Epidemiology of abdominal aortic aneurysms

Laparoscopy versus endovascular aneurysm repair for abdominal aortic aneurysm: A systematic review

Minimally invasive surgery is a useful alternative to open repair for patients with nonruptured abdominal aortic aneurysms (AAA). We aim to compare the clinical outcomes for three different minimally invasive techniques: hand-assisted laparoscopic surgery (HALS), total laparoscopic surgery (TLS), and endovascular aneurysm repair (EVAR). The electronic databases MEDLINE, Embase, Web of Science, Google Scholar, and the Cochrane Library were searched between January and March 2023. Cohort studies and randomized controlled trials (RCTs) comparing two minimally invasive techniques were eligible for inclusion. Primary outcomes were mortality (in-hospital, 30-day, or 1-year) and reintervention rates (30-day or 1-year). Length of surgery, blood loss, transfusion volume, conversion to open surgery, major complication rates, length of hospital stay, and length of intensive care unit (ICU) stay were also evaluated. Eight cohort studies and one RCT were included comparing patients undergoing HALS (n = 500), TLS (n = 263), and EVAR (n = 438) for elective AAA repair. The TLS group had the highest rate of 30-day postoperative reinterventions (p = 0.00056), the longest surgical duration (p = 0.0311), and the highest rate of conversion to open surgery (p < 0.001). TLS was also associated with the most blood loss during surgery, the highest blood transfusion volumes, and the longest length of ICU stay, although these results did not reach statistical significance. Subgroup analysis revealed superior contemporary EVAR outcomes compared to TLS. Laparoscopic surgery (LAS) and EVAR have comparable mortality rates. However, LAS, particularly TLS, is significantly less efficacious than EVAR in terms of intraoperative conversions to open surgery and 30-day reintervention rates. Further controlled trials with larger sample sizes are needed to confirm the evidence.

Changes in global mortality from aortic aneurysm

OBJECTIVE

Globally, there has been a marked increase in aortic aneurysm-related deaths between 1990 and 2019. We sought to understand the underlying etiologies for this mortality trend by examining secular changes in both demographics and the prevalence of risk factors, and how these changes may vary across sociodemographic index (SDI) regions.

METHODS

We queried the Global Burden of Disease Study (GBD) for aortic aneurysm deaths from 1990 to 2019 overall and by age group. We identified the percentage of aortic aneurysm deaths attributable to each risk factor identified by GBD modeling (smoking, hypertension, lead exposure, and high sodium diet) and their respective changes over time. We then analyzed aneurysm mortality by SDI region.

RESULTS

The number of aortic aneurysm-related deaths have increased from 94,968 in 1990 to 172,427 in 2019, signifying an 81.6% increase, which greatly exceeds the 18.2% increase in all-cause mortality observed over the same time interval. Examination of age-specific mortality demonstrated that the number of aortic aneurysm deaths markedly correlated with advancing age. However, when considering rate of death rather than mortality count, overall age-standardized death rates decreased 18% from 2.72 per 100,000 in 1990 to 2.21 per 100,000 in 2019. Analysis of the specific risk factors associated with aneurysm death revealed that the percentage of deaths attributable to smoking decreased from 45.6% in 1990 to 34.6% in 2019, and deaths attributable to hypertension decreased from 38.7% to 34.7%. Globally, hypertension surpassed smoking as the leading risk factor. The reported rate of death was consistently greater as SDI increased, and this effect was most pronounced among low-middle and middle SDI regions (173.2% and 170.4%, respectively).

CONCLUSIONS

Despite an overall increase in the number of aneurysm deaths, there was a decrease in the age-standardized death rate, demonstrating that the observed increased number of aortic aneurysm deaths between 1990 and 2019 was primarily driven by an overall increase in the age of the global population. Fortunately, it appears that the increase in overall aneurysm-related deaths has been modulated by improved risk factor modification, in particular smoking. Given the rise in aneurysm-related deaths, global expansion of vascular specialty capabilities is warranted and will serve to amplify improvements in population-based aneurysm health achieved with risk factor control.

