm rupture risk

We present comprehensive biomechanical analyses of abdominal aortic aneurysms (AAA) for 43 patients. We compare stress magnitudes and stress distributions within arterial walls of abdominal aortic aneurysms (AAA) obtained using two simulation and modelling methods: (a) Fully automated and computationally very efficient linear method embedded in the software platform Biomechanics based Prediction of Aneurysm Rupture Risk (BioPARR), freely available from https://bioparr.mech.uwa.edu.au/; (b) More complex and much more computationally demanding Non-Linear Iterative Stress Analysis (Non-LISA) that uses a non-linear inverse iterative approach and strongly non-linear material model. Both methods predicted localised high stress zones with over 90% of AAA model volume fraction subjected to stress below 20% of the 99th percentile maximum principal stress. However, for the non-linear iterative method, the peak maximum principal stress (and 99th percentile maximum principal stress) was higher and the stress magnitude in the low stress area lower than for the automated linear method embedded in BioPARR. Differences between the stress distributions obtained using the two methods tended to be particularly pronounced in the areas where the AAA curvature was large. Performance of the selected characteristic features of the stress fields (we used 99th percentile maximum principal stress) obtained using BioPARR and Non-LISA in distinguishing between the AAAs that would rupture and remain intact was for practical purposes the same for both methods.

Risk factors for anterior communicating artery aneurysm rupture: A protocol for systematic review and meta-analysis

BACKGROUND

Although the research on the risk factors of anterior communicating artery (AComA) aneurysm has made great progress, the independent effect of each risk factor on the rupture of AComA aneurysm is controversial among different studies. We will perform a protocol for systematic review and meta-analysis to investigate risk factors for AComA aneurysm rupture and quantify their independent effects.

METHODS

A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols guidelines in PubMed, Embase, and the Cochrane Library databases was conducted from inception to August 31, 2021 for published studies concerning risk factors for AComA aneurysm rupture. In the absence of statistical heterogeneity (ie, P > .10 and I2 < 50%), we will use a fixed-effects model to pool the results across sufficient studies. Otherwise, we will present the results employing the random-effects model. Quality assessment of the included studies will be evaluated using the Newcastle-Ottawa Scale. Statistical analyses will be performed using Stata16 (Stata Corporation, College Station, TX, USA) software.

RESULTS

The findings of this study will be submitted to peer-reviewed journals for publication.

CONCLUSION

This systematic review will provide evidence to determine the risk factors that affect the rupture of the AComA aneurysm and quantify their independent effects.

ETHICS AND DISSEMINATION

Since the proposed study uses pre-published data, ethical approval is not required.

REVIEW REGISTRATION NUMBER

CRD42021284262. (https://www.crd.york.ac.uk/PROSPERO/).

[SOS Aorte : a filiarisation of the management of aortic dissections in Île-de-France]

A FILIARISATION OF THE MANAGEMENT OF AORTIC DISSECTIONS IN ÎLE DE FRANCE Creation of a dedicated Aortic network for patients with an aortic emergency in Ile de France, via the SOS AORTE program, not only improves the times of immediate care and their 30-day mortality, but also offers a specialized and multidisciplinary follow-up, dedicated to chronic aortic pathology. The multidisciplinary "Aortic team" of cardiologists, radiologists, resuscitators, cardiac and vascular surgeons optimizes the patient's chances of benefiting from the most suited treatment to the type of dissection and its complications. After the acute phase, specialized rehabilitation to stress, psychological support and patient's education about his aortic pathology, allow his resumption of activity in the best conditions. Specialized monitoring of arterial hypertension associated with family and genetic investigations are the pledge of optimal medical treatment. Monitoring of chronic aortic disease using CT angiography should be continued, in order to avoid the risk of secondary aortic rupture.

