Women with abdominal aortic aneurysms have more extensive aortic neck pathology

Mid-term results of "off-label" use of the Endurant stentgraft in patients with infrarenal abdominal aortic aneurysms

OBJECTIVES

EVAR is the preferred treatment modality for patients with an infrarenal abdominal aortic aneurysm with suitable anatomy. Each manufacturer of aortic stentgrafts has specific anatomic requirements. In some patients, it is not possible to adhere to the instructions for use, but alternative treatment is also not possible. In these patients, EVAR can be performed outside instructions for use.

METHODS

In this study, all consecutive patients in whom an Endurant II or IIS stentgraft was used between 1 January and 31 December were reviewed. We compared the two patient groups in whom this stentgrafts was used outside and inside instructions for use. Patients with planned adjuvant therapy, for example, chimney procedure or iliac side branches, were excluded.

RESULTS

In 74 of 178 (41.6%) patients, the instructions for use were not adhered. The main reason was pathology of the aortic neck. There were more patients with type IA endoleak, this difference was borderline significant (p = .06). There were more patients with limb occlusion in the early postoperative period, but at the end of the follow-up period, the incidence was comparable. Aneurysm-related mortality and all-cause mortality were comparable in both groups.

CONCLUSION

In this study, real-life experience with the Endurant II and IIS stentgraft is described. Non-adherence with instructions for use was associated with a higher risk of endoleak type IA (p = .06). In the early postoperative period, there were more patients with limb occlusion; this finding was not observed anymore at the end of the follow-up period.

Sex-Related Differences in Proximal Neck Anatomy and Their Consequences in Patients after EVAR: A Matched Cohort Analysis

INTRODUCTION

Studies comparing male and female patients with abdominal aortic aneurysms have shown that female patients are generally older and more often experience postoperative complications after endovascular and open repair. There are also indications that female patients have more extensive neck pathologies and that they more often have postoperative complications related to proximal neck pathology.

MATERIAL AND METHODS

This retrospective study describes all consecutive female patients who underwent EVAR between 1 January 2012 and 31 December 2021. Propensity-score matching was used to obtain a matched control male cohort. Propensity scores were generated with the following anatomic parameters: infrarenal and suprarenal angulation, proximal and distal neck diameter and neck length. 1 Female patient was matched with 3 male patients.

RESULTS

A total of 160 patients were included, namely 120 male patients and 40 female patients. Due to matching, there were no significant differences regarding infrarenal and suprarenal angulation and proximal and distal neck diameter and length. All-cause and aneurysm-related mortality were comparable (p = 0.19 and p = 0.98). The necessity of neck-related secondary procedures was significantly higher in female patients (p = 0.02). In the multivariate analysis, the female sex was a significant predictor of endoleak type IA within 30 days. However, there was no significant association between intraoperative endoleak type IA and endoleak type IA at the end of follow-up.

CONCLUSIONS

This study suggests that there was a higher initial incidence of endoleak type IA in female patients, despite thematched preoperative anatomic parameter. Due to the relatively low number of included female patients, conclusions should be drawn carefully.

Risk factors of type 1A endoleak following endovascular aortic aneurysm repair

OBJECTIVES

Endovascular repair of infrarenal aortic aneurysms are the treatment of first choice. However, the proximal sealing of endovascular aneurysm repair is the Achilles' heel of the procedure. Insufficient proximal sealing can lead to endoleak type 1A and therefore expansion of the aneurysm sack and subsequent rupture.

METHODS

We performed a retrospective analysis of all consecutive patients with an infrarenal abdominal aneurysm treated with endovascular aneurysm repair. We studied whether demographic and anatomical features were risk factors for endoleak type 1A. Also, the results of different treatment strategies were described.

RESULTS

257 Patients were included in the study, most patients were male. In the multivariate analysis, female gender and infrarenal angulation were the most important risk factors for endoleak type 1A. Endoleak type 1A diagnosed at completion angiography disappeared in 77.8%. The occurrence of endoleak type 1A was associated with a higher risk of aneurysm-related mortality (p = 0.01).

CONCLUSION

Conclusions should be drawn with care, since the number of patients included in this study was small and there was a high incidence of patients lost to follow-up. This study suggests that endovascular aneurysm repair in female patients and patients with severe infrarenal angulation is associated with a higher risk of endoleak type 1A.

A novel pre-operative risk assessment tool to identify patients at risk of contrast associated acute kidney injury after endovascular abdominal aortic aneurysm repair

OBJECTIVES

Contrast-associated acute kidney injury (CA-AKI) after endovascular abdominal aortic aneurysm repair (EVAR) is associated with mortality and morbidity. Risk stratification remains a vital component of preoperative evaluation. We sought to generate and validate a pre-procedure CA-AKI risk stratification tool for elective EVAR patients.

METHODS

We queried the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) database for elective EVAR patients and excluded those on dialysis, with a history of renal transplant, death during procedure, and without creatinine measures. Association with CA-AKI (rise in creatinine > 0.5 mg/dL) was tested using mixed effects logistic regression. Variables associated with CA-AKI were used to generate a predictive model via a single classification tree. The variables selected by the classification tree were then validated by fitting a mixed effects logistic regression model into the Vascular Quality Initiative (VQI) dataset.

RESULTS

Our derivation cohort included 7,043 patients, 3.5% of whom developed CA-AKI. After multivariate analysis, age (OR 1.021, 95% CI 1.004-1.040), female sex (OR 1.393, CI 1.012-1.916), GFR < 30 ml/min (OR 5.068, CI 3.255-7.891), current smoking (OR 1.942, CI 1.067-3.535), COPD (OR 1.402, CI 1.066-1.843), maximum AAA diameter (OR 1.018, CI 1.006-1.029), and presence of iliac artery aneurysm (OR 1.352, CI 1.007-1.816) were associated with increased odds of CA-AKI. Our risk prediction calculator demonstrated that patients with a GFR <30 ml/min, females, and patients with a maximum AAA diameter of > 6.9 cm are at higher risk of CA-AKI after EVAR. Using the VQI dataset (N = 62,986), we found that GFR <30 ml/min (OR 4.668, CI 4.007-5.85), female sex (OR 1.352, CI 1.213-1.507), and maximum AAA diameter > 6.9 cm (OR 1.824, CI 1.212-1.506) were associated with increased risk of CA-AKI after EVAR.

