Radiation therapy for cancer is potentially associated with reduced growth of concomitant abdominal aortic aneurysm

PURPOSE

Co-prevalence of abdominal aortic aneurysm (AAA) and cancer poses a unique challenge in medical care since both diseases and their respective therapies might interact. Recently, reduced AAA growth rates were observed in cancer patients that received radiation therapy (RT). The purpose of this study was to perform a fine-grained analysis of the effects of RT on AAA growth with respect to direct (infield) and out-of-field (outfield) radiation exposure, and radiation dose-dependency.

METHODS

A retrospective single-center analysis identified patients with AAA, cancer, and RT. Clinical data, radiation plans, and aneurysm diameters were analyzed. The total dose of radiation to each aneurysm was computed. AAA growth under infield and outfield exposure was compared to patients with AAA and cancer that did not receive RT (no-RT control) and to an external noncancer AAA reference cohort.

RESULTS

Between 2003 and 2020, a total of 38 AAA patients who had received well-documented RT for their malignancy were identified. AAA growth was considerably reduced for infield patients (n = 18) compared to outfield patients (n = 20), albeit not significantly (0.8 ± 1.0 vs. 1.3 ± 1.6 mm/year, p = 0.28). Overall, annual AAA growth in RT patients was lower compared to no-RT control patients (1.1 ± 1.5 vs. 1.8 ± 2.2 mm/year, p = 0.06) and significantly reduced compared to the reference cohort (1.1 ± 1.5 vs. 2.7 ± 2.1 mm/year, p < 0.001). The pattern of AAA growth reduction due to RT was corroborated in linear regression analyses correcting for initial AAA diameter. A further investigation with respect to dose-dependency of radiation effects on AAA growth, however, revealed no apparent association.

CONCLUSION

In this study, both infield and outfield radiation exposure were associated with reduced AAA growth. This finding warrants further investigation, both in a larger scale clinical cohort and on a molecular level.

Neutrophil Extracellular Traps in Cardiovascular and Aortic Disease: A Narrative Review on Molecular Mechanisms and Therapeutic Targeting

Neutrophil extracellular traps (NETs), composed of DNA, histones, and antimicrobial proteins, are released by neutrophils in response to pathogens but are also recognized for their involvement in a range of pathological processes, including autoimmune diseases, cancer, and cardiovascular diseases. This review explores the intricate roles of NETs in different cardiovascular conditions such as thrombosis, atherosclerosis, myocardial infarction, COVID-19, and particularly in the pathogenesis of abdominal aortic aneurysms. We elucidate the mechanisms underlying NET formation and function, provide a foundational understanding of their biological significance, and highlight the contribution of NETs to inflammation, thrombosis, and tissue remodeling in vascular disease. Therapeutic strategies for preventing NET release are compared with approaches targeting components of formed NETs in cardiovascular disease. Current limitations and potential avenues for clinical translation of anti-NET treatments are discussed.

Reducing Abdominal Aortic Aneurysm Progression by Blocking Neutrophil Extracellular Traps Depends on Thrombus Formation

Neutrophil extracellular traps (NETs) are implicated in the pathogenesis of abdominal aortic aneurysm (AAA), located in adventitia and intraluminal thrombus. We compared the therapeutic potential of targeting upstream or downstream effector molecules of NET formation in 2 murine AAA models based on angiotensin II or peri-adventitial elastase application. In both models, NETs were detected in formed aneurysms at treatment start. Although NET inhibitors failed in the elastase model, they prevented progression of angiotensin II-induced aneurysms with thrombus, which resembles established human disease (including thrombus development). Blockade of upstream NET mediators was more effective than interference with downstream NET molecules.

GalNAc-conjugated siRNA targeting the DNAJB1-PRKACA fusion junction in fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma (FLC) is a rare liver cancer caused by a dominant recurrent fusion of the heat shock protein (DNAJB1) and the catalytic subunit of protein kinase A (PRKACA). Current therapies such as chemotherapy and radiation have limited efficacy, and new treatment options are needed urgently. We have previously shown that FLC tumors are dependent on the fusion kinase DNAJB1::PRKACA, making the oncokinase an ideal drug target. mRNA degrading modalities such as antisense oligonucleotides or small interfering RNAs (siRNAs) provide an opportunity to specifically target the fusion junction. Here, we identify a potent and specific siRNA that inhibits DNAJB1::PRKACA expression. We found expression of the asialoglycoprotein receptor in FLC to be maintained at sufficient levels to effectively deliver siRNA conjugated to the GalNAc ligand. We observe productive uptake and siRNA activity in FLC patient-derived xenografts (PDX) models in vitro and in vivo. Knockdown of DNAJB1::PRKACA results in durable growth inhibition of FLC PDX in vivo with no detectable toxicities. Our results suggest that this approach could be a treatment option for FLC patients.

Diagnostic Utility of a Combined MPO/D-Dimer Score to Distinguish Abdominal Aortic Aneurysm from Peripheral Artery Disease

Abdominal aortic aneurysm (AAA) and peripheral artery disease (PAD) share pathophysiological mechanisms including the activation of the fibrinolytic and innate immune system, which explains the analysis of D-dimer and myeloperoxidase (MPO) in both conditions. This study evaluates the diagnostic marker potential of both variables separately and as a combined MPO/D-dimer score for identifying patients with AAA versus healthy individuals or patients with PAD. Plasma levels of MPO and D-dimer were increased in PAD and AAA compared to healthy controls (median for MPO: 13.63 ng/mL [AAA] vs. 11.74 ng/mL [PAD] vs. 9.16 ng/mL [healthy], D-dimer: 1.27 μg/mL [AAA] vs. 0.58 μg/mL [PAD] vs. 0.38 μg/mL [healthy]). The combined MPO/D-dimer score (median 1.26 [AAA] vs. -0.19 [PAD] vs. -0.93 [healthy]) showed an improved performance in distinguishing AAA from PAD when analysed using the receiver operating characteristic curve (area under the curve) for AAA against the pooled data of healthy controls + PAD: 0.728 [MPO], 0.749 [D-dimer], 0.801 [score]. Diagnostic sensitivity and specificity ranged at 82.9% and 70.2% (for score cut-off = 0). These findings were confirmed for a separate collective of AAA patients with 35% simultaneous PAD. Thus, evaluating MPO together with D-dimer in a simple score may be useful for diagnostic detection and the distinction of AAA from athero-occlusive diseases like PAD.

Early experience with bridging stent graft deployment without sheath support in branched and fenestrated endovascular aortic repair

OBJECTIVE

To assess the early experience with modified version of simplified bare-wire target vessel (SMART) technique, implying delivery of bridging stent grafts without historically established sheath support, and to compare its outcome to standard endovascular aortic repair procedures with fenestrated/branched devices.

METHODS

A retrospective analysis of 102 consecutive patients treated with fenestrated/branched devices from January 2020 to December 2022 was undertaken. The study population was divided into three groups-a sheath group (SG), SMART group, and nonsheath group (NSG). Primary end points were radiation exposure (dose-area product), fluoroscopy time, dose of contrast agent, operation time, and incidence of intraoperative target vessel (TV) complications and additional procedures. Freedom from secondary TV related reinterventions at the three follow-up phases were defined as secondary end points.

RESULTS

A total of 183 TVs (38.8% visceral arteries [VA]; 56.3% renal arteries [RA]) in the SG, 36 TVs (44.4% VA, 55.6% RA) in the SMART group, and 168 TVs (47.6% VA; 50% RA) in the NSG were accessed. The mean number of fenestrations and bridging stent grafts was equally distributed in all three groups. The SMART group only included cases treated with fenestrated devices. The dose-area product was significantly lower in the SMART (median, 203 Gy × cm2; interquartile range [IQR], 179-365 Gy × cm2) and NSG (median, 340 Gy × cm2; IQR, 220-651 Gy × cm2) groups vs the SG (median, 464 Gy × cm2; IQR, 267-871 Gy × cm2; P = .007). Operation time was also significantly lower in the NSG (median, 265 minutes; IQR, 221-337 minutes) and SMART (median, 292 minutes; IQR, 234-351 minutes) groups vs the SG (median, 326 minutes; IQR, 277-375 minutes; P = .004), respectively. Intraoperative TV-related complications were most frequently observed in the SG (9/183 TVs; P = .008).

CONCLUSIONS

This study reports the outcomes of three currently available TV stenting approaches. Previously reported SMART technique, and its modified version (NSG) proved to be a safe alternative to historically established TV stenting technique with sheath support (SG).

Operation time and clinical outcomes for open infrarenal abdominal aortic aneurysms to remain stable in the endovascular era

Objective

Endovascular aortic repair (EVAR) has become a routine procedure worldwide. Ultimately, the increasing number of EVAR cases entails changing conditions for open surgical repair (OSR) regarding patient selection, complexity, and surgical volume. This study aimed to assess the time trends of open abdominal aortic aneurysm (AAA) repair in a high-volume single center in Austria over a period of 20 years, focusing on the operation time and clinical outcomes.

