Natural history, pathogenesis, and etiology of thoracic aortic aneurysms and dissections

Unveiling cellular and molecular aspects of ascending thoracic aortic aneurysms and dissections

Ascending thoracic aortic aneurysm (ATAA) remains a significant medical concern, with its asymptomatic nature posing diagnostic and monitoring challenges, thereby increasing the risk of aortic wall dissection and rupture. Current management of aortic repair relies on an aortic diameter threshold. However, this approach underestimates the complexity of aortic wall disease due to important knowledge gaps in understanding its underlying pathologic mechanisms.Since traditional risk factors cannot explain the initiation and progression of ATAA leading to dissection, local vascular factors such as extracellular matrix (ECM) and vascular smooth muscle cells (VSMCs) might harbor targets for early diagnosis and intervention. Derived from diverse embryonic lineages, VSMCs exhibit varied responses to genetic abnormalities that regulate their contractility. The transition of VSMCs into different phenotypes is an adaptive response to stress stimuli such as hemodynamic changes resulting from cardiovascular disease, aging, lifestyle, and genetic predisposition. Upon longer exposure to stress stimuli, VSMC phenotypic switching can instigate pathologic remodeling that contributes to the pathogenesis of ATAA.This review aims to illuminate the current understanding of cellular and molecular characteristics associated with ATAA and dissection, emphasizing the need for a more nuanced comprehension of the impaired ECM-VSMC network.

New Directions in Diagnostics for Aortic Aneurysms: Biomarkers and Machine Learning

This review article presents an appraisal of pioneering technologies poised to revolutionize the diagnosis and management of aortic aneurysm disease, with a primary focus on the thoracic aorta while encompassing insights into abdominal manifestations. Our comprehensive analysis is rooted in an exhaustive survey of contemporary and historical research, delving into the realms of machine learning (ML) and computer-assisted diagnostics. This overview draws heavily upon relevant studies, including Siemens' published field report and many peer-reviewed publications. At the core of our survey lies an in-depth examination of ML-driven diagnostic advancements, dissecting an array of algorithmic suites to unveil the foundational concepts anchoring computer-assisted diagnostics and medical image processing. Our review extends to a discussion of circulating biomarkers, synthesizing insights gleaned from our prior research endeavors alongside contemporary studies gathered from the PubMed Central database. We elucidate the prevalent challenges and envisage the potential fusion of AI-guided aortic measurements and sophisticated ML frameworks with the computational analyses of pertinent biomarkers. By framing current scientific insights, we contemplate the transformative prospect of translating fundamental research into practical diagnostic tools. This narrative not only illuminates present strides, but also forecasts promising trajectories in the clinical evaluation and therapeutic management of aortic aneurysm disease.

Review article: Accuracy of emergency physician performed point-of-care ultrasound of the thoracic aorta: A systematic review and narrative synthesis of the literature

Point-of-care ultrasound (POCUS) is becoming ubiquitous in emergency medicine. POCUS for abdominal aortic aneurysm is well established in practice. The thoracic aorta can also be assessed by POCUS for dissection and aneurysm and transthoracic echocardiography is endorsed by international guidelines as an initial test for thoracic aortic pathologies. A systematic search of Ovid Medline, PubMed, EMBASE, SCOPUS and Web of Science from January 2000 to August 2022 identified four studies evaluating diagnostic accuracy of emergency physician POCUS for thoracic aortic dissection (TAD) and five studies for thoracic aortic aneurysm (TAA). Study designs were heterogeneous including differing diagnostic criteria for aortic pathology. Convenience recruitment was frequent in prospective studies. Sensitivity and specificity ranges for studies of TAD were 41-91% and 94-100%, respectively when an intimal flap was seen. Sensitivity and specificity ranges for studies of thoracic aorta dilation >40 mm were 50-100% and 93-100%, respectively; for >45 mm ranges were 64-65% and 95-99%. Literature review identified that POCUS is specific for TAD and TAA. POCUS reduces the time to diagnosis of thoracic aortic pathology; however, it remains insensitive and cannot be recommended as a stand-alone rule-out test. We suggest that detection of thoracic aorta dilation >40 mm by POCUS at any site increases the suspicion of serious aortic pathology. Studies incorporating algorithmic use of POCUS, Aortic Dissection Detection Risk Score and D-dimer as decision tools are promising and may improve current ED practices. Further research is warranted in this rapidly evolving field.

Effect of hypertension on the delamination and tensile strength of ascending thoracic aortic aneurysm with a focus on right lateral region

Hypertension is a major predisposing factor to initiate thoracic aortopathy. The objective of this study is to investigate effect of hypertension on delamination and tensile strength of ascending thoracic aortic aneurysms (ATAAs). A total of 35 fresh ATAA samples were harvested from 19 hypertensive and 16 non-hypertensive patients during elective aortic surgery. Peeling tests with two extension rates were performed to determine delamination strength, while uniaxial tensile (UT) tests were employed to measure failure stresses. The delamination strength and failure stresses of the ATAAs were further correlated with patient ages for hypertensive and non-hypertensive groups. The delamination strength to peel apart the ATAA tissue along the longitudinal direction was statistically significantly lower for the hypertensive patients than that of the non-hypertensive patients (35 ± 11 vs. 49 ± 9 mN/mm, p = 0.02). A higher delamination strength was measured if peeling was performed with a higher extension rate. The circumferential failure stresses were significantly lower for the hypertensive ATAAs than those of the non-hypertensive ATAAs (1.03 ± 0.27 vs. 1.43 ± 0.38 MPa, p = 0.02). Histology showed that laminar structures of elastic fibers were mainly disrupted in the hypertensive ATAAs. The longitudinal delamination strength of the ATAAs was significantly decreased and strongly correlated with ages for the hypertensive patients. Strong inverse correlations were also identified between the circumferential and longitudinal failure stresses of the ATAAs and ages for the hypertensive patients. Results suggest that the ATAAs of the elderly hypertensive patients may have a higher propensity for dissection or rupture. The dissection properties of the ATAA tissue are rate dependent.

Targeted Proteomic Analysis of Patients with Ascending Thoracic Aortic Aneurysm

BACKGROUND

There is a need for clinical markers to aid in the detection of individuals at risk of harboring an ascending thoracic aneurysm (ATAA) or developing one in the future.

OBJECTIVES

To our knowledge, ATAA remains without a specific biomarker. This study aims to identify potential biomarkers for ATAA using targeted proteomic analysis.

METHODS

In this study, 52 patients were divided into three groups depending on their ascending aorta diameter: 4.0-4.5 cm (N = 23), 4.6-5.0 cm (N = 20), and >5.0 cm (N = 9). A total of 30 controls were in-house populations ethnically matched to cases without known or visible ATAA-related symptoms and with no ATAA familial history. Before the debut of our study, all patients provided medical history and underwent physical examination. Diagnosis was confirmed by echocardiography and angio-computed tomography (CT) scans. Targeted-proteomic analysis was conducted to identify possible biomarkers for the diagnosis of ATAA.

RESULTS

A Kruskal-Wallis test revealed that C-C motif chemokine ligand 5 (CCL5), defensin beta 1 (HBD1), intracellular adhesion molecule-1 (ICAM1), interleukin-8 (IL8), tumor necrosis factor alpha (TNFα) and transforming growth factor-beta 1 (TGFB1) expressions are significantly increased in ATAA patients in comparison to control subjects with physiological aorta diameter (p < 0.0001). The receiver-operating characteristic analysis showed that the area under the curve values for CCL5 (0.84), HBD1 (0.83) and ICAM1 (0.83) were superior to that of the other analyzed proteins.

CONCLUSIONS

CCL5, HBD1 and ICAM1 are very promising biomarkers with satisfying sensitivity and specificity that could be helpful in stratifying risk for the development of ATAA. These biomarkers may assist in the diagnosis and follow-up of patients at risk of developing ATAA. This retrospective study is very encouraging; however, further in-depth studies may be worthwhile to investigate the role of these biomarkers in the pathogenesis of ATAA.