CONCLUSIONS

Herein, we present a simple and novel risk assessment tool that can be used pre-operatively to identify patients at risk of CA-AKI after EVAR. Patients with a GFR < 30 ml/min, maximum AAA diameter > 6.9 cm, and females who are undergoing EVAR may be at risk for CA-AKI after EVAR. Prospective studies are needed to determine the efficacy of our model.

"Aortic Balloon-Molding" (ABM) During Ovation Endograft Implantation Expands Graft Use for Hostile Neck Anatomy

BACKGROUND

Challenging aortoiliac anatomy such as short neck and narrow access vessels is responsible for EVAR ineligibility in up to 50% of cases. The Ovation stent-graft helped widen the range of AAAs suitable for EVAR thanks to its low-profile delivery system and polymer-filled sealing rings. However, its advantages are offset by a tight sizing chart that can lead to increased risk of type Ia endoleak or endograft infolding from under or oversizing, respectively. We sought to assess the safety and efficacy of a novel endovascular technique developed to expand the use of the Ovation endograft while avoiding these issues.

METHODS

We conducted a retrospective review of all patients who underwent EVAR with the Ovation endograft at our institution between March 2019 and December 2020. "Aortic Balloon Molding" or ABM is a novel endovascular technique in which the graft is pre-cannulated and a compliant aortic balloon is inflated at the site of the graft's sealing rings during polymer administration. The technique was preferentially performed in patients with hostile neck anatomy (HNA) defined as any or all of angulation>60°, reverse taper configuration, ≥50% circumferential thrombus or calcification. Patients undergoing traditional deployment were compared to those in whom ABM was performed. Endpoints included neck-related adjunctive procedures, technical success, type Ia endoleak at completion angiogram and 1-year freedom from type Ia endoleak and migration.

RESULTS

A total of 43 patients were included in the study, of which, 26 (60.5%) were treated with the ABM technique. Mean follow-up was 7.9±6 months. Patients in the ABM group were more likely to have a reverse taper neck (61.5% vs. 41.2%, P=0.1), to have significant circumferential thrombus or calcium (23.1% vs. 5.9%, P=0.1) and to be treated outside of the Ovation IFU regarding anatomic characteristics (65.4% vs. 41.2%, P=0.1). Technical success was achieved in 100% of cases. However, patients in the ABM group were less likely to require a neck-related adjunctive procedure (7.7% vs. 23.5%, P=0.1). Only one type Ia endoleak was observed at completion angiogram in a patient treated without ABM. At one-year, freedom from type Ia endoleak or migration was 100% for both groups.

CONCLUSIONS

Aortic Balloon Molding proves to be a safe and effective adjunctive technique for the treatment of AAAs with hostile neck anatomy using the Ovation stent-graft. This may allow optimal endograft sizing to achieve adequate seal in complex aortic anatomies. Further research is warranted to evaluate the long-term outcomes of this technique.

A systematic review and meta-analysis on early mortality after abdominal aortic aneurysm repair in females in urgent and elective setting

OBJECTIVE

Females represent a group of patients with higher mortality after abdominal aortic aneurysm (AAA), endovascular (EVAR) or open (OSR), repair. This systematic review aimed to evaluate the 30-day mortality after AAA repair in females, comparing both EVAR and OSR, in elective and urgent settings.

METHODS

The protocol of the review was registered to the PROSPERO (CRD42021242686). A search of the English literature was conducted, using PubMed, EMBASE and CENTRAL databases, from inception to March 5, 2021, using the Systematic Reviews and Meta-Analysis guidelines (PRISMA). Only studies reporting on 30-day mortality of AAA repair, in urgent and elective setting, comparing EVAR and OSR, in female population were eligible. Patients were stratified according to the need for elective or urgent repair. Symptomatic and ruptured cases were included into the urgent group. Individual studies were assessed for risk of bias using the ROBINS-I tool. The GRADE approach was used to evaluate the quality of evidence. The primary outcome was 30-day mortality after AAA repair in the female population, comparing EVAR and OSR. The outcomes were summarized as odds ratio along with their 95% confidence intervals (CI), through a paired meta-analysis.

RESULTS

Eight studies reported data on 30-day mortality following AAA repair. A total of 56,982 females (22,995 EVAR vs. 33,987 OSR) were included. A significantly reduced total 30-day mortality rate was recorded among females that underwent EVAR compared to OSR (OR, 0.25; 95% CI, 0.23-0.27; P<.001, Ι²=86%). Also a reduced 30-day mortality was found in females that underwent elective EVAR compared to OSR (OR, 0.37; 95% CI, 0.33-0.41; P< .001, Ι²=48%). Despite that OSR was more frequently offered in the urgent setting (OR, 0.21; 95% CI, 0.19-0.23; P< .001, Ι²=84%), EVAR was associated with a reduced 30-day mortality (OR, 0.48; 95% CI, 0.40-0.57; P<.001, Ι²=0%).

CONCLUSIONS

In females, EVAR is associated with lower 30-day mortality in both elective and urgent AAA repair, although it appears as less likely to be offered in the setting of urgent AAA repair.

Anatomic eligibility for endovascular aneurysm repair preserved over 2 years of surveillance

OBJECTIVE

Endovascular aneurysm repair (EVAR) is a widely used option for patients with suitable vascular anatomy who have a large infrarenal abdominal aortic aneurysm (AAA). Patients with small AAAs are managed with careful surveillance and it is a common concern that their anatomy may change with AAA growth, and their option for EVAR may become limited. Device innovation has resulted in expanded ranges of anatomy that may be eligible for EVAR. This study sought to identify changes in anatomic eligibility for repair with contemporary endovascular devices in AAA patients, monitored by computed tomography scan over the course of 2 years.

