Aneurysm Screening Research Articles

Unruptured intracranial aneurysms: screening and management.

Unruptured intracranial aneurysms are found commonly in the general public, and more frequently in certain populations. This article focuses on the epidemiology, screening strategies, and management options for patients with unruptured aneurysms. Recent epidemiologic studies show the overall prevalence of intracranial aneurysms to be approximately 3%, with higher rates seen in familial aneurysm syndromes and in certain medical conditions, such as autosomal dominant polycystic kidney syndrome. Aneurysm treatment may include surgical or endovascular techniques, with increasing utilization of endovascular strategies over time. Increased aneurysm diameter, certain locations, and other anatomical considerations may be associated with higher risks of aneurysm rupture. Given the high morbidity and mortality associated with aneurysm rupture, screening for unruptured aneurysms is generally recommended for high-risk patients (patients who have at least two first-degree relatives with aneurysms, and patients with autosomal dominant polycystic kidney disease). Screening may be considered for other patients (eg, one first-degree relative with aneurysm) after discussion of the risks and benefits of imaging. Following identification of an aneurysm, decisions regarding observation or treatment should be based on patient characteristics, features of the aneurysm, and provider expertise.

Statins: The Holy Grail of Abdominal Aortic Aneurysm (AAA) Growth Attenuation? A Systematic Review of the Literature

In the era of Abdominal Aortic Aneurysm (AAA) screening, pharmacotherapies to attenuate AAA growth are sought. HMG Co-A reductase inhibitors (statins) have pleiotropic actions independent of their lipid lowering effects and have been suggested as potential treatment for small AAAs. We systematically review the clinical evidence for this effect. Medline, EMBASE and the Cochrane Central Register of Controlled Trials (1950-2011) were searched for studies reporting data on the role of statin therapy on AAA growth rate. No language restrictions were placed on the search. References of retrieved articles and pertinent journals were hand searched. Included studies were reviewed by 2 independent observers. The search retrieved 164 papers, 100 were irrelevant based on their title, 47 were reviews and 1 was a letter. 8 studies were excluded based on review of their abstract leaving 8 for inclusion in the study. Eight observational clinical studies with a total of 4,466 patients were reviewed. Four studies demonstrated reduced AAA expansion in statin users while 4 studies failed to demonstrate this effect. The method of determining AAA growth rates varied significantly between the studies and the ability of many studies to control for misclassification bias was poor. The claim that statins attenuate AAA growth remains questionable. Further prospective studies with stringent identification and verification of statin usage and a standardised method of estimating AAA growth rates are required. Statin type and dose also merit consideration.

Screening for Abdominal Aortic Aneurysm in 65-Year-old Men Remains Cost-effective with Contemporary Epidemiology and Management

The epidemiology and management of abdominal aortic aneurysms (AAA) has changed significantly, with lower prevalence, increased longevity of patients, increased use of endovascular aneurysm repair (EVAR), and improved outcome. The clinical and health economic effectiveness of one-time screening of 65-year-old men was assessed within this context. One-time ultrasound screening of 65-year-old men (invited) versus no screening (control) was analysed in a Markov model. Data on the natural course of AAA (risk of repair and rupture) was based on randomised controlled trials. Screening detected AAA prevalence (1.7%), surgical management (50% EVAR), repair outcome, costs, and long-term survival were based on contemporary population-based data. Incremental cost-efficiency ratios (ICER), absolute and relative risk reduction for death from AAA (ARR, RRR), numbers needed to screen (NNS), and life-years gained were calculated. Annual discounting was 3.5%. In base case at 13-years follow-up the ICER was €14,706 per incremental quality-adjusted life-year (QALY); ARR was 15.1 per 10,000 invited, NNS was 530, and QALYs gained were 56.5 per 10,000 invited. RRR was 42% (from 0.36% in control to 0.21% in invited). In a lifetime analysis the ICER of screening decreased to €7,570/QALY. The parameters with highest impact on the cost-efficiency of screening in the sensitivity analysis were the prevalence of AAA (threshold value <0.5%) and degree of incidental detection in the control cohort. In the face of recent changes in the management and epidemiology of AAA, screening men for AAA remains cost-effective and delivers significant clinical impact.