How to improve epidemiological trustworthiness concerning abdominal aortic aneurysms

BACKGROUND

Research on degenerative abdominal aortic aneurysms (AAA) is hampered by complex pathophysiology, sub-optimal pre-clinical models, and lack of effective medical therapies. In addition, trustworthiness of existing epidemiological data is impaired by elements of ambiguity, inaccuracy, and inconsistency. Our aim is to foster debate concerning the trustworthiness of AAA epidemiological data and to discuss potential solutions.

METHODS

We searched the literature from the last five decades for relevant epidemiological data concerning AAA development, rupture, and repair. We then discussed the main issues burdening existing AAA epidemiological figures and proposed suggestions potentially beneficial to AAA diagnosis, prognostication, and management.

RESULTS

Recent data suggest a heterogeneous scenario concerning AAA epidemiology with rates markedly varying by country and study cohorts. Overall, AAA prevalence seems to be decreasing worldwide while mortality is apparently increasing regardless of recent improvements in aortic-repair techniques. Prevalence and mortality are decreasing in high-income countries, whereas low-income countries show an increase in both. However, several pieces of information are missing or outdated, thus systematic renewal is necessary. Current AAA definition and surgical criteria do not consider inter-individual variability of baseline aortic size, further decreasing their reliability.

CONCLUSIONS

Switching from flat aortic-size thresholds to relative aortic indices would improve epidemiological trustworthiness regarding AAAs. Aortometry standardization focusing on simplicity, univocity, and accuracy is crucial. A patient-tailored approach integrating clinical data, multi-adjusted indices, and imaging parameters is desirable. Several novel imaging modalities boast promising profiles for investigating the aortic wall. New contrast agents, computational analyses, and artificial intelligence-powered software could provide further improvements.

Glycaemic Status and Risk of Abdominal Aortic Aneurysm: A Nationwide Cohort Study of Four Million Adults using Korean National Health Screening Data

OBJECTIVE

This retrospective cohort study aimed to confirm the previously reported inverse association between diabetes mellitus (DM) and abdominal aortic aneurysm (AAA) using large population based data. It also investigated the associations between AAA and impaired fasting glucose (IFG) and new onset DM (not yet treated).

METHODS

A representative dataset was obtained from the Korean National Health Insurance Service. Participants who were aged ≥ 50 years and received a national health examination in 2009 were included and followed until 31 December 2019. Glycaemic status was defined based on fasting plasma glucose level and the relevant diagnostic codes. AAA was ascertained using medical facility use records with relevant diagnostic codes or aneurysm repair surgery. A Cox proportional hazards model was used to examine the association between glycaemic status and AAA, with adjustment for confounders. Additionally, the interactions between glycaemic status and subgroups based on baseline characteristics were examined.

RESULTS

The study population comprised 4 162 640 participants. Participants with IFG or DM were significantly more likely to be male, older, and have comorbidities compared with normoglycaemic participants at baseline. The incidence of AAA was lower in participants with IFG or DM compared with normoglycaemic participants. The AAA risk was lower in patients with DM than in patients with IFG, and decreased linearly according to glycaemic status: the adjusted hazard ratio was 0.88 (95% confidence interval [CI] 0.85 - 0.91) for IFG, 0.72 (95% CI 0.67 - 0.78) for newly diagnosed DM, 0.65 (95% CI 0.61 - 0.69) for DM duration < 5 years, and 0.47 (95% CI 0.44 - 0.51) for DM duration ≥ 5 years compared with the normoglycaemia group. Both IFG and DM were related to reduced AAA risk in all subgroups, suggesting an independent association.

CONCLUSION

Both IFG and DM, even when not treated with antihyperglycaemic medication, were associated with a lower incidence of AAA. The AAA risk decreased linearly according to DM duration.

Metabolic syndrome and the risk of abdominal aortic aneurysm: A nationwide cohort study

BACKGROUND AND AIMS

The association between metabolic syndrome (MetS) and abdominal aortic aneurysm (AAA) remains unclear. We investigated the potential association between AAA and MetS and its components in a large population-based cohort.