METHODS

Patients from the Non-Invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA³CT, NCT01756833) were included in this analysis. Females had baseline AAA maximum transverse diameter between 3.5 and 4.5 cm, and males had baseline maximum transverse diameter between 3.5 and 5.0 cm. Patients were included in this analysis if they completed pre-enrollment and 2-year follow-up computed tomography imaging. Pertinent anatomic measurements were performed on a postprocessing workstation in a centralized imaging core laboratory. EVAR candidacy was determined by measuring proximal aortic neck diameter, AAA length, and infrarenal neck angulation. Patients were considered to be eligible for EVAR if they qualified for at least one of the seven studied devices' instructions for use at baseline and at 2 years. A paired t test analysis was used to detect differences in aortic measurements over 2 years, and the McNemar test was used to compare eligibility over 2 years.

RESULTS

We included 192 patients in this analysis-168 male and 24 female. Of these patients, 85% were eligible for EVAR at baseline and 85% after 2 years of follow-up (P = 1.00; 95% confidence interval -0.034 to 0.034). Of the 164 EVAR candidates at baseline, 160 (98%) remained eligible over 2 years of surveillance. Insufficient neck length was the most common reason for both ineligibility at baseline (18 of 28 patients) as well as loss of candidacy over 2 years (3 of 4 patients).

CONCLUSIONS

The majority of patients eligible for EVAR when entering a surveillance program for small AAA remain eligible after 2 years. Substantial changes in AAA neck anatomy resulting in loss of EVAR treatment options are infrequent. Patients with anatomic AAA progression beyond EVAR eligibility remain candidates for complex EVAR and open repair.

Is gender still a risk factor for mortality in patients who undergo elective repair of abdominal aortic aneurysms? Experience of a single center

BACKGROUND

Vascular Services Quality Improvement Program (VSQIP) was introduced to reduce mortality from elective repair of AAA in the UK. This study examines the differences in perioperative mortality and postoperative survival between men and women following elective repair of AAAs in the 10 years after implementation of the (VSQIP).

METHODS

Consecutive patients who underwent elective repair of AAA between 1^st January 2008 and 31^st March 2018 were included. All patients were assessed using the nationally agreed VSQIP pathway which involved cardiopulmonary exercise testing as well as contrast enhanced CT scan of aorta and multidisciplinary assessment to plan each treatment. CT scans were examined to assess the morphology of AAA. Patients were stratified by age, gender, AAA morphology and preoperative anaerobic threshold. Postoperative survival was assessed using Kaplan-Meier analysis. Cox regression analysis was used to determine predictors of postoperative mortality.

RESULTS

A total of 702 patients underwent elective repair of AAA of whom 632 were men and 70 were women. The mean age of study cohort was 73.5±7.3 years and mean AAA diameter was 62±9.9 mm. Two hundred and forty-four patients underwent open repair, 402 underwent infrarenal endovascular aneurysm repair (EVAR) and 56 underwent complex EVAR with perioperative and 30-day mortality of 1.13%. No significant difference was observed in perioperative/30-day mortality between men and women (χ²=0.06, P=0.81). Anaerobic threshold <8 (HR=0.68 [95% CI: 0.51-0.92]), complex aneurysm morphology (HR=1.7 [95% CI: 1.39-2.19]) risk category (HR=1.89 [95% CI: 1.48-2.42]) and patients age (HR=1.41 [95% CI: 1.13-1.89]) were independent risk factor for mortality following repair of AAA, whilst female gender (HR=0.89 [95% CI: 0.54-1.48]) and AAA size (HR=1.01 [95% CI: 0.84-1.22]) were not. There was no difference in postoperative survival between men and women who underwent elective repair of AAA (Log rank: 1.82, P=0.61).

CONCLUSIONS

Following the implementation of VSQIP female gender is no longer a significant risk factor for perioperative mortality or reduced survival following elective repair of large asymptomatic AAA.

Effect Modification of Sex and Age for the Hospital Volume-Outcome Relationship in Abdominal Aortic Aneurysm Treatment: Secondary Data Analysis of the Nationwide German Diagnosis Related Groups Statistics From 2005 to 2014

Background Trials and registries associated female sex and high age with unfavorable outcomes in abdominal aortic aneurysm treatment. Many studies showed an inverse correlation between annual hospital volume and in-hospital mortality. The volume-outcome relationship has not been investigated separately for women and men or across the age range. The aim was to analyze whether sex and age are effect modifiers or confounders of the volume-outcome association. Methods and Results In a nationwide setting, all in-hospital cases from 2005 to 2014 with a diagnosis of intact abdominal aortic aneurysm and procedure codes for endovascular or open aortic repair were included. Primary outcome was in-hospital mortality. Using a multilevel multivariable regression model, hospital volume was modeled as a continuous variable. Separate analyses were performed for women and men and for predefined age groups. A total of 94 966 cases were included (12% women; median age, 72 years). Mortality was 4.9% in women and 3.0% in men (3.2% overall). Mortality increased with age. Although there was no significant volume-outcome association in women (P=0.57), there was in men (P=0.02). The strongest volume-outcome association was found in younger men. The younger female subpopulation was found to show a trend for an inverse volume-outcome relationship, whereas an opposite association was found for the women aged >79 years. Conclusions Women have a higher mortality risk after elective abdominal aortic aneurysm treatment. Sex and age are modifiers of the volume-outcome relationship. Unlike in male patients, in women there is no consistent effect of hospital volume on outcome.

Pathogenic mechanisms and the potential of drug therapies for aortic aneurysm

Aortic aneurysm is a permanent focal dilation of the aorta. It is usually an asymptomatic disease but can lead to sudden death due to aortic rupture. Aortic aneurysm-related mortalities are estimated at ∼200,000 deaths per year worldwide. Because no pharmacological treatment has been found to be effective so far, surgical repair remains the only treatment for aortic aneurysm. Aortic aneurysm results from changes in the aortic wall structure due to loss of smooth muscle cells and degradation of the extracellular matrix and can form in different regions of the aorta. Research over the past decade has identified novel contributors to aneurysm formation and progression. The present review provides an overview of cellular and noncellular factors as well as enzymes that process extracellular matrix and regulate cellular functions (e.g., matrix metalloproteinases, granzymes, and cathepsins) in the context of aneurysm pathogenesis. An update of clinical trials focusing on therapeutic strategies to slow abdominal aortic aneurysm growth and efforts underway to develop effective pharmacological treatments is also provided.

