First-year results of a national abdominal aortic aneurysm screening programme in a single centre

Increased incidence of abdominal aortic aneurysm in women with early menopause

OBJECTIVE

In several countries, including the United States and United Kingdom, screening tests are conducted on men 65 years of age or older who smoke to diagnose abdominal aortic aneurysm (AAA) before rupture. In women, however, the incidence of AAA is low, so screening tests are not cost effective and therefore not recommended. Early detection and treatment of AAA are important for women as they face a four times higher risk of rupture and worse surgery outcomes compared with men. Accordingly, we analyzed how differences in the period of exposure to female hormones affect women's AAA risk to find unique risk factors.

METHODS

We collected data from the National Health Insurance System database for women aged 40 or older who underwent medical checkups and female cancer tests from January to December 2009 (n = 3,109,506). Those who were menopausal (n = 1,393,271) were included in the study. Participants were tracked until December 2019 to confirm whether AAA was diagnosed.

RESULTS

There were 3629 cases diagnosed with AAA. A comparison of the AAA and non-AAA cohorts showed a decreasing trend with advancing age at menopause. Compared with women who reached menopause before the age of 40, those who reached menopause after 55 had a 23% lower risk of AAA. Those who experienced more than 40 years of menstruation had a 20% lower risk of AAA compared with fewer than 30 years of menstruation.

CONCLUSIONS

Women with early menopause face a higher incidence of AAA, so attention should be paid to early diagnosis.

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.

Association between the non-HDL-cholesterol to HDL- cholesterol ratio and abdominal aortic aneurysm from a Chinese screening program

BACKGROUND

Abdominal aortic aneurysms (AAAs) can result in high mortality upon rupture but are usually undiagnosed because of the absence of symptoms in the early stage. Ultrasound screening is regarded as an impactful way to prevent the AAA-related death but cannot be performed efficiently; therefore, a target population, especially in Asia, for this procedure is lacking. Additionally, although dyslipidaemia and atherosclerosis are associated with AAA. However, it remains undetermined whether the non-high-density lipoprotein-cholesterol to high-density lipoprotein-cholesterol ratio (NHHR) is associated with AAA. Therefore, this study was aimed at examining whether NHHR is associated with AAA.

METHOD

A total of 9559 participants who underwent AAA screening at Guangdong Provincial People's Hospital and through screening in two communities in Dongguan, from June 2019 to June 2021 joined in this screening program. The diagnosis of AAA was confirmed by the ultrasound examination of the abdominal aorta rather than any known or suspected AAA. Clinical and laboratory data of participants were collected. The participants were separated into a normal group and an AAA group according to the abdominal aortic status. To eliminate confounding factors, a propensity score matching (PSM) approach was utilized. The independent relationship between NHHR and AAA was assessed through the utilization of multivariable logistic regression analysis. In addition, internal consistency was evaluated through subgroup analysis, which controlled for significant risk factors.

RESULTS

Of all the participants, 219 (2.29%) participants were diagnosed with AAA. A significant elevation in NHHR was identified in the AAA group when contrasted with that in the normal group (P < 0.001). As demonstrated by the results of the multivariable logistic regression analysis, AAA was independently associated with NHHR before (odds ratio [OR], 1.440, P < 0.001) and after PSM (OR, 1.515, P < 0.001). Significant extension was observed in the areas under the receiver operating characteristic curves (AUROCs) of NHHR compared to those of single lipid parameters before and after PSM. An accordant association between NHHR and AAA in different subgroups was demonstrated by subgroup analysis.

CONCLUSION

In the Chinese population, there is an independent association between NHHR and AAA. NHHR might be propitious to distinguish individuals with high risk of AAA.

Outcomes of a pilot abdominal aortic aneurysm screening program in a population of Central Greece

BACKGROUND

Abdominal aortic aneurysm (AAA) screening has contributed in the decrease of aneurysm related and all-cause mortality. The objective of our study is to present our experience from the only existing pilot AAA screening program in Greece.

METHODS

Men from both urban and rural areas in Central Greece, aged >60 years old without a previously known diagnosis of AAA were invited through the public primary health care units to participate to a screening program. Demographics, comorbidities, family history and anthropometric data were recorded. Aortic diameter values of >30 mm and common iliac artery (CIA) diameter values of >18 mm, were defined as aneurysmatic by ultrasound.

RESULTS

The screening program included 1256 individuals (1256/1814; response rate 69%). The incidence of AAA and CIA aneurysm was 2% (25/1256) and 2.3% (29/1256), respectively. Increased age (P<0.042), tobacco use (P<0.006) and its duration (P<0.008) were related to higher incidence of AAA, while diabetes mellitus to lower one (P<0.048). Multivariate analysis showed that AAA was associated to longer duration of smoking (1.05, CI: 0.02-6.6; P=0.01). Statin and antiplatelet therapy were administrated in 40% (10/25) and 44% (11/25), respectively of individuals with AAA. An additional analysis was provided between subjects with AD of 25-30 mm and AD <25 mm. In multivariate analysis, no factor was associated to AD of 25-30 mm.

CONCLUSIONS

The incidence of AAA and CIA aneurysm in Central Greece is 2% and 2.3%, respectively. Smoking duration was the strongest associated factor with AAA incidence. This provides to healthcare policy makers a strong valid point for the prevention strategies.