Carotid Artery Atherosclerosis Among 65-year-old Swedish Men – A Population-based Screening Study

There are limited contemporary epidemiological data on the prevalence of carotid atherosclerosis in the general population. The aim was to determine the prevalence of and risk factors associated with carotid artery atherosclerosis among 65-year-old men. This was a population-based screening study. All 65-year-old men in the County of Uppsala, Sweden, who attended screening for abdominal aortic aneurysm (AAA) 2007-2009, were invited for duplex scanning of the carotid arteries. Of 4801 men invited, 4657 (97%) accepted. Carotid plaques (>2 × 6 mm) were observed in 1169 (25%) men, 94 (2.0%) had carotid stenoses (50-99%), and 15 (0.3%) had occluded carotid arteries. In a multivariate logistic regression model, smoking (OR 1.7, 95% CI 1.5-1.9), hypertension (1.5, 95% CI 1.3-1.7), diabetes mellitus (1.2, 95% CI 1.0-1.5), and coronary artery disease (1.5, 95% CI 1.3-1.8) were associated with prevalence of carotid atherosclerosis (plaque and/or stenosis). The use of antiplatelet agents and statins in participants with a carotid plaque was 20% and 29%, respectively. The corresponding figures in participants with a stenosis were 42% and 41%. This study offers contemporary data on the prevalence of carotid atherosclerosis in a population-based cohort of 65-year-old men. Most of those at risk had no other clinical manifestation of atherosclerosis, and therefore had no secondary prevention.

Long-term, serial screening for intracranial aneurysms in individuals with a family history of aneurysmal subarachnoid haemorrhage: a cohort study

Individuals with two or more first-degree relatives who have had aneurysmal subarachnoid haemorrhage (aSAH) have an increased risk of aneurysms and aSAH. We investigated the yield of long-term serial screening for intracranial aneurysms in these individuals. In a cohort study, we reviewed the results of screening of individuals with a positive family history of aSAH (two or more first-degree relatives who had had aSAH or unruptured intracranial aneurysms) done at the University Medical Centre Utrecht (Utrecht, Netherlands) between April 1, 1993, and April 1, 2013. Magnetic resonance angiography or CT angiography was done from age 16-18 years to 65-70 years. After a negative screen, we advised individuals to contact us after 5 years, but did not actively call them for repeated screening. We recorded familial history of ruptured and unruptured intracranial aneurysms, smoking history, hypertension, previous aneurysms, screening dates, and screening results. We identified risk factors for positive initial and follow-up screens with univariable and multivariable regression analysis. We identified aneurysms in 51 (11%, 95% CI 9-14) of 458 individuals at first screening, in 21 (8%, 5-12) of 261 at second screening, in seven (5%, 2-11) of 128 at third screening, and three (5%, 1-14) of 63 at fourth screening. Five (3%, 95% CI 1-6) of 188 individuals without a history of aneurysms and with two negative screens had a de-novo aneurysm in a follow-up screen. Smoking (odds ratio 2·7, 95% CI 1·2-5·9), history of previous aneurysms (3·9, 1·2-12·7), and familial history of aneurysms (3·5, 1·6-8·1) were significant risk factors for aneurysms at first screening in the multivariable analysis. History of previous aneurysms was the only significant risk factor for aneurysms at follow-up screening (hazard ratio 4·5, 1·1-18·7). Aneurysms were identified in six (5%, 95% CI 2-10) of 129 individuals who were screened before age 30 years. One patient developed a de-novo aneurysm that ruptured 3 years after the last negative screen. In individuals with a family history of aSAH, the yield of long-term screening is substantial even after more than 10 years of follow-up and two initial negative screens. We advocate long-term serial screening in these individuals, although the risk of aSAH within screening intervals is not eliminated. The Dutch Heart Foundation.

Ultrasonography screening for abdominal aortic aneurysms: a systematic evidence review for the U.S. Preventive Services Task Force.

Long-term follow-up of population-based randomized, controlled trials (RCTs) has demonstrated that screening for abdominal aortic aneurysms (AAAs) measuring 3 cm or greater decreases AAA-related mortality rates in men aged 65 years or older. To systematically review evidence about the benefits and harms of ultrasonography screening for AAAs in asymptomatic primary care patients. MEDLINE, the Database of Abstracts of Reviews of Effects, the Cochrane Central Register of Controlled Trials (January 2004 through January 2013), clinical trial registries, reference lists, experts, and a targeted bridge search for population-based screening RCTs through September 2013. English-language, population-based, fair- to good-quality RCTs and large cohort studies for AAA screening benefits as well as RCTs and cohort and registry studies for harms in adults with AAA. Dual quality assessment and abstraction of study details and results. Reviews of 4 RCTs involving 137,214 participants demonstrated that 1-time invitation for AAA screening in men aged 65 years or older reduced AAA rupture and AAA-related mortality rates for up to 10 and 15 years, respectively, but had no statistically significant effect on all-cause mortality rates up to 15 years. Screening was associated with more overall and elective surgeries but fewer emergency operations and lower 30-day operative mortality rates at up to 10- to 15-year follow-up. One RCT involving 9342 women showed that screening had no benefit on AAA-related or all-cause mortality rates. Trials included mostly white men outside of the United States. Information for subgroups and about rescreening was limited. One-time invitation for AAA screening in men aged 65 years or older was associated with decreased AAA rupture and AAA-related mortality rates but had little or no effect on all-cause mortality rates. Agency for Healthcare Research and Quality.