Similar 5-year outcomes between female and male patients undergoing elective endovascular abdominal aortic aneurysm repair with the Ovation stent graft

OBJECTIVE

Female patients undergoing endovascular aneurysm repair (EVAR) for infrarenal abdominal aortic aneurysms present with more challenging anatomy and historically have worse outcomes compared with men. The Ovation Abdominal Stent Graft platform (Endologix, Irving, Calif) contains a polymer-filled proximal sealing ring and has a low-profile delivery system, potentially beneficial in female patients. We therefore investigated differences in long-term outcomes between men and women treated with this device.

METHODS

We used data collected prospectively in the Effectiveness of Custom Seal with Ovation: Review of the Evidence (ENCORE) database, comprising five trials and the European Post-Market Registry. Anatomic characteristics of the proximal aneurysm neck and iliac arteries were compared between male and female patients. Outcomes were 5-year freedom from type IA and type I/III endoleaks, abdominal aortic aneurysm-related reinterventions, and overall survival. We used Kaplan-Meier analysis to estimate survival proportions and tested univariate differences in survival using log-rank tests. Cox proportional hazards modeling was used to adjust for baseline differences.

RESULTS

We identified 1045 (81%) male and 251 (19%) female patients undergoing EVAR. Female patients were older (mean age, 75 ± 8.4 years vs 73 ± 8.1 years; P < .006). Aneurysm diameter (52 ± 7.5 mm vs 55 ± 9.2 mm; P < .001) and proximal neck diameter (21 ± 3.3 mm vs 23 ± 2.9 mm; P < .001) were smaller in female patients, but adjusted for body surface area, female patients had relatively larger aneurysms and aneurysm necks. Furthermore, female patients presented with shorter proximal necks, smaller iliac artery diameters, more angulated necks, and higher rates of reverse-tapered necks. Five-year freedom from type IA endoleak was similar between men and women (97% vs 96%; P = .38), as was freedom from type I/III endoleaks (91% vs 94%; P = .37) and reinterventions (91% vs 93%; P = .67). Five-year survival was 81% for female patients, similar to the 79% in male patients (P = .55), with one aneurysm-related death in female patients (0.4%) and five in male patients (0.8%; P = .76). Risk-adjusted analyses showed no association between sex and type IA endoleak (hazard ratio [HR], 1.4; 95% confidence interval [CI], 0.6-3.1; P = .41), type I/III endoleak (HR, 1.4; 95% CI, 0.7-2.8; P = .33), reintervention (HR, 1.0; 95% CI, 0.6-2.0; P = .77), and overall mortality (HR, 0.7; 95% CI, 0.4-1.1; P = .14).

CONCLUSIONS

Female patients undergoing EVAR with the Ovation platform presented with substantially more adverse proximal neck characteristics. Despite these differences, 5-year freedom from endoleaks and overall survival did not differ between sexes.

Impact of Gender on Outcomes Following Abdominal Aortic Aneurysm Repair

Objective:

The purpose of this study is to use a large, nationally representative vascular database to assess differences in patient characteristics, aortic neck anatomy, and outcomes between men and women following open (open aneurysm repair [OAR]) and endovascular (endovascular aneurysm repair [EVAR]) abdominal aortic aneurysm (AAA) repair.

Methods:

Patients undergoing AAA repair from 2003 to 2018 in Vascular Quality Initiative were identified and stratified by procedure (EVAR vs OAR). Thirty-day mortality and major in-hospital complications were assessed between genders within each operative cohort. An EVAR subset analysis was performed to assess differences in aortic neck anatomy; hostile neck anatomy was defined as length <15 mm (L < 15), angle >60° (A > 60), and/or diameter >28 mm (D > 28). Standard univariate and multivariable analyses were performed.

Results:

A total of 50 213 patients were identified: 9263 (19%) OAR and 40 950 (82%) EVAR. In both cohorts, majority of patients were men (OAR 73% and EVAR 81%). Women were more likely to have a hostile neck (31.7% vs 24.1%, P < .001), L < 15 (19.8% vs 11.9%, P < .001), and A > 60 (11.5% vs 5.4%, P < .001). Men had larger aneurysm (mean, 57 vs 55 mm, P < .001) and were more likely to have D > 28 (14.0% vs 10.6%, P < .001). Women undergoing EVAR were more likely to undergo aortic extensions (21.9% vs 16.0%) and receive higher contrast volume. After adjusting for potential confounders, female gender was associated with 86% and 50% increased risk of 30-day mortality in OAR and EVAR, respectively. Women were more likely than men to experience renal, cardiac, and pulmonary complications only in the EVAR cohort. Women had a 2-fold increased odds of developing type 1 endoleak.

Conclusion:

Our study demonstrates unfavorable neck anatomy occurs more frequently in women compared to men. Women were also at an increased risk of developing major complications, particularly following EVAR. Careful patient selection is indicated in all patients to reduce complications, with special attention in women with hostile neck.

Sex differences in repair rates and outcomes of patients with ruptured abdominal aortic aneurysm

BACKGROUND

Data are conflicting on sex differences in ruptured abdominal aortic aneurysm (rAAA) repair rates and outcomes have rarely been addressed. The aim of this study was to investigate differences in the management and outcome of rAAA in men and women, and to describe time trends over a 15-year interval.

METHODS

Data on patients with rAAA were extracted from the Swedish National Patient Registry and the Cause of Death Registry for the interval 2001-2015. The study included patients with rAAA whether or not they were admitted to any hospital in Sweden. A propensity score-matched model was used to determine sex differences in repair type and outcome after rupture. Time trends for rAAA events and mortality were investigated.