Yes-Associated Protein and Transcriptional Coactivator with PDZ-Binding Motif in Cardiovascular Diseases

Yes-associated protein (YAP, also known as YAP1) and its paralogue TAZ (with a PDZ-binding motif) are transcriptional coactivators that switch between the cytoplasm and nucleus and regulate the organ size and tissue homeostasis. This review focuses on the research progress on YAP/TAZ signaling proteins in myocardial infarction, cardiac remodeling, hypertension and coronary heart disease, cardiomyopathy, and aortic disease. Based on preclinical studies on YAP/TAZ signaling proteins in cellular/animal models and clinical patients, the potential roles of YAP/TAZ proteins in some cardiovascular diseases (CVDs) are summarized.

Age-dependent phenotypic modulation of smooth muscle cells in the normal ascending aorta

Objectives

Ascending aortic aneurysms are associated with pre-existing conditions, including connective tissue disorders (i.e., Marfan syndrome) and bicuspid aortic valves. The underlying mechanisms remain uncertain. Even less is known regarding ascending aortic aneurysms in individuals with normal (i.e., tricuspid) aortic valves (TAV), and without known aneurysm-associated disorders. Regardless of etiology, the risk of aortic complications increases with biological age. Phenotypic modulation of smooth muscle cells (SMCs) is a feature of ascending aortic aneurysms, whereby contractile SMCs are replaced with synthetic SMCs that are capable of degrading the aortic wall. We asked whether age itself causes dysfunctional SMC phenotype modulation, independent of aortic dilatation or pre-existing aneurysm-associated diseases.

Methods

Non-dilated ascending aortic samples were obtained intra-operatively from 40 patients undergoing aortic valve surgery (range: 20-82 years old, mean: 59.1 ± 15.2). Patients with known genetic diseases or aortic valve malformations were excluded. Tissue was divided, and a portion was formalin-fixed and immunolabeled for alpha-smooth muscle actin (ASMA), a contractile SMC protein, and markers of synthetic (vimentin) or senescent (p16/p21) SMCs. Another fragment was used for SMC isolation (n = 10). Cultured SMCs were fixed at cell passage 2 and stained for phenotype markers, or were cultured indefinitely to determine replicative capacity.

Results

In whole tissue, ASMA decreased (R² = 0.47, P < 0.0001), while vimentin increased (R² = 0.33, P = 0.02) with age. In cultured SMCs, ASMA decreased (R² = 0.35, P = 0.03) and vimentin increased (R² = 0.25, P = 0.04) with age. p16 (R² = 0.34, P = 0.02) and p21 (R² = 0.29, P = 0.007) also increased with age in SMCs. Furthermore, the replicative capacity of SMCs from older patients was decreased compared to that of younger patients (P = 0.03).

Conclusion

By investigating non-dilated aortic samples from individuals with normal TAVs, we found that age itself has a negative impact on SMCs in the ascending aortic wall, whereby SMCs switched from the contractile phenotype to maladaptive synthetic or senescent states with increased age. Therefore, based on our findings, modification of SMC phenotype should be studied as a therapeutic consideration against aneurysms in the future, regardless of etiology.

Conventional aortic root vs valve-sparing root replacement surgery in aortic dilatation syndromes: a comparison of mortality and postoperative complications

INTRODUCTION

Conventional aortic root and valve-sparing root replacement surgery are two current surgical treatments for aortic dilatation syndromes. This review article aims to review the current literature surrounding these two established techniques.

AREAS COVERED

This review article will address the current indications for valve-sparing root replacement surgery, technical considerations in surgical planning and a comparison of clinical outcomes between these two surgical techniques.

EXPERT OPINION

Valve-sparing root replacement surgery is a safe and established treatment for aortic syndromes. Valve-sparing surgery procedure avoids the inherent risk of prosthetic valve dysfunction and prosthesis infection by preserving the native aortic valve compared to conventional aortic root surgery. This has been demonstrated in various observational studies and should be considered in clinically and anatomically appropriate patients. Other technical considerations, such as reimplantation versus remodeling technique and aortic cusp repair in select patients, may impact in short-term procedural and long-term clinical success with valve-sparing surgery.

Predictive value of age, creatinine, and ejection fraction (ACEF) scoring system for operative mortality in patients with Stanford type A aortic dissection

Purpose

Stanford type A aortic dissection (TAAD) is the most common and fatal type of dissection. An easier-to-use risk stratification may help eliminate bias in patients at high risk of dissection. The age, serum creatinine, and ejection fraction (ACEF) score is a simple risk model developed to predict the mortality risk of elective coronary artery bypass graft surgery. This study aimed to evaluate the relationship between preoperative ACEF score and operative mortality in patients with TAAD undergoing emergency surgery.

Methods

In this retrospective cohort study, 113 patients diagnosed with TAAD between January 2017 and September 2021 were evaluated. The primary endpoint was operative mortality. Receiver operating characteristic analysis was performed for the ACEF score, ACEF II score, and European System for Cardiac Operative Risk Evaluation II. Univariate and multivariate analyses of operative mortality were performed using the logistic regression model.

Results

Operative mortality occurred in 23 (20.4%) patients. The cutoff ACEF score was calculated as 1.1 for predicting operative mortality (area under the curve = 0.712, P value = 0.002, sensitivity = 74.0%, specificity = 67.8%, likelihood ratio = 2.3). Based on the cutoff value, 46 (40.7%) patients had a high ACEF score (ACEF ≥ 1.1) and 67 (59.3%) patients had a low ACEF score (ACEF < 1.1). The high ACEF score was associated with an increased incidence of operative mortality compared with the low ACEF score (37.0% vs. 9.0%; P = 0.001).

Conclusions

The ACEF score can be used as a useful and relatively simple tool for risk stratification before TAAD surgery. However, the ACEF score is only indicated for risk assessment and should not affect treatment.

Onset of pain to surgery time in acute aortic dissections type A: a mandatory factor for evaluating surgical results?

Objective

An acute aortic dissection type A (AADA) is a rare but life-threatening event. The mortality rate ranges between 18% to 28% and mortality is often within the first 24 h and up to 1%-2% per hour. Although the onset of pain to surgery time has not been a relevant factor in terms of research in the field of AADA, we hypothesize that a patient's preoperative conditions depend on the length of this time.

Methods

Between January 2000 and January 2018, 430 patients received surgical treatment for acute aortic dissection DeBakey type I at our tertiary referral hospital. In 11 patients, the exact time point of initial onset of pain was retrospectively not detectable. Accordingly, a total of 419 patients were included in the study. The cohort was categorized into two groups: Group A with an onset of pain to surgery time < 6 h (n = 211) and Group B > 6 h (n = 208), respectively.

Results

Median age was 63.5 years (y) ((IQR: 53.3-71.4 y); (67.5% male)). Preoperative conditions differed significantly between the cohorts. Differences were detected in terms of malperfusion (A: 39.3%; B: 23.6%; P: 0.001), neurological symptoms (A: 24.2%; B: 15.4%; P: 0.024), and the dissection of supra-aortic arteries (A: 25.1%; B: 16.8%; P: 0.037). In particular, cerebral malperfusion (A 15.2%: B: 8.2%; P: 0.026) and limb malperfusion (A: 18%, B: 10.1%; P: 0.020) were significantly increased in Group A. Furthermore, Group A showed a decreased median survival time (A: 1,359.0 d; B: 2,247.5 d; P: 0.001), extended ventilation time (A: 53.0 h; B: 44.0 h; P: 0.249) and higher 30-day mortality rate (A: 25.1%; B: 17.3%; P: 0.051).

Conclusions

Patients with a short onset of pain to surgery time in cases of AADA present themselves not only with more severe preoperative symptoms but are also the more compromised cohort. Despite early presentation and emergency aortic repair, these patients show increased chances of early mortality. The "onset of pain to surgery time" should become a mandatory factor when making comparable surgical evaluations in the field of AADA.

Association of Thoracic Aortic Aneurysm Size With Long-term Patient Outcomes: The KP-TAA Study

Importance

The risk of adverse events from ascending thoracic aorta aneurysm (TAA) is poorly understood but drives clinical decision-making.

Objective

To evaluate the association of TAA size with outcomes in nonsyndromic patients in a large non-referral-based health care delivery system.

