Meta Analysis on Mortality of Ruptured Abdominal Aortic Aneurysms

MR Angiography for Aortic Diseases

Aortic pathologic conditions represent diverse disorders, including aortic aneurysm, acute aortic syndrome, traumatic aortic injury, and atherosclerosis. Given the nonspecific clinical features, noninvasive imaging is critical in screening, diagnosis, management, and posttherapeutic surveillance. Of the commonly used imaging modalities, including ultrasound, computed tomography, and MR imaging, the final choice often depends on a combination of factors: acuity of clinical presentation, suspected underlying diagnosis, and institutional practice. Further research is needed to identify the potential clinical role and define appropriate use criteria for advanced MR applications such as four-dimenional flow to manage patients with aortic pathologic conditions.

Retinal oculomics and risk of incident aortic aneurysm and aortic adverse events: a population-based cohort study

BACKGROUND

The asymptomatic onset and extremely high mortality rate of aortic aneurysm (AA) highlight the urgency of early detection and timely intervention. The alteration of retinal vascular features (RVFs) can reflect the systemic vascular properties, and be widely used as the biomarker for cardiovascular disease risk prediction. Therefore, we aimed to investigate associations of RVFs with AA and its progression.

METHODS

In this prospective population-based cohort study, participants with eligible fundus images and without a history of AA at recruitment were included for analysis. A fully automated Retina-based Microvascular Health Assessment System was used to quantify multidimensional RVFs including the branching angle, caliber, complexity, density, length, and tortuosity. Univariable and multivariable Cox regressions were used to estimate the association of RVFs with the incidence of AA and aortic adverse events (AAE). Furthermore, propensity score matching was performed to mitigate the confounding effects of baseline characteristics.

RESULTS

During a median follow-up of 11.0 years, 306 incident AA (164 with abdominal AA and 108 with thoracic AA) and 48 incident AAE were documented. In the fully adjusted model, the retinal arterial branching angle (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.77 to 0.99) and the central tendency and variability of minimum venular caliber were significantly associated with the risk of incident AA (HR 1.13-1.15), while the venular minimum angular asymmetry (0.48, 0.30 to 0.77) was significantly associated with the incidence of AAE. Moreover, specific alterations of RVFs were observed in different AA subtypes (caliber in abdominal AA [HR 1.21]; caliber [HR 1.21-1.28], complexity, length, and tortuosity [HR 0.77-0.82] in thoracic AA). Similar results were obtained after propensity score-matched analysis, confirming the stability of these associations.

CONCLUSIONS

We identified a significant association of certain RVFs with incident AA and AAE, implying that noninvasive, and convenient fundus photography could be a promising tool to facilitate the early detection of AA and subsequent preventative interventions.

Enhanced Vascular Smooth Muscle Cell and Extracellular Matrix Repair Using a Metal-Organic Framework-Based Co-Delivery System for Abdominal Aortic Aneurysm Therapy

The abdominal aortic aneurysm (AAA) is a severe and complex condition characterized by the pathological dilation of the abdominal aorta. Current therapeutic strategies are limited, with surgical repair being the most effective intervention due to the lack of medications that can slow aneurysmal expansion or prevent adverse events. In this study, an innovative nanoplatform, Mn-UiO-66-NH2@HA, designed to repair vascular smooth muscle cells (VSMCs), and the extracellular matrix (ECM) is developed, thereby enhancing arterial wall integrity. This nanoplatform utilizes the classic metal-organic framework (MOF) UiO-66-NH2, doped with manganese ions (Mn2+) and coated with hyaluronate tetrasaccharide (4-mer HA). The Mn-UiO-66-NH2@HA nanoparticles demonstrates excellent drug-loading efficiency, sustained release properties, and biocompatibility. In vitro, these nanoparticles significantly increases VSMC contractility and up-regulated elastin and lysyl oxidase expressions, crucial for ECM repair, while inhibiting matrix metalloproteinases. In vivo studies on an Ang II-induced AAA mouse model reveals that Mn-UiO-66-NH2@HA effectively reduces aneurysmal expansion and improves aortic structural integrity. This study presents a promising co-delivery system leveraging MOF carriers coated with 4-mer HA and Mn2+, offering a novel therapeutic strategy for the treatment and management of AAA.

External Validation of Eight Ruptured Abdominal Aortic Aneurysm Mortality Prediction Models Demonstrates Limited Predictive Accuracy

OBJECTIVE

Over a dozen ruptured abdominal aortic aneurysm (rAAA) mortality risk prediction models currently exist; however, lack of external validation limits their applicability. This study aimed to evaluate the accuracy of eight common rAAA mortality risk prediction models in a large, contemporary, external validation cohort.

METHODS

A retrospective review of rAAA repairs at a multicentre integrated regional healthcare system with large central quaternary referral facility (2010 - 2020) was performed. Eight models were used to predict 30 day post-operative death, including the Updated Glasgow Aneurysm Score (GAS), Vascular Study Group of New England rAAA Risk Score, Harborview Pre-operative rAAA Risk Score, Modified Harborview Risk Score, Vancouver Scoring System (VSS), Artificial Neural Network Score, Dutch Aneurysm Score, and Edinburgh Ruptured Aneurysm Score. The models were assessed for discrimination, calibration, and clinical utility using receiver operating characteristic curves (area under the curve [AUC]), Hosmer-Lemeshow χ2 test, Brier scores, and decision curve analysis. The proportion of unexpected survivors (survival despite > 80% predicted 30 day death) to expected deaths was compared across calculators, and both groups were compared using the model demonstrating the highest unexpected survival frequency.

RESULTS

Three hundred and fifteen rAAA repairs were included (mean age 73.6 ± 10.0 years; 72.1% male; 49.8% open repair) with a 30 day mortality rate of 32.1%. Three models had fair discrimination (AUC ≥ 0.70), with GAS having the highest AUC (0.74, 95% confidence interval 0.68 - 0.79). All models demonstrated poor to adequate calibration. Using VSS, unexpected survivors (n = 25) had less pre-operative shock (72% vs. 96%; p = .050) and statistically significantly less coagulopathy (median international normalised ratio 1.2 [interquartile range 1.1, 1.5] vs. 1.8 [1.3, 2.2]; p = .015) compared with expected deaths (n = 23).

CONCLUSION

Current rAAA risk prediction models demonstrated only fair discrimination and poor to adequate calibration. These findings suggest that existing risk prediction models have not sufficiently captured important physiological characteristics associated with rAAA death and should be applied cautiously to clinical practice.

Infrarenal endovascular repair of abdominal aortic aneurysm with hostile aortic neck configuration by primary placement of an infrarenal Palmaz stent followed by an endoprosthesis with suprarenal fixation (the "Neoneck" technique)

Background

The Endovascular Repair (EVAR) is the first-choice technique for Abdominal Aortic Aneurysm (AAA). Treatment success is dependent on favorable anatomy and an adequate sealing zone formed by a straight aortic neck (slightly angled). Endoprostheses implanted at critical aortic angles (above 75º) may result in unfavorable results such as fracture, migration, and type Ia endoleak. The technique for creating a proximal "Neoneck" consists of implanting the Palmaz stent in the proximal neck of the AAA, before placement of the endoprosthesis, allowing remodeling and rectification of the aortic neck.

Objectives

To describe the "Neoneck" technique and report the early results of three cases with rectification of the proximal neck angle using a Palmaz stent, enabling treatment in these cases with angulated necks.

Methods

We analyzed data collected from patients in whom Palmaz stents were placed, constructing a proximal Neoneck, during EVAR for infrarenal AAA with very tortuous proximal aortic neck, assessing anatomy, devices and perioperative results, including success rates, complications, mortality, and patency in the short and medium term.

Results

All patients presented satisfactory evolution with immediate technical success. There were no cases of migration, fracture, or type Ia endoleaks. There was evidence of aneurysmal sac reduction after six months. There were no complications related to surgical access or deaths.

Conclusions

In cases of angled aortic necks, when open AAA repair is not possible, in the absence of ideal devices or in urgent cases, prior rectification of the aortic neck deploying the Palmaz stent is feasible and effective. Long-term studies are still needed to validate the technique and assess safety.

Socioeconomic and regional variations in repair modality for ruptured abdominal aortic aneurysms

BACKGROUND

Previous studies report that patients of racial/ethnic minorities more frequently present with ruptured abdominal aortic aneurysms (rAAAs) than their counterparts. The distribution of rAAA treatment modality, whether open aneurysm repair (OAR) or endovascular aneurysm repair (EVAR), by race/ethnicity classification remains uncertain. This study aims to investigate disparities, as represented by race/ethnic classification, median income, and insurance status, in the management of rAAA in a national cohort.

METHODS

We conducted a retrospective analysis of patients admitted with rAAA managed with either OAR or EVAR from 2002 to 2020 using the National Inpatient Sample, comparing repair type by race/ethnicity group. Multilevel mixed effects logistic regression models, adjusted for patient- and system-level factors, were used to calculate difference in use of OAR or EVAR dependent on race/ethnicity classification.