RESULTS

Some 10 724 patients were identified. A higher percentage of men were admitted to hospital (79·8 versus 77·5 per cent; P = 0·011). Of those admitted, a higher percentage of men than women were treated (56·6 versus 40·4 per cent, P < 0·001). Women were less likely to be treated when diagnosed with rAAA (average treatment effect (ATE) in the model -0·080, 95 per cent c.i. -0·106 to -0·055; P < 0·001). Thirty-day mortality was also higher in women (ATE 0·094, 0·053 to 0·135; P < 0·001); this effect persisted to 1 year (ATE 0·095, 0·052 to 0·137; P < 0·001). Time trends indicated a decrease in rAAA incidence, mostly owing to a decrease among men.

CONCLUSION

In this study, fewer women with rAAA received surgery and 30-day mortality was higher than in men. There was an overall decrease in rAAA incidence, principally in men.

Gender differences in outcomes after aortic aneurysm surgery should foster further research to improve screening and prevention programmes

Background Gender-related biases in outcomes after thoracic aortic surgery are an important factor to consider in the prevention of potential complications related to aortic diseases and in the analysis of surgical results. Methods The aim of this study is to provide an up-to-date review of gender-related differences in the epidemiology, specific risk factors, outcome, and screening and prevention programmes in aortic aneurysms. Results Female patients affected by aortic disease still have worse outcomes and higher early and late mortality than men. It is difficult to plan new specific strategies to improve outcomes in women undergoing major aortic surgery, given that the true explanations for their poorer outcomes are as yet not clearly identified. Some authors recommend further investigation of hormonal or molecular explanations for the sex differences in aortic disease. Others stress the need for quality improvement projects to quantify the preoperative risk in high-risk populations using non-invasive tests such as cardiopulmonary exercise testing. Conclusions The treatment of patients classified as high risk could thus be optimised before surgery becomes necessary by means of numerous strategies, such as the administration of high-dose statin therapy, antiplatelet treatment, optimal control of hypertension, lifestyle improvement with smoking cessation, weight loss and careful control of diabetes. Future efforts are needed to understand better the gender differences in the diagnosis, management and outcome of aortic aneurysm disease, and for appropriate and modern management of female patients.

Screening women aged 65 years or over for abdominal aortic aneurysm: a modelling study and health economic evaluation

BACKGROUND

Abdominal aortic aneurysm (AAA) screening programmes have been established for men in the UK to reduce deaths from AAA rupture. Whether or not screening should be extended to women is uncertain.

OBJECTIVE

To evaluate the cost-effectiveness of population screening for AAAs in women and compare a range of screening options.

DESIGN

A discrete event simulation (DES) model was developed to provide a clinically realistic model of screening, surveillance, and elective and emergency AAA repair operations. Input parameters specifically for women were employed. The model was run for 10 million women, with parameter uncertainty addressed by probabilistic and deterministic sensitivity analyses.

SETTING

Population screening in the UK.

PARTICIPANTS

Women aged ≥ 65 years, followed up to the age of 95 years.

INTERVENTIONS

Invitation to ultrasound screening, followed by surveillance for small AAAs and elective surgical repair for large AAAs.

MAIN OUTCOME MEASURES

Number of operations undertaken, AAA-related mortality, quality-adjusted life-years (QALYs), NHS costs and cost-effectiveness with annual discounting.

DATA SOURCES

AAA surveillance data, National Vascular Registry, Hospital Episode Statistics, trials of elective and emergency AAA surgery, and the NHS Abdominal Aortic Aneurysm Screening Programme (NAAASP).

REVIEW METHODS

Systematic reviews of AAA prevalence and, for elective operations, suitability for endovascular aneurysm repair, non-intervention rates, operative mortality and literature reviews for other parameters.

RESULTS

The prevalence of AAAs (aortic diameter of ≥ 3.0 cm) was estimated as 0.43% in women aged 65 years and 1.15% at age 75 years. The corresponding attendance rates following invitation to screening were estimated as 73% and 62%, respectively. The base-case model adopted the same age at screening (65 years), definition of an AAA (diameter of ≥ 3.0 cm), surveillance intervals (1 year for AAAs with diameter of 3.0-4.4 cm, 3 months for AAAs with diameter of 4.5-5.4 cm) and AAA diameter for consideration of surgery (5.5 cm) as in NAAASP for men. Per woman invited to screening, the estimated gain in QALYs was 0.00110, and the incremental cost was £33.99. This gave an incremental cost-effectiveness ratio (ICER) of £31,000 per QALY gained. The corresponding incremental net monetary benefit at a threshold of £20,000 per QALY gained was -£12.03 (95% uncertainty interval -£27.88 to £22.12). Almost no sensitivity analyses brought the ICER below £20,000 per QALY gained; an exception was doubling the AAA prevalence to 0.86%, which resulted in an ICER of £13,000. Alternative screening options (increasing the screening age to 70 years, lowering the threshold for considering surgery to diameters of 5.0 cm or 4.5 cm, lowering the diameter defining an AAA in women to 2.5 cm and lengthening the surveillance intervals for the smallest AAAs) did not bring the ICER below £20,000 per QALY gained when considered either singly or in combination.

LIMITATIONS

The model for women was not directly validated against empirical data. Some parameters were poorly estimated, potentially lacking relevance or unavailable for women.

CONCLUSION

The accepted criteria for a population-based AAA screening programme in women are not currently met.

FUTURE WORK

A large-scale study is needed of the exact aortic size distribution for women screened at relevant ages. The DES model can be adapted to evaluate screening options in men.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015020444 and CRD42016043227.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Incidence, Treatment and Mortality in Patients with Abdominal Aortic Aneurysms

BACKGROUND

Aim of this study was to analyze hospital incidence, type of treatment, and hospital mortality rates of patients with abdominal aortic aneurysm (AAA) in Germany from 2005 to 2014.