A Comparison of Endovascular Aneurysm Repair and Open Repair for Ruptured Aortic Abdominal Aneurysms

Management modalities of ruptured abdominal aortic aneurysm (AAA) include ruptured open aneurysm repair (rOAR) and ruptured endovascular aneurysm repair (rEVAR). In this study, we aim to systematically review all the previously published randomized controlled trials (RCTs) that compared rOAR and rEVAR. A systematic search was performed in the following databases: PubMed, Scopus, Web of Science, Google Scholar, Clinical trials, and others with all the potentially relevant keywords that were adjusted to meet the search strategy for each database to collect all the relevant studies that were published up to January 2021. A total of 11 studies were identified through our comprehensive search. Among these studies, seven represented the IMPROVE trial, two represented the AJAX trial, and two represented the Nottingham and ECAR trials, each, while the remaining four studies were not RCTs; however, these were included in the discussion as they obtained data from the IMPROVE trial. The IMPROVE trials preferred EVAR use due to the potential survival benefit and improved quality of life, although the EVAR and OAR had similar mortality rates. In the AJAX and ECAR, the mortality rates favored EVAR over OAR with no significance while the opposite was noticed in the Nottingham trial with no significance also. Similar rates of re-interventions and complications were also noticed and some studies reported that EVAR is cost-effective. Overall evidence slightly favors EVAR over OAR and further studies are needed.

Circular RNA Expression: Its Potential Regulation and Function in Abdominal Aortic Aneurysms

Abdominal aortic aneurysms (AAAs) have posed a great threat to human life, and the necessity of its monitoring and treatment is decided by symptomatology and/or the aneurysm size. Accumulating evidence suggests that circular RNAs (circRNAs) contribute a part to the pathogenesis of AAAs. circRNAs are novel single-stranded RNAs with a closed loop structure and high stability, having become the candidate biomarkers for numerous kinds of human disorders. Besides, circRNAs act as molecular "sponge" in organisms, capable of regulating the transcription level. Here, we characterize that the molecular mechanisms underlying the role of circRNAs in AAA development were further elucidated. In the present work, studies on the biosynthesis, bibliometrics, and mechanisms of action of circRNAs were aims comprehensively reviewed, the role of circRNAs in the AAA pathogenic mechanism was illustrated, and their potential in diagnosing AAAs was examined. Moreover, the current evidence about the effects of circRNAs on AAA development through modulating endothelial cells (ECs), macrophages, and vascular smooth muscle cells (VSMCs) was summarized. Through thorough investigation, the molecular mechanisms underlying the role of circRNAs in AAA development were further elucidated. The results demonstrated that circRNAs had the application potential in the diagnosis and prevention of AAAs in clinical practice. The study of circRNA regulatory pathways would be of great assistance to the etiologic research of AAAs.

Cost-effectiveness of a population-based AAA screening program for men over 65 years old in Iran

BACKGROUND

Screening program tend to recognized patients in their early stage and consequently improve health outcomes. Cost-effectiveness of the abdominal aortic aneurysm (AAA) screening program has been scarcely studied in developing countries. We sought to evaluate the cost-effectiveness of a screening program for the abdominal aortic aneurysm (AAA) in men aged over 65 years in Iran.

METHODS

A Markov cohort model with 11 mutually exclusive health statuses was used to evaluate the cost-effectiveness of a population-based AAA screening program compared with a no-screening strategy. Transitions between the health statuses were simulated by using 3-month cycles. Data for disease transition probabilities and quality of life outcomes were obtained from published literature, and costs were calculated based on the price of medical services in Iran and the examination of the patients' medical records. The outcomes were life-years gained, the quality-adjusted life-year (QALY), costs, and the incremental cost-effectiveness ratio (ICER). The analysis was conducted for a lifetime horizon from the payer's perspective. Costs and effects were discounted at an annual rate of 3%. Uncertainty surrounding the model inputs was tested with deterministic and probabilistic sensitivity analyses.

RESULTS

The mean incremental cost of the AAA screening strategy compared with the no-screening strategy was $140 and the mean incremental QALY gain was 0.025 QALY, resulting in an ICER of $5566 ($14,656 PPP) per QALY gained. At a willingness-to-pay of 1 gross domestic product (GDP) per capita ($5628) per QALY gained, the probability of the cost-effectiveness of AAA screening was about 50%. However, at a willingness-to-pay of twice the GDP per capita per QALY gained, there was about a 95% probability for the AAA screening program to be cost-effective in Iran.

CONCLUSIONS

The results of this study showed that at a willingness-to-pay of 1 GDP per capita per QALY gained, a 1-time AAA screening program for men aged over 65 years could not be cost-effective. Nevertheless, at a willingness-to-pay of twice the GDP per capita per QALY gained, the AAA screening program could be cost-effective in Iran. Further, AAA screening in high-risk groups could be cost-effective at a willingness-to-pay of 1 GDP per capita per QALY gained.

Screening for abdominal aortic aneurysm in patients with clinically manifest vascular disease

AIMS

Declining prevalence of abdominal aortic aneurysm (AAA) might force a more targeted screening approach (high-risk populations only) in order to maintain (cost-)effectiveness. We aimed to determine temporal changes in the prevalence of screening-detected AAA, to assess AAA-related surgery, and evaluate all-cause mortality in patients with manifest vascular disease.