Materials and methods

A retrospective analysis of all patients treated for infrarenal AAAs with OSR or EVAR between January 2000 and December 2019 was performed. Infrarenal AAA was defined as the presence of a >10-mm aortic neck. Cases with ruptured or juxtarenal AAAs were excluded from the analysis. Two cohorts of patients treated with OSR at different time periods, namely, 2000-2009 and 2010-2019, were assessed regarding demographical and procedure details and clinical outcomes. The time periods were defined based on the increasing single-center trend toward the EVAR approach from 2010 onward.

Results

A total of 743 OSR and 766 EVAR procedures were performed. Of OSR cases, 589 were infrarenal AAAs. Over time, the EVAR to OSR ratio was stable at around 50:50 (p = 0.488). After 2010, history of coronary arterial bypass (13.4% vs. 7.2%, p = 0.027), coronary artery disease (38.1% vs. 25.1%, p = 0.004), peripheral vascular disease (35.1% vs. 21.3%, p = 0.001), and smoking (61.6% vs. 34.3%, p < 0.001) decreased significantly. Age decreased from 68 to 66 years (p = 0.023). The operation time for OSR remained stable (215 vs. 225 min, first vs. second time period, respectively, p = 0.354). The intraoperative (5.8% vs. 7.2%, p = 0.502) and postoperative (18.3% vs. 20.8%, p = 0.479) complication rates also remained stable. The 30-day mortality rate did not change over both time periods (3.0% vs. 2.4%, p = 0.666).

Conclusion

Balanced EVAR to OSR ratio, similar complexity of cases, and volume over the two decades in OSR showed stable OSR time without compromise in clinical outcomes.

Proteomic Atlas of Atherosclerosis: The Contribution of Proteoglycans to Sex Differences, Plaque Phenotypes, and Outcomes

BACKGROUND

Using proteomics, we aimed to reveal molecular types of human atherosclerotic lesions and study their associations with histology, imaging, and cardiovascular outcomes.

METHODS

Two hundred nineteen carotid endarterectomy samples were procured from 120 patients. A sequential protein extraction protocol was employed in conjunction with multiplexed, discovery proteomics. To focus on extracellular proteins, parallel reaction monitoring was employed for targeted proteomics. Proteomic signatures were integrated with bulk, single-cell, and spatial RNA-sequencing data, and validated in 200 patients from the Athero-Express Biobank study.

RESULTS

This extensive proteomics analysis identified plaque inflammation and calcification signatures, which were inversely correlated and validated using targeted proteomics. The inflammation signature was characterized by the presence of neutrophil-derived proteins, such as S100A8/9 (calprotectin) and myeloperoxidase, whereas the calcification signature included fetuin-A, osteopontin, and gamma-carboxylated proteins. The proteomics data also revealed sex differences in atherosclerosis, with large-aggregating proteoglycans versican and aggrecan being more abundant in females and exhibiting an inverse correlation with estradiol levels. The integration of RNA-sequencing data attributed the inflammation signature predominantly to neutrophils and macrophages, and the calcification and sex signatures to smooth muscle cells, except for certain plasma proteins that were not expressed but retained in plaques, such as fetuin-A. Dimensionality reduction and machine learning techniques were applied to identify 4 distinct plaque phenotypes based on proteomics data. A protein signature of 4 key proteins (calponin, protein C, serpin H1, and versican) predicted future cardiovascular mortality with an area under the curve of 75% and 67.5% in the discovery and validation cohort, respectively, surpassing the prognostic performance of imaging and histology.

CONCLUSIONS

Plaque proteomics redefined clinically relevant patient groups with distinct outcomes, identifying subgroups of male and female patients with elevated risk of future cardiovascular events.

Quantitation of oxidized nuclear and mitochondrial DNA in plasma samples of patients with abdominal aortic aneurysm

There is accumulating evidence that pro-inflammatory features are inherent to mitochondrial DNA and oxidized DNA species. 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) is the most frequently studied oxidatively generated lesion. Modified DNA reaches the circulation upon cell apoptosis, necrosis or neutrophil extracellular trap (NET) formation. Standard chromatography-based techniques for the assessment of 8-oxodGuo imply degradation of DNA to a single base level, thus precluding the attribution to a nuclear or mitochondrial origin. We therefore aimed to establish a protocol for the concomitant assessment of oxidized mitochondrial and nuclear DNA from human plasma samples. We applied immunoprecipitation (IP) for 8-oxodGuo to separate oxidized from non-oxidized DNA species and subsequent quantitative polymerase chain reaction (qPCR) to assign them to their subcellular source. The IP procedure failed when applied directly to plasma samples, i.e. isotype control precipitated similar amounts of DNA as the specific 8-oxodGuo antibody. In contrast, DNA isolation from plasma prior to the IP process provided assay specificity with little impact on DNA oxidation status. We further optimized sensitivity and efficiency of qPCR analysis by reducing amplicon length and targeting repetitive nuclear DNA elements. When the established protocol was applied to plasma samples of abdominal aortic aneurysm (AAA) patients and control subjects, the AAA cohort displayed significantly elevated circulating non-oxidized and total nuclear DNA and a trend for increased levels of oxidized mitochondrial DNA. An enrichment of mitochondrial versus nuclear DNA within the oxidized DNA fraction was seen for AAA patients. Regarding the potential source of circulating DNA, we observed a significant correlation of markers of neutrophil activation and NET formation with nuclear DNA, independent of oxidation status. Thus, the established method provides a tool to detect and distinguish the release of oxidized nuclear and mitochondrial DNA in human plasma and offers a refined biomarker to monitor disease conditions of pro-inflammatory cell and tissue destruction.

Micro- and Macrovascular Effects of Inflammation in Peripheral Artery Disease-Pathophysiology and Translational Therapeutic Approaches

Inflammation has a critical role in the development and progression of atherosclerosis. On the molecular level, inflammatory pathways negatively impact endothelial barrier properties and thus, tissue homeostasis. Conformational changes and destruction of the glycocalyx further promote pro-inflammatory pathways also contributing to pro-coagulability and a prothrombotic state. In addition, changes in the extracellular matrix composition lead to (peri-)vascular remodelling and alterations of the vessel wall, e.g., aneurysm formation. Moreover, progressive fibrosis leads to reduced tissue perfusion due to loss of functional capillaries. The present review aims at discussing the molecular and clinical effects of inflammatory processes on the micro- and macrovasculature with a focus on peripheral artery disease.

Comparing maximum diameter and volume when assessing the growth of small abdominal aortic aneurysms using longitudinal CTA data: cohort study

BACKGROUND

Monitoring of abdominal aortic aneurysms (AAAs) is currently based on serial measurements of maximum aortic diameter. Additional assessment of aneurysm volume has previously been proposed to possibly improve growth prediction and treatment decisions. To evaluate the use of supplementing volume measurements, the authors aimed to characterise the growth distribution of AAA volume and to compare the growth rates of the maximum diameter and volume at the patient level.

METHODS

Maximum diameter and volume were monitored every 6 months in 84 patients with small AAAs, with a total of 331 computed tomographic angiographies (with initial maximum diameters of 30-68 mm). A previously developed statistical growth model for AAAs was applied to assess the growth distribution of volume and to compare individual growth rates for volume and for maximum diameter.

RESULTS

The median (25-75% quantile) expansion in volume was 13.4 (6.5-24.7) % per year. Cube root transformed volume and maximum diameter showed a closely linear association with a within-subject correlation of 0.77. At the surgery threshold maximum diameter of 55 mm, the median (25-75% quantile) volume was 132 (103-167) ml. In 39% of subjects, growth rates for volume and maximum diameter were equivalent, in 33% growth was faster in volume and in 27% growth was faster in maximum diameter.

CONCLUSION

At the population level, volume and maximum diameter show a substantial association such that the average volume is approximately proportional to the average maximum diameter raised to a power of three. At the individual level, however, in the majority of patient's AAAs grow at different pace in different dimensions. Hence, closer monitoring of aneurysms with sub-critical diameter but suspicious morphology may benefit from complementing maximum diameter by volume or related measurements.

Evaluation of national institute for health and care excellence guidance for ruptured abdominal aortic aneurysms by emulating a hypothetical target trial

Objective

This retrospective study evaluates the performance of UK National Institute for Health and Care Excellence (NICE) Guidelines on management of ruptured abdominal aortic aneurysms in a "real world setting" by emulating a hypothetical target trial with data from two European Aortic Centers.

Methods

Clinical data was retrospectively collected for all patients who had undergone ruptured endovascular aneurysm repair (rEVAR) and ruptured open surgical repair (rOSR). Survival analysis was performed comparing NICE compliance to usual care strategy. NICE compliers were defined as: female patients undergoing rEVAR; male patients >70 years old undergoing rEVAR; and male patients ≤70 years old undergoing rOSR. Hemodynamic instability was considered additionally.

Results

This multicenter study included 298 patients treated for rAAA. The majority of patients were treated with rOSR (186 rOSR vs. 112 rEVAR). Overall, 184 deaths (68 [37%] with rEVAR and 116 [63%] with rOSR) were observed during the study period. Overall survival under usual care was 69.2% at 30 days, 56.5% at one year, and 42.4% at 5 years. NICE compliance gave survival outcomes of 73.1% at 30 days, 60.2% at 1 year and 42.9% at 5 years. The risk ratios at these time points, comparing NICE-compliance to usual care, were 0.88, 0.92 and 0.99, respectively.