RESULTS

We identified 10,788 admissions for rAAA repairs, of which 9506 (88.1%) were White, 605 (5.6%) were Black, 424 (3.9%) were Hispanic, and 253 (2.4%) were Asian/Native American. Asians/Native Americans underwent the highest frequency of OAR as compared with EVAR (61.7% vs 38.3%). In the adjusted model, there was no statistically significant difference in the use of OAR vs EVAR by race/ethnicity classification. In total, primary payer and median income were also not statistically significant predictors of AAA treatment modality.

CONCLUSIONS

Our study found no statistical evidence of disparities with respect to race, insurance, or median income and use of OAR or EVAR for the management of rAAA.

Influence of endovascular surgery on abdominal aortic aneurysm management strategies from a national health insurance database survey

BACKGROUND

Abdominal aortic aneurysm (AAA) is a significant global health concern, yet comprehensive population-based studies remain limited. This study aimed to evaluate the hospitalization rates, surgical trends, mortality, and reintervention rates for ruptured (r-AAA) and nonruptured (nr-AAA) AAA using data from a national health insurance database.

METHODS

A population-based retrospective cohort study was conducted utilizing data from the Taiwanese National Health Insurance Research Database from 2007 to 2018. The study included individuals aged 20 years and older with a newly diagnosed AAA.

RESULTS

Among 70 457 patients diagnosed with aortic aneurysm or dissection, 22 538 (32%) adult patients (≥20 years) were identified with AAA. The annual incidence of AAA ranged from 7.7 to 10.3 per 100 000 population, with r-AAA decreasing from 1.3 to 0.8 per 100 000 and nr-AAA from 9.0 to 6.8 per 100 000. Most patients with AAA were older adults (85%), with 15 392 (68%) hospitalized and 4885 (32%) undergoing surgery within 14 days of diagnosis. The use of endovascular aneurysm repair (EVAR) significantly increased from 28% to 96% over the study period. Long-term survival was higher in patients who underwent open surgical repair (OSR) compared to those who received EVAR or conservative management, irrespective of whether they had r-AAA or nr-AAA.

CONCLUSION

AAA predominantly affects older individuals, and the annual incidence shows a declining trend. Since the introduction of EVAR, its use has steadily increased while OSR rates have decreased. Although both EVAR and OSR are associated with reduced mortality in patients with r-AAA, OSR is linked to superior long-term survival outcomes.

In-hospital mortality risk after endovascular and open aortic aneurysm repairs for ruptured abdominal aortic aneurysms

OBJECTIVE

Observational studies demonstrate reduced mortality after endovascular (EVAR) compared with open aneurysm repair (OAR) for ruptured abdominal aortic aneurysms (rAAAs). We sought to determine national trends in repair type and in-hospital mortality rates for rAAAs.

METHODS

We analyzed patients with rAAAs managed with OAR or EVAR from 2002 to 2020 in the National Inpatient Sample and evaluated annual trends in volume and in-hospital mortality by repair type. Multilevel mixed effects logistic regression model was fit for patient and system-level risk adjustment. We assessed interactions between time, sex, and Elixhauser index with repair type.

RESULTS

We examined 13,376 patients with rAAAs. Of these, 8357 (62.5%) underwent OAR. Patients receiving EVAR were slightly older (73.7 vs 72.5 years; P < .001) with slightly higher mean Elixhauser index (4.0 vs 3.8; P < .001). Unadjusted in-hospital mortality was 37.4% vs 22.4% for OAR and EVAR, respectively. EVAR offered a risk-adjusted survival advantage (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.32-0.46). There was a statistically significant reduction of in-hospital mortality over time in the EVAR group (interaction OR, 0.96; 95% CI, 0.95-0.98). The interaction between Elixhauser index and repair was not statistically significant (interaction OR, 0.95; 95% CI, 0.87-1.05).

CONCLUSIONS

Survival rates for OAR and EVAR improved over time. EVAR persistently provided a substantial survival advantage over OAR in patients with rAAAs over the past 2 decades.

A Decade-Long Retrospective Study of Factors Influencing Survival in Ruptured Abdominal Aortic Aneurysm

Background: Ruptured abdominal aortic aneurysm (rAAA) carries a high mortality risk, requiring rapid diagnosis and intervention. This study assesses various clinical factors influencing rAAA management outcomes in alignment with evolving guidelines from 2011 to 2024. Methods: A retrospective analysis of 62 rAAA patients treated at Vivantes Clinic, Berlin, from July 2014 to May 2024 was conducted. Data were obtained from medical records, focusing on vital parameters at admission and during treatment. Both numerical and categorical variables were analyzed to identify survival determinants. Results: The overall survival rate was 55%. Significant differences in systolic and diastolic blood pressures during surgery were noted between survivors and non-survivors, with lower pressures observed in non-survivors at critical surgical stages. Other vital signs showed no significant variations. Survival was significantly associated with gender, fluid therapy, and aneurysm location. Conclusions: Effective blood pressure management during surgery is crucial for improving survival in rAAA cases. This study emphasizes adherence to current clinical guidelines and highlights the need for ongoing research to fill existing knowledge gaps. Further investigations are essential to enhance patient care and outcomes in rAAA.

Repair of Contained Rupture of an Infrarenal Aortic Aneurysm Using Autologous Superficial Femoral Vein

Introduction

Contained ruptured abdominal aortic aneurysm (CR-AAA) refers to an acute aortic wall disruption leading to expansion of perivascular haematoma that is sealed off by peri-aortic structures. Low and middle income countries have a critical gap in managing abdominal aortic aneurysm (AAA). In Ethiopia, AAA screening is not routine and open surgical repair (OSR) using donated grafts remains the only treatment option. This case shows the first experience at Hawassa University Hospital treating CR-AAA using the superficial femoral vein (SFV) for aortic reconstruction due to lack of prosthetic grafts.

Report

A 40 year old woman presented with three months of abdominal and back pain, vomiting, and a pulsatile abdominal swelling. Imaging showed an 8 cm infrarenal CR-AAA. Due to lack of graft material, a 15 cm SFV was harvested from the left thigh and prepared as a tube graft. OSR via midline laparotomy revealed a 3 cm rupture on the right lateral aortic wall. The reversed SFV graft was anastomosed proximally to the infrarenal aorta, 3 cm below the renal artery, using a 3-0 Prolene suture. Distally, the graft was spatulated for optimal size matching and sewn with a 3-0 Prolene suture at the aortic bifurcation. The procedure lasted 10 hours. Due to the lack of a Cell Saver at the centre, 4 units of whole blood and 4 units of fresh frozen plasma were transfused. Post-operatively, the patient developed bilateral lower extremity swelling, and ultrasound revealed bilateral deep venous thrombosis. Oral anticoagulation was promptly initiated. Follow up imaging confirmed an intact anastomosis with good distal flow. The patient showed clinical improvement in leg swelling at one and three month follow ups. She is scheduled for a six month follow up and will continue regular monitoring.

Discussion

SFV use in ruptured AAA shows promise in resource limited settings. Sub-Saharan Africa's unique AAA patterns highlight specific healthcare needs. Global collaboration is vital to expand vascular care, funding, and research for better AAA treatment.

The Year in Aortic Surgery: Selected Highlights From 2023

This article reviews the recent and relevant literature to the field of aortic surgery. Specific areas highlighted include outcomes of Stanford type A dissection, management of acute aortic syndromes, management of aortic aneurysms, and traumatic aortic injury. Although the focus was on articles from 2023, literature from prior years also was included, given that this article is the first of a series. Notably, the pertinent sections from the 2022 American College of Cardiology/American Heart Association Guidelines for the Diagnosis and Management Aortic Disease are discussed.

Ruptured AAA: bridging the gap between international guidelines and local clinical realities

BACKGROUND

Treatment of asymptomatic Abdominal Aortic Aneurysms (AAA) presents a clinical challenge, requiring a delicate balance between rupture risk, patient comorbidities, and intervention-related complications. International guidelines recommend intervention for specific AAA size thresholds, but these are based on historical trials with limited female representation. We aimed to analyse disease characteristics, AAA size at rupture, and intervention outcomes in patients with ruptured AAA from 2009 to 2023 to investigate the gap between guidelines and local realities.

METHODS

This single-centre retrospective cohort study analysed electronic health records of patients treated for a ruptured AAA, excluding those who were managed palliatively. The study assessed patients' demographics, risk factors, comorbidities, clinical presentation, radiological characteristics, and outcomes.

RESULTS

Of 164 patients (41 females, 123 males, median age 73.5), 93.3% presented with abdominal or back pain. The median AAA size at rupture was 8.0 cm in males and 7.6 cm in females. No significant correlations were found between demographic characteristics, risk factors, AAA size, repair modality, and outcomes. Trends show a decline in AAA prevalence and rupture rates, aligning with global health initiatives. Post-intervention survival rates at 30 days were 70.7% (67.5% in males and 80.0% in females), and at 2 years were 65.85% (61.7% in males and 70.0% in females).

