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In order to avoid aneurysm rupture, flow-diverting stents are deployed. This research presents a simplified patient-specific abdominal aortic model to test and assess the effects of three different not-covered flow-diverting stents (NCFDS): WALLSTENT™ is a commercially available NCFDS, while STENT BS and STENT PFS are numerically designed NCFDSs. Flow characteristics in abdominal aortic aneurysms (AAA) were studied using computational fluid dynamics (CFD) techniques on each stent before and after the procedure. We computed and compared the estimated flow structure, pressure, and wall shear stress (WSS) related indices between the three NCFDSs; these are crucial factors for evaluating aneurysm occlusion and rupture. The minimum estimated flow, pressure, and time average wall shear stress (TAWSS) and the maximum oscillatory shear index (OSI) and endothelial cell action potential (ECAP) are associated with using STENT PFS. Therefore, it may contribute to establishing a thrombus within the aneurysm sac and aneurysm shrinkage. [ABSTRACT FROM AUTHOR]

Reported in this paper is a cutting‐edge computational investigation into the influence of geometric characteristics on abdominal aortic aneurysm (AAA) rupture risk, beyond the traditional measure of maximum aneurysm diameter. A Comprehensive fluid–structure interaction (FSI) analysis was employed to assess risk factors in a range of patient scenarios, with the use of three‐dimensional (3D) AAA models reconstructed from patient‐specific aortic data and finite element method. Wall shear stress (WSS), and its derivatives such as time‐averaged WSS (TAWSS), oscillatory shear index (OSI), relative residence time (RRT) and transverse WSS (transWSS) offer insights into the force dynamics acting on the AAA wall. Emphasis is placed on these WSS‐based metrics and seven key geometric indices. By correlating these geometric discrepancies with biomechanical phenomena, this study highlights the novel and profound impact of geometry on risk prediction. This study demonstrates the necessity of a multidimensional assessment approach, future efforts should complement these findings with experimental validations for an applicable approach for clinical use. [ABSTRACT FROM AUTHOR]

Abstract Background The aim was to investigate the total prevalence of known and undiagnosed diabetes mellitus (DM), and the association of DM with perioperative complications following elective, infrarenal, open surgical (OSR) or endovascular (EVAR), Abdominal Aortic Aneurysm (AAA) repair. Methods In this Norwegian prospective multicentre study, 877 patients underwent preoperative screening for DM by HbA1c measurements from November 2017 to December 2020. Diabetes was defined as screening detected HbA1c ≥ 48 mmol/mol (6.5%) or previously diagnosed diabetes. The association of DM with in-hospital complications, length of stay, and 30-day mortality rate were evaluated using adjusted and unadjusted logistic regression models. Results The total prevalence of DM was 15% (95% CI 13%,17%), of which 25% of the DM cases (95% CI 18%,33%) were undiagnosed upon admission for AAA surgery. The OSR to EVAR ratio was 52% versus 48%, with similar distribution among DM patients, and no differences in the prevalence of known and undiagnosed DM in the EVAR versus the OSR group. Total 30-day mortality rate was 0.6% (5/877). Sixty-six organ-related complications occurred in 58 (7%) of the patients. DM was not statistically significantly associated with a higher risk of in-hospital organ-related complications (OR 1.23, 95% CI 0.57,2.39, p = 0.57), procedure-related complications (OR 1.48, 95% CI 0.79,2.63, p = 0.20), 30-day mortality (p = 0.09) or length of stay (HR 1.06, 95% CI 0.88,1.28, p = 0.54). According to post-hoc-analyses, organ-related complications were more frequent in patients with newly diagnosed DM (n = 32) than in non-DM patients (OR 4.92; 95% CI 1.53,14.3, p = 0.005). Conclusion Twenty-five percent of all DM cases were undiagnosed at the time of AAA surgery. Based on post-hoc analyses, undiagnosed DM seems to be associated with an increased risk of organ related complications following AAA surgery. This study suggests universal DM screening in AAA patients to reduce the number of DM patients being undiagnosed and to improve proactive diabetes care in this population. The results from post-hoc analyses should be confirmed in future studies.

Introduction: Abdominal aortic aneurysm (AAA) is a growing public health problem, and not all patients have access to surgery when needed. This study aimed to analyze spatiotemporal variations in AAA mortality and surgical procedures in Brazilian intermediate geographic regions and explore the impact of different surgical techniques on operative mortality. Methods: A retrospective longitudinal study was conducted to evaluate AAA mortality from 2008 to 2020 using space–time cube (STC) analysis and the emerging hot spot analysis tool through the Getis-Ord Gi* method. Results: There were 34,255 deaths due to AAA, 13,075 surgeries to repair AAA, and a surgical mortality of 14.92%. STC analysis revealed an increase in AAA mortality rates (trend statistic = +1.7693, p = 0.0769) and a significant reduction in AAA surgery rates (trend statistic = −3.8436, p = 0.0001). Analysis of emerging hotspots revealed high AAA mortality rates in the South, Southeast, and Central-West, with a reduction in procedures in São Paulo and Minas Gerais States (Southeast). In the Northeast, there were extensive areas of increasing mortality rates and decreasing procedure rates (cold spots). Conclusion: AAA mortality increased in several regions of the country while surgery rates decreased, demonstrating the need for implementing public health policies to increase the availability of surgical procedures, particularly in less developed regions with limited access to services. [ABSTRACT FROM AUTHOR]