Conclusions

We support NICE recommendations to manage men below the age of 71 years and hemodynamic stability with rOSR. There was a slight survival advantage for NICE compliers overall, in men >70 years and women of all ages.

Toll-like Receptors as Pro-Thrombotic Drivers in Viral Infections: A Narrative Review

Toll-like receptors (TLRs) have a critical role in the pathogenesis and disease course of viral infections. The induced pro-inflammatory responses result in the disturbance of the endovascular surface layer and impair vascular homeostasis. The injury of the vessel wall further promotes pro-thrombotic and pro-coagulatory processes, eventually leading to micro-vessel plugging and tissue necrosis. Moreover, TLRs have a direct role in the sensing of viruses and platelet activation. TLR-mediated upregulation of von Willebrand factor release and neutrophil, as well as macrophage extra-cellular trap formation, further contribute to (micro-) thrombotic processes during inflammation. The following review focuses on TLR signaling pathways of TLRs expressed in humans provoking pro-thrombotic responses, which determine patient outcome during viral infections, especially in those with cardiovascular diseases.

Soluble ST2 in Patients with Carotid Artery Stenosis-Association with Plaque Morphology and Long-Term Outcome

Interleukin (IL-33) and the ST2 receptor are implicated in the pathogenesis of atherosclerosis. Soluble ST2 (sST2), which negatively regulates IL-33 signaling, is an established biomarker in coronary artery disease and heart failure. Here we aimed to investigate the association of sST2 with carotid atherosclerotic plaque morphology, symptom presentation, and the prognostic value of sST2 in patients undergoing carotid endarterectomy. A total of 170 consecutive patients with high-grade asymptomatic or symptomatic carotid artery stenosis undergoing carotid endarterectomy were included in the study. The patients were followed up for 10 years, and the primary endpoint was defined as a composite of adverse cardiovascular events and cardiovascular mortality, with all-cause mortality as the secondary endpoint. The baseline sST2 showed no association with carotid plaque morphology assessed using carotid duplex ultrasound (B 0.051, 95% CI -0.145-0.248, p = 0.609), nor with modified histological AHA classification based on morphological description following surgery (B -0.032, 95% CI -0.194-0.130, p = 0.698). Furthermore, sST2 was not associated with baseline clinical symptoms (B -0.105, 95% CI -0.432-0.214, p = 0.517). On the other hand, sST2 was an independent predictor for long-term adverse cardiovascular events after adjustment for age, sex, and coronary artery disease (HR 1.4, 95% CI 1.0-2.4, p = 0.048), but not for all-cause mortality (HR 1.2, 95% CI 0.8-1.7, p = 0.301). Patients with high baseline sST2 levels had a significantly higher adverse cardiovascular event rate as compared to patients with lower sST2 (log-rank p < 0.001). Although IL-33 and ST2 play a role in the pathogenesis of atherosclerosis, sST2 is not associated with carotid plaque morphology. However, sST2 is an excellent prognostic marker for long-term adverse cardiovascular outcomes in patients with high-grade carotid artery stenosis.

Biomarkers of Spinal Cord Injury in Patients Undergoing Complex Endovascular Aortic Repair Procedures-A Narrative Review of Current Literature

Complex endovascular aortic repair (coEVAR) of thoracoabdominal aortic aneurysms (TAAA) has greatly evolved in the past decades. Despite substantial improvements of postoperative care, spinal cord injury (SCI) remains the most devastating complication of coEVAR being associated with impaired patient outcome and having an impact on long-term survival. The rising number of challenges of coEVAR, essentially associated with an extensive coverage of critical blood vessels supplying the spinal cord, resulted in the implementation of dedicated SCI prevention protocols. In addition to maintenance of adequate spinal cord perfusion pressure (SCPP), early detection of SCI plays an integral role in intra- and postoperative patient care. However, this is challenging due to difficulties with clinical neurological examinations during patient sedation in the postoperative setting. There is a rising amount of evidence, suggesting that subclinical forms of SCI might be accompanied by an elevation of biochemical markers, specific to neuronal tissue damage. Addressing this hypothesis, several studies have attempted to assess the potential of selected biomarkers with regard to early SCI diagnosis. In this review, we discuss biomarkers measured in patients undergoing coEVAR. Once validated in future prospective clinical studies, biomarkers of neuronal tissue damage may potentially add to the armamentarium of modalities for early SCI diagnosis and risk stratification.

MetAAA trial patients show superior quality of life compared to patients under regular surveillance for small AAA: a single-center retrospective cohort study

BACKGROUND

Abdominal aortic aneurysm (AAA) is a multifactorial vascular disease associated with high morbidity and mortality. Currently, surgical intervention is the only treatment option, and there is no drug therapy available for AAA. Hence, surveillance of AAA until indication for surgery may impact patient quality of life (QoL). There is a paucity of high-quality observational data on health status and QoL, particularly among AAA patients participating in randomized controlled trials. The objective of this study was to compare the QoL scores of AAA patients on surveillance to those of AAA patients enrolled in the MetAAA trial.

MATERIAL AND METHODS

Overall, 54 MetAAA trial patients and 23 AAA patients under regular surveillance for small AAA (part of a longitudinal monitoring study) were asked to complete three established and validated (in total 561 longitudinally collected) QoL questionnaires: the 36-Item Short Form Health Survey (SF-36), the Aneurysm Symptom Rating Questionnaire (ASRQ), and the Aneurysm-Dependent Quality of Life questionnaire (ADQoL).

RESULTS

A superior health status and QoL was found in AAA patients participating in the MetAAA trial compared to AAA patients under regular surveillance. In detail, MetAAA trial patients showed superior general health perception ( P =0.012), higher energy level ( P =0.036) as well as enhanced emotional well-being ( P =0.044) and fewer limitations due to general malaise ( P =0.021), which was subsequently reflected in an overall superior current QoL score ( P =0.039) compared to AAA patients under regular surveillance.

CONCLUSION

AAA patients enrolled in the MetAAA trial showed superior health status and QoL compared to AAA patients under regular surveillance.

Elevated EMMPRIN Serum Levels Indicate Plaque Vulnerability in Patients With Asymptomatic High Grade Carotid Stenosis

OBJECTIVE

Carotid atherosclerosis is an important cause of cerebral ischaemic stroke. Sonographic plaque characteristics are inappropriate for exact prediction of possible future ischaemic events. Additional markers are needed to predict the clinical outcome in high grade carotid stenosis. This study aimed to test extracellular matrix metalloproteinase inducer (EMMPRIN), due to its involvement in plaque formation and destabilisation, as a potential marker of high risk vulnerable plaques.

METHODS

EMMPRIN was analysed in pre-operative serum samples from patients with symptomatic and asymptomatic carotid artery stenosis by a specific ELISA. Pre-operative duplex sonography classified the atherosclerotic plaque due to echogenicity. Histopathological analysis of vulnerable and non-vulnerable plaques was based on the American Heart Association (AHA) classification.

RESULTS

The study included 265 patients undergoing carotid endarterectomy: 90 (m:f, 69:21) patients with symptomatic and 175 (m:f, 118:57) with asymptomatic disease. Analysis of circulating EMMPRIN revealed significantly higher levels in patients with echolucent plaques (4 480; IQR 3 745, 6 144 pg/mL) compared with echogenic plaques (4 159; IQR 3 418, 5 402 pg/mL; p = .025). Asymptomatic patients with vulnerable plaques had significantly higher levels of EMMPRIN (4 875; IQR 3 850, 7 016 pg/mL) compared with non-vulnerable plaques (4 109; IQR 3 433, 5 402 pg/mL; p < .001). In logistic regression analysis, duplex sonography combined with age, gender, and clinical risk factors predicted vulnerable plaques in asymptomatic patients with an AUC of 0.71 (95% CI 0.61 - 0.80). EMMPRIN significantly improved the AUC in asymptomatic patients (AUC 0.79; 95% CI 0.71 - 0.87; p = .014).

CONCLUSION

Patients with high risk plaques according to ultrasound and histopathological characteristics demonstrated increased serum EMMPRIN levels. EMMPRIN on top of clinical risk factors, including age, gender, and duplex sonography may be used for pre-operative risk stratification in asymptomatic patients.

Endovascular Repair of Penetrating Thoracic Aortic Ulcers Using Tubular Stent Grafts Versus Stent Grafts With a Proximal Scallop

PURPOSE

In penetrating aortic ulcers (PAUs), limited data support tubular thoracic endovascular aortic repair (TEVAR) as a viable treatment option. For treatment of more proximal PAUs, hybrid approaches and-more recently-scalloped TEVAR (scTEVAR) have been advocated. Outcomes of scTEVAR specifically for PAUs have not yet been reported. This study reports long-term outcomes for tubular and scTEVAR in PAUs and compares the safety profile in both cohorts regarding the significantly more proximal landing zone (LZ) for scTEVAR.

MATERIALS AND METHODS

This single-center retrospective cohort study includes all nonacute patients treated for complicated PAU with scTEVAR and tubular TEVAR. Patient and PAU characteristics as well as procedural success, complication and reintervention rates, and all-cause and aortic mortality were analyzed.