CONCLUSION

Evolving AAA trends and improved post-intervention survival rates warrant a critical reassessment of existing intervention recommendations. Adjusting intervention thresholds to larger sizes may be justified to optimise the risk-benefit ratio.

Acute Intraoperative Conversion from Endovascular to Open vs Planned Open Operation for Abdominal Aortic Aneurysm: A Propensity-Score Matched Study from the American College of Surgeons NSQIP-Targeted Database

BACKGROUND

Evaluating outcomes for acute intraoperative conversion to open surgery during endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) was difficult due to low incidence. This study aimed to compare 30-day outcomes between patients with acute intraoperative conversion during EVAR and planned open surgery, and to identify risk factors associated with acute conversion.

STUDY DESIGN

Patients who underwent EVAR or planned open AAA repair were identified in American College of Surgeons NSQIP-targeted databases from 2012 to 2021. Patients with acute intraoperative conversion during EVAR were selected. A 1:3 propensity-score matching was used to match demographics, baseline characteristics, surgical indications, aneurysm size and extent, and emergency cases between the conversion open and planned open groups. Thirty-day postoperative outcomes were assessed.

RESULTS

Of 20,566 EVAR cases, 177 (0.86%) had acute intraoperative conversion to open surgery. The conversion open group was matched to 504 of 5,249 planned open patients. Conversion open and planned open groups had comparable 30-day mortality (23.43% vs 17.46%, p = 0.09) and organ system complications, including major adverse cardiovascular event (14.86% vs 10.71%, p = 0.17), pulmonary complications (17.71% vs 24.01%, p = 0.09), and renal complications (8.57% vs 11.11%, p = 0.39). The conversion open group had lower bleeding requiring transfusion (48.57% vs 75.60%, p < 0.01), shorter operation time (p < 0.01), and shorter length of stay (p < 0.01). Other postoperative outcomes did not differ. Risk factors associated with acute intraoperative conversion included ruptured aneurysm with or without hypotension. Protective factors included hypertension and aortic distal aneurysm extent.

CONCLUSIONS

Although this study does not endorse a universal "EVAR first" strategy for all patients with AAA, EVAR can be attempted first in eligible patients with AAA. Even when EVAR is unsuccessful, intraoperative conversion to open surgery still appears to be safe compared with planned open repair.

The 5-Factor Modified Frailty Index is a Succinct yet Effective Predictor of Adverse Outcomes in Patients Undergoing Open Surgery for Abdominal Aortic Aneurysm

BACKGROUND

Frailty is an age-related, clinically recognizable state marked by increased susceptibility. The 5-item Modified Frailty Index (mFI-5) offers a concise assessment of frailty and has demonstrated its efficacy in various surgical fields. While the mFI-5 has been validated for endovascular aneurysm repair for abdominal aortic aneurysm (AAA), its applicability in open surgical repair (OSR) for AAA remains largely unexplored. This study sought to evaluate the utility of mFI-5 in predicting 30-day outcomes following OSR for AAA.

METHODS

Patients underwent OSR for AAA were identified in American College of Surgeons National Surgical Quality Improvement Program-targeted database from 2012 to 2021. Patients were stratified into 3 cohorts: mFI-5 score of 0 (control), 1, and 2+. Multivariable logistic regression was used to compare 30-day perioperative outcomes between frail patients and controls adjusting preoperative variables with P value <0.1.

RESULTS

Of the 5,249 patients who underwent OSR for AAA, 1,043 were controls, 2,938 had an mFI-5 score of 1 and 1,268 had an mFI-5 score of 2+. When compared to the control group, patients with an mFI-5 = 1 were more likely to have pulmonary events (adjusted odds ratio (aOR) = 1.452, P < 0.01), bleeding events (aOR = 1.33, P < 0.01), wound complications (aOR = 2.214, P < 0.01), ischemic colitis (aOR = 1.616, P = 0.01), and unplanned reoperation (aOR = 1.292, P = 0.04). Those with an mFI-5 = 2+ demonstrated higher risks of mortality (aOR = 1.709, P < 0.01), major adverse cardiovascular events (aOR = 1.347, P = 0.04), pulmonary events (aOR = 2.045, P < 0.01), renal dysfunction (aOR = 1.568, P < 0.01), sepsis (aOR = 1.587, P = 0.01), bleeding events (aOR = 1.429, P < 0.01), wound complications (aOR = 2.338, P < 0.01), ischemic colitis (aOR = 1.775, P = 0.01), unplanned reoperation (aOR = 1.445, P = 0.01), operation over 4 hours (aOR = 1.34, P < 0.01), length of stay over 7 days (aOR = 1.324, <0.01), discharge not to home (aOR = 1.547, P < 0.01), 30-day readmission (aOR = 1.657, P = 0.01).

CONCLUSIONS

The mFI-5 emerges as a succinct yet effective indicator of frailty for patients undergoing OSR for AAA. Especially, an mFI-5 score of 2+ is linked with increased 30-day mortality and complications. As such, mFI-5 can be used as a valuable screening tool for frailty in patients undergoing OSR for AAA.

Racial and sex disparities in inpatient outcomes of patients with ruptured abdominal aortic aneurysms in the United States

BACKGROUND

Ruptured abdominal aortic aneurysm (AAA) is a medical emergency that requires immediate surgical intervention. The aim of this analysis was to identify the sex- and race-specific disparities that exist in outcomes of patients hospitalized with this condition in the United States using the National Inpatient Sample (NIS) to identify targets for improvement and support of specific patient populations.

METHODS

In this descriptive, retrospective study, we analyzed the patients admitted with a primary diagnosis of ruptured AAA between January 1, 2016, and December 31, 2020, using the NIS database. We compared demographics, comorbidities, and in-hospital outcomes in AAA patients, and compared these results between different racial groups and sexes.

RESULTS

A total of 22,395 patients with ruptured AAA were included for analysis. Of these, 16,125 patients (72.0%) were male, and 6270 were female (28.0%). The majority of patients (18,655 [83.3%]) identified as Caucasian, with the remaining patients identifying as African American (1555 [6.9%]), Hispanic (1095 [4.9%]), Asian or Pacific Islander (470 [2.1%]), or Native American (80 [0.5%]). Females had a higher risk of mortality than males (OR, 1.7; 95% confidence interval [CI], 1.45-1.96; P < .001) and were less likely to undergo endovascular aortic repair (OR, 0.70; 95% CI, 0.61-0.81; P < .001) or fenestrated endovascular aortic repair (OR, 0.71; 95% CI, 0.55-0.91; P = .007). Relative to Caucasian race, patients who identified as African American had a lower risk of inpatient mortality (OR, 0.50; 95% CI, 0.37-0.68; P < .001).

CONCLUSIONS

In this retrospective study of the NIS database from 2016 to 2020, females were less likely to undergo endovascular intervention and more likely to die during their initial hospitalization. African American patients had lower rates in-hospital mortality than Caucasian patients, despite a higher burden of comorbidities. Future studies are needed to elucidate the potential factors affecting racial and sex disparities in ruptured AAA outcomes, including screening practices, rupture risk stratification, and more personalized guidelines for both elective and emergent intervention.

Current Prognostic Biomarkers for Abdominal Aortic Aneurysm: A Comprehensive Scoping Review of the Literature

Abdominal aortic aneurysm (AAA) is a progressive dilatation of the aorta that can lead to aortic rupture. The pathophysiology of the disease is not well characterized but is known to be caused by the general breakdown of the extracellular matrix within the aortic wall. In this comprehensive literature review, all current research on proteins that have been investigated for their potential prognostic capabilities in patients with AAA was included. A total of 45 proteins were found to be potential prognostic biomarkers for AAA, predicting incidence of AAA, AAA rupture, AAA growth, endoleak, and post-surgical mortality. The 45 proteins fell into the following seven general categories based on their primary function: (1) cardiovascular health, (2) hemostasis, (3) transport proteins, (4) inflammation and immunity, (5) kidney function, (6) cellular structure, (7) and hormones and growth factors. This is the most up-to-date literature review on current prognostic markers for AAA and their functions. This review outlines the wide pathophysiological processes that are implicated in AAA disease progression.

Editor's Choice - An Endovascular Approach to Abdominal Aortic Aneurysm Rupture is Associated With Improved Outcomes for Patients With Prior Aortic Repair

OBJECTIVE

To assess whether outcomes of rupture repair differ by aortic repair history and determine the ideal approach for rupture repair in patients with previous aortic repair.

METHODS

This retrospective review included all patients who underwent repair of a ruptured infrarenal abdominal aortic aneurysm from 2003 - 2021 recorded in the Vascular Quality Initiative (VQI) registry. Pre-operative characteristics and post-operative outcomes and long term survival were compared between patients with and without prior aortic repair. To assess the impact of open and endovascular approaches to rupture, a subgroup analysis was then performed among patients who ruptured after a prior infrarenal aortic repair. Univariable and adjusted analyses were performed to account for differences in patient characteristics and operative details.