Background: The aim was to investigate the total prevalence of known and undiagnosed diabetes mellitus (DM), and the association of DM with perioperative complications following elective, infrarenal, open surgical (OSR) or endovascular (EVAR), Abdominal Aortic Aneurysm (AAA) repair. Methods: In this Norwegian prospective multicentre study, 877 patients underwent preoperative screening for DM by HbA1c measurements from November 2017 to December 2020. Diabetes was defined as screening detected HbA1c ≥ 48 mmol/mol (6.5%) or previously diagnosed diabetes. The association of DM with in-hospital complications, length of stay, and 30-day mortality rate were evaluated using adjusted and unadjusted logistic regression models. Results: The total prevalence of DM was 15% (95% CI 13%,17%), of which 25% of the DM cases (95% CI 18%,33%) were undiagnosed upon admission for AAA surgery. The OSR to EVAR ratio was 52% versus 48%, with similar distribution among DM patients, and no differences in the prevalence of known and undiagnosed DM in the EVAR versus the OSR group. Total 30-day mortality rate was 0.6% (5/877). Sixty-six organ-related complications occurred in 58 (7%) of the patients. DM was not statistically significantly associated with a higher risk of in-hospital organ-related complications (OR 1.23, 95% CI 0.57,2.39, p = 0.57), procedure-related complications (OR 1.48, 95% CI 0.79,2.63, p = 0.20), 30-day mortality (p = 0.09) or length of stay (HR 1.06, 95% CI 0.88,1.28, p = 0.54). According to post-hoc-analyses, organ-related complications were more frequent in patients with newly diagnosed DM (n = 32) than in non-DM patients (OR 4.92; 95% CI 1.53,14.3, p = 0.005). Conclusion: Twenty-five percent of all DM cases were undiagnosed at the time of AAA surgery. Based on post-hoc analyses, undiagnosed DM seems to be associated with an increased risk of organ related complications following AAA surgery. This study suggests universal DM screening in AAA patients to reduce the number of DM patients being undiagnosed and to improve proactive diabetes care in this population. The results from post-hoc analyses should be confirmed in future studies. [ABSTRACT FROM AUTHOR]

Background: The COVID‐19 virus not only has significant pathogenicity but also influences the progression of many diseases, altering patient prognosis. Cardiovascular diseases, particularly aortic aneurysms, are among the most life‐threatening conditions. Main Idea: COVID‐19 infection is reported to accelerate the progression of abdominal aortic aneurysms (AAAs) and increase the risk of rupture; however, a comprehensive understanding of the underlying mechanisms remains elusive. This article primarily reviews the relevant foundational research, focusing on disruptions in the renin‐angiotensin‐aldosterone system (RAAS), immune system activation, and coagulation disorders. Furthermore, we summarize related clinical research, including the epidemiology of aortic aneurysms during the pandemic and specific case studies. Conclusion: COVID‐19 infection can influence the onset and progression of aortic aneurysms by affecting the RAAS, triggering inflammation and immune dysregulation in the arterial wall, and inducing a hypercoagulation state. It is crucial to comprehensively understand the impact of pandemic viral infections on aortic diseases at the foundational and clinical levels, thereby identifying potential preventative or therapeutic approaches and preparing for potential future outbreaks. [ABSTRACT FROM AUTHOR]

Aortic aneurysm is the narrowing of the aortic valve. Treatment for unruptured Abdominal Aortic Aneurysm (AAA) that does not require surgery involves exposing patients to specific physiological threshold conditions like maximal diameter and keeping a check over the expansion rate. Despite these thresholds, there are chances of rupture. Thus, it is crucial to find more accurate indicators of rupture risk and include their assessment in therapeutic decisionmaking. This study employs Computational Fluid Dynamics (CFD) to investigate pulsatile flow characteristics in generalized AAA models. It prioritizes rebuilding the intricate aspects of fluid dynamics that cannot be directly quantified in vivo, specifically focusing on how varied degrees of dilations influence these aspects. Thus, a numerical analysis uses a finite volume approach in order to investigate three-dimensional symmetric, incompressible, laminar, and transient flow characteristics in analyzing and exploring rupture potential. It is observed that the shear stress had a low magnitude within the aneurysm segment of the blood vessel, while the distal constriction of the aneurysm displayed localized peak values. It is observed that the WSS is lowered from 40% in the steady flow conditions to 20% in the dilated pipe for transient conditions, indicating that wall shear stress can also be considered a factor for analyzing aneurysmal conditions. Authors' findings also show that mapping the geographical and temporal development of flow patterns and vorticity reveals regions with low shear stress. These observations can help in clinical decision-making. [ABSTRACT FROM AUTHOR]

ABSTRACT Abdominal aortic aneurysm (AAA) is a large-vessel disease with high mortality, characterized by complex pathogenic mechanisms. Current therapeutic approaches remain insufficient to halt its progression. Fungi are important members of the gut microbiota. However, their characteristic alterations and roles in AAA remain unclear. This study investigated the role of gut fungal communities in the development of AAA through metagenomic sequencing of fecal samples from 31 healthy individuals and 33 AAA patients. We observed significant dysbiosis in the gut mycobiomes of AAA patients compared to healthy individuals, characterized by an increase in pathogenic fungi like Candida species and a decrease in beneficial yeasts such as Saccharomyces cerevisiae. The changes in fungal populations correlated strongly with clinical indicators of AAA, highlighting their potential for diagnosing and predicting AAA progression. Furthermore, our animal experiments demonstrated that Saccharomyces cerevisiae significantly ameliorated pathological alterations in AAA mice, suggesting a protective role for specific yeast strains against AAA development. These findings underscore the significant impact of gut mycobiomes on AAA and suggest that modulating these fungal communities could offer a novel therapeutic approach. Our research advances the understanding of the influence of gut microbiome on vascular diseases and suggests potential non-surgical approaches for managing AAA. By elucidating the diagnostic and therapeutic potential of gut fungi in AAA, this study provided important clues for future clinical strategies and therapeutic developments in the field of vascular medicine.IMPORTANCEOur research highlights the crucial role of gut fungi in abdominal aortic aneurysm (AAA) development. By analyzing fecal samples from AAA patients and healthy controls, we discovered significant dysbiosis in gut fungal communities, characterized by an increase in harmful Candida species and a decrease in beneficial yeasts like Saccharomyces cerevisiae. This dysbiosis was correlated with the severity of AAA. Importantly, in animal experiments, supplementing with Saccharomyces cerevisiae significantly slowed AAA progression. These findings suggest that modulating gut fungi may offer a novel, non-surgical approach to the diagnosis and treatment of AAA, potentially reducing the need for invasive procedures.

Abdominal aortic aneurysms (AAAs) are characterized by permanent dilatation of the abdominal aorta, which is accompanied by inflammation, degradation of the extracellular matrix (ECM) and disruption of vascular smooth muscle cell (VSMC) homeostasis. Endoplasmic reticulum (ER) stress is involved in the regulation of inflammation, oxidative stress and VSMC apoptosis, all of which are critical factors in AAA development. Although several studies have revealed the occurrence of ER stress in AAA development, the specific biological functions of ER stress in AAA development remain largely unknown. Given that targeting ER stress is a promising strategy for treating AAAs, further investigation of the physiological and pathological roles of ER stress in AAA development is warranted.