RESULTS

Of 212 TEVAR procedures reviewed, 21 patients with tubular TEVAR and 19 patients with scTEVAR were included. Patient and PAU characteristics were similar, and LZ was significantly more proximal in the scTEVAR cohort (p=0.0001), with similar number and types of supra-aortic revascularization procedures. Clinical success was reached in all 40 patients (100%), and reintervention rate was 2/21 (9.5%) and 1/19 (5.3%), respectively. Over the mean follow-up of 63 (TEVAR) and 53 (scTEVAR) months, clinical success was stable in all patients with one (abdominal) aortic-related mortality in the scTEVAR cohort.

CONCLUSION

Treatment of complicated PAUs with TEVAR as well as scTEVAR provides excellent and similar clinical success, stability of clinical success, and aortic survival with acceptable complication and reintervention rates. Scalloped TEVAR safely lengthens the proximal sealing zone to address more proximal pathologies.

CLINICAL IMPACT

Treatment of asymptomatic complicated penetrating aortic ulcers (PAUs) with thoracic endovascular aortic repair (TEVAR) provides excellent clinical success and acceptable complication and reintervention rates. More patients become amenable to endovascular treatment by including scalloped TEVAR (scTEVAR) as a means to safely lengthen the proximal sealing zone to address more proximal pathologies.

Case Report: Auricular vagus nerve stimulation possibly alleviates COVID-19 disease on a high-risk patient

Introduction: SARS-CoV-2 is a highly contagious virus that was identified as the cause of COVID-19 disease in early 2020. The infection is clinically similar to interstitial pneumonia and acute respiratory distress syndrome (ARDS) and often shows cardiovascular damage. Patients with cardiovascular risk factors are more prone to COVID-19 disease and their sequelae. Due to the anti-inflammatory effect and the improvement in pulmonary function, auricular vagus nerve stimulation (aVNS) therapy might alleviate a COVID-19 infection. Patient and Methods: A high-risk patient with cardiovascular diseases and Implantable Cardioverter Defibrillator (ICD), type 2 diabetes and peripheral arterial disease IV, according to Rutherford`s classification, became infected with COVID-19. The patient underwent wound surgery because of an infected necrosis with a methicillin-resistant Staphylococcus aureus (MRSA) of his small toe and was already on aVNS therapy to relieve his leg pain and improve microcirculation. AVNS was performed with the AuriStim device (Multisana GmbH, Austria), which stimulates vagally innervated regions of the auricle by administering electrical stimulation via percutaneous electrodes for 6 weeks. Results: The multimorbid high-risk patient, who was expected to go through a severe course of the COVID-19 disease, showed hardly any symptoms during ongoing aVNS therapy, while other family members, being much younger and healthy suffered from a more serious course with headache, pneumonia and general weakness. Conclusion: The auricular vagus nerve stimulation is a clinically tested and safe procedure and might represent an alternative and effective way of treating COVID-19 disease. Nevertheless, due to several limitations of this case report, randomized controlled studies are needed to evaluate the efficacy of aVNS therapy on COVID-19 disease.

Oncogenic Addiction of Fibrolamellar Hepatocellular Carcinoma to the Fusion Kinase DNAJB1-PRKACA

PURPOSE

Gene fusions are drivers of many pediatric tumors. In fibrolamellar hepatocellular carcinoma (FLC), a fusion of DNAJB1 and PRKACA is the dominant recurrent mutation. Expression of the DNAJB1-PRKACA fusion gene in mice results in a tumor that recapitulates FLC. However, it is not known whether transient expression of DNAJB1-PRKACA is sufficient only to trigger tumor formation or whether ongoing expression is necessary for maintenance and progression.

EXPERIMENTAL DESIGN

We screened short hairpin RNAs (shRNA) tiled over the fusion junction and identified several potent and specific candidates in vitro and two independent FLC patient-derived xenografts (PDX).

RESULTS

We show that continued DNAJB1-PRKACA expression is not only required for continued tumor growth, but additionally its inhibition results in cell death. Inhibition of DNAJB1-PRKACA by an inducible shRNA in cells of PDX of FLC resulted in cell death in vitro. Induction of the shRNA inhibits FLC tumors growing in mice with no effect on xenografts from a hepatocellular carcinoma cell line engineered to express DNAJB1-PRKACA.

CONCLUSIONS

Our results validate DNAJB1-PRKACA as the oncogene in FLC and demonstrate both a continued requirement for the oncogene for tumor growth as well as an oncogenic addiction that can be exploited for targeted therapies. We anticipate our approach will be useful for investigations of other fusion genes in pediatric cancers and spur development of precision therapies.

Small cell lung cancer: circulating tumor cell lines and expression of mediators of angiogenesis and coagulation

Aim

Coagulation is frequently activated in cancer patients and has been correlated with an unfavorable prognosis. To evaluate whether a putative release of tissue factor (TF) by circulating tumor cells (CTCs) represents a target to impair the dissemination of small cell lung cancer (SCLC), the expression of relevant proteins in a panel of permanent SCLC and SCLC CTC cell lines that have been established at the Medical University of Vienna.

Methods

Five CTC and SCLC lines were analyzed using a TF enzyme-linked immunosorbent assay (ELISA) tests, RNA sequencing, and western blot arrays covering 55 angiogenic mediators. Furthermore, the influence of topotecan and epirubicin as well as hypoxia-like conditions on the expression of these mediators was investigated.

Results

The results demonstrate that the SCLC CTC cell lines express no significant amounts of active TF but thrombospondin-1 (TSP-1), urokinase-type plasminogen activator receptor (uPAR), vascular endothelial-derived growth factor (VEGF) and angiopoietin-2 in two cases. The major difference between the SCLC and SCLC CTC cell lines found was the loss of the expression of angiogenin in the blood-derived CTC lines. Topotecan and epirubicin decreased the expression of VEGF, whereas hypoxia-like conditions upregulated VEGF.

Conclusions

Active TF capable of triggering coagulation seems not to be expressed in SCLC CTC cell lines in significant levels and, thus, CTC-derived TF seems dispensable for dissemination. Nevertheless, all CTC lines form large spheroids, termed tumorospheres, which may become trapped in clots of the microvasculature and extravasate in this supportive microenvironment. The contribution of clotting to the protection and dissemination of CTCs in SCLC may be different from other solid tumors such as breast cancer.

Monoplane versus biplane fluoroscopy in patients undergoing fenestrated/branched endovascular aortic repair

OBJECTIVE

Endovascular aortic repair (EVAR) with fenestrated (F-EVAR) or branched (B-EVAR) endografts represents an indispensable tool of modern patient care in vascular surgery. The purpose of this retrospective study was to evaluate the center's initial experience of F/B-EVAR procedures performed under biplane angiography guidance compared with a historical control group.

METHODS

From January 2020 to March 2022, 80 consecutive patients underwent F/B-EVAR under general anesthesia at a single institution. As from January 2021, the deployment of complex stent grafts was performed using an alternative intraoperative imaging modality-a biplane fluoroscopy and angiography. The cohort was divided into monoplane (MPA) and biplane (BPA) groups according to the imaging modality applied. The end points were operation time, fluoroscopy time, radiation exposure, dose of contrast agent, and technical success.

RESULTS

The MPA group included 59 patients (78% male; median age; 74 years; interquartile range [IQR], 66-78 years) and the BPA group 21 patients (85.7% males; median age, 75 years; IQR, 69-79 years). Operation time (median, 320 minutes; IQR, 266-376 minutes) versus (median, 275 minutes; IQR, 216-333 minutes) was significantly lower in the BPA group (P = .006). The median fluoroscopy time (median, 82 minutes; IQR, 57-110 minutes vs median, 68 minutes; IQR, 54-92 minutes), contrast agent volume applied (median, 220 mL; IQR, 179-250 mL vs median, 200 mL; IQR, 170-250 mL), and radiation dose (dose-area product, median, 413 Gy × cm²; IQR, 249-736 Gy × cm²; vs median, 542 Gy × cm²; IQR, 196-789 Gy × cm²) were similar in both groups. Technical success of 96.6% (57/59 cases) versus 100% (21/21 cases) could be achieved in MPA and BPA group, respectively.

CONCLUSIONS

F/B-EVAR procedures performed under BPA guidance were associated with a significant decrease in operation time.

Radiation and chemotherapeutics are associated with altered aortic aneurysm growth in cancer patients

INTRODUCTION

Co-prevalence of aorto-iliac aneurysm (i.e. AAA) and cancer confronts patients and physicians with two life-threatening diseases. Modern chemotherapeutics and target therapies might impact the aneurysm wall integrity and subsequently affect growth. The purpose of this study was to assess associations between malignancy, therapeutic regimens and the growth rates of aorto-iliac aneurysms.

PATIENTS AND METHODS

A retrospective single-center analysis identified patients with aneurysm + cancer. Patients with ≥2 CT angiograms over ≥6 months and additional malignancy were included. Clinical data and aneurysm diameters were analyzed. AAA growth under cancer therapy (chemotherapy/radiation) was compared to a non-cancer AAA control cohort and to meta-analysis data. Statistics included t-tests and a linear regression model with correction for initial aortic diameter and type of treatment.