Design, Setting, and Participants

The Kaiser Permanente Thoracic Aortic Aneurysm (KP-TAA) cohort study was a retrospective cohort study at Kaiser Permanente Northern California, a fully integrated health care delivery system insuring and providing care for more than 4.5 million persons. Nonsyndromic patients from a regional TAA safety net tracking system were included. Imaging data including maximum TAA size were merged with electronic health record (EHR) and comprehensive death data to obtain demographic characteristics, comorbidities, medications, laboratory values, vital signs, and subsequent outcomes. Unadjusted rates were calculated and the association of TAA size with outcomes was evaluated in multivariable competing risk models that categorized TAA size as a baseline and time-updated variable and accounted for potential confounders. Data were analyzed from January 2018 to August 2021.

Exposures

TAA size.

Main Outcomes and Measures

Aortic dissection (AD), all-cause death, and elective aortic surgery.

Results

Of 6372 patients with TAA identified between 2000 and 2016 (mean [SD] age, 68.6 [13.0] years; 2050 female individuals [32.2%] and 4322 male individuals [67.8%]), mean (SD) initial TAA size was 4.4 (0.5) cm (828 individuals [13.0% of cohort] had initial TAA size 5.0 cm or larger and 280 [4.4%] 5.5 cm or larger). Rates of AD were low across a mean (SD) 3.7 (2.5) years of follow-up (44 individuals [0.7% of cohort]; incidence 0.22 events per 100 person-years). Larger initial aortic size was associated with higher risk of AD and all-cause death in multivariable models, with an inflection point in risk at 6.0 cm. Estimated adjusted risks of AD within 5 years were 0.3% (95% CI, 0.3-0.7), 0.6% (95% CI, 0.4-1.3), 1.5% (95% CI, 1.2-3.9), 3.6% (95% CI, 1.8-12.8), and 10.5% (95% CI, 2.7-44.3) in patients with TAA size of 4.0 to 4.4 cm, 4.5 to 4.9 cm, 5.0 to 5.4 cm, 5.5 to 5.9 cm, and 6.0 cm or larger, respectively, in time-updated models. Rates of the composite outcome of AD and all-cause death were higher than for AD alone, but a similar inflection point for increased risk was observed at 6.0 cm.

Conclusions and Relevance

In a large sociodemographically diverse cohort of patients with TAA, absolute risk of aortic dissection was low but increased with larger aortic sizes after adjustment for potential confounders and competing risks. Our data support current consensus guidelines recommending prophylactic surgery in nonsyndromic individuals with TAA at a 5.5-cm threshold.

Endovascular Repair of Descending Thoracic Aortic Aneurysms

Descending thoracic aortic aneurysms (DTAAs) are an important cause of morbidity and mortality in the elderly. Once diagnosed, they should be surveilled and then repaired at a diameter of 5.5 to 6 cm, depending on the individual patient's physiologic and anatomic risk of repair. Thoracic endovascular aortic repair (TEVAR) is the preferred approach for repair and there are multiple procedural adjuncts that can expand indications for and use of TEVAR. Spinal cord injuries are an important and highly morbid complication after TEVAR and it is imperative to mitigate this risk.

Interaction of the Blood Components with Ascending Thoracic Aortic Aneurysm Wall: Biomechanical and Fluid Analyses

BACKGROUND

Ascending thoracic aortic aneurysm (ATAA) is an asymptomatic localized dilation of the aorta that is prone to rupture with a high rate of mortality. While diameter is the main risk factor for rupture assessment, it has been shown that the peak wall stress from finite element (FE) simulations may contribute to refinement of clinical decisions. In FE simulations, the intraluminal boundary condition is a single-phase blood flow that interacts with the thoracic aorta (TA). However, the blood is consisted of red blood cells (RBCs), white blood cells (WBCs), and plasma that interacts with the TA wall, so it may affect the resultant stresses and strains in the TA, as well as hemodynamics of the blood.

METHODS

In this study, discrete elements were distributed in the TA lumen to represent the blood components and mechanically coupled using fluid-structure interaction (FSI). Healthy and aneurysmal human TA tissues were subjected to axial and circumferential tensile loadings, and the hyperelastic mechanical properties were assigned to the TA and ATAA FE models.

RESULTS

The ATAA showed larger tensile and shear stresses but smaller fluid velocity compared to the ATA. The blood components experienced smaller shear stress in interaction with the ATAA wall compared to TA. The computational fluid dynamics showed smaller blood velocity and wall shear stress compared to the FSI.

CONCLUSIONS

This study is a first proof of concept, and future investigations will aim at validating the novel methodology to derive a more reliable ATAA rupture risk assessment considering the interaction of the blood components with the TA wall.

Medial degeneration and atherosclerosis show discrete variance around the circumference of ascending aorta aneurysms

Medial degeneration is the most common histological finding in ascending aortic aneurysms with lesser but significant involvement by atherosclerosis. The overall extent and severity can be potentially underrated because of their uneven distribution and macroscopic inconspicuousness of medial degeneration. This study aims to compare the distribution of degenerative and atherosclerotic lesions around ascending aorta circumference, also considering aortic valve cuspidity. We evaluated 88 cases of resected ascending aortae, 25 with a tricuspid aortic valve and 63 with a malformed aortic valve, oriented by a cardiac surgeon and sent for pathological examination. We applied the consensus documents from 2015 and 2016 for microscopic evaluation of aortic specimens. The medial degeneration and atherosclerosis were graded semi-quantitatively for each aortic quadrant: convexity, anterior wall, concavity, and posterior wall. Nearly all quadrants showed at least mild medial degeneration; more severe findings of medial degeneration and atherosclerosis were in the aneurysms associated with the tricuspid valve. In the aneurysms with the tricuspid aortic valve, there was more frequent and more severe atherosclerosis at the concavity than at the anterior wall (p = .046); the frequency and severity of medial degeneration did not differ significantly. The aneurysms with a malformed aortic valve showed more severe medial degeneration at the concavity compared to the convexity (p = .011); atherosclerosis was less common and did not show any significant differences. More than half of the samples also revealed at least a one-grade (mostly one-grade) difference among the quadrants in individual cases for both atherosclerosis and medial degeneration. Extreme differences were rare except for atherosclerosis in the tricuspid group. The results revealed only slight overall differences around the aortic circumference, with concavity being the most susceptible. Still, thanks to occurring inter- and intraindividual variability, the examination of all quadrants seems meaningful not to miss the most severe changes and to underscore the findings.

On strain-based rupture criterion for ascending aortic aneurysm: the role of fiber waviness

We propose a new approach for constructing strain-based rupture criterion for ascending thoracic aortic aneurysm. The rupture metric is formulated using an effective strain, which is a measure of net strain that the collagen bundles experience after fiber uncrimping. The effective strain is a function of the total strain and the waviness properties of the collagen fibers. In the present work, the waviness properties are obtained from fitting biaxial response data to constitutive models that explicitly consider the collagen waviness and fiber recruitment. Inflation test data from 10 ascending thoracic aortic aneurysm specimens are analyzed. For each specimen, tension-strain data at ∼2300 material points are garnered. The effective strain fields in the configuration immediately before rupture are computed. It is found that the hotspots of the effective strain match the rupture sites very well in all 10 samples. More importantly, the values of effective strain at the hotsopts are closely clustered around 0.1, in contrast to a much wider distribution of the total strain. The study underscores the importance of considering the fiber recruitment in formulating strain-based rupture metric, and suggests that ϵ¯≈0.1, where ϵ¯ is the effective strain metric defined in this work, can be considered as a criterion for assessing the imminent rupture risk of ascending aortic aneurysms.

A rare case of thoracic-abdominal aortic aneurysm in conjunction with bilateral superficial femoral artery occlusion, documented with computed tomography angiography

Aneurysms represent bulging of the weakened blood vessel area, as a result of cystic medial degeneration. Aneurysms chance of rupturing increases over time, resulting in bleeding and death. Therefore, patients with aortic aneurysms require frequent monitoring with magnetic resonance and computed tomography angiography, as well as undergoing open repair surgery and endovascular aneurysm repair.

We present a case of ruptured thoracic aortic aneurysm in conjunction with bilateral superficial femoral occlusion, as incidental findings in Covid-19 positive patient.

The patient, a 62-years-old female, presented with cough, shortness of breath, fever and leg claudication. Doppler ultrasonography of the lower limbs was conducted to rule out thromboembolism, revealing bilateral superficial femoral arteries occlusion. The patient was administered high doses of parenteral anticoagulants.

Hemoptysis ensued, prompting an MSCT scan, that showed right pleural effusion, atelectasis, and right active perihilar infiltrates with inter-lobar pleurisy. Due to inflammatory changes on the lung parenchyma, the patient got tested for Sars-Cov-2, and resulted positive.