METHODS

We used the Korean National Health Insurance Service database including 4,162,640 participants aged ≥50 years who received a routine health examination in 2009. Cox proportional hazards models were used to analyze the association between MetS and its components (elevated waist circumference, blood pressure, glucose, triglycerides, and reduced high-density lipoprotein cholesterol [HDL-C]) with AAA incidence, with adjustment for confounders.

RESULTS

During a median 9.4 years of follow-up, 18,160 participants developed incident AAA. MetS was associated with an increased risk of AAA compared to the non-MetS group (adjusted hazard ratio [aHR], 1.38; 95% confidence interval [CI], 1.34-1.43). Among the individual components, elevated waist circumference, blood pressure, triglycerides, and reduced HDL-C were associated with increased AAA risk, while elevated glucose alone was associated with reduced AAA risk (aHR, 0.85; 95% CI, 0.82-0.87). AAA risk also increased linearly with the increasing number of MetS components, with the highest risk found in the presence of all 5 components (aHR, 1.98, 95% CI, 1.83-2.15).

CONCLUSIONS

MetS and its individual components, with the exclusion of elevated glucose, were associated with higher risk of AAA. Further studies are warranted to elucidate the association between MetS and AAA.

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Highlights and Perioperative Implications from the 2022 American College of Cardiology and American Heart Association Guidelines for Diagnosis and Management of Aortic Disease

As the understanding of aortic diseases and their complications grow, increasing importance of uniformity in diagnosis and management is crucial for optimal care of this patient population. The 2022 American College of Cardiology and American Heart Association Guidelines for Diagnosis and Management of Aortic Disease discusses these considerations in detail. The purpose of this review is to highlight essential recommendations that are of relevance to the perioperative physician who manages these patients. A few notable points include, shared decision-making with patients, creation of multidisciplinary aortic teams, lower diameter thresholds for surgery in certain situations, and increased testing for patients with heritable aortic diseases. In addition to briefly reviewing basics of aortic diseases, the authors discuss changes to guidelines that are especially relevant to perioperative care.

Intermediate pressure-normalized principal wall strain values are associated with increased abdominal aortic aneurysmal growth rates

Introduction

Current abdominal aortic aneurysm (AAA) assessment relies on analysis of AAA diameter and growth rate. However, evidence demonstrates that AAA pathology varies among patients and morphometric analysis alone is insufficient to precisely predict individual rupture risk. Biomechanical parameters, such as pressure-normalized AAA principal wall strain (ε ρ + ¯ /PP, %/mmHg), can provide useful information for AAA assessment. Therefore, this study utilized a previously validated ultrasound elastography (USE) technique to correlate ε ρ + ¯ /PP with the current AAA assessment methods of maximal diameter and growth rate.

Methods

Our USE algorithm utilizes a finite element mesh, overlaid a 2D cross-sectional view of the user-defined AAA wall, at the location of maximum diameter, to track two-dimensional, frame-to-frame displacements over a full cardiac cycle, using a custom image registration algorithm to produce ε ρ + ¯ /PP. This metric was compared between patients with healthy aortas and AAAs (≥3 cm) and compared between small and large AAAs (≥5 cm). AAAs were then separated into terciles based on ε ρ + ¯ /PP values to further assess differences in our metric across maximal diameter and prospective growth rate. Non-parametric tests of hypotheses were used to assess statistical significance as appropriate.

Results

USE analysis was conducted on 129 patients, 16 healthy aortas and 113 AAAs, of which 86 were classified as small AAAs and 27 as large. Non-aneurysmal aortas showed higher ε ρ + ¯ /PP compared to AAAs (0.044 ± 0.015 vs. 0.034 ± 0.017%/mmHg, p = 0.01) indicating AAA walls to be stiffer. Small and large AAAs showed no difference in ε ρ + ¯ /PP. When divided into terciles based on ε ρ + ¯ /PP cutoffs of 0.0251 and 0.038%/mmHg, there was no difference in AAA diameter. There was a statistically significant difference in prospective growth rate between the intermediate tercile and the outer two terciles (1.46 ± 2.48 vs. 3.59 ± 3.83 vs. 1.78 ± 1.64 mm/yr, p = 0.014).