METHODS AND RESULTS

We included patients with manifest vascular disease but without a history of AAA enrolled in the ongoing single-centre prospective UCC-SMART cohort study. Patients were screened at baseline for AAA by abdominal ultrasonography. We calculated sex- and age-specific prevalence of AAA, probability of survival in relation to the presence of AAA, and the proportion of patients undergoing AAA-related surgery. Prevalence of screening-detected AAA in 5440 screened men was 2.5% [95% confidence interval (CI) 2.1-2.9%] and in 1983 screened women 0.7% (95% CI 0.4-1.1%). Prevalence declined from 1997 until 2017 in men aged 70-79 years from 8.1% to 3.2% and in men aged 60-69 years from 5.7% to 1.0%. 36% of patients with screening-detected AAA received elective AAA-related surgery during follow-up (median time until surgery = 5.3 years, interquartile range 2.5-9.1). Patients with screening-detected AAA had a lower probability of survival (sex and age adjusted) compared to patients without screening-detected AAA (51%, 95% CI 41-64% vs. 69%, 95% CI 68-71%) after 15 years of follow-up.

CONCLUSION

The prevalence of screening-detected AAA has declined over the period 1997-2017 in men with vascular disease but exceeds prevalence in already established screening programs targeting 65-year-old men. Screening for AAA in patients with vascular disease may be cost-effective, but this remains to be determined.

[Prevalence and risk factors of sub-renal abdominal aortic aneurysm in an Algerian population aged over 60]

INTRODUCTION

The prevalence of abdominal aortic aneurysm (AAA) in the general population in our country is not known, our aim was to evaluate it in patients over 60 years of age, to specify the risk factors and to evaluate the extension of aneurysmal disease and multisite subclinical atherosclerosis.

METHODS

Descriptive, transversal, study collecting the data of a systematic ultrasound screening of sub-renal AAA in subjects receiving care in two Algerian hospital structures. Epidemiological data, AAA risk factors, cardiovascular disease risk factors (CVD RF) and the personal history (cardiovascular diseases, chronic obstructive pulmonary disease) and family history of AAA were collected during the screening. An abdominal echography was performed in all patients. A biological and morphological assessment was carried out for AAA cases detected. Multivariate logistic regression analysis was used to study the factors associated with AAA.

RESULTS

Systematic screening for 600 patients revealed an overall AAA prevalence of 2.2% (n=13). In multivariate analysis a positive association with AAA was observed with active smoking, its duration in years and its intensity in year-packages; with hypertension, dyslipidemia and a history of cardiovascular events. While a negative association was observed with a smoking cessation of more than 20 years, type 2 diabetes and android obesity. The study of detected AAA cases found five cases of aneurysm isolated from the primary iliac artery but no popliteal and/or femoral aneurysm. The carotids were atheromatous in more than 80% of cases and the arteries of the lower limbs in more than one-third of cases.

CONCLUSION

The prevalence of AAA in our population (2.2%) corresponds to the prevalence reported recently in Europe, but it would have been higher if the screening had targeted males and smokers. The factors associated with AAA in our patients are similar to those described in the literature.

[Identifying barriers to screening for abdominal aortic aneurysm in general practice: Qualitative study of 14 general practitioners in Paris]

INTRODUCTION

Abdominal aortic aneurysm (AAA) is a silent pathology with often fatal consequences in case of rupture. AAA screening, recommended in France and many other countries, has shown its effectiveness in reducing specific mortality. However, AAA screening rate remains insufficient.

OBJECTIVE

To identify barriers to AAA screening in general practice.

MATERIAL AND METHOD

Qualitative study carried out during 2016 among general practitioners based in Paris.

RESULTS

Fourteen physicians were included. Most of the barriers were related to the physician: unawareness about AAA and screening recommendations, considering AAA as a secondary question not discussed with the patient, abdominal aorta not included in cardiovascular assessment, no search for a familial history of AAA, AAA considered a question for the specialist, lack of time, lack of training, numerous screenings to propose, oversight. Some barriers are related to the patient: unawareness of the pathology and family history of AAA, refusal, questioning the pertinence of the doctor's comments, failure to respect the care pathway. Others are related to AAA: source of anxiety, low prevalence, rarity of complications. The remaining barriers are related to screening: cost-benefit and risk-benefit ratios, sonographer unavailability, constraint for the patient, overmedicalization.

CONCLUSION

Information and training of general practitioners about AAA must be strengthened in order to optimize AAA screening and reduce specific mortality.

Endothelium as a Potential Target for Treatment of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) was previously ascribed to weaken defective medial arterial/adventitial layers, for example, smooth muscle/fibroblast cells. Therefore, besides surgical repair, medications targeting the medial layer to strengthen the aortic wall are the most feasible treatment strategy for AAA. However, so far, it is unclear whether such drugs have any beneficial effect on AAA prognosis, rate of aneurysm growth, rupture, or survival. Notably, clinical studies have shown that AAA is highly associated with endothelial dysfunction in the aged population. Additionally, animal models of endothelial dysfunction and endothelial nitric oxide synthase (eNOS) uncoupling had a very high rate of AAA formation, indicating there is crucial involvement of the endothelium and a possible pharmacological solution targeting the endothelium in AAA treatment. Endothelial cells have been found to trigger vascular wall remodeling by releasing proteases, or recruiting macrophages along with other neutrophils, into the medial layer. Moreover, inflammation and oxidative stress of the arterial wall were induced by endothelial dysfunction. Interestingly, there is a paradoxical differential correlation between diabetes and aneurysm formation in retinal capillaries and the aorta. Deciphering the significance of such a difference may explain current unsuccessful AAA medications and offer a solution to this treatment challenge. It is now believed that AAA and atherosclerosis are two separate but related diseases, based on their different clinical patterns which have further complicated the puzzle. Therefore, a thorough investigation of the interaction between endothelium and medial/adventitial layer may provide us a better understanding and new perspective on AAA formation, especially after taking into account the importance of endothelium in the development of AAA. Moreover, a novel medication strategy replacing the currently used, but suboptimal treatments for AAA, could be informed with this analysis.