RESULTS

A total of 6 197 patients underwent rupture repair during the study period, including 337 (5.4%) with prior aortic repairs. Univariable analysis demonstrated an increased 30 day mortality rate in patients with prior repairs vs. without (42 vs. 36%; p = .034), and prior repair was associated with increased post-operative renal failure (35 vs. 21%; p < .001), respiratory complications (32 vs. 24%; p < .001), and wound complications (9 vs. 4%; p < .001). Following adjustment, all outcomes were similar with the exception of bowel ischaemia, which was decreased among patients with prior repair (OR 0.7, 95% CI 0.6 - 0.9). Subgroup analysis demonstrated that patients with a prior aortic repair history who underwent open rupture repair had increased odds for 30 day death (OR 1.3, 95% CI 1.2 - 1.7) and adverse secondary outcomes compared with those managed endovascularly.

CONCLUSION

Prior infrarenal aortic repair was not independently associated with increased morbidity or mortality following rupture repair. Patients with a prior aortic repair history demonstrated statistically significantly higher mortality and morbidity when treated with an open repair compared with an endovascular approach. An endovascular first approach to rupture should be strongly encouraged whenever feasible in patients with prior aortic repair.

Co-prevalence of arterial aneurysm location - a correlation analysis based on a retrospective cross-sectional observational study

Background: The aim of this retrospective single-centre cross-sectional observational study was to investigate co-prevalence of arterial aneurysm location systematically. Patients and methods: Patients with the diagnosis of any arterial aneurysm from January 2006 to January 2016 were investigated in a single centre. Patients with hereditary disorders of connective tissue, systemic inflammatory disease, or arterial pathologies other than true aneurysms were excluded. Aneurysm locations were assessed for every patient included. For patients with at least two co-existing aneurysms, co-prevalence of aneurysm location was investigated by calculating correlation coefficients and applying Fisher's exact test. This study report is prepared according to the STROBE statement. Results: Of 3107 identified patients with arterial aneurysms, 918 were excluded. Of the remaining 2189 patients, 951 patients with at least two aneurysms were included in the study. Bilateral aneurysm combinations of paired iliac, femoral and popliteal arteries showed the highest correlation (ϕ=0.35 to 0.67), followed by bilateral combinations of subclavian (ϕ=0.36) and internal carotid (ϕ=0.38) arteries. Abdominal aortic aneurysms in combination with visceral artery aneurysms (ϕ=-0.24 to -0.12), popliteal arteries (ϕ=-0.22) and the ascending aorta (ϕ=-0.19) showed the lowest correlation, followed by the descending aorta in combination with the common iliac arteries (ϕ=-0.12 to -0.13). Conclusions: In our study sample, aneurysm co-prevalence was highly non-random. This should be considered in the context of aneurysm screening programs.

Computed Tomography Angiography for Aortic Diseases

Aortic pathologies encompass a heterogeneous group of disorders, including acute aortic syndrome, traumatic aortic injury , aneurysm, aortitis, and atherosclerosis. The clinical manifestations of these disorders can be varied and non-specific, ranging from acute presentations in the emergency department to chronic incidental findings in an outpatient setting. Given the non-specific nature of their clinical presentations, the reliance on non-invasive imaging for screening, definitive diagnosis, therapeutic strategy planning, and post-intervention surveillance has become paramount. Commonly used imaging modalities include ultrasound, computed tomography (CT), and MR imaging. Among these modalities, computed tomography angiography (CTA) has emerged as a first-line imaging modality owing to its excellent anatomic detail, widespread availability, established imaging protocols, evidence-proven indications, and rapid acquisition time.

Medium-Term Survival After Unrepaired Ruptured Abdominal Aortic Aneurysm

PURPOSE

Ruptured abdominal aortic aneurysm (AAA) is almost always considered fatal without open surgical or endovascular repair. We report a case that has defied this norm and explore the possible factors involved in this exceedingly rare outcome.

CASE REPORT

An 87 year old gentleman presented with an acute ruptured AAA with left retroperitoneal hematoma. He was counseled for emergent repair, but opted for conservative management instead. He has remained well at the time of writing, 13 months from the rupture, with clinical resolution of symptoms along with radiological resolution of the hematoma.

CONCLUSION

Timely repair remains the mainstay of management for ruptured AAA, although this rare case highlights that it is possible for ruptured AAA to seal spontaneously with patient surviving up to 13 months. We have sought to hypothesize the factors in this case that may have contributed to prolonged survival following untreated ruptured AAA.

CLINICAL IMPACT STATEMENT

While the overwhelming evidence is that a ruptured AAA left unrepaired is fatal, our case report illustrates a rare case that shows it is possible for ruptured AAA to seal spontaneously, with patient surviving up to 13 months. We seek to hypothesize the factors that may contribute to such prolonged survival.

Hypertension during transfer is associated with poor outcomes in unstable patients with ruptured abdominal aortic aneurysm

OBJECTIVE

Limited data exist for optimal blood pressure (BP) management during transfer of patients with ruptured abdominal aortic aneurysm (rAAA). This study evaluates the effects of hypertension and severe hypotension during interhospital transfers in a cohort of patients with rAAA in hemorrhagic shock.

METHODS

We performed a retrospective, single-institution review of patients with rAAA transferred via air ambulance to a quaternary referral center for repair (2003-2019). Vitals were recorded every 5 minutes in transit. Hypertension was defined as a systolic BP of ≥140 mm Hg. The primary cohort included patients with rAAA with hemorrhagic shock (≥1 episode of a systolic BP of <90 mm Hg) during transfer. The primary analysis compared those who experienced any hypertensive episode to those who did not. A secondary analysis evaluated those with either hypertension or severe hypotension <70 mm Hg. The primary outcome was 30-day mortality.

RESULTS

Detailed BP data were available for 271 patients, of which 125 (46.1%) had evidence of hemorrhagic shock. The mean age was 74.2 ± 9.1 years, 93 (74.4%) were male, and the median total transport time from helicopter dispatch to arrival at the treatment facility was 65 minutes (interquartile range, 46-79 minutes). Among the cohort with shock, 26.4% (n = 33) had at least one episode of hypertension. There were no significant differences in age, sex, comorbidities, AAA repair type, AAA anatomic location, fluid resuscitation volume, blood transfusion volume, or vasopressor administration between the hypertensive and nonhypertensive groups. Patients with hypertension more frequently received prehospital antihypertensives (15% vs 2%; P = .01) and pain medication (64% vs 24%; P < .001), and had longer transit times (36.3 minutes vs 26.0 minutes; P = .006). Episodes of hypertension were associated with significantly increased 30-day mortality on multivariable logistic regression (adjusted odds ratio [aOR], 4.71; 95% confidence interval [CI], 1.54-14.39; P = .007; 59.4% [n = 19] vs 40.2% [n = 37]; P = .01). Severe hypotension (46%; n = 57) was also associated with higher 30-day mortality (aOR, 2.82; 95% CI, 1.27-6.28; P = .01; 60% [n = 34] vs 32% [n = 22]; P = .01). Those with either hypertension or severe hypotension (54%; n = 66) also had an increased odds of mortality (aOR, 2.95; 95% CI, 1.08-8.11; P = .04; 58% [n = 38] vs 31% [n = 18]; P < .01). Level of hypertension, BP fluctuation, and timing of hypertension were not significantly associated with mortality.

CONCLUSIONS

Hypertensive and severely hypotensive episodes during interhospital transfer were independently associated with increased 30-day mortality in patients with rAAA with shock. Hypertension should be avoided in these patients, but permissive hypotension approaches should also maintain systolic BPs above 70 mm Hg whenever possible.

Development of a comorbidity index for patients undergoing abdominal aortic aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) and open surgical repair (OSR) are two modalities to treat patients with abdominal aortic aneurysm (AAA). Alternative to individual comorbidity adjustment, a summary comorbidity index is a weighted composite score of all comorbidities that can be used as standard metric to control for comorbidity burden in clinical studies. This study aimed to develop summary comorbidity indices for patients who underwent AAA repair.

METHODS

Patients who went under EVAR or OSR were identified in National Inpatient Sample (NIS) between the last quarter of 2015 to 2020. In each group, patients were randomly sampled into experimental (2/3) and validation (1/3) groups. The weights of Elixhauser comorbidities were determined from a multivariable logistic regression and single comorbidity indices were developed for EVAR and OAR groups, respectively.

RESULTS

There were 34,668 patients underwent EVAR (2.19% mortality) and 4792 underwent OSR (10.98% mortality). Both comorbidity indices had moderate discriminative power (EVAR c-statistic, 0.641; 95% confidence interval [CI], 0.616-0.665; OSR c-statistic, 0.600; 95% CI, 0.563-0.630) and good calibration (EVAR Brier score, 0.021; OSR Brier score, 0.096). The indices had significantly better discriminative power (DeLong P <.001) than the Elixhauser Comorbidity Index (ECI) (EVAR c-statistic, 0.572; 95% CI, 0.546-0.597; OSR c-statistic, 0.502; 95% CI, 0.472-0.533). For internal validation, both indices had similar performance compared with individual comorbidity adjustment (EVAR DeLong P = .650; OSR DeLong P = .431). These indices demonstrated good external validation, exhibiting comparable performance to their respective validation groups (EVAR DeLong P = .891; OSR DeLong P = .757).