Discussion

There was no correlation between AAA diameter and ε ρ + ¯ /PP, indicating biomechanical markers of AAA pathology are likely independent of diameter. AAAs in the intermediate tercile of ε ρ + ¯ /PP values were found to have nearly double the growth rates than the highest or lowest tercile, indicating an intermediate range of ε ρ + ¯ /PP values for which patients are at risk for increased AAA expansion, likely necessitating more frequent imaging follow-up.

The Management of Ruptured Abdominal Aortic Aneurysms: An Ongoing Challenge

BACKGROUND

despite improvements in the diagnosis and treatment of elective AAAs, ruptured abdominal aortic aneurysms (RAAAs) continue to cause a substantial number of deaths. The choice between an open or endovascular approach remains a challenge, as does postoperative complications in survivors. The aim of this manuscript is to offer an overview of the contemporary management of RAAA patients, with a focus on preoperative and intraoperative factors that could help surgeons provide more appropriate treatment.

METHODS

we performed a search on MEDLINE, Embase, and Scopus from 1 January 1985 to 1 May 2023 and reviewed SVS and ESVS guidelines. A total of 278 articles were screened, but only those with data available on ruptured aneurysms' incidence and prevalence, preoperative scores, and mortality rates after emergency endovascular or open repair for ruptured AAA were included in the narrative synthesis. Articles were not restricted due to the designs of the studies.

RESULTS

the centralization of RAAAs has improved outcomes after both surgical and endovascular repair. Preoperative mortality risk scores and knowledge of intraoperative factors influencing mortality could help surgeons with decision-making, although there is still no consensus about the best treatment. Complications continue to be an issue in patients surviving intervention.

CONCLUSIONS

RAAA still represents a life-threatening condition, with high mortality rates. Effective screening and centralization matched with adequate preoperative risk-benefit assessment may improve outcomes.

Intravascular Ultrasound Versus Computed Tomography Angiography in Sizing and Operative Management of Endovascular Aortic Aneurysm Repair

OBJECTIVES

An abdominal aortic aneurysm (AAA) is a potentially life-threatening condition, the management of which has dramatically evolved over the past 2 decades with an increasing tendency toward endovascular repair (EVAR) rather than open surgical repair. Classically, contrast-enhanced multislice computed tomography (CT) angiography (CTA) is performed preoperatively for procedure sizing and EVAR planning. This entails voluminous contrast injection with risk of allergic reaction, nephropathy, and radiation exposure. Intra-vascular ultrasound (IVUS) has been increasingly used to guide EVAR procedures intraoperatively. The aim of this study is to investigate the accuracy of IVUS in sizing AAAs, device selection, and EVAR planning compared to the gold standard CTA.

DESIGN

This is a prospective observational study enrolling 10 patients who underwent standard infrarenal EVAR procedures performed for unruptured infrarenal AAAs over the course of 1 year. All patients had a preoperative CTA done upon which aneurysm sizing and device planning were performed, and the measurements obtained were compared to those obtained from intraoperative IVUS.

METHODS

All participating patients had unruptured infrarenal AAA, had no renal impairment, and had anatomical suitability for EVAR according to the instructions for use (IFU) of the device manufacturer. Primary endpoint was comparing anatomical measurements recorded by IVUS with those obtained from the preoperative CTA.

RESULTS

Mean age was 65.6 (±6.19), all patients were males and hypertensives and 4 (40%) had a positive family history for AAA. On comparing mean measurements taken by CTA and IVUS, there was no statistically significant differences with exception of maximal aortic diameter and aortic diameter at site of bifurcation (both p-values <.001). There were no statistically significant differences in length measurements between the 2 imaging modalities. Computed tomography angiography was more associated with neck thrombus detection, and IVUS was more associated with calcification detection.

CONCLUSION

Although CT angiography is still the gold standard imaging modality for AAA, IVUS use is very beneficial in EVAR sizing and planning, in addition to intra-operative guidance of the procedure, saving the patient significant time, contrast administration, and radiation exposure, especially in patients with renal impairment and contrast allergy.