Multimodal imaging of a rare interventricular septum dissecting aneurysm: A case report

We report the case of a patient who presented with chest pain and palpitation, and in whom multimodality imaging, including transthoracic echocardiography, computer tomography angiogram, and coronary angiogram led to the diagnosis of interventricular septum dissecting aneurysm resulting from the rupture of a sinus of Valsalva aneurysm and paravalvular aortic root pseudoaneurysm. The patient underwent the modified Cabrol procedure in the cardiac surgery department. His ruptured sinus of Valsalva aneurysm was repaired and its communication with the pseudoaneurysm was closed. This case report highlights the role of multimodality cardiac imaging.

Development and multi-level validation of a computational model to predict traumatic aortic injury

Traumatic aortic injury (TAI) is one of the leading causes of fatalities in blunt impact. However, there is no consensus on the injury mechanism of TAI in traffic accidents, mainly due to the complexity of occurrence scenarios and limited real-world crash data relevant to TAI. In this study, a computational model of the aorta with nonlinear mechanical characteristics and accurate morphology was developed and integrated within a thorax finite element model that included all major anatomical structures. To maximize the model's capability for predicting TAI, a multi-level process was presented to validate the model comprehensively. At the component level, the in vitro aortic pressurization testing was simulated to mimic the aortic burst pressure. Then, a sled test of a truncated cadaver was modeled to evaluate aorta response under posterior acceleration. The frontal chest pendulum impact was utilized to validate the performance of the aorta within full body model under direct chest compression. A parametric study was implemented to determine an injury tolerance for the aorta under these different loading conditions. The simulated peak pressure before aortic rupture was within the range of the experimental burst pressure. For the sled test, the simulated chest deflection and cross-sectional pressure of the aorta were correlated with the experimental measurement. No aorta injury was observed in simulated results of both sled test and chest pendulum impact, which matched the experimental findings. The present model will be a useful tool for understanding the TAI mechanisms, evaluating injury tolerance, and developing prevention strategies for aortic injuries.

An unusual case of painless type A aortic dissection

The pathogenesis of acute aortic dissection (AAD) is not fully elucidated yet, but it was recently shown that inflammation contributes to the occurrence and development of both Stanford type A and type B AAD. We describe a rare case of a painless type A aortic dissection that occurred in an 85-year-old male, with moderate calcified aortic stenosis and a moderately dilated ascending aorta in 6-month clinical and echocardiographic follow-up. A chronic calculous cholecystitis with neutrophilic leukocytosis and severely increased C reactive protein was diagnosed in the last 3 months. In this patient, a chronic systemic inflammatory state might have contributed to generate the intimal entry tear in the aortic root. In particular, a neutrophil mobilization might have played a causative role in aortic rupture.

Acute Mesenteric Ischemia: A Challenge for the Acute Care Surgeon

Acute mesenteric ischemia is considered uncommon, but it appears to be more frequent cause of acute abdomen than appendicitis or ruptured abdominal aortic aneurysm in elderly patients. Surgical treatment without revascularization is associated with high overall mortality, up to 80%. The modern treatment of acute mesenteric ischemia requires collaboration of gastrointestinal surgeons, vascular surgeons, and interventional radiologists. Early revascularization may reduce the overall mortality associated with acute mesenteric ischemia by up to 50%. Clinical suspicion and contrast-enhanced computed tomography performed at early stage are keys to improve outcomes of acute mesenteric ischemia treatment. This review summarizes what the acute care surgeon needs to know about acute mesenteric ischemia with special emphasis on slowly progressing "acute on chronic" mesenteric ischemia.