RESULTS

From 2003 - 2020, 217 patients (median age 70 years; 92% male) with 246 aneurysms (58.8% AAA) and 238 malignancies were identified. Prostate (27%) and lung (16%) cancer were most frequently seen, 157 patients (72%) received chemotherapy and 105 patients (48%) radiation, thereof 79 (36.4%) both. Annual AAA growth was not significantly different for cancer and non-cancer patients (2.0±2.3 vs. 2.8±2.1mm/y, p=0.20). However, subgroup analyses revealed that radiation was associated with a significantly reduced aneurysm growth rate compared to cancer patients without radiation (1.1±1.3 vs. 1.6±2.1 mm/y, p=0.046) and to the non-cancer control cohort (1.7±1.9 vs. 2.8±2.1 mm/y, p=0.007). Administration of antimetabolites showed significantly increased AAA growth (+0.9mm/year, p=0.011), while e.g. topoisomerase inhibitors (-0.8mm/year, p=0.17) and anti-androgens (-0.5mm/year, p=0.27) showed a possible trend for reduced growth. Similar was observed for iliac aneurysms (n=85). Additionally, effects were persistent in combinations of chemotherapies (2.6±1.4 substances/patient).

CONCLUSION

Cancer patients with concomitant aortic aneurysms may require intensified monitoring when undergoing specific therapies, such as antimetabolites, since they may experience an increased aneurysm growth rate. Radiation may be associated with reduced aneurysm growth.

3D Ultrasound Measurements Are Highly Sensitive to Monitor Formation and Progression of Abdominal Aortic Aneurysms in Mouse Models

Background

Available mouse models for abdominal aortic aneurysms (AAAs) differ substantially in the applied triggers, associated pathomechanisms and rate of vessel expansion. While maximum aortic diameter (determined after aneurysm excision or by 2D ultrasound) is commonly applied to document aneurysm development, we evaluated the sensitivity and reproducibility of 3D ultrasound to monitor aneurysm growth in four distinct mouse models of AAA.

Methods

The models included angiotensin-II infusion in ApoE deficient mice, topical elastase application on aortas in C57BL/6J mice (with or without oral administration of β-aminoproprionitrile) and intraluminal elastase perfusion in C57BL/6J mice. AAA development was monitored using semi-automated 3D ultrasound for aortic volume calculation over 12 mm length and assessment of maximum aortic diameter.

Results

While the models differed substantially in the time course of aneurysm development, 3D ultrasound measurements (volume and diameter) proved highly reproducible with concordance correlation coefficients > 0.93 and variations below 9% between two independent observers. Except for the elastase perfusion model where aorta expansion was lowest and best detected by diameter increase, all other models showed high sensitivity of absolute volume and diameter measurements in monitoring AAA formation and progression by 3D ultrasound. When compared to standard 2D ultrasound, the 3D derived parameters generally reached the highest effect size.

Conclusion

This study has yielded novel information on the robustness and limitations of semi-automated 3D ultrasound analysis and provided the first direct comparison of aortic volume increase over time in four widely applied mouse models of AAA. While 3D ultrasound generally proved highly sensitive in detecting early AAA formation, the 3D based volume analysis was found inferior to maximum diameter assessment in the elastase perfusion model where the extent of inflicted local injury is determined by individual anatomical features.

Use of a Steerable Sheath for Completely Femoral Access in Branched Endovascular Aortic Repair Compared to Upper Extremity Access

PURPOSE

To compare bridging stent graft (BSG) implantation in downward oriented branches in branched endovascular aortic repair (bEVAR), using a commercially available steerable sheath from an exclusively femoral access (TFA) with traditional upper extremity access (UEA).

METHODS

In a retrospective cohort study, 7 patients with 19 branches in the TFA cohort received BSG insertion using the Medtronic Heli FX steerable sheath from a femoral access, and 10 patients with 32 branches in the UEA cohort from a brachial approach. Technical success, total intervention time, fluoroscopy time, branch cannulation time, and complication rate were recorded.

RESULTS

Technical success was 19/19 branches in the TFA and 31/32 in the UEA cohort. The mean branch cannulation time was considerably shorter in the TFA group (17 vs. 29 min, p = 0.003), and total intervention time tended to be shorter (169 vs. 217 min, p = 0.176).

CONCLUSION

Using a commercially available steerable sheath allowed successful cannulation of all branches in this cohort and was associated with significantly shorter branch cannulation times. Potentially, this technique can lower the stroke and brachial puncture site complication risk as well as reduce total intervention time and radiation dose.

LEVEL OF EVIDENCE

2b, retrospective cohort study.

Effects of metformin on human bone-derived mesenchymal stromal cell-breast cancer cell line interactions

Metformin is used to treat patients with type 2 diabetes mellitus and was found to lower the incidence of cancer. Bone metastasis is a common impairment associated with advanced breast cancer. The present study investigated the effects of metformin on human bone-derived mesenchymal stromal cells (BM-MSC)—breast cancer cell line interactions. BM-MSCs grown from box chisels were tested for growth-stimulating and migration-controlling activity on four breast cancer cell lines either untreated or after pretreatment with metformin. Growth stimulation was tested in MTT tests and migration in scratch assays. Furthermore, the expression of adipokines of BM-MSCs in response to metformin was assessed using Western blot arrays. Compared to breast cancer cell lines (3.6 ± 1.4% reduction of proliferation), 500 µM metformin significantly inhibited the proliferation of BM-MSC lines (mean 12.3 ± 2.2 reduction). Pretreatment of BM-MSCs with metformin showed variable effects of the resulting conditioned media (CM) on breast cancer cell lines depending on the specific BM-MSC—cancer line combination. Metformin significantly reduced the migration of breast cancer cell lines MDA-MB-231 and MDA-MB-436 in response to CM of drug-pretreated BM-MSCs. Assessment of metformin-induced alterations in the expression of adipokines by BM-MSC CM indicated increased osteogenic signaling and possibly impairment of metastasis. In conclusion, the anticancer activities of metformin are the result of a range of direct and indirect mechanisms that lower tumor proliferation and progression. A lower metformin-induced protumor activity of BM-MSCs in the bone microenvironment seem to contribute to the positive effects of the drug in selected breast cancer patients.

The Femoral Vein as a Long-Term Aorto-Iliac Graft for Aortic Infection and Aortitis

Background

Reconstruction of the aorto-iliac segment with femoral vein (FV) as substitute for infected synthetic grafts or mycotic aneurysms constitutes the most sustainably convenient alternative. The aim of this study was to evaluate the long-term outcome of up to 16 years of follow-up, analysing the morphologic adaption of the FV with special emphasis on the distal and proximal anastomoses.

Methods

We conducted a retrospective study of 22 patients with 109 computed tomography angiograms (CTAs) treated between August 2001 and January 2020 in case of aortic infection/aortitis. Morphologic changes like anastomotic dilatation/stenosis as well as changes of FV wall thickness were retrospectively analysed in pre- and postoperative CTAs.

Results

Elective procedure was done in 17/22 (77%) cases, and 5/22 (23%) patients required emergent surgery. The median follow-up was 91.5 months (P₂₅;P₇₅ = 21;117). Cross-sectional diameter of proximal (20.38 ± 3.77 vs 22.04 ± 3.97 mm, p = 0.007) and distal anastomoses (13.05 ± 4.23 vs 14.61 ± 5.19 mm, p = 0.05) increased significantly, as well as the proximal and distal anastomotic areas (3.36 ± 1.29 vs 4.32 ± 1.63 mm², p = 0.04 and 0.99 ± 0.48 vs 1.25 ± 0.72 mm², p = 0.023, respectively). Venous wall thickness was significantly reduced at the anastomotic site (1.74 ± 0.46 vs 1.24 ± 0.31 mm, p = 0.001). The upper thigh diameter did not differ before and after harvesting of the FV (161.6 ± 29.1 vs. 178.2 ± 23.3 mm, p = 0.326, respectively).

Conclusion

This long-term CTA follow-up study showed that the FV wall becomes thinner at the anastomotic site, and the anastomoses dilate with time without rupture. The FV is a durable conductor after replacement of the aorto-iliac segment due to aortic infection. Further CTA studies from more centres are warranted to evaluate the risk of vein rupture.

A Real World 10-Year Experience With Vascular Closure Devices and Large-Bore Access in Patients Undergoing Transfemoral Transcatheter Aortic Valve Implantation

Transcatheter aortic valve replacement (TAVR) has established itself as a safe and efficient treatment option in patients with severe aortic valve stenosis, regardless of the underlying surgical risk. Widespread adoption of transfemoral procedures led to more patients than ever being eligible for TAVR. This increase in procedural volumes has also stimulated the use of vascular closure devices (VCDs) for improved access site management. In a single-center examination, we investigated 871 patients that underwent transfemoral TAVR from 2010 to 2020 and assessed vascular complications according to the Valve Academic Research Consortium (VARC) III recommendations. Patients were grouped by the VCD and both, vascular closure success and need for intervention were analyzed. In case of a vascular complication, the type of intervention was investigated for all VCDs. The Proglide VCD was the most frequently used device (n = 670), followed by the Prostar device (n = 112). Patients were old (median age 83 years) and patients suffered from high comorbidity burden (60% coronary artery disease, 30% type II diabetes, 40% atrial fibrillation). The overall rate of major complications amounted to 4.6%, it was highest in the Prostar group (9.6%) and lowest in the Manta VCD group (1.1% p = 0.019). The most frequent vascular complications were bleeding and hematoma (n = 110, 13%). In case a complication occurred, 72% of patients did not need any further intervention other than manual compression or pressure bandages. The rate of surgical intervention after complication was highest in the Prostar group (n = 15, 29%, p = 0.001). Temporal trends in VCD usage highlight the rapid adoption of the Proglide system after introduction at our institution. In recent years VCD alternatives, utilizing other closure techniques, such as the Manta device emerged and increased vascular access site management options. This 10-year single-center experience demonstrates high success rates for all VCDs. Despite successful closure, a significant number of patients does experience minor vascular complications, in particular bleeding and hematoma. However, most complications do not require surgical or endovascular intervention. Temporal trends display a marked increase in TAVR procedures and highlight the need for more refined vascular access management strategies.