Abstract Background Endovascular techniques are advancing with the change of treatment paradigm for abdominal aortic aneurysms. Fenestrated EVAR (fEVAR) and branched EVAR (bEVAR) are used for complex aortic aneurysm repair. Both fEVAR and bEVAR have their own advantages and disadvantages. Semi-branches are a new feature that attempt to combine the advantages of both fEVAR and bEVAR. Technique We describe the use of a 4-vessel semi-branched EVAR in a failed EVAR case with a type 1a endoleak. Conclusion The novel feature of semi-branches in custom-made EVAR devices in endovascular aortic treatment following failed EVAR appear to be a feasible option.

Background: Endovascular techniques are advancing with the change of treatment paradigm for abdominal aortic aneurysms. Fenestrated EVAR (fEVAR) and branched EVAR (bEVAR) are used for complex aortic aneurysm repair. Both fEVAR and bEVAR have their own advantages and disadvantages. Semi-branches are a new feature that attempt to combine the advantages of both fEVAR and bEVAR. Technique: We describe the use of a 4-vessel semi-branched EVAR in a failed EVAR case with a type 1a endoleak. Conclusion: The novel feature of semi-branches in custom-made EVAR devices in endovascular aortic treatment following failed EVAR appear to be a feasible option. [ABSTRACT FROM AUTHOR]

Introduction: Abdominal aortic aneurysm (AAA) is a relevant clinical problem due to the risk of rupture of progressively dilated infrarenal aorta. It is characterized by degradation of elastic fibers, extracellular matrix, and inflammation of the arterial wall. Though neutrophil infiltration is a known feature of AAA, markers of neutrophil activation are scarcely analyzed; hence, the main objective of this study. Methods: Plasma levels of main neutrophil activation markers were quantified in patients with AAA and a double control group (CTL) formed by healthy volunteers (HV) and patients with severe atherosclerosis submitted for carotid endarterectomy (CE). Calprotectin, a cytoplasmic neutrophil protein, was quantified, by Western blot, in arterial tissue samples from patients with AAA and organ donors. Colocalization of calprotectin and neutrophil elastase was assessed by immunofluorescence. Results: Plasma calprotectin and IL-6 were both elevated in patients with AAA compared with CTL (p ⩽ 0.0001) and a strong correlation was found between both molecules (p < 0.001). This difference was maintained when comparing with HV and CE for calprotectin but only with HV for IL-6. Calprotectin was also elevated in arterial tissue samples from patients with AAA compared with organ donors (p < 0.0001), and colocalized with neutrophils in the arterial wall. Conclusions: Circulating calprotectin could be a specific AAA marker and a potential therapeutical target. Calprotectin is related to inflammation and neutrophil activation in arterial wall and independent of other atherosclerotic events. [ABSTRACT FROM AUTHOR]

Background: The clinical data regarding the relationships between BMI and abdominal aortic aneurysm (AAA) are inconsistent, especially for the obese and overweight patients. The aims of this study were to determine whether obesity is associated with the presence of AAA and to investigate the quantitative relationship between BMI and the risk of AAA presence and postoperative mortality. Materials and methods: PubMed, Web of Science, and Embase databases were used to search for pertinent studies updated to December 2023. The pooled relative risk (RR) with 95% CI was estimated by conventional meta-analysis based on random effects model. Dose-response meta-analyses using robust-error meta-regression (REMR) model were conducted to quantify the associations between BMI and AAA outcome variables. Subgroup analysis, sensitivity analysis, and publication bias analysis were performed according to the characteristics of participants. Results: Eighteen studies were included in our study. The meta-analysis showed a higher prevalence of AAA with a RR of 1.07 in patients with obesity. The dose-response meta-analysis revealed a nonlinear relationship between BMI and the risk of AAA presence. A 'U' shape curve reflecting the correlation between BMI and the risk of postoperative mortality in AAA patients was also uncovered, suggesting the 'safest' BMI interval (28.55, 31.05) with the minimal RR. Conclusions: Obesity is positively but nonlinearly correlated with the increased risk of AAA presence. BMI is related to AAA postoperative mortality in a 'U' shaped curve, with the lowest RR observed among patients suffering from overweight and obesity. These findings offer a preventive strategy for AAA morbidity and provide guidance for improving the prognosis in patients undergone AAA surgical repair. [ABSTRACT FROM AUTHOR]

A proof-of-concept of a microwave imaging system for the fast detection of abdominal aortic aneurysms is shown. This experimental technology seeks to overcome the factors hampering the fast screening for these aneurysms with the usual equipment, such as high cost, long-time operation or hazardous exposure to chemical substances. The hardware system is composed of 16 twin antennas mastered by a microcontroller through a switching network, which connects the antennas to the measurement instrument for sequential measurement. The software system is run by a computer, mastering the whole system, automatizing the measurement process and running the signal processing and medical image generation algorithms. Two image generation algorithms are tested: Delay-and-Sum (DAS) and Improved Delay-and-Sum (IDAS). Own-modified versions of these algorithms adapted to the requirements of our system are proposed. The system is carefully calibrated and fine-tuned with known objects placed at known distances. An experimental proof-of-concept is shown with a human torso phantom, including an aorta phantom and an aneurysm phantom placed in different positions. The results show good imaging capabilities with the potential for detecting and locating possible abdominal aortic aneurysms and reporting acceptable errors. [ABSTRACT FROM AUTHOR]

As the use of endovascular aneurysm repair (EVAR) increases, anatomic constraints remain a challenge. In this case report, we describe the use of intravascular lithotripsy to facilitate EVAR in a patient with a severely calcified and stenotic aortic bifurcation. Future applications of intravascular lithotripsy could help expand the use of EVAR to patients with severely stenotic vasculature and optimize outcomes in the treatment of infrarenal abdominal aortic aneurysms.