CLINICAL IMPACT

A preoperative CT angiogram is the gold standard required investigation for planning and sizing EVARs, with subsequent contrast injection entailing a risk of contrast induced nephropathy and allergic reactions. IVUS has been used as an adjuvant technique to guide EVAR stent graft deployment. However, our study concluded that it can also be reliably used in sizing and planning of the EVAR stent graft along with complementary non contrast imaging, especially in patients with high risk for contrast induced nephropathy and contrast allergy.

Intraoperative cell salvage using swab wash and serial thromboelastography in elective abdominal aortic aneurysm surgery involving massive blood loss

The loss of 50% blood volume is one accepted definition of massive haemorrhage, which ordinarily would trigger the massive transfusion protocol, involving the administration of high ratios of fresh frozen plasma and platelets to allogeneic red cells. We investigated 53 patients who experienced >50% blood loss during open elective abdominal aortic aneurysm surgery to assess allogeneic blood component usage and coagulopathy. Specialist patient blood management practitioners used a tailored cell salvage technique including swab wash to maximise blood return. We assessed the proportion of patients who did not require allogeneic blood components and develop evidence of coagulopathy by thromboelastography (TEG) parameters. Blood loss was 50%-174% (mean [SD] 68% [27%]) of blood volume. The mean (SD) intraoperative decrease in haemoglobin concentration, assessed by arterial blood gas analysis, was 5 (13) g/l. No patient received allogeneic red cells intraoperatively. Four of the 53 (8%) patients received blood components in the first 24 h postoperatively at the anaesthetists' discretion. No patient had intraoperative TEG changes indicative of fibrinolysis or coagulopathy. The 30-day mortality was 2% (one of 53). Reduction of allogeneic transfusion is one aim of patient blood management techniques. We have demonstrated virtual avoidance of allogeneic blood product transfusion despite massive blood loss. These data show possible alternatives to the current massive transfusion protocols to the management of elective vascular surgical patients.

Bioinformatics-based identification of lipid- and immune-related biomarkers in abdominal aortic aneurysms

Background

Abdominal aortic aneurysm (AAA) manifest as a natural inflammatory process with permanent dilation and terminal rupture. Nevertheless, the pathogenesis of AAA remains a mystery, and treatment is still controversial. Lipid metabolism and immune system are involved in AAA progression, which has been well documented. However, lipid- and immune-related (LIR) biomarkers need to be further elucidated.

Methods

The AAA-related datasets were retrieved from the GEO database, and the datasets were analyzed for differential gene expression by NetworkAnalyst. GO and KEGG pathway enrichment analysis of differentially expressed mRNA (DE-mRNA) was performed using Metscape, and LIR DE-mRNA was further screened. AAA rat model was constructed using porcine pancreatic elastase to verify the differential expression of LIR DE-mRNA.

Results

The GSE47472 and GSE57691 datasets respectively identified 614 (containing 381 down-regulated and 233 up-regulated DE-mRNAs) and 384 (containing 218 down-regulated and 164 up-regulated DE-mRNAs) DE-mRNAs. Intersection and union of DE-mRNAs were 13 and 983, respectively. The main terms involved in the union of DE-mRNAs included "immune system process", "metabolic process", "Chemokine signaling pathway", "hematopoietic cell lineage" and "Cholesterol metabolism". In vivo experiments revealed that LIR DE-mRNAs of PDIA3, TYROBP, and HSPA1A were significantly low expression in AAA abdominal aortic tissues, and HCK and SERPINE1 were significantly high expression, which is consistent with the bioinformatics analysis.

Conclusions

PDIA3, TYROBP, HSPA1A, HCK and SERPINE1 may serve as LIR biomarkers of AAA, which provides new insights and theoretical guidance for the future treatment, early prevention and progression of AAA.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Association between neighborhood deprivation and presenting with a ruptured abdominal aortic aneurysm before screening age

OBJECTIVE

Recent data indicate social determinants of health (SDOH) have a great impact on prevention and treatment outcomes across a broad variety of disease states, especially cardiovascular diseases. The area deprivation index (ADI) is a validated measure of neighborhood level disadvantage capturing key social determinate factors. Abdominal aortic aneurysm rupture (rAAA) is highly morbid, but also preventable through evidence-based screening. However, the association between rAAA and SDOH is poorly characterized. Our objective is to study the association of SDOH with rAAA and screening age.