Statistical techniques for predicting rupture risk in abdominal aortic aneurysms: A contribution based on bootstrap

The morphometry of abdominal aortic aneurysms (AAA) has been recognized as one of the main factors that may predispose them to rupture. The need to quantify the morphometry of AAA on a patient-specific basis constitutes a valuable tool for assisting in rupture risk prediction. Previous results of this research group have determined the correlations between hemodynamic stresses and aneurysm morphometry by means of the Pearson coefficient. The present work aims to find how the AAA morphology correlates with the hemodynamic stresses acting on the arterial wall. To do so, the potential of the bootstrap technique has been explored. Bootstrap works appropriately in applications where few data are available (13 patient-specific AAA models were simulated). The methodology developed can be considered a contribution to predicting the hemodynamic stresses from the size and shape indices. The present work explores the use of a specific statistical technique (the bootstrap technique) to predict, based on morphological correlations, the patient-specific aneurysm rupture risk, provide greater understanding of this complex phenomenon that can bring about improvements in the clinical management of aneurysmatic patients. The results obtained using the bootstrap technique have greater reliability and robustness than those obtained by regression analysis using the Pearson coefficient, thus allowing to obtain more reliable results from the characteristics of the samples used, such as their small size and high variability. Additionally, it could be an indicator that other indices, such as AAA length, deformation rate, saccular index, and asymmetry, are important.

[Rupture of Tuberculous Infective Abdominal Aortic Aneurysm after Intravesical Bacillus Calmette-Guérin Instillation Therapy]

The patient was a 74-year-old male who had undergone intravesical Bacillus Calmette-Guérin(BCG) instillation therapy for bladder cancer. He visited our hospital with chief complaints of fever and abdominal pain. Abdominal aortic aneurysmal rupture and iliopsoas muscle abscess were confirmed by computed tomography( CT). We performed semi-emergency surgery, including replacement of the abdominal aorta with a synthetic graft, iliopsoas abscess debridement, and omentopexy. A rifampicin-bonded synthetic graft was used because of the possibility of tuberculous involvement after BCG instillation therapy. Examination of the tissues collected during surgery were positive for tuberculosis deoxyribonucleic acid (DNA) in a polymerase chain reaction (PCR), and showed multiple giant cell granulomas with caseous necrosis, which both strongly suggested involvement of tuberculosis. Therefore, 4 types of antituberculous drugs were administered for 40 days. This case shows that an infective aneurysm should be suspected when fever and abdominal pain develop after intravesical BCG instillation therapy.

[Thoracic Aortic Rupture of Stanford Type B Acute Aortic Dissection in a Patient with Polycystic Kidney Disease;Report of a Case]

We report a case of a 48-year-old man with polycystic kidney disease (PKD), who was emergently transported to our institution by ambulance because of thoracic aortic rupture of Stanford type B acute aortic dissection. PKD is a congenital disease associated with hypertension( 60%) and cerebrovascular disease (20%). Few reports have described sudden death due to the rupture of an abdominal aortic aneurysm and acute aortic dissection. In this case, emergency hemi-arch replacement was performed successfully. His postoperative course was uneventful, and he was discharged on the 15th postoperative day.

[Endovascular Treatment for Contained Rupture of a Mycotic Abdominal Aneurysm]

We present a 76-year-old male patient on chronic dialysis for over 10 years with contained rupture of a mycotic abdominal aortic aneurysm, which was successfully treated by thoracic endovascular aortic repair(TEVAR) and computed tomography(CT) guided percutaneous drainage. Endovascular repair of mycotic aortic aneurysm is nowadays feasible and can be a suitable alternative especially in frail patients.

[The Impact of Patient Transfer After Rupture of an Abdominal Aortic Aneurysm]

OBJECTIVE

determine whether patient transfer adversely affects the survival of ruptured abdominal aortic aneurysm (rAAA) patients after conventional surgery.

METHODS

We performed a retrospective review of all patients undergoing attempted repair of an rAAA at a tertiary center, over January 2008 and December 2014. Patients were divided into those presenting directly to our center and those transferred from another hospital. The main outcome variable was 24-hour or 30-day mortality, with secondary variables including time to surgical treatment, length of intensive care unit stay and total length hospitalization.