Endovascular treatment for ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) (pathological enlargement of the aorta) is a condition that can occur as a person ages. It is most commonly seen in men older than 65 years of age. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, which is fatal unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. Endovascular aneurysm repair (EVAR), a minimally invasive technique, has been shown to reduce early morbidity and mortality as compared to conventional open surgery for planned AAA repair. More recently emergency endovascular aneurysm repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in select patients; however, it is unclear if eEVAR will lead to significant improvements in outcomes for these patients or if indeed it can replace conventional open repair as the preferred treatment for this lethal condition. This is an update of the review first published in 2006.

OBJECTIVES

To assess the advantages and disadvantages of emergency endovascular aneurysm repair (eEVAR) in comparison with conventional open surgical repair for the treatment of ruptured abdominal aortic aneurysm (RAAA). This will be determined by comparing the effects of eEVAR and conventional open surgical repair on short-term mortality, major complication rates, aneurysm exclusion (specifically endoleaks in the eEVAR treatment group), and late complications.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register (last searched June 2016), CENTRAL (2016, Issue 5), and trials registries. We also checked reference lists of relevant publications.

SELECTION CRITERIA

Randomised controlled trials in which participants with a clinically or radiologically diagnosed RAAA were randomly allocated to eEVAR or conventional open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies identified for potential inclusion for eligibility. Two review authors also independently completed data extraction and quality assessment. Disagreements were resolved through discussion. We performed meta-analysis using fixed-effect models with odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous data and mean differences with 95% CIs for continuous data.

MAIN RESULTS

We included four randomised controlled trials in this review. A total of 868 participants with a clinical or radiological diagnosis of RAAA were randomised to receive either eEVAR or open surgical repair. Overall risk of bias was low, but we considered one study that performed randomisation in blocks by week and performed no allocation concealment and no blinding to be at high risk of selection bias. Another study did not adequately report random sequence generation, putting it at risk of selection bias, and two studies were underpowered. There was no clear evidence to support a difference between the two interventions for 30-day (or in-hospital) mortality (OR 0.88, 95% CI 0.66 to 1.16; moderate-quality evidence). There were a total of 44 endoleak events in 128 participants from three studies (low-quality evidence). Thirty-day complication outcomes (myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation, and respiratory failure) were reported in between one and three studies, therefore we were unable to draw a robust conclusion. We downgraded the quality of the evidence for myocardial infarction, renal complications, and respiratory failure due to imprecision, inconsistency, and risk of bias. Odds ratios for complications outcomes were OR 2.38 (95% CI 0.34 to 16.53; 139 participants; 2 studies; low-quality evidence) for myocardial infarction; OR 1.07 (95% CI 0.21 to 5.42; 255 participants; 3 studies; low-quality evidence) for renal complications; and OR 3.62 (95% CI 0.14 to 95.78; 32 participants; 1 study; low-quality evidence) for respiratory failure. There was low-quality evidence of a reduction in bowel ischaemia in the eEVAR treatment group, but very few events were reported (OR 0.37, 95% CI 0.14 to 0.94), and we downgraded the evidence due to imprecision and risk of bias. Six-month and one-year outcomes were evaluated in three studies, but only results from a single study could be used for each outcome, which showed no clear evidence of a difference between the interventions. We rated six-month mortality evidence as of moderate quality due to imprecision (OR 0.89, 95% CI 0.40 to 1.98; 116 participants).

AUTHORS' CONCLUSIONS

The conclusions of this review are currently limited by the paucity of data. We found from the data available moderate-quality evidence suggesting there is no difference in 30-day mortality between eEVAR and open repair. Not enough information was provided for complications for us to make a well-informed conclusion, although it is possible that eEVAR is associated with a reduction in bowel ischaemia. Long-term data were lacking for both survival and late complications. More high-quality randomised controlled trials comparing eEVAR and open repair for the treatment of RAAA are needed to better understand if one method is superior to the other, or if there is no difference between the methods on relevant outcomes.

Editor's Choice - Abdominal Compartment Syndrome After Surgery for Abdominal Aortic Aneurysm: A Nationwide Population Based Study

OBJECTIVE/BACKGROUND

The understanding of abdominal compartment syndrome (ACS), and its importance for outcome, has increased over time. The aim was to investigate the incidence and clinical consequences of ACS after open (OR) and endovascular repair (EVAR) for ruptured and intact infrarenal abdominal aortic aneurysm (rAAA and iAAA, respectively).

METHODS

In 2008, ACS and decompression laparotomy (DL) were introduced as variables in the Swedish vascular registry (Swedvasc), offering an opportunity to study this complication in a prospective, population based design. Operations carried out in the period 2008-13 were analysed. Of 6,612 operations, 1,341 (20.3%) were for rAAA (72.0% OR) and 5,271 (79.7%) for iAAA (41.9% OR). In all, 3,171 (48.0%) were operated on by OR and 3,441 by EVAR. Prophylactic open abdomen (OA) treatment was validated through case records. Cross-matching with the national population registry secured valid mortality data.