Introduction: Balancing the well-documented benefits of regular exercise, particularly its positive impact on cardiovascular risk factors like hypertension, with the potential risks for patients with aortic aneurysms presents a significant challenge. This narrative review aims to summarize the current evidence and guidelines to assist clinicians in making informed exercise and sports recommendations for patients with aortic aneurysms or post-aortic repair. Methods: Nine clinical trials on the effect of exercise on abdominal aortic aneurysms (AAAs) were identified, including one study on cardiopulmonary exercise testing (CPET) in AAA patients. As no clinical trials on exercise in thoracic aortic aneurysms (TAAs) were found, we extrapolated data from other studies on exercise in aortic diseases, including data from patients who have had an aortic dissection, as well as three studies on cardiac rehabilitation (CR) and one study on CPET after proximal aortic repair. Review articles and guidelines were also incorporated to ensure a comprehensive overview of the topic. Results: Currently, no clear correlation exists between intense sports activities and the development of aortic aneurysms or dissections. Conclusions: Light to moderate physical activity appears safe and beneficial for patients with aortic aneurysms and post-aortic repair. Given the lack of evidence linking athletic activity to aortic complications, caution is warranted in restricting such activities for athletes, underscoring the importance of shared decision-making. Regular follow-up and optimal management of cardiovascular risk factors are essential.

Abdominal aortic aneurysm (AAA) is defined as abnormal dilation of the infrarenal abdominal aortic diameter to 3.0 cm or greater. The natural history of AAA consists of progressive expansion and potential rupture. Although most AAAs are clinically silent, a pulsatile abdominal mass identified on physical examination may indicate the presence of an AAA. When an AAA is suspected, an imaging study is essential to confirm the diagnosis. This document reviews the relative appropriateness of various imaging procedures for the initial evaluation of suspected AAA. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation. [ABSTRACT FROM AUTHOR]

Background: Surveillance programs in abdominal aortic aneurysms (AAA) are mainly based on imaging and leave room for improvement to timely identify patients at risk for AAA growth. Many biomarkers are dysregulated in patients with AAA, which fuels interest in biomarkers as indicators of disease progression. We examined associations of 92 cardiovascular disease (CVD)-related circulating biomarkers with AAA and sac volume. Methods: In a cross-sectional analysis, we separately investigated (1) 110 watchful waiting (WW) patients (undergoing periodic surveillance imaging without planned intervention) and (2) 203 patients after endovascular aneurysm repair (EVAR). The Cardiovascular Panel III (Olink Proteomics AB, Sweden) was used to measure 92 CVD-related circulating biomarkers. We used cluster analyses to investigate protein-based subphenotypes, and linear regression to examine associations of biomarkers with AAA and sac volume on CT scans. Results: Cluster analyses revealed two biomarker-based subgroups in both WW and EVAR patients, with higher levels of 76 and 74 proteins, respectively, in one subgroup versus the other. In WW patients, uPA showed a borderline significant association with AAA volume. Adjusting for clinical characteristics, there was a difference of −0.092 (−0.148, −0.036) loge mL in AAA volume per SD uPA. In EVAR patients, after multivariable adjustment, four biomarkers remained significantly associated with sac volume. The mean effects on sac volume per SD difference were: LDLR: −0.128 (−0.212, −0.044), TFPI: 0.139 (0.049, 0.229), TIMP4: 0.110 (0.023, 0.197), IGFBP-2: 0.103 (0.012, 0.194). Conclusion: LDLR, TFPI, TIMP4, and IGFBP-2 were independently associated with sac volume after EVAR. Subgroups of patients with high levels of the majority of CVD-related biomarkers emphasize the intertwined relationship between AAA and CVD. ClinicalTrials.gov Identifier: NCT03703947. [ABSTRACT FROM AUTHOR]

Background and Objectives: This study aims to identify the minor allele of the single nucleotide polymorphisms (SNPs) DAB2IP rs7025486, IL6R rs2228145, CDKN2BAS rs10757278, LPA rs3798220, LRP1 rs1466535, and SORT1 rs599839 in order to assess the risk of abdominal aortic aneurysm (AAA) formation and define the linkage among these SNPs. Materials and Methods: A case-control study with AAA patients (AAA group) and non-AAA controls (control group) was carried out in a study population. DNA was isolated from whole blood samples; the SNPs were amplified using PCR and sequenced. Results: In the AAA group of 148 patients, 87.2% of the patients were male, 64.2% had a history of smoking, and 18.2% had relatives with AAA. The mean ± SD of age, BMI, and aneurysmal diameter in the AAA group were 74.8 ± 8.3 years, 27.6 ± 4.6 kg/m2, and 56.2 ± 11.8 mm, respectively. In comparison with 50 non-AAA patients, there was a significantly elevated presence of the SNPs DAB2IP rs7025486[A], CDKN2BAS rs10757278[G], and SORT1 rs599839[G] in the AAA group (p-values 0.040, 0.024, 0.035, respectively), while LPA rs3798220[C] was significantly higher in the control group (p = 0.049). A haplotype investigation showed that the SNPs DAB2IP, CDKN2BAS, and IL6R rs2228145[C] were significantly elevated in the AAA group (p = 0.037, 0.037, and 0.046) with minor allele frequencies (MAF) of 25.5%, 10.6%, and 15.4%, respectively. Only DAB2IP and CDKN2BAS showed significantly higher occurrences of a mutation (p = 0.028 and 0.047). Except for LPA, all SNPs were associated with a large aortic diameter in AAA (p < 0.001). Linkage disequilibrium detection showed that LPA to DAB2IP, to IL6R, to CDKN2BAS, and to LRP1 rs1466535[T] had D' values of 70.9%, 80.4%, 100%, and 100%, respectively. IL6R to LRP1 and to SORT1 had values for the coefficient of determination (r2) of 3.9% and 2.2%, respectively. Conclusions: In the investigated study population, the SNPs CDKN2BAS rs10757278, LPA rs3798220, SORT1 rs599839, DAB2IP rs7025486, and IL6R rs2228145 were associated with the development of abdominal aortic aneurysms. Individuals with risk factors for atherosclerosis and/or a family history of AAA should be evaluated using genetic analysis. [ABSTRACT FROM AUTHOR]