RESULTS

78 patients (88% men) underwent attempted open repair of an rAAA during this period, 69% (54 cases) were transferred from another institution. Both groups were similar in terms of demographic characteristics, comorbidities and hemodynamic stability. The overall mortality rate was 51% at 30 days. Transferred patients took twice as long as direct patients to get to the operating room (median 7,9 vs. 3,9 horas, p < 0,05), Although the difference for surgery treatment, there was no difference in 24-hour and 30-day mortality between the transferred group and direct group (26% e 50% vs. 29% e 58%, p < 0,05). Mean intensive care unit stay (median, 12 vs. 4 dias, p = 0,04) and total hospitalization (median 11 vs. 4 dias, p = 0,04) were sustantially superior in the transferred group.

CONCLUSIONS

Transfer of patients with RAAA in this series results in a doubling of the time interval between initial patient presentation and arrival in the operating room. This, however, did not result in any disadvantage in the survival rate between the groups. The total length and resources consumption were higher in the transfer group. These results may be attributed to a pre-selection of patients (clinically stable) who are able to tolerate such a delay in surgical treatment, secondary to transfer.

[A Patient with Lung Cancer Experiencing Abdominal Aortic Aneurysm Rupture during Bevacizumab Treatment-Case Report]

CASE

Right pleural effusion was detected on chest X-ray performed prior to surgery for a right inguinal hernia in a 63-yearold man. Adenocarcinoma was diagnosed based on pleural effusion cytology results. A CT scan revealed mediastinal lymphadenopathy and pleural dissemination, but no obvious lung tumor; other examinations also did not reveal a primary tumor. We, therefore, diagnosed primary lung cancer(c-TxN2M1a, Stage ⅣA, according to the General Rules for Clinical and Pathological Record of Lung Cancer, 8th edition). An abdominal aortic aneurysm was also observed on CT. Since he was diagnosed with EGFR-negative lung cancer with malignant pleural effusion, we selected chemotherapy with cisplatin, pemetrexed, and bevacizumab(CDDP/PEM/Bev)and administered 2 courses without problems. He experienced no adverse events during the 3rd course and was discharged on day 8. However, he was transported to our emergency room at 20: 45 on treatment day 10 when he developed abdominal pain and nearly fainted. An abdominal aortic rupture was diagnosed by CT, and he was transported to another hospital because he could not be treated at our hospital. Information that this patient had been treated with Bev was not provided to the doctor on duty, and abdominal aortic graft replacement was immediately performed. The patient had a good postoperative course without anastomotic leakage and was discharged on day 7 after surgery. Bev is a monoclonal antibody for vascular endothelial growth factor.

CONCLUSION

We report that this drug, bevacizumab, may be associated with abdominal aortic rupture.

[Infective Endocarditis with Pseudoaneurysms of the Sinus of Valsalva Ruptured into the Right Ventricle and the Left Atrium;Report of a Case]

A 65-year-old woman was admitted to our hospital with fever and left hemiplegia. She was diagnosed with infective endocarditis with multiple brain abscess. At first, heart failure was not present, and she was given medical treatment with antibiotics. But on day 12 after admission, she progressively developed heart failure. Transthoracic echocardiogram demonstrated pseudoaneurysm of the sinus of Valsalva, ruptured into the left atrium. At operation, another fistula to the right ventricular outflow tract was revealed. They were repaired with autologous pericardial patches, and the aortic valve was replaced with a bioprosthetic valve. The postoperative course was uneventful.