Contrast-enhanced MSCT also revealed thoracic-abdominal aortic aneurysm with its highest diameter measuring 10 cm, and massive per-aortal thrombus and/or hematoma of 5 cm, which was further ruptured and patient died untreated in the fourth day of hospitalization.

Questions arise whether Covid-19 was the primary cause of bilateral superficial femoral artery occlusion and whether high doses of parenteral anticoagulants were the primary cause of thoracic aortic aneurysm rupture.

Thus, a careful balance must be made between the detrimental and protective contributions of anticoagulants in the patients presenting with Covid-19 and thoracic-abdominal aortic aneurysm.

Differences in local immune cell landscape between Q fever and atherosclerotic abdominal aortic aneurysms identified by multiplex immunohistochemistry

Background:

Chronic Q fever is a zoonosis caused by the bacterium Coxiella burnetii which can manifest as infection of an abdominal aortic aneurysm (AAA). Antibiotic therapy often fails, resulting in severe morbidity and high mortality. Whereas previous studies have focused on inflammatory processes in blood, the aim of this study was to investigate local inflammation in aortic tissue.

Methods:

Multiplex immunohistochemistry was used to investigate local inflammation in Q fever AAAs compared to atherosclerotic AAAs in aorta tissue specimen. Two six-plex panels were used to study both the innate and adaptive immune systems.

Results:

Q fever AAAs and atherosclerotic AAAs contained similar numbers of CD68⁺ macrophages and CD3⁺ T cells. However, in Q fever AAAs, the number of CD68⁺CD206⁺ M2 macrophages was increased, while expression of GM-CSF was decreased compared to atherosclerotic AAAs. Furthermore, Q fever AAAs showed an increase in both the number of CD8⁺ cytotoxic T cells and CD3⁺CD8^-FoxP3⁺ regulatory T cells. Finally, Q fever AAAs did not contain any well-defined granulomas.

Conclusions:

These findings demonstrate that despite the presence of pro-inflammatory effector cells, persistent local infection with C. burnetii is associated with an immune-suppressed microenvironment.

Funding:

This work was supported by SCAN consortium: European Research Area - CardioVascualar Diseases (ERA-CVD) grant [JTC2017-044] and TTW-NWO open technology grant [STW-14716].

HDL cholesterol: A potential mediator of the association between serum levels of a mixture of metals and the risk of aortic dissection in a Chinese population

Aortic dissection (AD) is a severe cardiovascular disease with a high mortality rate. However, the associations between the serum levels of metals and the risk of AD remain unclear. One hundred twenty-seven patients with AD (type A and B) identified from 2017 to 2019 at the Second Affiliated Hospital of Nanjing Medical University were included; 183 controls that were also included. A logistic regression analysis was performed to determine the associations between serum levels of metals and the risk of AD. Weighted Quantile Sum (WQS) regression and Bayesian Kernel Machine Regression (BKMR) analyses were performed to explore the effects of mixtures of metals on the risk of AD. A linear regression analysis was performed to evaluate the relationships between the serum levels of metals and the white blood cells (WBCs) count and serum lipid levels and blood glucose. We conducted a mediation analysis to explore the contribution rates of WBC counts or serum lipid levels and blood glucose to the association between metal levels and the risk of AD. Exposure to serum levels of Cu (coefficient = 6.33; 95 % CI = 2.52, 10.14; p trend < 0.001) were significantly and positively associated with the risk of AD. In the WQS analysis, Cu (50.3 %), Ni (32.7 %) and Mo (17.1 %) contributed to the AD risk. In the BKMR analysis, Cu and Mo were shown to play important roles in the association with the AD risk. Moreover, serum concentrations of Cu were significantly and inversely associated with HDL-cholesterol levels. HDL-cholesterol levels mediated 7.42 % of the association between serum Cu levels and the prevalence of AD. Our study provided the first evidence that serum levels of mixtures of metals are associated with the AD risk in a Chinese population. Increased concentrations of metals, particularly Cu, may increase the risk of AD by reducing HDL-cholesterol levels.

Mechanical characterization of dissected and dilated human ascending aorta using Fung-type hyperelastic models with pre-identified initial tangent moduli for low-stress distensibility

Ascending aortic dissection (AD) is a potentially fatal vascular disease associated with degradation and fragmentation of the elastic fibers in the aortic media, increasing low-stress distensibility, and a dilated aorta may lead to dissection. In this study, a Fung-type hyperelastic model was formulated incorporating the initial tangent moduli (ITM) of stress-strain curves as an index of low-stress distensibility. ITM were correlated with the material constants by linearizing incompressible stress-strain relationships at zero strain. For uniaxial loading tests, the robustness of the material constants was examined in the stress ranges of 0-200, 0-180, and 0-160 kPa and to the ITM values of 100%, 95%, and 90%. Examination revealed stable changes in the material constants of 80% of the specimens. For equibiaxial stretch tests, the material constants were determined for each curve of the isotropic and anisotropic deformation groups by pre-identifying the ITM and minimizing fitting errors using isotropic or anisotropic models. The errors for all groups were <6% using a transversely isotropic model, and <10% for an orthotropic model. Comparisons with experimental curves showed that Fung-type models described both the ITM and significant stiffening at high stress levels. The mechanical characteristics of the aorta in the stage prior/posterior to dissection is such that while hardening occurs under both low- and high-stress levels with an increase in collagen content as an aging response, softening occurs under low-stress conditions due to histological abnormalities such as elastin deficiency and fragmentation. Numerical simulations using Fung-type models implied that elastic fiber degeneration and fragmentation in AD tissues reduced not only the low-stress stiffness but also the elastic stiffness with superimposed shear. The latter stiffness was modulated by the stiffening at high stress levels in tensile deformation behavior and normal-strain state under physiological loading conditions, and therefore provides further insight into wall rupture.

Prior Infrarenal Aortic Surgery is Not Associated with Increased Risk of Spinal Cord Ischemia Following Thoracic Endovascular Aortic Repair and Complex Endovascular Aortic Repair

OBJECTIVES

Patients with prior infrarenal aortic intervention represent an increasing demographic of patients undergoing thoracic endovascular aortic repair (TEVAR) and/or complex EVAR. Studies have suggested that prior abdominal aortic surgery is a risk factor for spinal cord ischemia (SCI). However, these results are largely based on single-center experiences with limited multi-institutional and national data assessing clinical outcomes in these patients. The objective of this study was to evaluate the effect of prior infrarenal aortic surgery on SCI.

METHODS

The Society for Vascular Surgery Vascular Quality Initiative database was retrospectively reviewed to identify all patients ≥18 years old undergoing TEVAR/complex EVAR from January 2012 to June 2020. Patients with previous thoracic or suprarenal aortic repairs were excluded. Baseline and procedural characteristics and postoperative outcomes were compared by group: TEVAR/complex EVAR with or without previous infrarenal aortic repair. The primary outcome was postoperative SCI. Secondary outcomes included postoperative hospital length of stay (LOS), bowel ischemia, renal ischemia, and 30-day mortality. Multivariate regression was used to determine independent predictors of postoperative SCI. Additional analysis was performed for patients undergoing isolated TEVAR.

RESULTS

A total of 9506 patients met the inclusion criteria: 8691 (91.4%) had no history of infrarenal aortic repair and 815 (8.6%) had previous infrarenal aortic repair. Patients with previous infrarenal repair were older with an increased prevalence of chronic kidney disease (p=0.001) and cardiovascular risk factors including hypertension, chronic obstructive pulmonary disease, and smoking history (p<0.001). These patients presented with larger maximal aortic diameters (6.06±1.47 cm versus 5.15±1.76 cm; p<0.001) and required more stent grafts (p<0.001) with increased intraoperative blood transfusion requirements (p<0.001), and longer procedure times (p<0.001). Univariate analysis demonstrated no difference in postoperative SCI, postoperative hospital LOS, bowel ischemia, or renal ischemia between the two groups. Thirty-day mortality was significantly higher in patients with prior infrarenal repair (p=0.001). On multivariate regression, prior infrarenal aortic repair was not a predictor of postoperative SCI, while aortic dissection (odds ratio [OR] 1.65; 95% confidence interval [CI] 1.26-2.16, p<0.001), number of stent grafts deployed (OR 1.45; 95% CI 1.30-1.62, p<0.001), and units of packed red blood cells transfused intraoperatively (OR 1.33; 95% CI 1.03-1.73, p=0.032) were independent predictors of SCI.