METHODS

This retrospective study included patients who underwent operative repair of a rAAA at a multihospital healthcare system (2003-2019). Deprivation was measured by the ADI (scale 1-100), grouped into quintiles for simplicity, with higher quintiles indicating greater deprivation. Patients with the highest quintile ADI (89-100) were categorized as the most deprived. We investigated the association between neighborhood deprivation with the odds of (i) undergoing repair for rAAA before screening age 65 and (ii) undergoing endovascular aortic repair (EVAR) using logistic regression, sequentially modeling nonmodifiable then both nonmodifiable and modifiable confounding variables.

RESULTS

There were 632 patients who met the inclusion criteria (aged 74.2 ± 9.4 years; 174 women [27.6%]; 564 White [89.2%]; ADI 66.8 ± 22.3). Those from the most deprived neighborhoods (n = 118) were younger (71.7 ± 10.0 years vs 74.8 ± 9.2 years; P = .002), more likely to be female (36% vs 26%; P = .031), more likely to be Black (5.9% vs 0.4%; P = .007), and fewer underwent EVAR (28% vs 39.5%; P = .020) compared with those from other neighborhoods. On sequential modeling, residing in the most deprived neighborhoods was associated with undergoing rAAA repair before age 65 after adjusting for nonmodifiable factors (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.39-2.95; P < .001), and nonmodifiable as well as modifiable factors (OR, 2.22; 95% CI, 1.56-3.16; P < .001). Those in the most deprived neighborhoods had a lower odds of undergoing EVAR compared with open repair after adjusting for nonmodifiable factors (OR, 0.64; 95% CI, 0.41-0.98; P = .042), and nonmodifiable as well as modifiable factors (OR, 0.61; 95% CI, 0.37-0.99; P = .047).

CONCLUSIONS

Among patients who underwent rAAA, residing in the most deprived neighborhoods was associated with greater adjusted odds of presenting under age 65 and undergoing an open repair. These neighborhoods represent tangible geographic targets that may benefit from a younger screening age, enhanced education, and access to care. These findings stress the importance of developing strategies for early prevention and diagnosis of cardiovascular diseases among patients with disadvantageous SDOH.

Dapagliflozin Ameliorates the Formation and Progression of Experimental Abdominal Aortic Aneurysms by Reducing Aortic Inflammation in Mice

Background. Dapagliflozin, a sodium glucose transporter protein-2 (SGLT-2) inhibitor, reduces the risk for cardiovascular diseases. However, the influence of dapagliflozin on nondissecting abdominal aortic aneurysms (AAAs) remains unclear. Methods. AAAs were created in male C57BL/6 mice via intra-aortic porcine pancreatic elastase (PPE) infusion. Mice were daily treated with dapagliflozin (1 or 5 mg/kg body weight) or an equal volume of vehicle through oral gavage beginning one day prior to PPE infusion for 14 days. To investigate its translational value, dapagliflozin or vehicle was also administered to mice with existing AAAs in another cohort. Aortic diameters were measured prior to (day 0 for baseline) and 14 days after PPE infusion. After sacrifice, mice aortae were collected, and following histological analyses were performed. Results. Dapagliflozin treatment significantly reduced aneurysmal aortic expansion following PPE infusion as compared to vehicle treatment especially at 5 mg/kg body weight (approximately 21% and 33% decreases in 1 and 5 mg/kg treatment groups, respectively). The dose-dependent attenuation of AAAs by dapagliflozin was also confirmed on histological analyses. Dapagliflozin remarkably reduced aortic accumulation of macrophages, CD4+ T cells, and B cells particularly following dapagliflozin treatment at 5 mg/kg. Dapagliflozin treatment also markedly attenuated medial SMC loss. Though the difference was not significant, dapagliflozin treatment tended to attenuate CD8+ T cells and elastin degradation. Dapagliflozin treatment at 5 mg/kg caused a 53% reduction in neovessel density. Furthermore, dapagliflozin treatment mitigated further progress of existing AAAs. Conclusion. Dapagliflozin treatment ameliorated PPE-induced AAAs by inhibiting aortic leukocytes infiltration and angiogenesis.