The aim of our study is to validate a totally automated deep learning (DL)-based segmentation pipeline to screen abdominal aortic aneurysms (AAA) in computed tomography angiography (CTA) scans. We retrospectively evaluated 73 thoraco-abdominal CTAs (48 AAA and 25 control CTA) by means of a DL-based segmentation pipeline built on a 2.5D convolutional neural network (CNN) architecture to segment lumen and thrombus of the aorta. The maximum aortic diameter of the abdominal tract was compared using a threshold value (30 mm). Blinded manual measurements from a radiologist were done in order to create a true comparison. The screening pipeline was tested on 48 patients with aneurysm and 25 without aneurysm. The average diameter manually measured was 51.1 ± 14.4 mm for patients with aneurysms and 21.7 ± 3.6 mm for patients without aneurysms. The pipeline correctly classified 47 AAA out of 48 and 24 control patients out of 25 with 97% accuracy, 98% sensitivity, and 96% specificity. The automated pipeline of aneurysm measurements in the abdominal tract reported a median error with regard to the maximum abdominal diameter measurement of 1.3 mm. Our approach allowed for the maximum diameter of 51.2 ± 14.3 mm in patients with aneurysm and 22.0 ± 4.0 mm in patients without an aneurysm. The DL-based screening for AAA is a feasible and accurate method, calling for further validation using a larger pool of diagnostic images towards its clinical use. [ABSTRACT FROM AUTHOR]

Recently, the relationship between Helicobacter cinaedi (H. cinaedi) infection and several diseases, including cardiovascular and central nervous system disorders, bone and soft tissue disorders, and infectious abdominal aortic aneurysms (AAAs), has been reported. Moreover, H. cinaedi may be associated with arteriosclerosis. In the present study, we investigated the association between H. cinaedi infection and clinically uninfected AAAs. Genetic detection of H. cinaedi in the abdominal aneurysm wall was attempted in 39 patients with AAA undergoing elective open surgery between June 2019 and June 2020. DNA samples extracted from the arterial wall obtained during surgery were analyzed using nested polymerase chain reaction (PCR). The target gene region was the H. cinaedi-specific cytolethal distending toxin subunit B (cdtB). Nine (23.1%) of 39 patients showed positive bands corresponding to H. cinaedi, and further sequencing analyses demonstrated the presence of H. cinaedi DNAs in their aneurysm walls. In contrast, all the non-aneurysm arterial walls in our patients were negative for H. cinaedi. In conclusion, this is the first report of the detection of H. cinaedi in the walls of a clinically non-infectious AAA. [ABSTRACT FROM AUTHOR]

Background: Endovascular aortic repair (EVAR) has become the mainstay treatment for abdominal aortic aneurysms and is associated with excellent clinical outcomes. However, there remains a risk of complications requiring reintervention. Several EVAR devices exist commercially, yet, the Terumo Aortic Fenestrated Anaconda™ has demonstrated outstanding results. The main scope of this study is to evaluate survival/longevity, target vessel patency (TVP), endograft migration and reintervention following Fenestrated Anaconda™ implantation and discuss relevant literature. Methods: The current study represents a 9-year cross-sectional international analysis of custom-made Fenestrated Anaconda™ device. For the statistical analysis, SPSS 28 for Windows and R was utilised. Pearson Chi-Square analysis was used to assess differences in cumulative distribution frequencies between variables. Statistical significance for all two-tailed tests was set at p < 0.05. Results: A total of 5058 patients received the Fenestrated Anaconda™ endograft. The Fenestrated Anaconda™ was indicated either due to complex anatomy for competitor devices (n = 3891, 76.9%) or based on surgeon preference (n = 1167, 23.1%). Both survival and TVP were 100% during the first 6 postoperative years but dropped to 77.1% and 81% thereafter. In the complex anatomy indication group, cumulative survival and TVP were both 100% until year 7 post-EVAR when they decreased to 82.8% and 75.7%. In the other indication group, survival and TVP were also 100% during the first 6 years but plateaued at 58.1% and 98.8% in years 7–9 of follow-up. No cases of endograft migration and reintervention were recorded. Conclusion: The Fenestrated Anaconda™ has been proven across the literature to be a highly effective EVAR endograft, as it has demonstrated excellent survival/longevity and TVP as well as minimal endograft migration and reintervention. [ABSTRACT FROM AUTHOR]

The mechanisms of abdominal aortic aneurysm (AAA) formation and rupture are controversial in the literature. While the intraluminal thrombus (ILT) plays a crucial role in reducing oxygen flux to the tissue and therefore decreasing the aortic wall strength, other physiological parameters such as the vasa vasorum (VV) oxygen flow and its consumption contribute to altered oxygenation responses of the arterial tissue as well. The goal of this research is to analyse the importance of the aforementioned parameters on oxygen delivery to the aneurysmal wall in a patient-specific AAA. Numerical simulations of coupled blood flow and mass transport with varying levels of VV concentration and oxygen reaction rate coefficient are performed. The hypoperfusion of the adventitial VV and high oxygen consumption are observed to have critical effects on reducing aneurysmal tissue oxygen supply and can therefore exacerbate localized oxygen deprivation.

Endovascular abdominal aortic aneurysm repair (EVAR) has gained widespread acceptance in the treatment of patients with abdominal aortic aneurysm (AAA). The applicability of EVAR is limited by the absence of adequate infrarenal neck or involvement of the visceral arteries, such as in juxtarenal and pararenal AAA (JAAA/PAAA). Current guidelines recommend that elective management of JAAA/PAAA and the choice of different techniques and different options should be considered based on patient status, anatomy, local routines, team expertise, and patient preference. The main advantage of endovascular techniques lies in the avoidance of aortic cross-clamping and subsequent lower risk of renal dysfunction, less surgical trauma and faster recovery, which may be advantageous for patients at high risk of open surgery. However, recent reports show that JAAA/PAAA patients can be treated in high-volume aortic centers with low short-term mortality and morbidity and good medium and long-term results that are equal in both groups. Low-surgical-risk patients might benefit from open surgery, while high-risk patients might benefit from the endovascular first approach of JAAA/ PAAA. This provides useful information to help clinicians and patients choose between the two procedures when both are available.