Association of Lipoproteins with Neutrophil Extracellular Traps in Patients with Abdominal Aortic Aneurysm

Neutrophil extracellular traps (NETs) are DNA–protein structures released by neutrophils in response to various stimuli, including oxidized, low-density lipoprotein (oxLDL). Accumulating evidence suggests a role for NETs in the pathogenesis of abdominal aortic aneurysm (AAA). In this study, we investigated the potential association of lipoprotein particles and NETs in AAA in comparison to non-AAA control groups. The concentrations of neutrophil myeloperoxidase (MPO), the NET parameters citrullinated histone H3 (citH3) and circulating cell-free DNA (cfDNA), as well as of blood lipids were determined in plasma or serum of patients with AAA (n = 40), peripheral artery occlusive disease (PAD; n = 40) and healthy donors (n = 29). A sandwich ELISA detecting oxidized phosphatidylcholine in association with apolipoprotein B-100 (oxPL/apoB) was applied to measure oxidized phospholipids in circulation. The effect of lipoparticles on NET formation was tested using a DNA release assay with isolated human neutrophils. Plasma MPO, citH3 and cfDNA levels were significantly increased in AAA patients in comparison to healthy donors and PAD patients. Plasma concentrations of citH3 positively correlated with serum oxPL/apoB in AAA patients. In functional in vitro assays, the addition of oxLDL induced NET formation in pre-stimulated neutrophils. In conclusion, our data suggest a promoting role of oxLDL on NET formation in AAA patients.

AAA Revisited: A Comprehensive Review of Risk Factors, Management, and Hallmarks of Pathogenesis

Despite declining incidence and mortality rates in many countries, the abdominal aortic aneurysm (AAA) continues to represent a life-threatening cardiovascular condition with an overall prevalence of about 2-3% in the industrialized world. While the risk of AAA development is considerably higher for men of advanced age with a history of smoking, screening programs serve to detect the often asymptomatic condition and prevent aortic rupture with an associated death rate of up to 80%. This review summarizes the current knowledge on identified risk factors, the multifactorial process of pathogenesis, as well as the latest advances in medical treatment and surgical repair to provide a perspective for AAA management.

The prognostic impact of vascular calcification on abdominal aortic aneurysm progression

OBJECTIVE

The maximal aortic diameter is currently the only clinically applied predictor of abdominal aortic aneurysm (AAA) progression. It is known that risk of rupture is associated with aneurysm size, hence accurate monitoring of AAA expansion is crucial. Aneurysmal vessel wall calcification and its implication on AAA expansion are insufficiently explored. We evaluated the vascular calcification using longitudinal computed tomography angiographies (CTA) of AAA patients and its association with AAA growth.

METHODS

We conducted a retrospective study of 102 AAA patients with a total number of 389 abdominal CTAs at six-month intervals, treated and followed-up at the Division of Vascular Surgery, Department of General Surgery, Medical University of Vienna. Digitally stored CTAs were reviewed for vascular calcification (volume and score) of the infrarenal aorta and common iliac arteries as well as for morphometric AAA analysis. In the prognostic setting, slow versus fast AAA progression was defined as < 2 or ≥ 2 mm increase in AAA diameter over six months. In addition, to analyze the association of vascular calcification and AAA growth rate with longitudinal monitoring data, a specifically tailored log-linear mixed model was employed.

RESULTS

An inverse relation of increased abdominal vessel wall calcification and short-term AAA progression was detected. Compared to fast progressing AAA, the median calcification volume of the infrarenal aorta (1225.3 vs 519.8 mm³, P = 0.003), the median total calcification volume (2014.1 vs 1434.9 mm³, P = 0.008) and the median abdominal total customized Agatston calcium (cAC) score (1663.5 vs 718.4, P = 0.003) were significantly increased in slow progressing AAA. Importantly, a log-linear mixed model efficiently predicted AAA expansion based on current diameter and abdominal total cAC score (P = 0.042).

CONCLUSION

We assessed the prognostic value of CTA-measured vascular calcification for AAA progression. Increased vascular calcification stabilizes the aortic aneurysmal wall and likely protects against progressive AAA expansion, resulting in a significant decrease of aneurysm growth over time. As a consequence, this may have implications for rupture risk, mortality, morbidity, and cost.

Growth prediction model for abdominal aortic aneurysms

BACKGROUND

The most relevant determinant in scheduling monitoring intervals for abdominal aortic aneurysms (AAAs) is maximum diameter. The aim of the study was to develop a statistical model that takes into account specific characteristics of AAA growth distributions such as between-patient variability as well as within-patient variability across time, and allows probabilistic statements to be made regarding expected AAA growth.

METHODS

CT angiography (CTA) data from patients monitored at 6-month intervals with maximum AAA diameters at baseline between 30 and 66 mm were used to develop the model. By extending the model of geometric Brownian motion with a log-normal random effect, a stochastic growth model was developed. An additional set of ultrasound-based growth data was used for external validation.

RESULTS

The study data included 363 CTAs from 87 patients, and the external validation set comprised 390 patients. Internal and external cross-validation showed that the stochastic growth model allowed accurate description of the distribution of aneurysm growth. Median relative growth within 1 year was 4.1 (5-95 per cent quantile 0.5-13.3) per cent. Model calculations further resulted in relative 1-year growth of 7.0 (1.0-16.4) per cent for patients with previously observed rapid 1-year growth of 10 per cent, and 2.6 (0.3-8.3) per cent for those with previously observed slow growth of 1 per cent. The probability of exceeding a threshold of 55 mm was calculated to be 1.78 per cent at most when adhering to the current RESCAN guidelines for rescreening intervals. An online calculator based on the fitted model was made available.

CONCLUSION

The stochastic growth model was found to provide a reliable tool for predicting AAA growth.

Concomitantly discovered visceral artery aneurysms do rarely grow during cancer therapy

Visceral artery aneurysms (VAA) are a rare entity of arterial aneurysms with the imminent threat of rupture. The impact of cancer and chemotherapy on the growth of VAAs is unknown. A retrospective dual center cohort study of patients with concomitant VAA and different types of cancer was conducted and the impact of various chemotherapeutic agents on VAA growth was studied by sequential CT analysis. For comparison, a non-cancer all comer cohort with VAAs and no cancer was studied to compare different growth rates. The primary endpoint was aneurysm progress or regression >1.75 mm. Chi-square test, Fisher's exact test and Mann-Whitney test was used for statistical comparison. In the 17-year-period from January 2003 to March 2020, 59 patients with 30 splenic artery aneurysms, 14 celiac trunk aneurysms, 11 renal artery aneurysms and 4 other VAA and additional malignancy were identified. 20% of patients suffered from prostate cancer, the rest were heterogeneous. The most prevalent chemotherapies were alkylating agents (23%), antimetabolites (14%) and mitose inhibitors (10%). Eight patients had relevant growth of their VAA and one patient showed diameter regression (average growth rate 0.1 ± 0.5 mm/year). Twenty-nine patients with 14 splenic, 11 RAAs (seven right) and 4 celiac trunk aneurysms were available in the non-cancer comparison cohort (average growth rate 0.5 ± 0.9 mm/year, p = 0.058). However, the growth rate of patients receiving operative treatment for relevant VAA growth was significantly higher (p = 0.004). VAAs grow rarely, and rather slow. Cancer and/or chemotherapy do not significantly influence the annual growth rate. Additional control examinations seem unnecessary.

Bursted auricular vagus nerve stimulation alters heart rate variability in healthy subjects

Objective.Recent research suggests that percutaneous auricular vagus nerve stimulation (pVNS) beneficially modulates the autonomic nervous system (ANS). Bursted pVNS seems to be efficient for nerve excitation. Bursted pVNS effects on cardiac autonomic modulation are not disclosed yet.Approach.For the first time, the present study evaluates the effect of pVNS on cardiac autonomic modulation in healthy subjects (n = 9) using two distinct bursted stimulation patterns (biphasic and triphasic stimulation) and heart rate variability analysis (HRV). Stimulation was delivered via four needle electrodes in vagally innervated regions of the right auricle. Each of the two bursted stimulation patterns was applied twice in randomized order over four consecutive stimulation sessions per subject.Main results.Bursted pVNS did not change heart rate, blood pressure, and inflammatory parameters in study subjects. pVNS significantly increased the standard deviation of heart inter-beat intervals, from 46.39 ± 10.4 ms to 63.46 ± 22.47 ms (p < 0.05), and the total power of HRV, from 1475.7 ± 616.13 ms²to 3190.5 ± 2037.0 ms²(p < 0.05). The high frequency (HF) power, the low frequency (LF) power, and theLF/HFratio did not change during bursted pVNS. Both stimulation patterns did not show any significant differences in cardiac autonomic modulation. Stimulation intensity to reach a tingling sensation was significantly lower in triphasic compared to biphasic stimulation (p< 0.05). Bursted stimulation was well tolerated.Significance.Bursted pVNS seems to affect cardiac autonomic modulation in healthy subjects, with no difference between biphasic and triphasic stimulation, the latter requiring lower stimulation intensities. These findings foster implementation of more efficient pVNS stimulation.