CONCLUSIONS

Although TEVAR/complex EVAR patients with prior infrarenal aortic repair constituted a sicker cohort with higher 30-day mortality, the rate of SCI was comparable to patients without prior repair. Previous infrarenal repair was not associated with risk of SCI.

[Resultados a corto y medio plazo de la técnica de Florida]

Introducción:

La dilatación de la raíz aórtica es una patología frecuente que afecta a pacientes jóvenes y su tratamiento es quirúrgico. Las técnicas quirúrgicas de elección en pacientes jóvenes son las de preservación de la válvula aórtica para evitar el implante de una prótesis valvular.

Objetivo:

El presente trabajo tiene como objetivo describir la técnica de Florida Sleeve y los resultados de nuestra experiencia.

Método:

Entre noviembre de 2015 y enero de 2017 fueron intervenidos en nuestro centro tres casos de pacientes con insuficiencia aórtica severa secundaria a anulectasia aórtica en los que se realizó la técnica de Florida Sleeve.

Resultados:

En los tres casos se obtuvieron excelentes resultados postoperatorios, libres de insuficiencia aórtica residual y de reoperación por cualquier causa, resultados que se mantuvieron a los tres años de seguimiento.

Conclusiones:

La técnica de Florida Sleeve es una técnica segura, reproducible con una curva de aprendizaje y tiempos quirúrgicos inferiores a las técnicas tradicionales. Los resultados clínicos a medio plazo en términos de morbimortalidad son buenos.

Dissected aorta segmentation using convolutional neural networks

BACKGROUND AND OBJECTIVE

Aortic dissection is a severe cardiovascular pathology in which an injury of the intimal layer of the aorta allows blood flowing into the aortic wall, forcing the wall layers apart. Such situation presents a high mortality rate and requires an in-depth understanding of the 3-D morphology of the dissected aorta to plan the right treatment. An accurate automatic segmentation algorithm is therefore needed.

METHOD

In this paper, we propose a deep-learning-based algorithm to segment dissected aorta on computed tomography angiography (CTA) images. The algorithm consists of two steps. Firstly, a 3-D convolutional neural network (CNN) is applied to divide the 3-D volume into two anatomical portions. Secondly, two 2-D CNNs based on pyramid scene parsing network (PSPnet) segment each specific portion separately. An edge extraction branch was added to the 2-D model to get higher segmentation accuracy on intimal flap area.

RESULTS

The experiments conducted and the comparisons made show that the proposed solution performs well with an average dice index over 92%. The combination of 3-D and 2-D models improves the aorta segmentation accuracy compared to 3-D only models and the segmentation robustness compared to 2-D only models. The edge extraction branch improves the DICE index near aorta boundaries from 73.41% to 81.39%.

CONCLUSIONS

The proposed algorithm has satisfying performance for capturing the aorta structure while avoiding false positives on the intimal flaps.

ACR Appropriateness Criteria® Suspected Acute Aortic Syndrome

Acute aortic syndrome (AAS) includes the entities of acute aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer. AAS typically presents with sudden onset of severe, tearing, anterior, or interscapular back pain. Symptoms may be dominated by malperfusion syndrome, due to obstruction of the lumen of the aorta and/or a side branch when the intimal and medial layers are separated. Timely diagnosis of AAS is crucial to permit prompt management; for example, early mortality rates are reported to be 1% to 2% per hour after the onset of symptoms for untreated ascending aortic dissection. The appropriateness assigned to each imaging procedure was based on the ability to obtain key information that is used to plan open surgical, endovascular, or medical therapy. This includes, but is not limited to, confirming the presence of AAS; classification; characterization of entry and reentry sites; false lumen patency; and branch vessel compromise. Using this approach, CT, CTA, and MRA are all considered usually appropriate in the initial evaluation of AAS if those procedures include intravenous contrast administration. Ultrasound is also considered usually appropriate if the acquisition is via a transesophageal approach. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Impact of solitons on the progression of initial lesion in aortic dissection

Aortic dissection (AD) is the most common catastrophic disease reported at cardiovascular emergency in hospitals. Herein, a tear in the tunica intima results into separation of layers of aortic wall leading to rupture and torrential bleed. Hypoxia and oxidative stress are associated with AD. The release of hypoxia inducible factor (HIF)-1[Formula: see text] from the initial flap lesion in the tunica intima is the basis for aneurysmal prone factors. We framed a boundary value problem (BVP) to evaluate homeostatic saturation for oxygen dynamics using steady-state analysis. We prove uniqueness and existence of the solution of the BVP for gas exchange at capillary–tissue interface as a normal physiological function. Failure of homeostatic mechanism establishes hypoxia, a new quasi-steady-state in AD. We model permeation of two-layer fluid comprised of blood and HIF-1[Formula: see text] through tunica media as a generalized [Formula: see text]-dimensional nonlinear evolution equation and solve it using Lie group of transformations method. We note that the two-layer fluid permeates the tunica media as solitary wave including solitons such as bright soliton, dark soliton, peregrine soliton, topological soliton, kink soliton, breather soliton and multi-soliton complex. Also, we introduce the main result and discuss the implications of soliton solution, using graphic interpretation, to describe the early stage of progression of AD.

Clinical features and risk factors of postoperative in-hospital mortality following surgical repair of Stanford type A acute aortic dissection

Background

To investigate the clinical features of patients with Stanford type A acute aortic dissection (AAD) and analyze the risk factors affecting postoperative in-hospital mortality rate.

Methods

The demographic and clinical data were retrospectively collected and analyzed from 118 AAD patients admitted to the Affiliated Hospital of Hangzhou Normal University from June 2016 to April 2019. All patients underwent surgical treatment and were grouped into death and survival groups. The risk factors affecting postoperative in-hospital death were analyzed using multivariate logistic regression analysis.

Results

The male to female ratio in the patients was 3.8:1 and the mean age was 50.11 ± 9.91 years. The patient’s main comorbidities were hypertension (70.33%) and coronary heart disease (10.17%). The main symptoms included chest pain and back pain (72.89%). The highest incidence of complications was pericardial effusion (48.31%), followed by pleural effusion (22.88%). The mean systolic blood pressure, white blood cell count and D-dimer in the patients were over the ranges of normal people. The incidences of cardiac and renal insufficiency were 18.64% and 16.95% respectively, and the postoperative in-hospital mortality rate was 12.71%. Univariable analysis showed that age, renal insufficiency, cardiac insufficiency, D-dimer level, cardiopulmonary bypass time, operation time, blood transfusion volume and postoperative hemostasis were significant factors leading to the death (P < 0.05). Multivariate logistic regression analysis showed that age > 65, renal insufficiency, cardiopulmonary bypass time ≥ 250 min and postoperative hemostasis were independent risk factors for the death (P < 0.05).

Conclusions

AAD patients frequently have underlying diseases with pain as the main symptom. Age > 65 years, renal insufficiency, cardiopulmonary bypass time ≥ 250 min and postoperative hemostasis are significantly risk factors for postoperative mortality.

Aortic arch aneurysm. Tracheobronchial compression as a vital indication for emergency surgery: A case report

INTRODUCTION

Giant thoracic aortic aneurysms and aortic arch dissections are accompanied by high mortality rates, cardiac and neurologic events and pulmonary complications. Tracheobronchial compression with aorta-tracheal fistula is a rare complication of the aorta aneurysms. Aortic arch replacement in such case presents several formidable challenges.

PRESENTATION OF CASE

This is the case report of successful surgical treatment of giant aortic arch aneurysm, complicated by airway compression, aorta-tracheal fistula and recurrent community-acquired pneumonia.

DISCUSSION

Urgent indications for the aortic arch aneurysms surgery include significant size and high risk of rupture. As well as a visceral compression are presented. Bronchoscopy can be used to successfully treatment at all stages from trachea intubation to extubation.

CONCLUSION

Aggressive surgical approach with careful pre-operative diagnostic are the key to success and the only one chance for patients with aortic arch aneurysm, complicated by airway compression.