METHODS

Microdata of the diagnosis-related group (DRG) statistics compiled by the German Federal Statistical Office for the years 2005-2014 were analyzed. Patients who were hospitalized for a ruptured AAA (rAAA, ICD-10 code I71.3, treated either surgically or conservatively) or received surgical treatment for an unruptured AAA (nrAAA, ICD-10-Code I71.4, treated either with open surgery or an endovascular procedure) were included in the analysis. The "European Standard Population 2013" was used for direct standardization of the hospital incidences. In-hospital mortality was calculated with standardization for age and risk.

RESULTS

The standardized overall hospital incidence of AAA was 27.9 and 3.3 cases per 100 000 people for men and women, respectively; over the period of the study, the incidence of rAAA fell by 30% in both sexes and that of nrAAA rose by 16% in men and 42% in women. The percentage of patients receiving endovascular treatment rose from 29% to 75% in patients with nrAAA and from 8% to 36% in patients with rAAA. The age- and risk-standardized in-hospital mortality of nrAAA was 3.3% in men and 5.3% in women. The in-hospital mortality of surgically treated rAAA was 39% in men and 48% in women.

CONCLUSION

The hospital incidence of AAA rose from 2005 to 2014, while that of rAAA fell. Endovascular treatment became more common for nrAAA as well as rAAA, and in-hospital mortality fell for both.

Sex differences in national rates of repair of emergency abdominal aortic aneurysm

BACKGROUND

The aim of this study was to assess the sex differences in both the rate and type of repair for emergency abdominal aortic aneurysm (AAA) in England.

METHODS

Hospital Episode Statistics (HES) data sets from April 2002 to February 2015 were obtained. Clinical and administrative codes were used to identify patients who underwent primary emergency definitive repair of ruptured or intact AAA, and patients with a diagnosis of AAA who died in hospital without repair. These three groups included all patients with a primary AAA who presented as an emergency. Sex differences between repair rates and type of surgery (endovascular aneurysm repair (EVAR) versus open repair) over time were examined.

RESULTS

In total, 15 717 patients (83·3 per cent men) received emergency surgical intervention for ruptured AAA and 10 276 (81·2 per cent men) for intact AAA; 12 767 (62·0 per cent men) died in hospital without attempted repair. The unadjusted odds ratio for no repair in women versus men was 2·88 (95 per cent c.i. 2·75 to 3·02). Women undergoing repair of ruptured AAA were older and had a higher in-hospital mortality rate (50·0 versus 41·0 per cent for open repair; 30·9 versus 23·5 per cent for EVAR). After adjustment for age, deprivation and co-morbidities, the odds ratio for no repair in women versus men was 1·34 (1·28 to 1·40). The in-hospital mortality rate after emergency repair of an intact AAA was also higher among women.

CONCLUSION

Women who present as an emergency with an AAA are less likely to undergo repair than men. Although some of this can be explained by differences in age and co-morbidities, the differences persist after case-mix adjustment.

Abdominal aortic aneurysms

An abdominal aortic aneurysm (AAA) is a localized dilatation of the infrarenal aorta. AAA is a multifactorial disease, and genetic and environmental factors play a part; smoking, male sex and a positive family history are the most important risk factors, and AAA is most common in men >65 years of age. AAA results from changes in the aortic wall structure, including thinning of the media and adventitia due to the loss of vascular smooth muscle cells and degradation of the extracellular matrix. If the mechanical stress of the blood pressure acting on the wall exceeds the wall strength, the AAA ruptures, causing life-threatening intra-abdominal haemorrhage - the mortality for patients with ruptured AAA is 65-85%. Although AAAs of any size can rupture, the risk of rupture increases with diameter. Intact AAAs are typically asymptomatic, and in settings where screening programmes with ultrasonography are not implemented, most cases are diagnosed incidentally. Modern functional imaging techniques (PET, CT and MRI) may help to assess rupture risk. Elective repair of AAA with open surgery or endovascular aortic repair (EVAR) should be considered to prevent AAA rupture, although the morbidity and mortality associated with both techniques remain non-negligible.

Gender differences in abdominal aortic aneurysm therapy - a systematic review

This article analyses if and to what extent gender differences exist in abdominal aortic aneurysm (AAA) therapy. For this purpose Medline (PubMed) was searched from January 1999 to January 2018. Keywords were: "abdominal aortic aneurysm", "gender", "prevalence", "EVAR", and "open surgery of abdominal aortic aneurysm". Regardless of open or endovascular treatment of abdominal aortic aneurysms, women have a higher rate of complications and longer hospitalizations compared to men. The majority of studies showed that women have a lower survival rate for surgical and endovascular treatment of abdominal aneurysms after both elective and emergency interventions. Women receive less surgical/interventional and protective medical treatment. Women seem to have a higher risk of rupture, a lower survival rate in AAA, and a higher rate of complications, regardless of endovascular or open treatment. The gender differences may be due to a higher age of women at diagnosis and therapy associated with higher comorbidity, but also because of genetic, hormonal, anatomical, biological, and socio-cultural differences. Strategies for treatment in female patients must be further defined to optimize outcome.

Should Abdominal Aortic Aneurysms in Women be Repaired at a Lower Diameter Threshold?

Abdominal aortic aneurysm (AAA) primarily affects male patients; however, female patients with AAA have a faster rate of aneurysm growth, have higher risk of rupture even at smaller diameters, and have worse outcomes following repair of ruptured and intact aneurysms. Furthermore, early natural history studies and randomized controlled trials evaluating surveillance versus repair in small aneurysms were conducted primarily in male patients. Therefore, there are limited data regarding the ideal threshold for elective repair of AAA in women, either by aortic diameter or by alternative measures. We review the existing literature regarding AAA in women and consider the most appropriate threshold for repair.

Nationwide analysis of risk factors for in-hospital mortality in patients undergoing abdominal aortic aneurysm repair

BACKGROUND

There is increasing awareness that women may have worse outcomes following repair of abdominal aortic aneurysm (AAA). The aim of this study was to analyse the association between sex, age and in-hospital mortality after AAA using hospital episode data collected routinely at the nationwide level.