RESULTS

After rAAA repair, ACS developed in 6.8% after OR versus 6.9% after EVAR (p = 1.0). All major complications were more common after ACS (p < .001). Prophylactic OA was performed in 10.7% of patients after OR. For ACS, DL was performed in 77.3% after OR and 84.6% after EVAR (p = .433). The 30 day mortality rate was 42.4% with ACS and 23.5% without ACS (p < .001); at 1 year it was 50.7% versus 31.8% (p < .001). After iAAA repair, ACS developed in 1.6% of patients after OR versus 0.5% after EVAR (p < .001). Among those with ACS, DL was performed in 68.6% after OR and in 25.0% after EVAR (p = .006). Thirty day mortality was 11.5% with ACS versus 1.8% without it (p < .001); at 1 year it was 27.5% versus 6.3% (p < .001). When ACS developed, renal failure, multiple organ failure, intestinal ischaemia, and prolonged intensive care were much more frequent (p < .001). Morbidity and mortality were similar, regardless of primary surgical technique (OR/EVAR/iAAA/rAAA).

CONCLUSION

ACS and OA were common after treatment for rAAA. ACS is a devastating complication after surgery for rAAA and iAAA, irrespective of operative technique, emphasizing the importance of prevention.

Endovascular repair or open repair for ruptured abdominal aortic aneurysm: a Cochrane systematic review

OBJECTIVES

Emergency endovascular aneurysm repair (eEVAR) may improve outcomes for patients with ruptured abdominal aortic aneurysm (RAAA). The study aim was to compare the outcomes for eEVAR with conventional open surgical repair for the treatment of RAAA.

SETTING

A systematic review of relevant publications was performed. Randomised controlled trials (RCTs) comparing eEVAR with open surgical repair for RAAA were included.

PARTICIPANTS

3 RCTs were included, with a total of 761 patients with RAAA.

INTERVENTIONS

Meta-analysis was performed with fixed-effects models with ORs and 95% CIs for dichotomous data and mean differences with 95% CIs for continuous data.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was short-term mortality. Secondary outcome measures included aneurysm-specific and general complication rates, quality of life and economic analysis.

RESULTS

Overall risk of bias was low. There was no difference between the 2 interventions on 30-day (or in-hospital) mortality, OR 0.91 (95% CI 0.67 to 1.22; p=0.52). 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation and respiratory failure. Reporting was incomplete, and no robust conclusion was drawn. For complication outcomes that did include at least 2 studies in the meta-analysis, there was no clear evidence to support a difference between eEVAR and open repair. Longer term outcomes and cost per patient were evaluated in only a single study, thus precluding definite conclusions.

CONCLUSIONS

Outcomes between eEVAR and open repair, specifically 30-day mortality, are similar. However, further high-quality trials are required, as the paucity of data currently limits the conclusions.

Association of Resting Heart Rate with Infrarenal Aortic Diameter: A Cross Sectional Study in Chinese Hypertensive Adults

OBJECTIVE

Elevated resting heart rate (RHR) has been shown to be a risk marker for cardiovascular disease. Results from studies on the effects of RHR in large arteries are limited to the functional changes of those arteries, while the association between RHR and aortic diameter remains largely understudied.

METHODS

This was a cross sectional study of hypertensive Chinese adults from rural areas. The maximum infrarenal aortic diameter (maxIAD) from renal arteries to the iliac bifurcation was obtained by ultrasound. MaxIADs in different RHR groups were compared in males and females separately because of the significant differences between sexes. Multiple regression analysis was used to determinate the correlation between RHR and maxIAD. Further interactions between three factors (BMI, smoking, and anti-hypertensive regimens) and RHR for maxIAD were examined using subgroup analysis.

RESULTS

19,200 subjects were enrolled in the study, with an average age of 64.8±7.4 years and 61.6% females. Only 22 cases (0.11%) were detected with AAA, with males (n = 17) presenting a higher AAA incidence than females (n = 5). In subjects ≥65 years, there were 18 (0.19%) AAA, and 15 (83.3%) had a history of smoking. In the total subjects, the mean maxIAD ranged from 15.7±2.1 mm to 15.2±2.2 mm as RHR changed from the lowest quartile to the highest (≥84 bpm) in males, with a similar tendency observed in females. The correlation coefficient of RHR on maxIAD was -0.17 in males and -0.12 in females. Further subgroup analysis revealed that smoking exaggerated the correlation between RHR and maxIAD, but only in females.

CONCLUSIONS

A low AAA incidence was observed in this hypertensive Chinese population. There was a negative association between RHR and maxIAD, potentially exaggerated by smoking, especially in females.

The prevalence of abdominal aortic aneurysm is consistently high among patients with coronary artery disease

OBJECTIVE

Emerging evidence suggests high prevalence of abdominal aortic aneurysm (AAA) among patients with coronary disease. Accurate characterization of the association between coronary disease and AAA and of the actual prevalence of AAA among patients with angiography-verified coronary artery disease (CAD) is needed to evaluate the possible benefits of systematic screening for AAA.