CONCLUSIONS

ECI, the comorbidity index formulated for the general population, exhibited suboptimal performance in patients who underwent AAA repair. In response, we developed summary comorbidity indices for both EVAR and OSR for AAA repair, which were internally and externally validated. The EVAR and OSR comorbidity indices outperformed the ECI in discriminating in-hospital mortality rates. They can standardize comorbidity measurement for clinical studies in AAA repair, especially for studies with small samples such as single-institute data sources to facilitate replication and comparison of results across studies.

Causal Relationship between Gut Microbiota and Aneurysm: A Mendelian Randomization Study

INTRODUCTION

Observational studies have suggested a possible relationship between gut microbiota (GM) and aneurysm development. However, the nature of this association remains unclear due to the inherent limitations of observational research, such as reverse causation and confounding factors. To address this knowledge deficit, this study aimed to investigate and establish a causal link between GM and aneurysm development.

METHODS

Summary statistics regarding GM and aneurysms were collected from relevant genome-wide association studies. Two samples were used in mendelian randomization (MR). The principal MR technique utilized was inverse-variance weighting, a technique renowned for producing reliable causal effect estimations. Additional MR methods, including weighted median (WM), MR-Egger, MR-PRESSO, and simple mode methods, were employed to ensure the robustness of the aforementioned association and investigate potential biases. Sensitivity analyses were performed to determine the consistency of the MR findings.

RESULTS

Varying associations were observed between specific microbial taxa and the different aneurysms analyzed. A negative correlation was observed between aortic aneurysm (AA) and Lentisphaerae, Lentisphaeria, and Victivallales. Conversely, the genus FamilyXIIIUCG001 exhibited an increased risk association. Regarding abdominal AA, Victivallaceae showed a reduced risk, and Bilophila and Catenibacterium were associated with an increased risk. For thoracic AA, negative and positive correlations were observed with Lentisphaerae and Turicibacter, respectively. Lastly, in the case of cerebral aneurysm (CA), Firmicutes and Haemophilus were associated with a decreased risk, and Lachnoclostridium demonstrated an increased risk of association.

CONCLUSION

Our research has established causal relationships between specific GM components and various aneurysms. The obtained knowledge may aid in the development of microbiome-based interventions and the identification of novel biomarkers for targeted prevention strategies.

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.

MR Angiography for Aortic Diseases

Aortic pathologic conditions represent diverse disorders, including aortic aneurysm, acute aortic syndrome, traumatic aortic injury, and atherosclerosis. Given the nonspecific clinical features, noninvasive imaging is critical in screening, diagnosis, management, and posttherapeutic surveillance. Of the commonly used imaging modalities, including ultrasound, computed tomography, and MR imaging, the final choice often depends on a combination of factors: acuity of clinical presentation, suspected underlying diagnosis, and institutional practice. Further research is needed to identify the potential clinical role and define appropriate use criteria for advanced MR applications such as four-dimenional flow to manage patients with aortic pathologic conditions.

Automatic segmentation of abdominal aortic aneurysms from CT angiography using a context-aware cascaded U-Net

We delineate abdominal aortic aneurysms, including lumen and intraluminal thrombosis (ILT), from contrast-enhanced computed tomography angiography (CTA) data in 70 patients with complete automation. A novel context-aware cascaded U-Net configuration enables automated image segmentation. Notably, auto-context structure, in conjunction with dilated convolutions, anisotropic context module, hierarchical supervision, and a multi-class loss function, are proposed to improve the delineation of ILT in an unbalanced, low-contrast multi-class labeling problem. A quantitative analysis shows that the automated image segmentation produces comparable results with trained human users (e.g., DICE scores of 0.945 and 0.804 for lumen and ILT, respectively). Resultant morphological metrics (e.g., volume, surface area, etc.) are highly correlated to those parameters generated by trained human users. In conclusion, the proposed automated multi-class image segmentation tool has the potential to be further developed as a translational software tool that can be used to improve the clinical management of AAAs.

Effect of after-hours presentation in ruptured abdominal aortic aneurysm

OBJECTIVE

Ruptured abdominal aortic aneurysms (RAAAs) are surgical emergencies that require immediate and expert treatment. It has been unclear whether presentation during evenings and weekends, when "on call" teams are primarily responsible for patient care, is associated with worse outcomes. Our objective was to evaluate the outcomes of patients presenting with RAAAs after-hours vs during the workday.

METHODS

A retrospective cohort study of all RAAAs in Nova Scotia between 2005 and 2015 was performed through linkage of administrative databases. Patients who had presented to the hospital with RAAAs during the workday (Monday through Friday, 6 am to 6 pm) were compared with those who had presented after-hours (6 pm to 6 am during the week and on weekends). The baseline and operative characteristics were identified for all patients through the available databases and a review of the medical records. Mortality before surgery, 30-day mortality, and operative mortality were compared between groups using multivariable logistic regression, adjusting for factors clinically significant on univariable analysis.

RESULTS

A total of 390 patients with RAAAs were identified from 2005 to 2015, of whom 205 (53%) had presented during the workday and 185 (47%) after-hours. The overall chance of survival (OCS) was 45% overall, 49% if admitted to hospital, and 64% if surgery had been performed. During the workday, the OCS was 43% overall, 48% if admitted to hospital, and 67% if surgery had been performed. After-hours, the OCS was 46% overall, 49% if admitted to hospital, and 61% if surgery had been performed. Mortality before surgery was increased for patients who had presented to the hospital during the workday compared with after-hours (36% vs 26%; P = .04). The 30-day mortality (57% vs 54%; P = .62), rates of operative management (63% vs 72%; P = .06), and operative mortality (33% vs 39%; P = .33) were similar between the workday and after-hours groups (57% vs 54%; P = .06). After adjusting for significant clinical variables, the patients who had presented with RAAAs after-hours had had a similar odds of dying before surgery (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.41-1.03), operative management (OR, 1.47; 95% CI, 0.93-2.31), 30-day mortality (OR, 0.98; 95% CI, 0.63-1.51), and operative mortality (OR, 1.33; 95% CI, 0.78-2.26). In the subgroup of patients presenting to a hospital with endovascular capabilities, patients presenting after-hours had had similar odds of 30-day mortality (OR, 1.07; 95% CI, 0.57-2.02), and operative mortality (OR, 1.14; 95% CI, 0.58-2.23).

CONCLUSIONS

We found that patients presenting to the hospital with RAAAs after-hours did not have increased adjusted odds of mortality before surgery, operative management, 30-day mortality, or operative mortality.

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

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

Elective Endovascular vs Open Repair for Elective Abdominal Aortic Aneurysm in Patients ≥80 years of Age: A Systematic Review and Meta-Analysis

OBJECTIVE

To provide updated, pooled evidence on clinical outcomes among octogenarians (aged ≥80 years) with abdominal aortic aneurysm (AAA) managed by elective endovascular repair, compared to conventional open repair.

METHODS

PubMed, Embase, and Scopus databases were systematically searched. Studies that were either observational or randomized controlled trials were considered for the review. Included studies were conducted in elderly subjects (≥80 years) with AAA, and clinical and mortality outcomes were compared between endovascular and open surgical repair. Those reporting on outcomes of patients with urgent repair were excluded. The primary outcomes of interest were mortality and risk of complications. The pooled effect sizes were reported as odds ratio (OR) for categorical outcomes and weighted mean difference (WMD) for continuous outcomes. STATA software was used for statistical analysis.

RESULTS

The meta-analysis included 15 studies. Compared to those undergoing open repair, patients receiving endovascular repair had significantly reduced risk of immediate post-operative mortality (OR .23, 95% CI: .20, .27), overall complication (OR .30, 95% CI: .20, .44), cardiac (OR .23, 95% CI: .16, .35), renal (OR .29, 95% CI: .18, .46), pulmonary (OR .14, 95% CI: .09, .21) and bleeding related (OR .59, 95% CI: .42, .83) complications. The risk of mortality at latest follow up (at 36 months and 60 months) was similar in the two groups. The total blood loss (ml) (WMD -1126.47, 95% CI: -1497.81, -755.13), operative time (min) (WMD -29.40, 95% CI: -56.19, -2.62), length of intensive care unit stay (days) (WMD -2.27, 95% CI: -3.43, -2.12) and overall hospital stay (days) (WMD -6.64, 95% CI: -7.60, -5.68) was significantly lower in those undergoing endovascular repair.

CONCLUSIONS

Endovascular repair appears to be better than open repair of AAA in this high-risk, frail population, with respect to short term outcomes. The benefits of reduced risk of short term mortality, complications, and better peri and post-operative outcomes may be considered when making a choice between these two surgical approaches. Randomized controlled trials are needed to provide reliable evidence on the effect of EVAR on long term survival.