Kunming mouse strain is less susceptible to elastase‐induced abdominal aortic aneurysms

Background

Porcine pancreatic elastase (PPE) is successfully used to induce abdominal aortic aneurysm (AAA) in mice. However, differences between mouse strains in susceptibility to PPE induction have been reported. Kunming mouse is one of the most frequently used strains in China but whether it is suitable for induction of AAA by PPE application remains unclear.

Methods

PPE infusion (1.5 units/ml) in temporary controlled aorta was performed to induce AAAs in both C57BL/6J and Kunming mice. Phosphate‐buffered saline (PBS) application was used as vehicle control. The aorta diameters of all mice were measured at days 0 and 14 after surgery to evaluate the AAA formation.

Results

After 14 days of PPE or PBS infusion, all mice were sacrificed and aorta tissues were collected for histological staining analysis. At the 14th day after infusion, PPE successfully induced aortic dilation in Kunming mice and typical AAA in C57BL/6J mice. The aorta diameter increased by 0.23 mm in Kunming mice after PPE infusion, while it was 0.72 mm in the C57BL/6J strain. PPE induced mild elastin degradation, smooth muscle cell (SMC) depletion and mural leucocyte infiltration in Kunming mice, but in PPE‐sensitive C57BL/6J mice, it induced total loss of SMCs, elastin disappearance and diffused infiltrated leucocytes in aortic aneurysmal segments. The effects of PPE in inducing angiogenesis and upregulating matrix metalloproteinase 2 and 9 expression in Kunming mice were also weaker than that in C57BL/6J mice.

Conclusion

At the reported dose of PPE, Kunming mouse is not as susceptible to AAA formation as C57BL/6J mice. The failure of PPE to induce AAA formation in Kunming mice may be associated to its inability to boost a strong inflammatory response.

Beyond Vessel Diameters: Non-invasive Monitoring of Flow Patterns and Immune Cell Recruitment in Murine Abdominal Aortic Disorders by Multiparametric MRI

The pathophysiology of the initiation and progression of abdominal aortic aneurysms (AAAs) and aortic dissections (AADs) is still unclear. However, there is strong evidence that monocytes and macrophages are of crucial importance in these processes. Here, we utilized a molecular imaging approach based on background-free ¹⁹F MRI and employed perfluorocarbon nanoemulsions (PFCs) for in situ ¹⁹F labeling of monocytes/macrophages to monitor vascular inflammation and AAA/AAD formation in angiotensin II (angII)-treated apolipoproteinE-deficient (apoE^-/-) mice. In parallel, we used conventional ¹H MRI for the characterization of aortic flow patterns and morphology. AngII (1 μg/kg/min) was infused into apoE^-/- mice via osmotic minipumps for 10 days and mice were monitored by multiparametric ¹H/¹⁹F MRI. PFCs were intravenously injected directly after pump implantation followed by additional applications on day 2 and 4 to allow an efficient ¹⁹F loading of circulating monocytes. The combination of angiographic, hemodynamic, and anatomical measurements allowed an unequivocal classification of mice in groups with developing AAAs, AADs or without any obvious aortic vessel alterations despite the exposure to angII. Maximal luminal and external diameters of the aorta were enlarged in AAAs, whereas AADs showed either a slight decrease of the luminal diameter or no alteration. ¹H/¹⁹F MRI after intravenous PFC application demonstrated significantly higher ¹⁹F signals in aortae of mice that developed AAAs or AADs as compared to mice in which no aortic disorders were detected. High resolution ¹H/¹⁹F MRI of excised aortae revealed a patchy pattern of the ¹⁹F signals predominantly in the adventitia of the aorta. Histological analysis confirmed the presence of macrophages in this area and flow cytometry revealed higher numbers of immune cells in aortae of mice that have developed AAA/AAD. Importantly, there was a linear correlation of the ¹⁹F signal with the total number of infiltrated macrophages. In conclusion, our approach enables a precise differentiation between AAA and AAD as well as visualization and quantitative assessment of inflammatory active vascular lesions, and therefore may help to unravel the complex interplay between macrophage accumulation, vascular inflammation, and the development and progression of AAAs and AADs.