Synergistic cytotoxicity of the CDK4 inhibitor Fascaplysin in combination with EGFR inhibitor Afatinib against Non-small Cell Lung Cancer

In the absence of suitable molecular markers, non-small cell lung cancer (NSCLC) patients have to be treated with chemotherapy with poor results at advanced stages. Therefore, the activity of the anticancer marine drug fascaplysin was tested against primary NSCLC cell lines established from pleural effusions. Cytotoxicity of the drug or combinations were determined using MTT assays and changes in intracellular phosphorylation by Western blot arrays. Fascaplysin revealed high cytotoxicity against NSCLC cells and exhibit an activity pattern different of the standard drug cisplatin. Furthermore, fascaplysin synergizes with the EGFR tyrosine kinase inhibitor (TKI) afatinib to yield a twofold increased antitumor effect. Interaction with the Chk1/2 inhibitor AZD7762 confirm the differential effects of fascplysin and cisplatin. Protein phosphorylation assays showed hypophosphorylation of Akt1/2/3 and ERK1/2 as well as hyperphosphorylation of stress response mediators of H1299 NSCLC cells. In conclusion, fascaplysin shows high cytotoxicity against pleural primary NSCLC lines that could be further boosted when combined with the EGFR TKI afatinib.

Interactions of BRCA1-mutated Breast Cancer Cell Lines with Adipose-derived Stromal Cells (ADSCs)

Lipofilling may constitute a technique to assist reconstruction of breasts following prophylactic mastectomy for patients with mutated BRCA1 or BRCA2 genes. However, to date it is not clear whether adipose-derived stromal cells (ADSCs) increase the risk of tumor initiation and progression in this situation. Therefore, the interactions of BRCA1 mutated breast cancer cell lines with normal ADSCs were investigated in the present study. Characteristics of MDA-MB-436 (BRCA1 c.5277 + 1G > A) and HCC1937 (BRCA1 p.Gln1756.Profs*74) were compared to MDA-MB-231 and T47D BRCA1/2 wild-type breast cancer cell lines. ADSCs were cultivated from lipoaspirates of a panel of BRCA1/2- wildtype patients. Interactions of conditioned medium (CM) of these cells with the breast cancer lines were studied using proliferation and migration assays as well as adipokine expression western blot arrays. CM of ADSCs exhibit a dose-dependent stimulation of the proliferation of the breast cancer cell lines. However, of the ADSC preparations tested, only 1 out of 18 samples showed a significant higher stimulation of BRCA1-mutated MDA-MB-436 versus wildtype MDA-MB-231 cells, and all CM revealed lower stimulatory activity for BRCA1-mutated HCC1937 versus wildtype T47D cells. Additionally, migration of breast cancer cells in response to CM of ADSCs proved to be equivalent or slower for BRCA1/2 mutated versus nonmutated cancer cells and, with exception of angiopoietin-like 2, induced expression of adipokines showed no major difference. Effects of media conditioned by normal ADSCs showed largely comparable effects on BRCA1-mutated and wildtype breast cancer cell lines thus advocating lipofilling, preferentially employing allogeneic non-mutated ADSCs.

Histone citrullination as a novel biomarker and target to inhibit progression of abdominal aortic aneurysms

Neutrophil extracellular traps (NETs) have been implicated in the pathogenesis of abdominal aortic aneurysms (AAAs). This study has addressed the notion that NET components might serve as AAA biomarkers or novel targets of AAA therapy. Thus, parameters of neutrophil activation and NET formation were measured in plasma. Their diagnostic marker value was explored in 41 AAA patients and 38 healthy controls. The NET parameter citrullinated histone H3 (citH3) was then validated in 63 AAA patients and 63 controls matched for cardiovascular disease. The prognostic marker potential was investigated in 54 observation periods of AAA growth over 6 months. NETs were further assessed in conditioned medium and sections of aortic tissue. CitH3 was found to be increased in blood (median 362 vs 304 ng/mL, P = 0.004) and aortic tissue (50 vs 1.5 ng/mg, P < 0.001) of AAA patients compared to healthy controls and accumulated in the intraluminal thrombus (629 ng/mg). The diagnostic potential of citH3 ranged at 0.705 area under the ROC curve (AUROC) and was validated with the independent sample set. Furthermore, plasma citH3 predicted AAA growth over the next 6 months (AUROC: 0.707, P = 0.015) and dropped significantly after surgical aneurysm repair. In an angiotensin II - based mouse model of experimental AAA, an inhibitor of histone citrullination was applied to block NET formation and AAA progression. Of note, further growth of an established aneurysm was prevented in mice treated with the NET inhibitor (P = 0.040). In conclusion, histone citrullination represents a promising AAA biomarker and potential therapeutic target to control disease progression.

Endovascular Stent-Graft Repair of the Ascending Aorta: Assessment of a Specific Novel Stent-Graft Design in Phantom, Cadaveric, and Clinical Application

Purpose

To test a stent-graft specifically designed for the ascending aorta in phantom, cadaver, and clinical application, and to measure deployment accuracy to overcome limitations of existing devices.

Methods

A stent-graft has been designed with support wires to fixate the apices toward the inner curvature, thereby eliminating the forward movement of the proximal end which can happen with circumferential tip capture systems. The device was deployed in three aortic phantoms, and in four cadavers, deployment precision was measured. Subsequently, the device was implanted in a patient to exclude a pseudoaneurysm originating from the distal anastomosis after ascending aortic replacement.

Results

The stent-grafts were successfully deployed in all phantoms and cadavers. Deployment accuracy of the proximal end of the stent-graft was within 1 mm proximally and 14 mm distally to the intended landing zone on the inner curvature, and 2–8 mm distal to the intended landing zone on the outer curvature. In clinical application, the pseudoaneurysm could be successfully excluded without complications.

Conclusion

The novel stent-graft design promises accurate placement in the ascending aorta. The differential deployment of the apices at the inner and outer curvatures allows deployment perpendicular to the aortic axis.

Level of Evidence

No level of evidence.

Abdominal aortic aneurysm and virus infection: A potential causative role for cytomegalovirus infection?

An abdominal aortic aneurysm (AAA) is a multifactorial disease with a variety of genetic and environmental risk factors, but the exact mechanism of AAA formation and progression is still not well understood. The present study investigated the frequency of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and papillomavirus types 6 and 11 (HPV6 and HPV11), their impact on clinical manifestations of cardiovascular diseases, and their possible association with inflammation in patients with AAA and healthy volunteers. Genotyping of CMV UL75, EBV LMP-1, and HPV6, and HPV11 E6 was performed by polymerase chain reaction (PCR), while the viral DNA loads were measured by quantitative real-time PCR. Cytokine levels were determined by enzyme-linked immunosorbent assays. The CMV UL75 was detected more frequently in the blood of patients with AAA than in the blood of healthy volunteers (32.7% vs. 6.3%, p < .0001). Neither EBV LMP-1 nor HPV6 E6 was found in blood and aortic wall biopsies, while the HPV11 E6 was detected in 36.4% of AAA walls. The CMV infection in patients with AAA was associated with an increased risk of hypertension and coronary artery disease (OR, 9.057; 95% CI, 1.141-71.862; p = .037; and OR, 2.575; 95% CI, 1.002-6.615; p = .049, respectively). Additionally, CMV-infected patients with AAA had higher tumor necrosis factor-α levels compared with noninfected subjects (p = .017). Our findings suggest that CMV infection can stimulate local inflammation in the aorta but is not a direct cause of most abdominal aortic aneurysms.

ELISA detection of MPO-DNA complexes in human plasma is error-prone and yields limited information on neutrophil extracellular traps formed in vivo

Over the past years, neutrophil extracellular traps (NETs) were shown to contribute to states of acute and chronic inflammatory disease. They are composed of expelled chromatin and decorated by neutrophil-derived proteins. Therefore, the analysis of DNA complexes with myeloperoxidase (MPO) by ELISA has become an attractive tool to measure NET formation in in vitro and in vivo samples. When we used a published MPO-DNA ELISA protocol and included an isotype control for the anti-MPO coating antibody, we observed high assay specificity for in vitro prepared NET samples, whereas the specificity for in vivo plasma samples was low. In addition, the assay failed to detect in vitro generated MPO-DNA complexes when spiked into plasma. Therefore, we set out to improve the specificity of the MPO-DNA ELISA for plasma samples. We found that the use of Fab fragments or immunoglobulins from different species or reversal of the antibody pair led to either a high background or a low dynamic range of detection that did not improve the specificity for plasma samples. Also, the use of higher plasma dilutions or pre-clearing of plasma immunoglobulins were ineffective. Finally, we found that a commercial reagent designed to block human anti-mouse antibodies and multivalent substances increased the detection window between the MPO antibody and isotype control for highly diluted plasma. We applied this modified ELISA protocol to analyze MPO-DNA complexes in human blood samples of acute and chronic inflammatory conditions. While markers of neutrophil activation and NET formation such as MPO, elastase and citrullinated histone H3 correlated significantly, we observed no correlation with the levels of MPO-DNA complexes. Therefore, we conclude that ELISA measurements of MPO-DNA complexes in human plasma are highly questionable regarding specificity of NET detection. In general, plasma analyses by ELISA should more frequently include isotype controls for antibodies to demonstrate target specificity.