Interleukin-38 suppresses abdominal aortic aneurysm formation in mice by regulating macrophages in an IL1RL2-p38 pathway-dependent manner

Macrophages play crucial roles in abdominal aortic aneurysm (AAA) formation through the inflammatory response and extracellular matrix degradation; therefore, regulating macrophages may suppress AAA formation. Interleukin-38 (IL-38) is a member of the IL-1 family, which binds to IL-36 receptor (IL1RL2) and has an anti-inflammation effect. Because macrophages express IL1RL2, we hypothesized that IL-38 suppresses AAA formation by controlling macrophages. We assessed a C57BL6/J mouse angiotensin II-induced AAA model with or without IL-38 treatment. RAW 264.7 cells were cultured with tumor necrosis factor-α and treated with or without IL-38. Because p38 has important roles in inflammation, we assessed p38 phosphorylation in vitro and in vivo. To clarify whether the IL-38 effect depends on the p38 pathway, we used SB203580 to inhibit p38 phosphorylation. IL1RL2+ macrophage accumulation along with matrix metalloproteinase (MMP)-2 and -9 expression was observed in mouse AAA. IL-38 reduced the incidence of AAA formation along with reduced M1 macrophage accumulation and MMP-2 and -9 expression in the AAA wall. Macrophage activities including inducible nitric oxide, MMP-2, and MMP-9 production and spindle-shaped changes were significantly suppressed by IL-38. Furthermore, we revealed that inhibition of p38 phosphorylation diminished the effects of IL-38 on regulating macrophages to reduce AAA incidence, indicating the protective effects of IL-38 depend on the p38 pathway. IL-38 plays protective roles against AAA formation through regulation of macrophage accumulation in the aortic wall and modulating the inflammatory phenotype. Using IL-38 may be a novel therapy for AAA patients.

Biomechanical Rupture Risk Assessment in Management of Patients with Abdominal Aortic Aneurysm in COVID-19 Pandemic

Background: The acute phase of the COVID-19 pandemic requires a redefinition of healthcare system to increase the number of available intensive care units for COVID-19 patients. This leads to the postponement of elective surgeries including the treatment of abdominal aortic aneurysm (AAA). The probabilistic rupture risk index (PRRI) recently showed its advantage over the diameter criterion in AAA rupture risk assessment. Its major improvement is in increased specificity and yet has the same sensitivity as the maximal diameter criterion. The objective of this study was to test the clinical applicability of the PRRI method in a quasi-prospective patient cohort study. Methods: Nineteen patients (fourteen males, five females) with intact AAA who were postponed due to COVID-19 pandemic were included in this study. The PRRI was calculated at the baseline via finite element method models. If a case was diagnosed as high risk (PRRI > 3%), the patient was offered priority in AAA intervention. Cases were followed until 10 September 2021 and a number of false positive and false negative cases were recorded. Results: Each case was assessed within 3 days. Priority in intervention was offered to two patients with high PRRI. There were four false positive cases and no false negative cases classified by PRRI. In three cases, the follow-up was very short to reach any conclusion. Conclusions: Integrating PRRI into clinical workflow is possible. Longitudinal validation of PRRI did not fail and may significantly decrease the false positive rate in AAA treatment.

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.

Edaravone Attenuated Angiotensin II-Induced Atherosclerosis and Abdominal Aortic Aneurysms in Apolipoprotein E-Deficient Mice

Background: The aim of the study was to define whether edaravone, a free-radical scavenger, influenced angiotensin II (AngII)-induced atherosclerosis and abdominal aortic aneurysms (AAAs) formation. Methods: Male apolipoprotein E-deficient mice (8–12 weeks old) were fed with a normal diet for 5 weeks. Either edaravone (10 mg/kg/day) or vehicle was injected intraperitoneally for 5 weeks. After 1 week of injections, mice were infused subcutaneously with either AngII (1000 ng/kg/min, n = 16–17 per group) or saline (n = 5 per group) by osmotic minipumps for 4 weeks. Results: AngII increased systolic blood pressure equivalently in mice administered with either edaravone or saline. Edaravone had no effect on plasma total cholesterol concentrations and body weights. AngII infusion significantly increased ex vivo maximal diameters of abdominal aortas and en face atherosclerosis but was significantly attenuated by edaravone administration. Edaravone also reduced the incidence of AngII-induced AAAs. In addition, edaravone diminished AngII-induced aortic MMP-2 activation. Quantitative RT-PCR revealed that edaravone ameliorated mRNA abundance of aortic MCP-1 and IL-1β. Immunostaining demonstrated that edaravone attenuated oxidative stress and macrophage accumulation in the aorta. Furthermore, edaravone administration suppressed thioglycolate-induced mice peritoneal macrophages (MPMs) accumulation and mRNA abundance of MCP-1 in MPMs in male apolipoprotein E-deficient mice. In vitro, edaravone reduced LPS-induced mRNA abundance of MCP-1 in MPMs. Conclusions: Edaravone attenuated AngII-induced AAAs and atherosclerosis in male apolipoprotein E-deficient mice via anti-oxidative action and anti-inflammatory effect.

Point-of-care ultrasound for identification of ruptured infrarenal abdominal aortic aneurysm

Ruptured abdominal aortic aneurysms (rAAA) are associated with high mortality rates and require prompt diagnosis with subsequent intervention. CT scan is considered the gold standard for diagnosis, however, in the acute setting ultrasound may be a reasonable diagnostic test for certain patients. We report a case that demonstrates the utility of point-of-care ultrasound (PoCUS) in diagnosing rAAA for a patient in extremis. Also, we provide a brief review of literature for the diagnosis of rAAA with ultrasound.

Identification of Risk Factors and Development of Predictive Risk Score Model for Mortality after Open Ruptured Abdominal Aortic Aneurysm Repair

Background and Objectives: Despite the relatively large number of publications concerning the validation of these models, there is currently no solid evidence that they can be used with absolute precision to predict survival. The goal of this study is to identify preoperative factors that influenced 30-day mortality and to create a predictive model after open ruptured abdominal aortic aneurysm (RAAA) repair. Materials and Methods: This was a retrospective single-center cohort study derived from a prospective collected database, between 1 January 2009 and 2016. Multivariate logistic regression analysis was used to identify all significant predictive factors. Variables that were identified in the multivariate analysis were dichotomized at standard levels, and logistic regression was used for the analysis. To ensure that dichotomized variables were not overly simplistic, the C statistic was evaluated for both dichotomized and continuous models. Results: There were 500 patients with complete medical data included in the analysis during the study period. Of them, 37.6% were older than 74 years, and 83.8% were males. Multivariable logistic regression showed five variables that were predictive of mortality: age > 74 years (OR = 4.01, 95%CI 2.43−6.26), loss of consciousness (OR = 2.21, 95%CI 1.11−4.40), previous myocardial infarction (OR = 2.35, 95%CI 1.19−4.63), development of ventricular arrhythmia (OR = 4.54, 95%CI 1.75−11.78), and DAP < 60 mmHg (OR = 2.32, 95%CI 1.17−4.62). Assigning 1 point for each variable, patients were stratified according to the preoperative RAAA mortality risk score (range 0−5). Patients with 1 point suffered 15.3% mortality and 3 points 68.2% mortality, while all patients with 5 points died. Conclusions: This preoperative RAAA score identified risk factors readily assessed at the bedside and provides an accurate prediction of 30-day mortality after open repair of RAAA.

Multiperspective Bistatic Ultrasound Imaging and Elastography of the Ex Vivo Abdominal Aorta

Knowledge of aneurysm geometry and local mechanical wall parameters using ultrasound (US) can contribute to a better prediction of rupture risk in abdominal aortic aneurysms (AAAs). However, aortic strain imaging using conventional US is limited by the lateral lumen-wall contrast and resolution. In this study, ultrafast multiperspective bistatic (MP BS) imaging is used to improve aortic US, in which two curved array transducers receive simultaneously on each transmit event. The advantage of such bistatic US imaging on both image quality and strain estimations was investigated by comparing it to single-perspective monostatic (SP MS) and MP monostatic (MP MS) imaging, i.e., alternately transmitting and receiving with either transducer. Experimental strain imaging was performed in US simulations and in an experimental study on porcine aortas. Different compounding strategies were tested to retrieve the most useful information from each received US signal. Finally, apart from the conventional sector grid in curved array US imaging, a polar grid with respect to the vessel's local coordinate system is introduced. This new reconstruction method demonstrated improved displacement estimations in aortic US. The US simulations showed increased strain estimation accuracy using MP BS imaging bistatic imaging compared to MP MS imaging, with a decrease in the average relative error between 41% and 84% in vessel wall regions between transducers. In the experimental results, the mean image contrast-to-noise ratio was improved by up to 8 dB in the vessel wall regions between transducers. This resulted in an increased mean elastographic signal-to-noise ratio by about 15 dB in radial strain and 6 dB in circumferential strain.

Underutilization of Guideline-based Abdominal Aortic Aneurysm Screening in an Academic Health System

OBJECTIVES

The US Preventive Services Task Force (USPSTF) recommends a 1-time screening for AAA with ultrasonography in men aged 65-75 who have ever smoked. Our objectives were to identify the AAA screening rates in a large academic health system and assess factors associated with receipt of screening.