METHODS

Data were extracted from the nationwide statutory Diagnosis Related Group statistics provided by the German Federal Statistical Office. Patients with a diagnosis of intact (non-ruptured) AAA (ICD-10 GM I71.4) and procedure codes (OPS; 2005-2013) for endovascular aneurysm repair (EVAR) (5-38a.1*) or open aneurysm repair (5-384.5, 5-384.7), treated from 2005 to 2013, were included. A multilevel multivariable regression model was applied to adjust for medical risk (using the Elixhauser co-morbidity score), type of procedure, type of admission, and to account for clustering of patients within centres. The primary outcome was in-hospital mortality.

RESULTS

Some 84 631 patients were identified, of whom 10 039 (11·9 per cent) were women. Women were significantly older than men at admission (median 74 (i.q.r. 69-80) versus 72 (66-77) years; P < 0·001). EVAR was used less frequently in women (48·1 versus 54·7 per cent; P < 0·001). The in-hospital mortality rate was higher in women, overall (5·0 versus 3·1 per cent; relative risk 1·60, 95 per cent c.i. 1·45 to 1·75), and for EVAR (2·8 versus 1·5 per cent; RR 1·90, 1·60 to 2·30) and open repair (6·8 versus 5·0 per cent; RR 1·36, 1·22 to 1·52). In-hospital mortality increased with age and was highest in patients aged over 80 years. In multivariable regression analysis, female sex (RR 1·20, 1·07 to 1·35) and age per 10-year increase (RR 1·83, 1·73 to 1·95) were independent risk factors for higher in-hospital mortality.

CONCLUSION

In Germany, women were older when undergoing AAA repair and were less likely to receive EVAR. Mortality rates were higher in older patients and in women, irrespective of the surgical technique used.

A Majority of Admitted Patients With Ruptured Abdominal Aortic Aneurysm Undergo and Survive Corrective Treatment: A Population-Based Retrospective Cohort Study

Background

Abdominal aortic aneurysm (AAA) is an asymptomatic, potentially lethal condition predominantly found in elderly. The mortality is 100 % if rupture occurs and left untreated, but even in treated patients the mortality is substantial. Female sex and treatment with open repair rather than endovascular aortic repair (EVAR) have been reported to negatively affect outcome. The objective was to describe the contemporary care and outcome of all treated and untreated patients with ruptured AAA (rAAA) admitted to hospital.

Method

Population-based retrospective investigation, including all patients admitted to the emergency departments within Stockholm County diagnosed with rAAA 2009–2013. All identified patients’ charts (n = 297) were analyzed; the study cohort includes 283 verified patients.

Results

Men were in majority [214 (76 %), 69 (24 %) women] and were younger than women (78 vs 82 years, p < 0.001). A majority of patients were treated (212/283, 75 %), a similar proportion of women and men. Untreated patients had a higher mean age (84 vs 77 years, p < 0.001). The proportion treated with EVAR was 27 %, and they were older than OR treated (79 vs 76 years, p = 0.043). Forty-seven percentage of patients admitted with rAAA survived 30 days, and 62 % of treated patients survived 30 days. The 30-day mortality for women and men was similar.

Conclusions

Our results and other contemporary series show a shift toward a higher rate of treated patients with rAAA, and improving outcomes, similar for women and men. The increased use of EVAR contributes to this improvement in short-term outcome. High age influences the willingness to treat patients with rAAA.

Sex differences in mortality after abdominal aortic aneurysm repair in the UK

BACKGROUND

The UK abdominal aortic aneurysm (AAA) screening programmes currently invite only men for screening because the benefit in women is uncertain. Perioperative risk is critical in determining the effectiveness of screening, and contemporary estimates of these risks in women are lacking. The aim of this study was to compare mortality following AAA repair between women and men in the UK.

METHODS

Anonymized data from the UK National Vascular Registry (NVR) for patients undergoing AAA repair (January 2010 to December 2014) were analysed. Co-variables were extracted for analysis by sex. The primary outcome measure was in-hospital mortality. Secondary outcome measures included mortality by 5-year age groups and duration of hospital stay. Logistic regression was performed to adjust for age, calendar time, AAA diameter and smoking status. NVR-based outcomes were checked against Hospital Episode Statistics (HES) data.

RESULTS

A total of 23 245 patients were included (13·0 per cent women). Proportionally, more women than men underwent open repair. For elective open AAA repair, the in-hospital mortality rate was 6·9 per cent in women and 4·0 per cent in men (odds ratio (OR) 1·48, 95 per cent c.i. 1·08 to 2·02; P = 0·014), whereas for elective endovascular AAA repair it was 1·8 per cent in women and 0·7 per cent in men (OR 2·86, 1·72 to 4·74; P < 0·001); the results in HES were similar. For ruptured AAA, there was no sex difference in mortality within the NVR; however, in HES, for ruptured open AAA repair, the in-hospital mortality rate was higher in women (33·6 versus 27·1 per cent; OR 1·36, 1·16 to 1·59; P < 0·001).

CONCLUSION

Women have a higher in-hospital mortality rate than men after elective AAA repair even after adjustment. This higher mortality may have an impact on the benefit offered by any screening programme offered to women.

Morphological suitability for endovascular repair, non-intervention rates, and operative mortality in women and men assessed for intact abdominal aortic aneurysm repair: systematic reviews with meta-analysis

BACKGROUND

Prognosis for women with abdominal aortic aneurysm might be worse than the prognosis for men. We aimed to systematically quantify the differences in outcomes between men and women being assessed for repair of intact abdominal aortic aneurysm using data from study periods after the year 2000.