Endovascular aneurysm repair (EVAR) has rapidly become the preferred management of abdominal aortic aneurysm (AAA). Sac regression status post-EVAR has been linked to clinical outcomes as well as the choice of EVAR device. The aim of this narrative review is to investigate the relationship between sac regression and clinical outcomes post-EVAR in AAA. Another aim is to compare sac regression achieved with the main EVAR devices. We carried out a comprehensive literature search on multiple electronic databases. Sac regression was usually defined as a decrease in the sac diameter (>10 mm) over follow-up. This revealed that individuals who had sac regression post-EVAR had significantly lower mortality, and higher event-free survival rates. Further, lower rates of endoleak and reintervention were observed in patients with regressing aneurysm sacs. Sac regression patients also had significantly lower odds of rupture compared to counterparts with stable or expanded sacs. The choice of EVAR device was also shown to impact regression, with the Fenestrated Anaconda showing favorable results. Sac regression post-EVAR in AAA is an important prognostic factor as it translates to improved mortality and morbidity. Therefore, this relationship must be seriously taken into consideration during follow-up. [ABSTRACT FROM AUTHOR]

Background: Abdominal aortic aneurysm (AAA) is a severe cardiovascular disease. The mortality rate for an AAA rupture is very high. Understanding the risk factors for AAA rupture would help AAA management, but little is known about these risk factors in the Chinese population. Methods: This retrospective study included patients that were diagnosed with AAA during the last 5 years in a large national hospital in southern China. AAA patients were divided into a rupture and non-rupture group. Clinical data were extracted from the hospital medical record system. Clinical features were compared between the rupture and non-rupture groups. The associations between potential risk factors and rupture risk were evaluated using a multivariate logistic regression analysis. Results: A total of 337 AAA patients were included for analysis in the present study. AAA diameter was significantly larger, and high-sensitivity C-reactive protein (hs- CRP) and serum creatinine levels were both significantly higher in AAA rupture patients. High-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) levels were significantly lower in AAA rupture patients. After adjustment, the multivariate logistic analysis found that AAA diameter and hs-CRP were independently positively associated with AAA rupture, and HDL-C level was adversely associated with AAA rupture. Conclusions: Our data suggests that larger AAA diameter and higher hs-CRP level are associated with a higher risk of AAA rupture, and higher HDL-C level is associated with a lower risk of AAA rupture. The results of this study may be helpful for the management of AAA patients in southern China. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the short and long term clinical outcomes of endovascular (EVAR) vs. open surgical repair (OSR) of juxtarenal (JAAAs) and pararenal abdominal aortic aneurysms (PAAAs) in five high volume European academic centres. This was a retrospective multicentre cohort study of five high volume European academic centres (> 50 open or 50 endovascular abdominal aortic aneurysm repairs annually) including 834 consecutive patients who were operated on and prospectively followed. Using propensity score matching (PSM) each patient who underwent OSR was matched with one patient who underwent EVAR in a 1:1 ratio (145 patients per group). The primary endpoint was long term all cause mortality, while the secondary endpoint was freedom from aortic related re-intervention. After a follow up of 87 months, no difference in overall survival between the two groups was observed (38.6% for EVAR vs. 42.1% for OSR; p =.88). Patients undergoing EVAR underwent aortic related re-interventions more frequently (24.1% vs. 6.9%; p <.001). Acute kidney injury (AKI) occurred more frequently in patients in the OSR group (40.7% vs. 24.8%; p =.006). However, most patients who suffered from AKI recovered without further progression to renal failure. In hospital (3.4% for EVAR vs. 4.1% for OSR; p = 1.0) and 30 day (4.1% for EVAR vs. 5.5% for OSR; p =.80) mortality rates did not differ between groups. Both open and endovascular treatment can be performed in high volume aortic centres with low short term mortality and morbidity rates, and good long term outcomes. These data provide useful information to help patients choose between the two procedures when both are feasible. [ABSTRACT FROM AUTHOR]

A proof-of-concept of a microwave imaging system for the fast detection of abdominal aortic aneurysms is shown. This experimental technology seeks to overcome the factors hampering the fast screening for these aneurysms with the usual equipment, such as high cost, long-time operation or hazardous exposure to chemical substances. The hardware system is composed of 16 twin antennas mastered by a microcontroller through a switching network, which connects the antennas to the measurement instrument for sequential measurement. The software system is run by a computer, mastering the whole system, automatizing the measurement process and running the signal processing and medical image generation algorithms. Two image generation algorithms are tested: Delay-and-Sum (DAS) and Improved Delay-and-Sum (IDAS). Own-modified versions of these algorithms adapted to the requirements of our system are proposed. The system is carefully calibrated and fine-tuned with known objects placed at known distances. An experimental proof-of-concept is shown with a human torso phantom, including an aorta phantom and an aneurysm phantom placed in different positions. The results show good imaging capabilities with the potential for detecting and locating possible abdominal aortic aneurysms and reporting acceptable errors.

Determination of abdominal aortic aneurysm (AAA) rupture risk involves the accurate prediction of mechanical stresses acting on the arterial tissue, as well as the wall strength which has a correlation with oxygen supply within the aneurysmal wall. Our laboratory has previously reported the significance of an intraluminal thrombus (ILT) presence and morphology on localized oxygen deprivation by assuming a uniform consistency of ILT. The aim of this work is to investigate the effects of ILT structural composition on oxygen flow by adopting a multilayered porous framework and comparing a two-layer ILT model with one-layer models. Three-dimensional idealized and patient-specific AAA geometries are generated. Numerical simulations of coupled fluid flow and oxygen transport between blood, arterial wall, and ILT are performed, and spatial variations of oxygen concentrations within the AAA are obtained. A parametric study is conducted, and ILT permeability and oxygen diffusivity parameters are individually varied within a physiological range. A gradient of permeability is also defined to represent the heterogenous structure of ILT. Results for oxygen measures as well as filtration velocities are obtained, and it is found that the presence of any ILT reduces and redistributes the concentrations in the aortic wall markedly. Moreover, it is found that the integration of a porous ILT significantly affects the oxygen transport in AAA and the concentrations are linked to ILT’s permeability values. Regardless of the ILT stratification, maximum variation in wall oxygen concentrations is higher in models with lower permeability, while the concentrations are not sensitive to the value of the diffusion coefficient. Based on the observations, we infer that average one-layer parameters for ILT material characteristics can be used to reasonably estimate the wall oxygen concentrations in aneurysm models.