METHODS

Data were extracted from electronic health record data from the Duke University Health System and the US Census Bureau. Index screening eligibility date was defined as the 65^th birthdate for male patients with a history of smoking. Patients with an index screening eligibility date between 1/1/2016 and 12/31/2018 were included in the study population and followed through 12/31/2019. Screened patients were identified by procedure codes for ultrasonography, CT or MRI.

RESULTS

Among 6,682 eligible patients who turned 65 years old between 1/1/2016 and 12/31/2018 with at least 1 year of follow-up, only 463 (6.9%) received AAA screening during the study period. The odds of receiving AAA screening within 1 year of index eligibility were 27% lower for Black patients compared to whites [OR=0.73, 95% CI (0.58,0.93)]. Patients who visited a PCP or had hypertension had 75% and 41% greater odds of receiving screening, respectively [OR 1.75, 95% CI (1.36,2.25)] and [OR 1.41 95% CI (1.11,1.80)] compared with patients who did not. Among 4,580 men with 2 years of follow-up, AAA screening rate increased to 13.0%. Patients who visited a PCP had 64% greater odds of receiving screening within 2 years of index eligibility compared to those who did not [OR=1.64, 95% CI (1.30,2.06)].

CONCLUSION

Screening for AAA per USPSTF guidelines is underutilized with evidence of a racial disparity. Although PCP visit is the most consistent predictor of screening, provider screening rates are low.

Abdominal Aortic Aneurysm: An Overlooked Etiology of Low Back Pain

Low back pain is very common and the vast majority of cases are related to non-specific etiologies. Low back pain due to serious pathologies is very rare. We present the case of a 66-year-old man with progressively worsening low back pain. His past medical history was remarkable for poorly controlled hypertension, diabetes mellitus, and dyslipidemia. He had several visits to the outpatient clinics and was diagnosed as having low back pain due to musculoskeletal etiology. He was prescribed multiple oral non-steroidal anti-inflammatory drugs and underwent multiple sessions of physiotherapy. However, his condition progressed, and did not show any clinical improvement. He underwent a plain radiograph of the lumbosacral spine which revealed decreased intervertebral disc spaces with multiple osteophytes. However, aneurysmal dilatation of the abdominal aorta was noted with atheromatous calcification. Computed tomography angiography confirmed the diagnosis of abdominal aortic aneurysm. The patient underwent endovascular repair of the aneurysm. The patient had complete resolution of his low back pain and remained symptom-free after six months of follow-up. The present case highlighted that those common presentations such as low back pain can be indicative of serious underlying pathology. Early diagnosis and management of abdominal aortic aneurysms can improve the prognosis and survival.

Nationwide study in France investigating the impact of diabetes on mortality in patients undergoing abdominal aortic aneurysm repair

The aim of this nationwide study was to analyze the impact of diabetes on post-operative mortality in patients undergoing AAA repair in France. This 10-year retrospective, multicenter study based on the French National electronic health data included patients undergoing AAA repair between 2010 and 2019. In-hospital post-operative mortality was analyzed using Kaplan–Meier curve survival and Log-Rank tests. A multivariate regression analysis was performed to calculate Hazard Ratios. Over 79,935 patients who underwent AAA repair, 61,146 patients (76.5%) had at least one hospital-readmission after the AAA repair, for a mean follow-up of 3.5 ± 2.5 years. Total in-hospital mortality over the 10-year study was 16,986 (21.3%) and 4581 deaths (5.8%) occurred during the first hospital stay for AAA repair. Age over 64 years old, the presence of AAA rupture and hospital readmission at 30-day were predictors of post-operative mortality (AdjHR = 1.59 CI 95% 1.51–1.67; AdjHR = 1.49 CI 95% 1.36–1.62 and AdjHR = 1.92, CI 95% 1.84–2.00). The prevalence of diabetes was significantly lower in ruptured AAA compared to unruptured AAA (14.8% vs 20.9%, P < 0.001 for type 2 diabetes and 2.5% vs 4.0%, P < 0.001 for type 1 diabetes). Type 1 diabetes was significantly associated with post-operative mortality (AdjHR = 1.30 CI 95% 1.20–1.40). For type 2 diabetes, the association was not statistically significant (Adj HR = 0.96, CI 95% 0.92–1.01). Older age, AAA rupture and hospital readmission were associated with deaths that occurred after discharge from the first AAA repair. Type 1 diabetes was identified as a risk factor of post-operative mortality. This study highlights the complex association between diabetes and AAA and should encourage institutions to report long-term follow-up after AAA repair to better understand its impact.

Outcomes and predictors of mortality in a Belgian population of patients admitted with ruptured abdominal aortic aneurysm and treated by open repair in the contemporary era

BACKGROUND

Abdominal aortic aneurysm (AAA) rupture is a serious condition that results in extremely high mortality rates. Some improvements in outcome have been reported during the last 2 decades. The objective of the present study was to determine the overall and operative (by open repair) mortality related to ruptured AAA in the contemporary era and to identify preoperative, intraoperative, and early postoperative parameters associated with poor outcomes.

METHODS

We performed a retrospective review of all consecutive patients admitted to our single institution with a diagnosis of ruptured AAA between 2004 and 2013. A total of 103 parameters, including demographic characteristics, medical history, clinical and biological parameters, cardiovascular risk factors, emergency level, diagnostic modalities, time from symptoms to diagnosis and treatment, type of operative procedure and postoperative complications, were analyzed. The primary endpoint considered in this study was the cumulative incidence rate of mortality. The secondary endpoint was the identification, by logistic regression methods, of risk factors for overall mortality as well as for operative, and postoperative mortality.

RESULTS

Within our study period, 104 patients were admitted for a ruptured AAA. The majority of patients (84.6%) were male, and the AAA was known in 34.6% of the patients. Rupture occurred for a maximal diameter lower than 55 mm in 25% of the female population, compared to 5.7% of the male population (P = 0.030). The proportions of admitted patients who died before (preoperative mortality), during (intraoperative mortality) or after (postoperative hospital mortality) surgery was 17.3%, 16.3%, and 18.3%, respectively, yielding a cumulative in-hospital mortality of 51.9%. In the multivariate analysis, age ≥ 80 (P = 0.001), myocardial ischemia on the admission ECG (P = 0.046), and management by the physician response unit (P = 0.002) were the only preoperative parameters associated with a higher risk of hospital mortality. Four risk factors were found to be associated with a higher risk of postoperative mortality in the multivariate analysis, and all patients presenting with 3 or more of these risk factors (n = 5) died.

CONCLUSIONS

The overall mortality of ruptured AAA in a contemporary cohort of patients who underwent open repair remains high and does not seem to have decreased during recent decades. Ruptures occur at smaller diameters in women than in men, supporting a lower threshold for intervention in women with known AAA. We developed risk scores to predict the mortality of patients with rAAA at different times of their hospital course. The validity of these scores should be assessed in prospective clinical studies.

A comparison of endovascular versus open repair for ruptured abdominal aortic aneurysm - Meta-analysis of propensity score-matched data

BACKGROUND

Optimal management of ruptured abdominal aortic aneurysms (rAAA) has been heavily debated in the literature. The aim of this review is to assess comparative outcomes from propensity-matched studies of endovascular versus open for rAAA.

METHODS

Electronic databases (MEDLINE and Embase) were searched in January 2021 using the Healthcare Databases Advanced Search interface. Eligible studies compared endovascular versus open repair for rAAA using propensity-matched cohorts. Pooled estimates of perioperative outcomes were calculated using odds ratio (OR) or mean difference (MD) and 95% confidence interval (CI) using the random-effects model. Time-to-event data meta-analysis was conducted using the inverse-variance method and reported as summary hazard ratio (HR) and associated 95% CI. The quality of evidence was graded using a system developed by the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) working group.

RESULTS

Six studies published between 2010 and 2020 were selected for qualitative and quantitative synthesis, reporting a total of 6731 patients. The odds of perioperative mortality after endovascular aneurysm repair (EVAR) were significantly lower than after open surgical repair (OSR) (OR 0.52, 95% CI 0.41-0.65). The hazard of overall mortality during follow-up was lower, although not significantly, after EVAR than after OSR (HR 0.79, 95% CI 0.62-1.01). The odds of acute kidney injury and early aneurysm-related reintervention were both significantly lower after EVAR than after OSR (OR 0.34, 95% CI 0.14-0.78 and OR 0.57, 95% CI 0.33-0.98, respectively). Patients treated with EVAR stayed in hospital for significantly less time than those treated with OSR (MD -5.13, 95% CI -7.94 to -2.32). The certainty of the body of evidence for perioperative mortality was low and for overall mortality was very low.

CONCLUSION

The evidence suggests that EVAR confers a significant benefit on perioperative mortality.