METHODS

We searched for studies that reported the association between AAA and CAD or coronary heart disease (CHD; wider phenotype definition) in the general population (randomized controlled trials, prospective population cohorts) and those that reported the prevalence of AAA among patients with angiography-verified CAD through PubMed, Embase, and reference lists for the period between 1980 and 2014. Random-effects models were applied because of the high heterogeneity between included studies.

RESULTS

Among the general population, 23 studies reported the association between CHD and the occurrence of subclinical AAA (positive ultrasound screening; meta-analyzed odds ratio of 2.38 with 95% confidence interval [CI] of 1.78-3.19; P = 4.1 × 10(-9)). According to four prospective studies, CHD is a strong predictor of future AAA events (fatal and nonfatal; meta-analyzed hazard ratio of 3.49 with 95% CI of 2.56-4.76; P = 2.4 × 10(-15)). Altogether, 10 studies reported the prevalence of AAA among patients with angiography-verified CAD or undergoing coronary artery bypass grafting. Among men, meta-analyzed prevalence was 9.5% (95% CI, 7.6%-11.7%). Among men undergoing coronary artery bypass grafting or with three-vessel disease, the prevalence was 11.4% (95% CI, 9.1%-13.9%). Among women, the prevalence was low (0.35%).

CONCLUSIONS

The risk of subclinical AAA and future AAA events is high among patients with coronary disease. Screening for AAA among CAD patients by cardiologists would be easy and inexpensive, with possible benefits to survival and risk evaluation.

Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers in Patients With Abdominal Aortic Aneurysms

Objective—

The renin–angiotensin system is thought to play a pivotal role in the pathogenesis of abdominal aortic aneurysms (AAAs). However, effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor blockers (ARBs) on human AAAs remain unclear. We therefore examined whether treatment with ACEIs or ARBs influenced hard clinical end points in a nation-wide cohort of patients with AAA.

Approach and Results—

All patients diagnosed with AAA during the period 1995 to 2011 were identified from the Danish nation-wide registries. Subjects were divided according to ACEI and ARB treatment status and followed up for an average of 5 years. Study outcomes were evaluated by time-dependent Cox proportional hazard models. Of 9441 patients with AAA, 12.6% were treated with ACEIs and 5.0% received ARBs. Incidence rates of death from AAA per 100 patient-years were 3.7, 3.6, 4.0, and 4.7 for treatment with ACEIs or ARBs, ACEIs, ARBs, and no ACEI/ARB, respectively. Hazard ratios of death from AAA were 0.64 (95% confidence interval, 0.51–0.80; P <0.001) for patients receiving ACEIs and 0.65 (95% confidence interval, 0.48–0.88; P =0.006) for those receiving ARBs, respectively ( P for difference=0.944). The risk of surgery for AAA was significantly reduced in patients receiving ACEIs (hazard ratio, 0.86 [95% confidence interval, 0.74–0.99]; P =0.040) but not in patients receiving ARBs (hazard ratio, 1.02 [95% confidence interval, 0.84–1.23]; P =0.867; P for difference=0.119).

Conclusions—

In this observational study, treatment with ACEIs or ARBs was associated with a comparable reduction in mortality but not in surgery for AAA among patients with AAA. Randomized controlled trials are warranted to confirm these findings.

Risk profiles for aortic dissection and ruptured or surgically treated aneurysms: a prospective cohort study

BACKGROUND

Community screening to guide preventive interventions for acute aortic disease has been recommended in high-risk individuals. We sought to prospectively assess risk factors in the general population for aortic dissection (AD) and severe aneurysmal disease in the thoracic and abdominal aorta.

METHODS AND RESULTS

We studied the incidence of AD and ruptured or surgically treated aneurysms in the abdominal (AAA) or thoracic aorta (TAA) in 30 412 individuals without diagnosis of aortic disease at baseline from a contemporary, prospective cohort of middle-aged individuals, the Malmö Diet and Cancer study. During up to 20 years of follow-up (median 16 years), the incidence rate per 100 000 patient-years at risk was 15 (95% CI 11.7 to 18.9) for AD, 27 (95% CI 22.5 to 32.1) for AAA, and 9 (95% CI 6.8 to 12.6) for TAA. The acute and in-hospital mortality was 39% for AD, 34% for ruptured AAA, and 41% for ruptured TAA. Hypertension was present in 86% of individuals who subsequently developed AD, was strongly associated with incident AD (hazard ratio [HR] 2.64, 95% CI 1.33 to 5.25), and conferred a population-attributable risk of 54%. Hypertension was also a risk factor for AAA with a smaller effect. Smoking (HR 5.07, 95% CI 3.52 to 7.29) and high apolipoprotein B/A1 ratio (HR 2.48, 95% CI 1.73 to 3.54) were strongly associated with AAA and conferred a population-attributable risk of 47% and 25%, respectively. Smoking was also a risk factor for AD and TAA with smaller effects.

CONCLUSIONS

This large prospective study identified distinct risk factor profiles for different aortic diseases in the general population. Hypertension accounted for more than half of the population risk for AD, and smoking for half of the population risk of AAA.

Endovascular treatment for ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) (pathological enlargement of the aorta) can develop in both men and women as they grow older. It is most commonly seen in men over the age of 65 years. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, a fatal event unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. A newer minimally invasive technique, endovascular aneurysm repair (EVAR), has been shown to reduce early morbidity and mortality as compared to conventional open surgery for planned AAA repair. Emergency endovascular aneurysm repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in selected patients. However, it is not yet known if eEVAR will lead to significant improvements in outcomes for these patients or indeed if it can replace conventional open repair as the preferred treatment for this lethal condition.