This article discusses a study conducted by Franco and colleagues on trends in mortality and surgical volume for abdominal aortic aneurysm (AAA) treatment in Brazil. The study found that there is an increasing rate of mortality due to AAA in multiple regions of the country, particularly in the south and west, which coincides with a decreasing rate of surgical repair. Endovascular aneurysm repair had a lower postoperative mortality rate compared to open aneurysm repair. The article emphasizes the importance of using spatiotemporal data analysis to inform resource allocation and improve outcomes in vascular care. [Extracted from the article]

Endovascular aortic aneurysm repair is a minimally invasive procedure with low mortality and morbidity. Clinical studies have revealed that a displacement force (DF) can cause stent graft (SG) migration in some circumstances requiring repeated intervention. This study aims to determine the relationship between the SG curvature and the calculated DF from four patient-specific computational fluid dynamics models. The SG's curvature was defined according to the centrelines of the implanted SG's branches. The centrelines were defined as either intersecting or separated lines. The centreline curvature (CLC) metrics were calculated based on the local curvature radii and the distances from the centrelines of idealized straight branches. The average CLC value and average variation were calculated to represent the entire graft's curvature. These CLC calculations were compared, and the method that gave the best correlation to the calculated DF was found. The optimal correlation is obtained from calculating the CLC average variation using separated centrelines and distance from straight lines, with an R2 = 0.89. Understanding the relationship between vascular morphology and DF can help identify at-risk patients before the procedure. In these cases, we can provide appropriate treatment and follow up with the patient to prevent future failure.

Background: Abdominal aortic aneurysms (AAA) are an important cause of cardiovascular deaths. The loss of vascular smooth muscle cells (VSMCs) has been reported to be related to the pathology of AAA. This study focused on investigating the function of circ_0002168 in VSMC apoptosis. Methods: Levels of genes and proteins were measured by quantitative real-time-polymerase chain reaction (qRT-PCR) and Western blot. The growth of VSMCs was determined by using cell counting kit-8 assay, 5-ethynyl-2′-deoxyuridine (EdU) assay, flow cytometry and the evaluation of caspase-3 activity analysis, reactive oxygen species (ROS) production as well as lactate dehydrogenase (LDH) activity. The binding between miR-545-3p and circ_0002168 or Cytoskeleton-associated protein 4 (CKAP4) was confirmed by bioinformatics analysis, dual-luciferase reporter, RNA immunoprecipitation, and pull-down assays. Results: Circ_0002168 decreased in the aortic tissues of patients with AAA. Functionally, ectopic overexpression of circ_0002168 dramatically induced proliferation and suppressed apoptosis in VSMCs. Mechanistically, circ_0002168 sequestered miR-545-3p to release CKAP4 expression via the ceRNA mechanism, indicating the circ_0002168/miR-545-3p/CKAP4 feedback loop in VSMCs. Increased miR-545-3p and a decreased CKAP4 expression were observed in patients with AAA. Rescue experiments showed that miR-545-3p reversed the protective effects of circ_0002168 on VSMC proliferation. Moreover, inhibition of miR-545-3p could restrain the apoptosis of VSMCs, which was abolished by CKAP4 silencing. Conclusion: Circ_0002168 has a protective effect on VSMC proliferation by regulating the miR-545-3p/CKAP4 axis, adding further understanding of the pathogenesis of AAA and a potential therapeutic approach in AAA management. [ABSTRACT FROM AUTHOR]

The abdominal aortic aneurysm (AAA) is characterized by segmental expansion of the abdominal aorta and a high mortality rate. The characteristics of AAA suggest that apoptosis of smooth muscle cells, the production of reactive oxygen species, and inflammation are potential pathways for the formation and development of AAA. Long non-coding RNA (lncRNA) is becoming a new and essential regulator of gene expression. Researchers and physicians are focusing on these lncRNAs to use them as clinical biomarkers and new treatment targets for AAAs. LncRNA studies are beginning to emerge, suggesting that they may play a significant but yet unidentified role in vascular physiology and disease. This review examines the role of lncRNA and their target genes in AAA to increase our understanding of the disease's onset and progression, which is crucial for developing potential AAA therapies. [ABSTRACT FROM AUTHOR]

Platelets, once thought to only play a role in blood clotting, are now recognized as circulating biosensors that respond to external signals and adapt to diseased conditions. Patients with atherosclerotic arterial disease or peripheral artery disease often have altered platelet reactivity, increasing their risk of thrombosis. Platelets are sensitive to biomechanical forces, with patients with abdominal aortic aneurysms showing increased platelet reactivity due to disturbed blood flow. Research suggests that mean platelet volume may predict type II endoleaks in patients who have undergone endovascular abdominal aortic repair, offering potential insights for personalized treatment strategies. [Extracted from the article]

Endovascular abdominal aortic aneurysm repair (EVAR) is a preferred surgery to prevent aneurysm sac enlargement and minimize the risk of life-threatening rupture in patients with AAA. Serious complications of type II endoleaks following EVAR can cause sac expansion and increase rupture risk. This study focused on evaluating clinical and blood characteristics in patients with type II endoleaks to refine our understanding of systemic fluctuations associated with unsuccessful EVAR.This retrospective study included 146 patients with AAA who underwent primary elective endovascular procedures (EVAR/fEVAR) between 2013 and 2021. Clinical characteristics, complete blood count (CBC) and imaging data were analyzed from patients who did and did not develop type II endoleaks.Mean platelet volume (MPV) was significantly increased in patients who developed type II endoleaks after EVAR. Receiver operating characteristic analysis showed that MPV has a satisfactory discriminatory performance in distinguishing post-EVAR patients who developed type II endoleaks, yielding an area under the curve (AUC) value of 0.64. A risk stratification panel incorporating MPV, type II diabetes history, and administration of dual antiplatelet therapies yielded an AUC of 0.70 and predicted an endoleak-free survival rate with a hazard ratio of 2.94. A nomogram revealed that MPV had the highest scoring weight among all significant variables.Patients with type II endoleaks following EVAR have elevated MPV indicative of different phenotypes of circulating platelets. MPV presents an attractive predictive criteria for assessing the occurrence of type II endoleaks in patients with AAA. [ABSTRACT FROM AUTHOR]

Aneurysmal lesion of the abdominal aorta is a common disease, the frequency of which exceeds 8% [1, 2]. A quarter of the initially examined patients at risk of this pathology are diagnosed with complicated forms [3], which negatively affects the life expectancy of this category of patients. Their lethality reaches 83% [4]. The frequency of various complications associated with the duration and trauma of open surgical interventions ranges from 7 to 39% [5, 6]. At the same time, the existing algorithms for examining patients with AAA, aimed at the timely detection of preand postoperative complications, require significant correction [6, 7]. The presented data and the variety of X-ray methods and techniques for diagnosing an aneurysm of the abdominal aorta indicate the need for further search for ways to solve this urgent problem. Determining the role of magnetic resonance imaging in the algorithm for radiological diagnosis of diseases and complications of abdominal aortic aneurysm.