Neutrophil Extracellular Traps and Their Implications in Cardiovascular and Inflammatory Disease

Neutrophils are primary effector cells of innate immunity and fight infection by phagocytosis and degranulation. Activated neutrophils also release neutrophil extracellular traps (NETs) in response to a variety of stimuli. These NETs are net-like complexes composed of cell-free DNA, histones and neutrophil granule proteins. Besides the evolutionarily conserved mechanism to capture and eliminate pathogens, NETs are also associated with pathophysiological processes of various diseases. Here, we elucidate the mechanisms of NET formation and their different implications in disease. We focused on autoinflammatory and cardiovascular disorders as the leading cause of death. Neutrophil extracellular traps are not only present in various cardiovascular diseases but play an essential role in atherosclerotic plaque formation, arterial and venous thrombosis, as well as in the development and progression of abdominal aortic aneurysms. Furthermore, NETosis can be considered as a source of autoantigens and maintains an inflammatory milieu promoting autoimmune diseases. Indeed, there is further need for research into the balance between NET induction, inhibition, and degradation in order to pharmacologically target NETs and their compounds without impairing the patient’s immune defense. This review may be of interest to both basic scientists and clinicians to stimulate translational research and innovative clinical approaches.

Complement Factor C5a Is Increased in Blood of Patients with Abdominal Aortic Aneurysm and Has Prognostic Potential for Aneurysm Growth

In this observational case-control study, circulating levels of complement factors C3a and C5a and leukotriene B4 (LTB4) were analysed in abdominal aortic aneurysm (AAA) patients regarding their association with diagnosis and prognosis. Serum C5a was significantly raised in AAA patients compared to healthy controls—median 84.5 ng/ml (IQR = 37.5 ng/ml) vs. 67.7 ng/ml (IQR = 26.2 ng/ml), p = 0.007—but was not elevated in patients with athero-occlusive disease. Serum C5a levels correlated significantly with the increase in maximum AAA diameter over the following 6 months (r = 0.319, p = 0.021). The median growth in the lowest quartile of C5a (< 70 ng/ml) was 50% less compared to the highest C5a quartile (> 101 ng/ml): 1.0 mm/6 months (IQR = 0.8 mm) vs. 2.0 mm/6 months (IQR = 1.5 mm), p = 0.014. A log-linear mixed model predicted AAA expansion based on current diameter and C5a level. To our knowledge, this is the first study linking complement activation, in particular C5a serum level, with AAA progression.

Novel prefabricated bovine pericardial grafts as alternate conduit for septic aortoiliac reconstruction

OBJECTIVE

Infection of prosthetic aortic grafts represents a serious complication with high morbidity and mortality. Replacement with autologous material is recommended; however, in its absence, biological material should be favored. In the present retrospective cohort study, we evaluated the short- and midterm results with the use of commercially available prefabricated bovine pericardium grafts (BPGs) used for the management of aortic graft infection or aortic reconstructive surgery in the presence of systemic infection.

METHODS

We performed a retrospective analysis of patients in whom BPGs had been used for aortic reconstruction at two vascular centers. Prefabricated vascular pericardium grafts were preferred over other biological reconstruction techniques for selected cases. Comorbidities, procedure-related details, perioperative morbidity, clinical outcomes, and mortality were analyzed.

RESULTS

From 2014 to 2019, 21 patients had received BPGs at two Austrian vascular centers. Their median age was 63 years (interquartile range [IQR], 55-71 years), the patients were predominantly male (76%), and the median body mass index was 25.3 kg/m² (IQR, 21.7-27.3 kg/m²). The major comorbidities included arterial hypertension, peripheral artery disease, smoking, and chronic pulmonary disease. The indications for surgery were vascular graft or endograft infection in 62% and aortic reconstruction in the presence of systemic infection in 38%. Three patients (14%) had aortoenteric fistulas. Surgery was technically successful in all cases. The median follow-up was 21.6 months (IQR, 6.0-34.6 months). The 30-day mortality was 9.5%. The 1- and 2-year overall survival was 84% and 75%, respectively. Of the 21 patients, 89% had remained free of recurrent infection. One of the two reinfections had resolved after treatment of the underlying focus. At 2 years, the primary and assisted primary patency rates were 86% and 94%, respectively. No limbs were lost during follow-up.

CONCLUSIONS

Prefabricated BPGs represent a promising alternative for the management of aortic graft infections and aortoiliac reconstruction in the presence of systemic infection.

Effects of metformin on adipose-derived stromal cell (ADSC) - Breast cancer cell lines interaction

AIMS

Metformin is a clinical drug administered to patients to treat type 2 diabetes mellitus that was found to be associated with a lower risk of occurrence of cancer and cancer-related death. The present study investigated the effects of metformin on human adipose-derived stromal cells (ADSC) - breast cancer cell line interactions.

MAIN METHODS

ADSCs grown from lipoaspirates were tested for growth-stimulating and migration-controlling activity on breast cancer cell lines after pretreatment with metformin. Furthermore, secreted proteins of ADSCs, phosphorylation of intracellular proteins and the effect of metformin on adipocytic differentiation of ADSCs were assayed.

KEY FINDINGS

Compared to breast cancer cell lines (4.0 ± 3.5% reduction of proliferation), 2 mM metformin significantly inhibited the proliferation of ADSC lines (19.2 ± 8.4% reduction of proliferation). This effect on ADSCs seems to be mediated by altered phosphorylation of GSK-3, CREB and PRAS40. Furthermore, treatment with metformin abolished the induction of differentiation of three ADSC lines to adipocytes. 1 and 2 mM metformin significantly impaired the migration of breast cancer cell lines MDA-MB-231 and MDA-MB-436 in scratch assays.

SIGNIFICANCE

Metformin showed low direct inhibitory effects on breast cancer cell lines at physiological concentrations but exerted a significant retardation of the growth and the adipocytic differentiation of ADSCs. Thus, the anticancer activity of metformin in breast cancer at physiological drug concentrations seems to be mediated by an indirect mechanism that lowers the supportive activity of ADSCs.

Non-invasive Auricular Vagus Nerve Stimulation as a Potential Treatment for Covid19-Originated Acute Respiratory Distress Syndrome

Background: Covid-19 is an infectious disease caused by an invasion of the alveolar epithelial cells by coronavirus 19. The most severe outcome of the disease is the Acute Respiratory Distress Syndrome (ARDS) combined with hypoxemia and cardiovascular damage. ARDS and co-morbidities are associated with inflammatory cytokine storms, sympathetic hyperactivity, and respiratory dysfunction. Hypothesis: In the present paper, we present and justify a novel potential treatment for Covid19-originated ARDS and associated co-morbidities, based on the non-invasive stimulation of the auricular branch of the vagus nerve. Methods: Auricular vagus nerve stimulation activates the parasympathetic system including anti-inflammatory pathways (the cholinergic anti-inflammatory pathway and the hypothalamic pituitary adrenal axis) while regulating the abnormal sympatho-vagal balance and improving respiratory control. Results: Along the paper (1) we expose the role of the parasympathetic system and the vagus nerve in the control of inflammatory processes (2) we formulate our physiological and methodological hypotheses (3) we provide a large body of clinical and preclinical data that support the favorable effects of auricular vagus nerve stimulation in inflammation, sympatho-vagal balance as well as in respiratory and cardiac ailments, and (4) we list the (few) possible collateral effects of the treatment. Finally, we discuss auricular vagus nerve stimulation protective potential, especially in the elderly and co-morbid population with already reduced parasympathetic response. Conclusions: Auricular vagus nerve stimulation is a safe clinical procedure and it could be either an effective treatment for ARDS originated by Covid-19 and similar viruses or a supplementary treatment to actual ARDS therapeutic approaches.

Genetics and Epigenetics of Sex Bias: Insights from Human Cancer and Autoimmunity

High-throughput sequencing and genome-wide association studies have revealed a sex bias in human diseases. The underlying molecular mechanisms remain, however, unknown. Here, we cover recent advances in cancer and autoimmunity focusing on intrinsic genetic and epigenetic differences underlying sex biases in human disease. These studies reveal a central role of genome regulatory mechanisms including genome repair, chromosome folding, and epigenetic regulation in dictating the sex bias. These highlight the importance of considering sex as a variable in both basic science and clinical investigations. Understanding the molecular mechanisms underlying sex bias in human diseases will be instrumental in making a first step forwards into the era of personalized medicine.