Appraisal of transthoracic echocardiography for opportunistic screening of abdominal aortic aneurysm

ABSTRACT

Abdominal aortic aneurysm is a life threatening disease. Most of the patients diagnosed incidentally because of the asymptomatic nature of this disease. This study aimed to determine the frequency of abdominal aortic aneurysm and evaluate the value of opportunistic screening during transthoracic echocardiography.A total of 5138 patients referred for echocardiographic evaluation for any reason were screened for abdominal aortic aneurysm between November 2014 to July 2019. The aneurysm was defined as an abdominal aorta with a diameter greater than 30 mm, or segmental dilatation of more than 50% of its size in non-dilated parts.The overall frequency of abdominal aortic aneurysm was 2.2% (n = 109) in the study population. Male sex (P < .001), older age (P < .001), presence of diastolic dysfunction (P = .036), hypertension (P < .001), coronary artery disease (P < .001), and hyperlipidemia (P < .001) were associated with abdominal aortic aneurysm. Patients with aneurysm had significantly increased diameters of the aortic trunk (P < .001) and ascending aorta (P < .001), significantly thicker interventricular septum (P < .001) and posterior wall (P < .001), significantly increased end-diastolic diameter (P < .001) and enlarged left atrium (P < .001), and significantly decreased ejection fraction (P < .001). The mostly met criteria for screening abdominal aortic aneurysm in international guidelines was the age of the patients.Based on the results of this study, screening patients over 60 years of age who undergo a transthoracic echocardiography for any reason would be beneficial to detect an asymptomatic abdominal aortic aneurysm in Turkish population.

Proteomics applications in biomarker discovery and pathogenesis for abdominal aortic aneurysm

Introduction: Abdominal aortic aneurysm (AAA) is a common, complex, and life-threatening disease. Currently, the pathogenesis of AAA is not well understood. No biomarkers or specific drugs are available for AAA in clinical applications. Proteomics is a powerful tool in biomarker discovery, exploration of pathogenesis, and drug target identification.Areas covered: We review the application of mass spectrometry-based proteome analysis in AAA patients within the last ten years. Differentially expressed proteins associated with AAA were identified in multiple sample sources, including vascular tissue, intraluminal thrombus, tissue secretome, blood, and cells. Some potential disease biomarkers, pathogenic mechanisms, or therapeutic targets for AAA were discovered using proteome analysis. The challenges and prospects of proteomics applied to AAA are also discussed.Expert opinion: Since most of the previous proteomic studies used relatively small sample sizes, some promising biomarkers need to be validated in multicenter cohorts to accelerate their clinical application. With the rapid development of mass spectrometry technology, modification-specific proteomics and multi-omics research in the future will enhance our understanding of the pathogenesis of AAA and promote biomarker discovery and drug development for clinical translation.

Configuration of vascular services: a multiple methods research programme

Background

Vascular services is changing rapidly, having emerged as a new specialty with its own training and specialised techniques. This has resulted in the need for reconfiguration of services to provide adequate specialist provision and accessible and equitable services.

Objectives

To identify the effects of service configuration on practice, resource use and outcomes. To model potential changes in configuration. To identify and/or develop electronic data collection tools for collecting patient-reported outcome measures and other clinical information. To evaluate patient preferences for aspects of services other than health-related quality of life.

Design

This was a multiple methods study comprising multiple systematic literature reviews; the development of a new outcome measure for users of vascular services (the electronic Personal Assessment Questionnaire – Vascular) based on the reviews, qualitative studies and psychometric evaluation; a trade-off exercise to measure process utilities; Hospital Episode Statistics analysis; and the development of individual disease models and a metamodel of service configuration.

Setting

Specialist vascular inpatient services in England.

Data sources

Modelling and Hospital Episode Statistics analysis for all vascular inpatients in England from 2006 to 2018. Qualitative studies and electronic Personal Assessment Questionnaire – Vascular evaluation with vascular patients from the Sheffield area. The trade-off studies were based on a societal sample from across England.

Interventions

The data analysis, preference studies and modelling explored the effect of different potential arrangements for service provision on the resource use, workload and outcomes for all interventions in the three main areas of inpatient vascular treatment: peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. The electronic Personal Assessment Questionnaire – Vascular was evaluated as a potential tool for clinical data collection and outcome monitoring.

Main outcome measures

Systematic reviews assessed quality and psychometric properties of published outcome measures for vascular disease and the relationship between volume and outcome in vascular services. The electronic Personal Assessment Questionnaire – Vascular development considered face and construct validity, test–retest reliability and responsiveness. Models were validated using case studies from previous reconfigurations and comparisons with Hospital Episode Statistics data. Preference studies resulted in estimates of process utilities for aneurysm treatment and for travelling distances to access services.

Results

Systematic reviews provided evidence of an association between increasing volume of activity and improved outcomes for peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. Reviews of existing patient-reported outcome measures did not identify suitable condition-specific tools for incorporation in the electronic Personal Assessment Questionnaire – Vascular. Reviews of qualitative evidence, primary qualitative studies and a Delphi exercise identified the issues to be incorporated into the electronic Personal Assessment Questionnaire – Vascular, resulting in a questionnaire with one generic and three disease-specific domains. After initial item reduction, the final version has 55 items in eight scales and has acceptable psychometric properties. The preference studies showed strong preference for endovascular abdominal aortic aneurysm treatment (willingness to trade up to 0.135 quality-adjusted life-years) and for local services (up to 0.631 quality-adjusted life-years). A simulation model with a web-based interface was developed, incorporating disease-specific models for abdominal aortic aneurysm, peripheral arterial disease and carotid artery disease. This predicts the effects of specified reconfigurations on workload, resource use, outcomes and cost-effectiveness. Initial exploration suggested that further reconfiguration of services in England to accomplish high-volume centres would result in improved outcomes, within the bounds of cost-effectiveness usually considered acceptable in the NHS.

Limitations

The major source of evidence to populate the models was Hospital Episode Statistics data, which have limitations owing to the complexity of the data, deficiencies in the coding systems and variations in coding practice. The studies were not able to address all of the potential barriers to change where vascular services are not compliant with current NHS recommendations.

Conclusions

There is evidence of potential for improvement in the clinical effectiveness and cost-effectiveness of vascular services through further centralisation of sites where major vascular procedures are undertaken. Preferences for local services are strong, and this may be addressed through more integrated services, with a range of services being provided more locally. The use of a web-based tool for the collection of clinical data and patient-reported outcome measures is feasible and can provide outcome data for clinical use and service evaluation.

Future work

Further evaluation of the economic models in real-world situations where local vascular service reconfiguration is under consideration and of the barriers to change where vascular services do not meet NHS recommendations for service configuration is needed. Further work on the electronic Personal Assessment Questionnaire – Vascular is required to assess its acceptability and usefulness in clinical practice and to develop appropriate report formats for clinical use and service evaluation. Further studies to assess the implications of including non-health-related preferences for care processes, and location of services, in calculations of cost-effectiveness are required.

Study registration

This study is registered as PROSPERO CRD42016042570, CRD42016042573, CRD42016042574, CRD42016042576, CRD42016042575, CRD42014014850, CRD42015023877 and CRD42015024820.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 5. See the NIHR Journals Library website for further project information.

Iatrogenic abdominal aortic pseudoaneurysm repaired by percutaneous image-guided translumbar embolization

Aortic injury is a frequently encountered condition that can present as a life-threatening emergency. When this injury occurs in the retroperitoneal portion of the aorta, it can be difficult to diagnose and treat because of the location. Although surgical repair remains the mainstay of treatment, surgery might not be an option for some patients. We have presented a case of a 54-year-old nonoperative candidate who had experienced iatrogenic retroperitoneal abdominal aortic rupture with pseudoaneurysm formation. The patient was successfully treated with the novel use of a proven technique: direct percutaneous embolization of the pseudoaneurysm sac via a translumbar approach under image guidance.

Sources of inconsistency in mean mechanical response of abdominal aortic aneurysm tissue

INTRODUCTION

There is a striking difference in the reported mean response of abdominal aortic aneurysm tissue in academic literature depending on the type of tests (uniaxial vs biaxial) performed. In this paper, the hypothesis variability caused by differences in experimental protocols is explored using porcine aortic tissue as a substitute for aneurysmal tissue.

METHODS

Nine samples of porcine aorta were created and both uniaxial and biaxial tests were performed. Three effects were investigated. (i) Effect of sample (non) preconditioning, (ii) effect of objective function used (normalised vs non-normalised), and (iii) effect of chosen procedure used for mean response calculation: constant averaging (CA) vs fit to averaged response (FAR) vs fit to all data (FAD). Both the overall shape of mean curve and mean initial stiffness were compared.

RESULTS

(i) Non-preconditioning led to a much stiffer response, and initial stiffness was about three times higher for a non-preconditioned response based on uniaxial data compared to a preconditioned biaxial response. (ii) CA led to a much stiffer response compared to FAR and FAD procedures which gave similar results. (iii) Normalised objective function produced a mean response with six times lower initial stiffness and more pronounced nonlinearity compared to non-normalised objective function.

DISCUSSION

It is possible to reproduce a mechanically inconsistent response purely by using the chosen experimental protocol. Non-preconditioned data from failure tests should be used for FE simulation of the elastic response of aneurysms. CA should not be used to obtain a mean response.