Purpose: To analyze the effect of the physiological deformation of the vessel wall on the hemodynamics in the abdominal aortic aneurysm (AAA), this paper compared the hemodynamics in AAA based on the moving boundary (MB) simulation and the rigid wall (RW) simulation.Method: Patient-specific models were reconstructed to generate mesh based on four-dimensional computed tomography angiography (4D CT) data. The dynamic mesh technique was used to achieve deformation of the vessel wall, surface mesh and volume mesh of the fluid domain were successively remeshed at each time step. Besides, another rigid wall simulation was performed. Hemodynamics obtained from these two simulations were compared.Results: Flow field and wall shear stress (WSS) distribution are similar. When using the moving boundary method (MBM), mean time-averaged wall shear stress (TAWSS) is lower, mean oscillatory shear index (OSI) and mean relative residence time (RRT) are higher. When using the 10th and 20th percentile values for TAWSS and 80th and 90th percentile values for RRT, the ratios of areas with low TAWSS, high OSI and high RRT to the entire vessel wall are higher than those assuming the vessel as rigid. In addition, one overlapping region of low TAWSS, high OSI and high RRT by using the MBM is consistent with the location of thrombus obtained from the follow-up imaging data.Conclusion: The hemodynamics results by using the MBM reflect a higher blood retention effect. This paper presents a potential tool to assess the risk of intraluminal thrombus (ILT) formation based on the MBM.

In this study, the biomechanical role of intraluminal thrombus (ILT) in an abdominal aortic aneurysm (AAA) is investigated. The implications of ILT in AAA are controversial in literature. Previous studies have demonstrated that ILT provides a biomechanical advantage by decreasing wall stress, whereas other studies have associated ILT with inhibiting oxygen transport and inducing aortic wall weakening. Therefore, we sought to explore the connection between ILT, mechanical stresses, and oxygen flow in different geometries of patient-specific aneurysms with varying ILT morphologies. The objective is to investigate the extent to which ILT influences the prediction of aneurysmal wall stresses that are associated with rupture, as well as oxygen concentrations to measure tissue oxygen deprivation. Three patient-specific AAA geometries are considered, and two models, one with ILT and one without ILT, are created for each patient to assess the effect of ILT presence. A fluid–structure interaction approach is used to couple the blood flow, wall deformation, and oxygen mass transport. Results are presented for hemodynamics patterns, wall stress measures, and oxygen metrics within the arterial wall. While ILT is found to reduce wall stress, simulations confirm that ILT decreases oxygen transport within the tissue significantly, leading to wall hypoxia. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to compare treatment outcomes between graft replacement and aneurysmorrhaphy with ligation of the aortic side branches for type 2 endoleaks after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms., Methods: We retrospectively analyzed multicenter data of patients who underwent open surgical conversion, including graft replacement or aneurysmorrhaphy with ligation of the aortic side branches (graft preservation) for the treatment of type 2 endoleaks between 2007 and 2022. The endpoints were postoperative complications, 30-day mortality, overall survival, and reintervention or sac expansion after open surgical conversion., Results: Forty patients underwent open surgical conversion (graft replacement, n=9; graft preservation, n=31). There were no significant differences in patient characteristics or anatomical data of the initial EVAR between the groups. The median operative time and amount of blood loss were significantly lesser in the graft preservation group than in the replacement group (179 vs. 318 min, P < .001 and 710 vs. 2,567 mL, P = .030, respectively). There was no difference in the occurrence of postoperative complications between the two groups (P = .645). No 30-day mortality was observed in any of the groups. Overall survival rate at 5 years after open surgical conversion was 85.7% in the graft replacement group and 77.8% in the graft preservation group (P = .789). Freedom from sac expansion or reintervention rate at 5 years after open surgical conversion was 100% in the graft replacement group and 76.0% in the graft preservation group (P = .239)., Conclusions: Aneurysmorrhaphy with ligation of the aortic side branches was less invasive treatment compared with graft replacement, although there were no differences in postoperative complications. No reintervention was needed after graft replacement; however, some patients required reintervention after graft preservation. Further studies are needed to determine the optimal surgical procedure for the treatment of type 2 endoleak., (Copyright © 2025 Elsevier Inc. All rights reserved.)

Abdominal aortic aneurysm (AAA) is a severe cardiovascular disease (CVD) that is partly attributable to endothelial dysfunction, inflammatory response, and angiogenesis. G protein-coupled receptor 4 (GPR4), a proton-sensitive G protein-coupled receptor that is abundantly expressed in vascular endothelial cells, has been associated with numerous physiological functions. Nevertheless, its potential involvement in the development of AAA remains unexplored. In this study, we examined the impact of GPR4 deletion on the development of AAA in ApoE-deficient mice. The mice were categorized into four distinct groups: the ApoE-/- with saline group, the ApoE-/-GPR4-/- with saline group, the ApoE-/- with Ang II group, and the ApoE-/-GPR4-/- with Ang II group. AAA were induced in the ApoE-/- mice through the perfusion of angiotensin II (Ang II). Notably, GPR4 was substantially elevated in the AAA tissues from both human subjects and experimental mice. The deletion of GPR4 substantially decreased the formation of Ang II-induced AAA, damages to elastin, and the expression of aortic inflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), as well as vascular endothelial growth factor A/vascular endothelial growth factor receptor 2 (VEGF-A/VEGF-R2), in ApoE-/- mice. Human aortic endothelial cells (HAECs) were transfected with lenti-viral GPR4 shRNA and subsequently stimulated with Ang II. Our findings indicate that the knockout of GPR4 attenuated Ang II-induced angiogenic tube formation in HAECs by decreasing the expression of VEGF-A and VEGF-R2. Furthermore, GPR4 knockout also hindered the activation of specificity protein-1 (SP-1) by reducing its expression and transcriptional activity. Notably, the overexpression of SP-1 reversed the inhibitory effects of GPR4 knockout on angiogenic tube formation and the expression of VEGF-A/VEGF-R2. This suggests that the protective effects of GPR4 knockout are achieved through the inhibition of SP-1. In summary, the absence of GPR4 impeded AAA formation, indicating that GPR4 could potentially serve as a therapeutic target for AAA., (© 2025 Wiley Periodicals LLC.)