Femoral versus axillary cannulation in acute type A aortic dissections: A meta-analysis

OBJECTIVE

There has been a growing interest in antegrade cannulation techniques in type A aortic dissection surgery. Axillary cannulation has previously been reported to provide better outcomes in terms of short-term mortality and neurological event. Consensus regarding the best cannulation strategy still remains controversial.

METHOD

The MEDLINE and EMBASE databases were conducted up until October 3, 2020. Data regarding mortality, stroke, reoperation for bleeding and length of hospital stay, wound infection and cardiopulmonary bypass time were extracted and submitted to a meta-analysis using random-effects modelling and the I² -test for heterogeneity. Fourteen retrospective observational studies were included, enrolling a total of 2621 patients.

RESULTS

There were a total of 2621 patients (1327 axillary cannulation and 874 femoral cannulation). Axillary cannulation was associated with reduced short term mortality (pooled odds ratio [OR] = +0.42, 95% confidence interval [CI] = +0.25 to +0.70; p = .0009) compared to femoral cannulation. Axillary cannulation was also associated with a lower incidence of neurological events (pooled OR = +0.63, 95% CI = +0.42 to +0.94; p = .02).

CONCLUSION

Our meta-analyses suggests that axillary cannulation has superior outcomes in terms of mortality and stroke following emergency surgery for type A aortic dissection. However, the lack of high quality randomized controlled trials does not make this recommendation generalisable to all units.

Failure Properties of Healthy and Diabetic Rabbit Thoracic Aortas and Their Potential Correlation with Mass Fractions of Collagen

PURPOSE

Diabetes Mellitus (DM) plays an important role in aortic remodeling and alters the wall mechanics. The purpose of this study is to investigate and compare multi-directional failure properties of healthy and diabetic thoracic aortas.

METHODS

Thirty adult rabbits (1.6-2.2 kg) were collected and type 1 diabetic rabbit model was induced by injection of alloxan. A total of 10 control and 20 diabetic (with different time exposure to diabetic condition) rabbit descending thoracic aortas were harvested. Uniaxial tensile (UT) and radial tension (RT) tests were performed to determine circumferential, axial and radial failure stresses of the control and diabetic aortas, which were further correlated with mass fractions (MFs) of collagen.

RESULTS

Throughout the UT test, there was a clear indication of anisotropic mechanical responses for some diabetic aorta specimens in the high loading domain. There was a trend towards an increase in the mean circumferential and axial failure stresses for the diabetic aortas when compared to the control aortas. However, differences were not statistically significant. The quantified failure stresses in the circumferential direction were, in general, higher than the stress values in the axial direction for both control and diabetic groups. For the RT test, the radial failure stresses of the diabetic aortas (in 8 weeks) were significantly higher than those of the control aortas (95 ± 17 vs. 63 ± 15 kPa, p = 0.01). Strong correlations were identified between the circumferential failure stresses and the MFs of collagen for both control and diabetic aortas. Nevertheless, this correlation was not present in the axial and radial directions.

CONCLUSION

The results suggest that there is a lower propensity of radial tear occurrence within the diabetic aortic wall. More importantly, time exposure to diabetic condition is not a factor that may change failure properties of the rabbit descending thoracic aortas in the circumferential and axial directions.

The Real Need for Regenerative Medicine in the Future of Congenital Heart Disease Treatment

Bioabsorbable materials made from polymeric compounds have been used in many fields of regenerative medicine to promote tissue regeneration. These materials replace autologous tissue and, due to their growth potential, make excellent substitutes for cardiovascular applications in the treatment of congenital heart disease. However, there remains a sizable gap between their theoretical advantages and actual clinical application within pediatric cardiovascular surgery. This review will focus on four areas of regenerative medicine in which bioabsorbable materials have the potential to alleviate the burden where current treatment options have been unable to within the field of pediatric cardiovascular surgery. These four areas include tissue-engineered pulmonary valves, tissue-engineered patches, regenerative medicine options for treatment of pulmonary vein stenosis and tissue-engineered vascular grafts. We will discuss the research and development of biocompatible materials reported to date, the evaluation of materials in vitro, and the results of studies that have progressed to clinical trials.

Identification of Molecular Regulatory Features and Markers for Acute Type A Aortic Dissection

BACKGROUND

Acute type A aortic dissection (ATAAD) is one of the most lethal cardiovascular diseases, and its molecular mechanism remains unclear.

METHODS

Differentially expressed genes (DEGs) between ATAAD and control were detected by limma R package in GSE52093, GSE153434, GSE98770, and GSE84827, respectively. The coexpression network of DEGs was identified by the WGCNA package. Enrichment analysis was performed for module genes that were positively correlated with ATAAD using clusterProfiler R package. In addition, differentially methylated markers between aortic dissection and control were identified by ChAMP package. After comparing with ATAAD-related genes, a protein-protein interaction (PPI) network was established based on the STRING database. The genes with the highest connectivity were identified as hub genes. Finally, differential immune cell infiltration between ATAAD and control was identified by ssGSEA.

RESULTS

From GSE52093 and GSE153434, 268 module genes were obtained with consistent direction of differential expression and high correlation with ATAAD. They were significantly enriched in T cell activation, HIF-1 signaling pathway, and cell cycle. In addition, 2060 differentially methylated markers were obtained from GSE84827. Among them, 77 methylation markers were ATAAD-related DEGs. Using the PPI network, we identified MYC, ITGA2, RND3, BCL2, and PHLPP2 as hub genes. Finally, we identified significantly differentially infiltrated immune cells in ATAAD.

CONCLUSION

The hub genes we identified may be regulated by methylation and participate in the development of ATAAD through immune inflammation and oxidative stress response. The findings may provide new insights into the molecular mechanisms and therapeutic targets for ATAAD.

Does adding an aortic root replacement or sinus repair during arch repair increase postoperative mortality? Evidence from the Canadian Thoracic Aortic Collaborative

 

OBJECTIVES

The aim of this study was to examine the effect of the addition of an aortic root replacement or sinus repair on mortality and morbidity during aortic arch repair.

METHODS

A total of 2472 patients underwent proximal or total aortic arch repair with hypothermic circulatory arrest between 2002 and 2018 at 12 centres. Multivariable logistic regressions (MV) and propensity score (PS) with inverse probability of treatment weighting (IPTW) analyses were performed.

RESULTS

A total of 1099 (44.5%) patients had additional aortic root replacement (n = 934) or sinus repair (n = 165). Those with aortic root interventions were younger (61 ± 13 vs 64 ± 13 years, P < 0.001) and had less females (23% vs 35%, P < 0.001), less dissection (31% vs 36%, P = 0.004), less urgent cases (35% vs 39%, P = 0.047), more connective tissue disease (7% vs 3%, P < 0.001) and less total arch replacements (14% vs 22%, P < 0.001). On adjusted analyses, the addition of aortic root procedure was associated with increased mortality [MV: odds ratio (OR) 1.41, 95% confidence interval (CI) 1.03-1.92; PS-IPTW: risk increased by 3.7%, 95% CI 1.2-6.3%, P = 0.004]. Reoperation for bleeding was also increased with the addition of aortic root intervention (MV: OR 1.48, 95% 1.10-1.99; PS-IPTW: risk increased by 3.2%, 95% CI 0.8-5.6%, P = 0.009). The risks of stroke and dialysis-dependent renal failure were similar. When looking only at non-elective cases, the increased risk of mortality was more pronounced (MV: OR 1.60, 95% CI 1.11-2.32, P = 0.013; PS-IPTW: risk increased by 6.8%, 95 CI 1.7-11.8%, P = 0.008, and a number need to harm of 15 patients to cause 1 additional death).

CONCLUSIONS

The addition of aortic root replacement or sinus repair during proximal or total aortic arch repair seems to increase postoperative mortality only in non-elective cases.

Acute aortic dissection type A: Impact of aortic specialists on short and long term outcomes

OBJECTIVES

Acute aortic dissection type-A (AADA) is a life threatening condition which requires emergency surgery. Surgery is usually performed by cardiac surgeons with various levels of aortic surgical experience. We compared the short-term perioperative outcome and long-term survival of patients operated by specialist aortic surgeons (SASs)and those who were operated by surgeons without specialist expertise.