METHODS

In these systematic reviews and meta-analysis, we identified studies (randomised, cohort, or cross-sectional) by searching MEDLINE, Embase, CENTRAL, and grey literature published between Jan 1, 2005, and Sept 2, 2016, for two systematic reviews and Jan 1, 2009, and Sept 2, 2016, for one systematic review. Studies were included if they were of both men and women, with data presented for each sex separately, with abdominal aortic aneurysms being assessed for aneurysm repair by either endovascular repair (EVAR) or open repair. We conducted three reviews based on whether studies reported the proportion morphologically suitable (within manufacturers' instructions for use) for EVAR (EVAR suitability review), non-intervention rates (non-intervention review), and 30-day mortality (operative mortality review) after intact aneurysm repair. Studies had to include at least 20 women (for the EVAR suitability review), 20 women (for the non-intervention review), and 50 women (for the operative mortality review). Studies were excluded if they were review articles, editorials, letters, or case reports. For the operative review, studies were also excluded if they only provided hazard ratios or only reported in-hospital mortality. We assessed the quality of the studies using the Newcastle-Ottawa scoring system, and contacted authors for the provision of additional data if needed. We combined results across studies by random-effects meta-analysis. This study is registered with PROSPERO, number CRD42016043227.

FINDINGS

Five studies assessed the morphological eligibility for EVAR (1507 men, 400 women). The overall pooled proportion of women eligible (34%) for EVAR was lower than it was in men (54%; odds ratio [OR] 0·44, 95% CI 0·32-0·62). Four single-centre studies reported non-intervention rates (1365 men, 247 women). The overall pooled non-intervention rates were higher in women (34%) than men (19%; OR 2·27, 95% CI 1·21-4·23). The review of 30-day mortality included nine studies (52 018 men, 11 076 women). The overall pooled estimate for EVAR was higher in women (2·3%) than in men (1·4%; OR 1·67, 95% CI 1·38-2·04). The overall estimate for open repair also was higher in women (5·4%) than in men (2·8%; OR 1·76, 95% CI 1·35-2·30).

INTERPRETATION

Compared with men, a smaller proportion of women are eligible for EVAR, a higher proportion of women are not offered intervention, and operative mortality is much higher in women for both EVAR and open repair. The management of abdominal aortic aneurysm in women needs improvement.

FUNDING

National Institute for Health Research (UK).

Sex differences in mortality and morbidity following repair of intact abdominal aortic aneurysms

OBJECTIVE

Medicare studies have shown increased perioperative mortality in women compared with men following endovascular and open abdominal aortic aneurysm (AAA) repair. However, a recent regional study of high-volume centers, adjusting for anatomy but limited in sample size, did not show sex to be predictive of worse outcomes. This study aimed to evaluate sex differences after intact AAA repair in a national clinical registry.

METHODS

The targeted vascular module of the National Surgical Quality Improvement Program was queried to identify patients undergoing endovascular aneurysm repair (EVAR) or open repair for intact, infrarenal AAA from 2011 to 2014. Univariate analysis was performed using the Fisher exact test and Mann-Whitney test. Multivariable logistic regression was used to account for differences in comorbidities, aneurysm details, and operative characteristics.

RESULTS

We identified 6611 patients (19% women) who underwent intact AAA repair (87% EVAR; 83% women vs 88% men; P < .001). Women were older (median age, 76 vs 73 years; P < .001), had smaller aneurysms (median, 5.4 vs 5.5 cm; P < .001), and had more chronic obstructive pulmonary disease (22% vs 17%; P < .001). Among patients undergoing EVAR, women had longer operative times (median, 138 [interquartile range, 103-170] vs 131 [106-181] minutes; P < .01) and more often underwent renal (6.3% vs 4.1%; P < .01) and lower extremity (6.6% vs 3.8%; P < .01) revascularization. After open repair, women had shorter operative time (215 [177-304] vs 226 [165-264] minutes; P = .02), but women less frequently underwent lower extremity revascularization (3.1% vs 8.2%; P = .03). Thirty-day mortality was higher in women after EVAR (3.2% vs 1.2%; P < .001) and open repair (8.0% vs 4.0%; P = .04). After adjusting for repair type, age, aneurysm diameter, and comorbidities, female sex was independently associated with mortality (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1-2.6; P = .02) and major complications (OR, 1.4; CI, 1.1-1.7; P < .01) after intact AAA repair. However, after adjusting for aortic size index rather than for aortic diameter, the association between female sex and mortality (OR, 1.5; CI, 0.98-2.4; P = .06) and major complications (OR, 1.1; CI, 0.9-1.4; P = .24) was reduced.

CONCLUSIONS

Women were at higher risk for 30-day death and major complications after intact AAA repair. Some of this disparity may be explained by differences in aortic size index, which should be further evaluated to determine the ideal threshold for repair.

Male gender and smoking are related to single, but not to multiple, human aortic aneurysms

There is scanty information concerning multiple aortic aneurysms. Thus, we verified if clinical or pathological characteristics are different in patients with multiple (two or more) aortic aneurysms in comparison with those with only one.

MATERIAL AND METHODS

We selected at the necropsy files of the Heart Institute, São Paulo University School of Medicine, the last 100 cases with aortic aneurysms, comparing between the two groups: sex, age, presence of systemic arterial hypertension, diabetes, dyslipedemia, history of smoking habit, cause of the aneurysm, cause of death, and if the diagnosis was reached during life. Age was analysed by Mann-Whitney test, and the other variables by chi-square or Fisher's exact test.

RESULTS

Multiple aneurysms corresponded to 14% of cases. The proportion of women among patients with multiple aneurysms was higher than among those with single aneurysm (64.3% versus 20.9%, P<.01), even if only cases with atherosclerosis were taken into consideration (women among multiple-6/10, 60.0%; among single-14/70, 20.0%; P=.01). Smoking was less reported in cases with multiple (4/14, 28.6%) than with single aneurysm (53/86, 61.6%; P=.04); considering cases with atherosclerosis, such difference decreases (40.0% of multiple versus 68.6% of single, P=.09).

CONCLUSION

although atherosclerosis is present in most cases of both single and multiple aortic aneurysms, male gender and smoking, considered highly influential in such lesions, are less frequent in patients with multiple than in patients with single aneurysms. Thus mechanisms underlying multiple aortic aneurysms are probably different from those related to single, more common aneurysms.