OBJECTIVES

To assess the advantages and disadvantages of emergency endovascular aneurysm repair (eEVAR) in comparison with conventional open surgical repair for the treatment of ruptured abdominal aortic aneurysm (RAAA). This will be determined by the effect on short-term mortality, major complication rates, aneurysm exclusion, and late complications when compared with the effects in patients who have had conventional open repair of RAAA.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched February 2014) and CENTRAL (2014, Issue 2). Reference lists of relevant publications were also checked.

SELECTION CRITERIA

Randomised controlled trials in which patients with a clinically or radiologically diagnosed RAAA were randomly allocated to eEVAR or conventional open surgical repair.

DATA COLLECTION AND ANALYSIS

Studies identified for potential inclusion were independently assessed for eligibility by at least two review authors. Data extraction and quality assessment were also completed independently by two review authors. Disagreements were resolved through discussion. Meta-analysis was performed using fixed-effect models with odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous data and mean differences with 95% CIs for continuous data.

MAIN RESULTS

Three randomised controlled trials were included in this review. A total of 761 patients with a clinical or radiological diagnosis of RAAA were randomised to receive either eEVAR or open surgical repair. Overall risk of bias was low but one study did not adequately report random sequence generation, putting it at risk of selection bias, two studies did not report on outcomes identified in their protocol, indicating reporting bias, and one study was underpowered. There was no clear evidence to support a difference between the two interventions on 30-day (or in-hospital) mortality, OR of 0.91 (95% CI 0.67 to 1.22; P = 0.52). The 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, re-operation, amputation, and respiratory failure. Individual complication outcomes were reported in only one or two studies and therefore no robust conclusion can currently be drawn. For complication outcomes that did include at least two studies in the meta-analysis there was no clear evidence to support a difference between eEVAR and open repair. Six-month outcomes were evaluated in only a single study, which included mortality and re-operation, with no clear evidence of a difference between the interventions and no overall association. Cost per patient was only evaluated in a single study and therefore no overall associations can currently be derived.

AUTHORS' CONCLUSIONS

The conclusions of this review are currently limited by the paucity of data. From the data available there is no difference in the outcomes evaluated in this review between eEVAR and open repair, specifically 30-day mortality. Not enough information was provided for complications in order to make a well informed conclusion at this time. Long-term data are lacking for both survival and late complications. More high quality, randomised controlled trials comparing eEVAR and open repair for the treatment of RAAA are needed in order to better understand if one method is superior to the other, or if there is no difference between the methods on relevant outcomes.

Abdominal aortic aneurysm screening program in Poland

BACKGROUND

Screening for abdominal aortic aneurysms (AAA) is currently recommended by several vascular societies. In countries where it has been introduced the prevalence of AAAs differed greatly and was mainly related to cigarette smoking. The screening program also had an enormous impact on the decrease of AAA ruptures and reduced mortality rate. These facts have led to the introduction of the first screening program for AAAs in Poland.

OBJECTIVE

The aim of the study was to determine the prevalence of AAAs among men aged 60 years and older undergoing ultrasound examination of the abdominal aorta.

MATERIAL AND METHODS

A single ultrasonography of the abdomen was performed to assess the aorta from the renal arteries to the bifurcation and the diameter of the aorta was measured at its widest point. The cut-off value for determining an aortic aneurysm was set at a diameter of ≥ 30 mm. All ultrasonography measurements were performed by physicians in outpatient departments throughout the Kuyavian-Pomeranian Province. Additionally, each subject had to fill out a questionnaire with demographic data, smoking habits, existing comorbidities and familial occurrence of AAAs. The study was conducted from October 2009 to November 2011.

RESULTS

The abdominal aorta ultrasound examinations were carried out in 1556 men aged 60 years and older. The prevalence of AAA in the study population was 6.0 % (94 out of 1556). The average age of the men was 69 years (SD 6 years, range 60-92 years). In the study population 55 % of the men smoked or had smoked and 3 % were aware of the presence of AAAs in family members. There were three risk factors significantly associated with the presence of AAAs: age (p < 0.05), smoking (72.3 % vs 53.9 %, p = 0.004) and family history of AAAs (9.6 % vs 2.7 %, p = 0.017).

CONCLUSION

The prevalence of AAAs among men in Poland is higher than in other European countries and the USA. The screening program for AAAs is an easy and reliable method for detecting early stages of the disease and risk factors which are the driving forces for the development of AAAs.

Prevalence and trends of the abdominal aortic aneurysms epidemic in general population--a meta-analysis

OBJECTIVE

To conduct a meta-analysis assessing the prevalence and trends of the abdominal aortic aneurysms (AAA) epidemic in general population.

METHOD

Studies that reported prevalence rates of AAA from the general population were identified through MEDLINE, EMBASE, Web of Science, and reference lists for the period between 1988 and 2013. Studies were included if they reported prevalence rates of AAA in general population from the community. In stratified analyses possible sources of bias, including areas difference, age, gender and diameter of aneurysms were examined. Publication bias was assessed with Egger's test method.