METHODS

A single center retrospective review of 232 patients who underwent acute surgery for AADA was conducted between 2005 and 2020. The cohort was divided into those operated on by SASs (Group A, n = 186) and those operated on by nonaortic surgeons (Group B, n = 46). Statistical comparison was done using regression modelling and groups were propensity matched. Kaplan-Meier comparison was undertaken using STATA14.

RESULTS

Of 232 patients, 186 were operated on by an aortic specialist and 46 were operated by a nonaortic specialist. Overall 30-day mortality was 10% in Group A compared to 26.0% in Group B (unadjusted: p = .01, multivariate: p = .02, and propensity matched p = .05). Long-term mortality at 14 years was 26% in Group A compared to 52.0% in Group B (unadjusted: p = .001, multivariate: p = .001, and propensity matched: p = .01). Aortic surgeons performed a significantly higher number of aortic root procedures (43.0% vs. 17.3%, p = .001). The cross-clamp time and bypass time was significantly shorter in Group A patients (89 vs. 105 min, p < .01 and 153 vs. 185, p = < .001). Postoperative requirement for renal filtration was (19% vs. 37%, unadjusted p = .01, multivariate p = .03 and propensity matched p = .04). Although postoperative bleeding was less in Group A (4.0% vs. 11.0%, unadjusted p = .05) after propensity matching it was not statistically significant.

CONCLUSIONS

In patients with AADA, surgery performed by aortic specialist's results in improved outcomes. Aortic specialists replaced more of dissected aorta, resulting in an increased number of complex procedures, which may explain improved long-term survival after AADA in this cohort. This study adds further support in establishing a specialist aortic surgical service in cardiac centers.

Patient-specific computational evaluation of stiffness distribution in ascending thoracic aortic aneurysm

Quantifying local aortic stiffness properties in vivo is acknowledged as essential to assess the severity of an ascending thoracic aortic aneurysm (ATAA). Recently, the LESI (local extensional stiffness identification) methodology has been established to quantify non-invasively local stiffness properties of ATAAs using electrocardiographic-gated computed tomography (ECG-gated CT) scans. The aim of the current study was to determine the most sensitive markers of local ATAA stiffness estimation with the hypothesis that direct measures of local ATAA stiffness could better detect the high-risk patients. A cohort of 30 patients (12 BAV and 18 TAV) referred for aortic size evaluation by ECG-gated CT were recruited. For each patient, the extensional stiffness Q was evaluated by the LESI methodology whilst computational flow analyses were also performed to derive hemodynamics markers such as the wall shear stress (WSS). A strong positive correlation was found between the extensional stiffness and the aortic pulse pressure (R = 0.644 and p < 0.001). Interestingly, a significant positive correlation was also found between the extensional stiffness and patients age for BAV ATAAs (R = 0.619 and p = 0.032), but not for TAV ATAAs (R = -0.117 and p = 0.645). No significant correlation was found between the extensional stiffness and WSS evaluated locally. There was no significant difference either in the extensional stiffness between BAV ATAAs and TAV ATAAs (Q = 3.6 ± 2.5 MPa.mm for BAV ATAAs vs Q = 5.3 ± 3.1 MPa.mm for TAV ATAAs, p = 0.094). Future work will focus on relating the extensional stiffness to the patient-specific rupture risk of ATAAs on larger cohorts to confirm the promising interest of the LESI methodology.

Impact of time between diagnosis to treatment in Acute Type A Aortic Dissection

There is a paucity of data describing the effect of time interval between diagnosis and surgery for Acute Type A Aortic Dissection. We describe our 8-year experience and investigate the impact of time interval between symptom onset, diagnosis and surgery on outcomes. Retrospective single-center study utilizing our Society of Thoracic Surgeons registry and patient records. Subjects were grouped by time interval between radiographic diagnosis and surgical treatment: Group A (0-4 h), Group B (4.1-8 h), Group C (8.1-12 h), and Group D (12.1 + h). Data were analyzed to identify factors associated with mortality and outcomes. 164 patients were included. Overall mortality was 21.3%. Group C had the greatest intervals between symptom onset to diagnosis to surgery, and also the highest mortality (66.7%). Preoperative tamponade, cardiac arrest, malperfusion, elevated creatinine, cardiopulmonary bypass time, and blood transfusions were associated with increased mortality, while distance of referring hospital was not. Time intervals between symptom onset, diagnosis and surgery have a significant effect on mortality. Surgery performed 8-12 h after diagnosis carries the highest mortality, which may be exacerbated by longer interval since symptom onset. Time-dependent effects should be considered when determining optimal strategy especially if inter-facility transfer is necessary.

Effect of the urgency and landing zone on rates of in-hospital death, stroke, and paraplegia after thoracic endovascular aortic repair in Japan

OBJECTIVE

The present study used data from the Japanese Committee for Stentgraft Management's national registry, which contains unique surgical data, including surgical timing, anatomic factors, and pathologic factors, to determine the generalized community experience with thoracic endovascular abdominal aortic repair (TEVAR).

METHODS

The medical background and short-term outcomes were reviewed for patients who had undergone TEVAR for a thoracic aortic aneurysm (TAA; 14,235 cases) or aortic dissection (AD; 990 type A and 4259 type B) from 2008 to 2015. TEVAR for AD was separated from that for TAAs; only the background and short-term outcomes were evaluated. The technical outcomes of TEVAR for TAA were also evaluated. All the cases were categorized as follows: elective, urgent (within 24 hours after admission), or emergent (immediately after admission). The outcomes included in-hospital mortality and persistent stroke and paraplegia diagnosed at discharge. The number of debranching bypasses, proximal landing zone (0, 1, 2, ≥3), and zone length were included in the logistic regression analysis.

RESULTS

The mortality, stroke, and paraplegia rates in the TAA and AD groups were 4.4%, 4.6%, and 3.7% and 4.0%, 2.9%, and 2.8%, respectively. After analyzing the TAA cohort, we found that urgent and emergent cases were associated with all adverse outcomes. The rate of paraplegia increased drastically in the patients with stent graft coverage that extended for six or more zones. Massive atheroma was associated with stroke and paraplegia. The cumulative survival rate of the TAA group was stratified by the urgency (ie, elective, urgent, emergent; P < .001). We found that the more proximal (0, 1, and 2) the landing zone, the greater the risk of stroke. Likewise, the longer (six or more zones) the coverage, the greater the risk of paraplegia.

CONCLUSIONS

Urgency was strongly associated with mortality, stroke, and paraplegia, and the classification of urgent and emergent, according to the surgical timing after admission, successfully stratified the population in the long-term overall survival analysis. A proximal landing zone involving the aortic arch and debranching bypasses were associated with the occurrence of stroke, and the length of stent graft coverage for six or more zones was associated with paraplegia. Identifying these risk factors will help operators of TEVAR develop appropriate operative strategies to mitigate patient risk.

Femoral arterial cannulation remains a safe and reliable option for aortic dissection repair

Background

The optimal cannulation site for repair of type A aortic dissection remains controversial. The concern for Malperfusion syndrome has initiated a national trend away from femoral cannulation to axillary artery and direct ascending aortic cannulation. The purpose of this study was to report a single center experience with femoral artery cannulation for the repair of a type A dissection.

Methods

A retrospective study was performed on 52 patients who underwent surgical repair for a type A dissection between January 1^st, 2012 and June 30^th, 2019 at a single institution. Of the 52 patients analyzed, 35 (67.3%) underwent femoral artery, 11 (21.2%) direct ascending aortic, and 6 (11%) axillary artery cannulation for arterial access. Deep hypothermic circulatory arrest was used in all the patients. Rates of postoperative complication and mortality were reported.

Results

The mortality and bleeding rates for all the patients undergoing repair of the type A dissection repairs were 27% (14/52) and 19% (10/52), respectively. Cardiopulmonary bypass was established in 100% of the patients that had femoral arterial cannulation. There were no complications specifically related to femoral arterial cannulation nor the axillary or direct aortic approach. Specifically, there was no episodes of malperfusion syndrome, bleeding, or injury with femoral artery cannulation. Bleeding rates were higher in cases that proceeded with a femoral (13%) versus alternate (6%) approach however; neither of the bleeding was related to the cannulation site. None of the mortalities identified were directly attributable to the cannulation approach in each case.

Conclusions

Despite the recent shift away from femoral cannulation, the results of the study show that femoral artery cannulation is safe and produces excellent results for establishing cardiopulmonary bypass. The concerns for malperfusion syndrome related to femoral cannulation were not seen.