Clinical course of abdominal aortic aneurysms in Behçet disease: a retrospective analysis

Arterial aneurysms are rare manifestations of Behçet Disease (BD) with high morbidity and mortality. This study aimed to investigate the clinical course of BD patients with abdominal aortic aneurysms (AAA). We retrospectively searched charts of BD patients, followed up between 1988 and 2011, to identify those with AAA with at least 6-month clinical and radiological follow-up data. Chart review revealed 12 patients (11 males) with AAA amongst 1224 patients; follow-up data from 11 patients were available. The most common symptoms were lower back and abdominal pain. The only pre-treatment complication was a spontaneous rupture. All but one patient received corticosteroid and cyclophosphamide pulses for the induction, and corticosteroid and azathioprine for the maintenance treatment; one patient received only the maintenance treatment. Two patients had surgical graft interposition, without postoperative complications. Seven patients had endovascular stenting; five of them (71.4%) showed radiological regression after 32.5 (13.4-53.8) months, while four (57%) had clinical improvement after 11.8 (0.2-29.4) months. However, one non-responsive patient developed stent infection and exsanguinated during percutaneous drainage, and one patient developed femoral artery pseudo-aneurysm at the catheter insertion site. Another patient developed a new aneurysm under the maintenance treatment. Medical treatment alone yielded radiological regression in one of two patients. Current immunosuppressive, surgical or endovascular approaches can provide clinical and radiological improvements lately in BD patients with AAA. Furthermore, complication rates seem to be high with interventional approaches. These findings suggest an unmet need for safer alternative treatments.

Diabetes Reduces Severity of Aortic Aneurysms Depending on the Presence of Cell Division Autoantigen 1 (CDA1)

Diabetes is a negative risk factor for aortic aneurysm, but the underlying explanation for this phenomenon is unknown. We have previously demonstrated that cell division autoantigen 1 (CDA1), which enhances transforming growth factor-β signaling, is upregulated in diabetes. We hypothesized that CDA1 plays a key role in conferring the protective effect of diabetes against aortic aneurysms. Male wild-type, CDA1 knockout (KO), apolipoprotein E (ApoE) KO, and CDA1/ApoE double-KO (dKO) mice were rendered diabetic. Whereas aneurysms were not observed in diabetic ApoE KO and wild-type mice, 40% of diabetic dKO mice developed aortic aneurysms. These aneurysms were associated with attenuated aortic transforming growth factor-β signaling, reduced expression of various collagens, and increased aortic macrophage infiltration and matrix metalloproteinase 12 expression. In the well-characterized model of angiotensin II-induced aneurysm formation, concomitant diabetes reduced fatal aortic rupture and attenuated suprarenal aortic expansion, changes not seen in dKO mice. Furthermore, aortic CDA1 expression was downregulated ∼70% within biopsies from human abdominal aortic aneurysms. The identification that diabetes is associated with upregulation of vascular CDA1 and that CDA1 deletion in diabetic mice promotes aneurysm formation provides evidence that CDA1 plays a role in diabetes to reduce susceptibility to aneurysm formation.

Regarding 'Diabetes mellitus increases the risk of ruptured abdominal aortic aneurysms'

Abdominal aortic aneurysm (AAA) is a life-threatening disease, associated with high rates of mortality in case of aortic rupture. While the disease is often associated with atherosclerosis and cardiovascular risk factors, the majority of epidemiological studies published so far have highlighted a negative association between diabetes and AAA. However, a recent publication from epidemiological data of the National Health Fund in Poland reported a higher incidence of AAA and rupture in diabetic patients compared to non-diabetics. Here, we discuss issues and methodological considerations hoping to shed light on these unexpected results.

Comment to 'Regarding "Diabetes mellitus increases the risk of ruptured abdominal aortic aneurysms"'

This publication is a commentary on the Letter to the Editor by Juliette Raffort and Fabien Lareyre. This article clarifies a number of concerns about the method of calculating the index of prevalence of ruptured abdominal aortic aneurysms (AAA). The method of qualifying patients for the study and the method of calculating the index of prevalence of ruptured AAA in cohorts of diabetic and non-diabetic patients was presented. Most researchers calculate the Index of Prevalence per 100,000 of the general population. This gives the misleading result that diabetes reduces the risk of AAA rupture.We used a method which calculated prevalence per 100,000 with diabetes mellitus and per 100,000 without diabetes mellitus. This method confirms that diabetes mellitus increases the risk of ruptured AAA.