RESULTS

56 studies were identified. The overall pooled prevalence of AAA was 4.8% (4.3%, 5.3%). Stratified analyses showed the following results, areas difference: America 2.2% (2.2%, 2.2%), Europe 2.5% (2.4%, 2.5%), Australia 6.7% (6.5%, 7.0%), Asia 0.5% (0.3%, 0.7%); gender difference: male 6.0% (5.3%, 6.7%), female 1.6% (1.2%, 1.9%); age difference: 55-64years 1.3% (1.2%, 1.5%), 65-74 years 2.8% (2.7%, 2.9%), 75-84 years1.2%(1.1%, 1.3%), ≥85years0.6% (0.4%, 0.7%); aortic diameters difference: 30-39 mm, 3.3% (2.8%, 3.9%), 40-49 mm,0.7% (0.4%,1.0%), ≥50 mm, 0.4% (0.3%, 0.5%). The prevalence of AAA has decreased in Europe from 1988 to 2013. Hypertension, smoking, coronary artery disease, dyslipidemia, respiratory disease, cerebrovascular disease, claudication and renal insufficiency were risk factors for AAA in Europe.

CONCLUSION

AAA is common in general population. The prevalence of AAA is higher in Australia than America and Europe. The pooled prevalence in western countries is higher than the Asia. Future research requires a larger database on the epidemiology of AAA in general population.

Growth of screen-detected abdominal aortic aneurysms in men: a bayesian analysis

There is considerable interindividual variability in the growth of abdominal aortic aneurysms (AAAs), but an individual's growth observations, risk factors, and biomarkers could potentially be used to tailor surveillance. To assess the potential for tailoring surveillance, this study determined the accuracy of individualized predictions of AAA size at the next surveillance observation. A hierarchical Bayesian model was fitted to a total of 1,732 serial ultrasound measurements from 299 men in whom ultrasound screening identified an AAA. The data were best described by a nonlinear model with a constant first derivative of the AAA growth rate with size. The area under the receiver operating characteristic (ROC) curves for predicting whether an AAA was ≥40 or ≥50 mm at the next observation were 0.922 and 0.979, respectively, and the median root mean squared error was 2.52 mm. These values were nearly identical for models with or without plasma D-dimer effects.CPT: Pharmacometrics & Systems Pharmacology (2012) 1, e12; doi:10.1038/psp.2012.13; advance online publication 24 October 2012.

Management of the tense abdomen or difficult abdominal closure after operation for ruptured abdominal aortic aneurysms

Increased intra-abdominal pressure (IAP) and abdominal compartment syndrome (ACS) are important clinical problems after repair of ruptured abdominal aortic aneurysms and are reviewed here. IAP >20 mm Hg occurs in approximately 50% of patients treated with open abdominal aortic aneurysm repair after rupture, and approximately 20% develop organ failure or dysfunction, fulfilling the criteria for ACS. Patients selected for endovascular aneurysm repair are often more hemodynamically stable, perhaps related to not handling the viscera or more favorable anatomy, resulting in less bleeding and, consequently, decreased risk of developing ACS. Centers that treat most patients with endovascular aneurysm repair tend to have the same proportion of ACS as after open repair. There are no randomized data on these aspects. Early nonsurgical therapy can prevent development of ACS. Medical therapy includes neuromuscular blockade and the combination of positive end-expiratory pressure, albumin, and furosemide. This proactive strategy can reduce the number of decompressive laparotomies, an important detail because treatment of ACS with open abdomen is a morbid procedure. When treatment with an open abdomen is necessary, it is important to choose a temporary abdominal closure that maintains sterile conditions during often prolonged treatment. In addition, it should prevent lateralization of the bowel wall and adhesions between the intestines and the bowel wall. Enteroatmospheric fistulae must be prevented. Many alternative methods have been suggested, but we prefer the combination of vacuum-assisted wound closure with mesh-mediated traction, which will be described.

Downregulation of transforming growth factor, beta receptor 2 and Notch signaling pathway in human abdominal aortic aneurysm

OBJECTIVE

Mutations in FBN1 and TGFBR2 genes are the main causative mutations identified in Marfan syndrome (MFS). The major vascular complication of MFS is aneurysm formation. Abdominal aortic aneurysm (AAA) is an acquired disease of later life of unknown etiology. The aim of this study was to examine if genetic aberrations in MFS-related genes FBN1 and TGFBR2 are present in patients with AAA.

METHODS

We assessed the presence of copy number variation (CNV) in FBN1 and TGFBR2 genes in AAA biopsies from twelve patients. We also analyzed the expression of these genes in AAA biopsies compared to control biopsies from six organ donors. In addition we assessed the expression of two members of the Notch signaling pathway NOTCH3 and HEY2 as well as aortic smooth muscle cell (AoSMC) differentiation marker TAGLN in AAA and control biopsies.

RESULTS

Loss of one copy (deletion) of the FBN1 exon 66 sequence and TGFBR2 exon 8 was identified in 7 (58%) and 11 (92%) of the 12 AAA biopsies. No copy number amplifications (duplications) were detected. Patients carrying TGFBR2 exon 8 deletion showed marked downregulation of this gene in AAA biopsies compared to control biopsies (0.699 vs. 1.765, p = 0.038). Notch signaling components NOTCH3 and HEY2 were markedly downregulated in AAA, while expression of the AoSMC differentiation marker TAGLN did not differ between AAA and control biopsies (0.468 vs. 0.486, p = 0.546).

CONCLUSION

This study suggests an acquired impairment in TGF-β signaling that along with downregulation of the Notch signaling pathway may contribute to the pathogenesis of AAA.