TAZ Is Related to Postoperative In-Hospital Mortality of Acute Type A Aortic Dissection

Background: Surgical repair of acute type A aortic dissection (ATAAD) has high risk and mortality, and there are few biomarkers of postoperative in-hospital mortality until now. This study investigated the association between WW domain–containing transcription regulator protein 1 (TAZ) and the postoperative in-hospital mortality of ATAAD patients.

Methods: This is a retrospective cohort study. Data and blood samples were collected from 95 consecutive patients with ATAAD who underwent surgeries in our hospital from July 1, 2016, to December 31, 2016. The data collection included all the risk factors introduced by the modified EuroSCORE (European System for Cardiac Operative Risk Evaluation). The predictors of postoperative in-hospital death were confirmed by univariate regression analysis. Multivariable logistic regressions were used to analyze the association of the preoperative plasma level of TAZ and the postoperative in-hospital mortality of ATAAD patients. In addition, we used the generalized additive model to identify non-linear relationships.

Results: Three models were used in the multivariable logistic regression analysis of the relationship between the preoperative plasma level of TAZ and postoperative in-hospital death. In the crude model, the preoperative plasma level of TAZ showed a positive correlation with postoperative in-hospital death [odds ratio (OR) = 1.33, 95% confidence interval (CI): 1.01–1.74, P = 0.04]. In adjusted model I and adjusted model II, similar results were found (OR = 1.35, 95% CI: 1.01–1.80, P = 0.04 and OR = 1.35, 95% CI: 1.01–1.81, P = 0.04). The risk of postoperative in-hospital death in the preoperative plasma level of the TAZ≥12.70 ng/mL group was 10.08 times (OR = 10.08, 95% CI: 1.63–62.37; P = 0.01) that of the preoperative plasma level of the TAZ <12.70 ng/mL group.

Conclusions: The high preoperative plasma level of TAZ suggested poor surgical prognosis for ATAAD patients. The patients with a preoperative plasma level of TAZ ≥ 12.7 ng/ml had much higher postoperative in-hospital mortality.

The association between simple renal cyst and aortic diseases: A systematic review and meta-analysis of observational studies

OBJECTIVE

The objective of this meta-analysis of observational studies was to evaluate the association between simple renal cysts (SRC) and presence of aortic pathology such as aortic aneurysms and dissection.

METHODS

We conducted searches in Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials from January 1960 to August 2019 to identify observational studies that examined the association between SRCs and any aortic diseases, including aortic aneurysms and dissection. Two reviewers independently extracted the data and assessed the risk of bias. The meta-analysis was performed by STATA 14.1.

RESULTS

In total, 11 observational studies with 19 719 participants were included in this meta-analysis. Compared to individuals without SRCs, patients with SRCs had higher odds of abdominal aortic aneurysm (AAA) (adjusted OR = 2.61, 95% CI 2.34-2.91, P < 0.001, I²   = 0%), ascending thoracic aortic aneurysm (TAA) (adjusted OR = 1.98, 95% CI 1.09-3.63, P = 0.03, I²   = 90.1%), descending TAA (adjusted OR = 3.44, 95% CI, 2.67-4.43, P < 0.001, I²   = 0%), type A aortic dissection (AD) (adjusted OR = 1.98, 95% CI 1.32-2.96, P = 0.001, I²   = 12.9%), and type B AD (adjusted OR = 2.55, 95% CI, 1.31-4.96, P = 0.006, I²   = 76.2%). There was a higher average in the sum of diameter of SRCs among AAA compared to patients without AAA (WMD = 19.80 mm, 95% CI 13.92-25.67, P < 0.001, I²   = 63.8%).

CONCLUSION

SRC is associated with higher odds of aortic diseases including AAA, ascending and descending TAA, type A and type B dissection even after adjusting for confounders.

Management of acute type B aortic dissection

BACKGROUND

The best management of acute uncomplicated type B aortic dissection is currently a controversial area. Recent advances in endovascular intervention have begun to establish pre-emptive thoracic endovascular aortic repair as a potential strategy. A review about the management for type B aortic dissection has been conducted.

METHODS

A narrative review consisting of 157 original articles, meta-analyses and guidelines was conducted. The findings were synthesized and summarized using 70 articles.

RESULTS

There are clear guidelines directing surgical management of acute complicated type B aortic dissection. However, the best management of acute uncomplicated disease is more ambiguous, which is especially concerning in a condition which is associated with significant morbidity and mortality. Medical management alone is generally favoured. Endovascular intervention is now being considered by some surgeons, but it can be technically difficult, while exposing the patient to potential surgical risks.

CONCLUSIONS

Clinical and anatomical risk factors have been identified to help vascular surgeons make decisions about treatment in acute uncomplicated type B aortic dissection. New endovascular strategies are being developed to reduce surgical risk and address technical challenges. Registry data should be used to support future best management.

Quantifying the learning curve of emergent total arch replacement in acute type A aortic dissection

Background

Acute type A aortic dissection with arch involvement is a life-threatening condition, which requires immediate surgical attention. Emergent total arch replacement and root reconstruction is a technically demanding operation with varying outcomes based on surgeon experience. The human factors in total arch replacement in the emergent setting have never been systematically investigated. The ability of surgeons with low volumes to achieve acceptable results in their start-up period is not known.

Methods

From January 2013 to December 2016, patients with acute type A aortic dissection who underwent emergent total arch replacement with three surgeons were enrolled. Basic characteristics, procedural and postoperative outcomes were collected. The time of critical surgical steps and operative mortality were calculated using descriptive statistics and cumulative SUM (CUSUM) analysis.

Results

A total of 300 patients (age 53.8±11.5 years, female 63, 21.0%) with acute type A aortic dissection underwent emergent total arch replacement. A total of 219 patients (73.0%) had root reinforcement, 295 patients (98.3%) underwent frozen elephant trunk repair. Mean circulatory arrest and cross-clamp times were 29.8±9.8 and 112.3±32.1 min, respectively. The operative mortality was 6.7%, the stroke rate was 4.0%. The mean length of postoperative ICU and hospital stays were 8.4±10.6 and 18.0±12.2 days, respectively. By CUSUM depictions, surgeons appeared to have different learning curves with regards to operative time. By CUSUM failure analysis on operative mortality, two newly appointed surgeons in their start-up period stayed in an acceptable range, while one senior surgeon with higher volumes experienced superior outcomes and better performance.

Conclusions

Although emergent total arch replacement for acute type A dissection is a complex scenario, surgeons well-trained in adult cardiac surgery are able to achieve acceptable results in their start-up period.

Stanford type a aortic dissection with cerebral infarction: a rare case report

Background

Aortic dissection (AoD) is a disease with a high mortality rate. Its clinical manifestations are diverse and covert, which makes diagnosis and treatment challenging. Here, we report a very rare case of aortic dissection leading to bilateral cerebral cortex ischaemia and epilepsy.

Case presentation

A 54-year-old man was admitted to the hospital with acute onset of right limb weakness accompanied by slurred speech. He had a history of hypertension as well as tobacco and alcohol use. The patient was found to have aphasia and right hemiplegia on physical examination. No bleeding was seen on the skull CT. Acute cerebral infarction was considered after admission, and rt-PA was administered for intravenous thrombolysis. During intravenous thrombolysis, the patient suddenly developed epilepsy, and diazepam was given immediately by intravenous injection to control the symptoms. Emergency skull diffusion-weighted imaging (DWI) was performed, and the results showed a small, patchy, high signal that was scattered throughout the left brain hemisphere, right frontal parietal lobe and centrum semiovale. Head and neck CT angiography (CTA) was performed; dissection was found in the ascending aorta, aortic arch, bilateral common carotid artery, proximal part of the internal carotid artery, and initial segment of the left external carotid artery. The laceration was located in the upper part of the ascending aorta. AoD complicated by acute cerebral infarction and epilepsy was considered, and the patient was immediately transferred to the cardiovascular surgery specialist hospital for surgical treatment.

Conclusions

Some aortic dissections have no typical manifestations of chest pain, and the onset is covert. Atypical clinical manifestations of epilepsy secondary to bilateral cerebral hemisphere infarction may appear. AoD with cerebral infarction is a contraindication for intravenous thrombolysis; surgical treatment is the best way to reduce mortality.