Reasons for non-participation in population-based abdominal aortic aneurysm screening

A population-based screening programme for abdominal aortic aneurysm (AAA) started in 2010 in Stockholm County, Sweden. This present study used individual data from Sweden's extensive healthcare registries to identify the reasons for non-participation in the AAA screening programme. All 65-year-old men in Stockholm are invited to screening for AAA; this study included all men invited from July 2010 to July 2012. Participants and non-participants were compared for socioeconomic factors, travel distance to the examination centre and healthcare use. The influence of these factors on participation was analysed using univariable and multivariable logistic regression models. The participation rate for AAA screening was 77·6 per cent (18 876 of 24 319 men invited). The prevalence of AAA (aortic diameter more than 2·9 cm) among participants was 1·4 per cent. The most important reasons for non-participation in the multivariable regression analyses were: recent immigration (within 5 years) (odds ratio (OR) 3·25, 95 per cent confidence interval 1·94 to 5·47), low income (OR 2·76, 2·46 to 3·10), marital status single or divorced (OR 2·23, 2·08 to 2·39), low level of education (OR 1·28, 1·16 to 1·40) and long travel distance (OR 1·23, 1·10 to 1·37). Non-participants had a higher incidence of stroke (4·5 versus 2·8 per cent; P < 0·001) and chronic pulmonary disease (2·9 versus 1·3 per cent; P < 0·001). Daily smoking was more common in residential areas where the participation rate for AAA screening was low. Efforts to improve participation in AAA screening should target the groups with low income, a low level of education and immigrants. The higher morbidity in the non-participant group, together with a higher rate of smoking, make it probable that this group also has a high risk of AAA.

Leveraging the electronic medical record to implement an abdominal aortic aneurysm screening program

Screening for abdominal aortic aneurysms (AAAs) reduces aneurysm-related mortality and has been recommended by the U.S. Preventive Services Task Force and American Heart Association since 2005. Medicare has covered a one-time screening ultrasound for new male enrollees with a familial or smoking history since 2007. Nevertheless, in the U.S., screening has remained underutilized. Review of patients with ruptured AAA in our system in 2007 showed the majority were undiagnosed, yet met U.S. Preventive Services Task Force and American Heart Association screening guidelines. To reduce the number of preventable AAA ruptures and deaths in our patients, we implemented an AAA screening program using our electronic medical record (EMR). This study describes the design, implementation, and early results of that screening program. Between March 2012 and June 2013, men aged 65 to 75 years with any history of smoking were targeted for screening. Medical records were reviewed electronically to exclude patients with abdominal imaging studies within 10 years that would have diagnosed an AAA. Best practice alerts (BPA) were created in the EMR so when an appropriate patient is seen, office staff and providers are prompted to order an aortic ultrasound. AAA was defined as aortic diameter ≥3.0 cm or greater, and ultrasound reports contained a standard template providing guidance for patient management when an aneurysm was identified. Newly identified AAAs were triaged for vascular surgery consultation or follow-up with their primary physician. The number of eligible patients, unscreened patients, and AAAs identified were tabulated by our Regional Outpatient Safety Net Program. In a population of 3.6 million, 55,610 patients initially met screening criteria, and 26,837 (48.26%) were excluded from the BPA because of prior abdominal imaging studies. After 15 months, there were 68,164 patients who met screening criteria, 54,356 (79.74%) of whom had undergone an abdominal imaging study. Thus, 27,519 patients underwent an imaging study after the BPA was activated. During the study period, 731 new AAAs were diagnosed, 165 over 4.0 cm in diameter. Screening rates have increased at all medical centers where the BPA was activated, and the percentage of unscreened patients has been reduced from 51.74% to 20.26% system-wide. In an integrated health care system using an EMR, AAA screening can be implemented with a dramatic reduction in unscreened patients. Further analysis is required to assess the impact of the screening program on AAA rupture rate and cost-effectiveness in our system.

Abstract W MP33: Brain and Aortic Aneurysm Screening - Cost-Effectiveness of Screening for Intracranial Aneurysms

Introduction: Intracranial aneurysm (IA) and abdominal aortic aneurysm (AAA) rupture carry high mortality (40% and 75% respectively) and substantial morbidity in survivors. Recent research suggests that IA and AAA share genetic risk in addition to environmental factors. Retrospective data from our institution identified a population harboring both IA and AAA and showed a high rupture rate for IA (44.2%). We previously demonstrated that screening for AAA in patients with IA is cost-effective based on estimated and published data. We hypothesize that screening for IA in patients with AAA is also cost-effective. Method: We developed a decision-making model using TreeAge Pro 2013 software assuming a hypothetical population with known AAA and truncated screening versus no screening for IA using magnetic resonance angiography. Based on IA size and location, patients were either treated endovascularly or placed on surveillance. Proportions, risks, utilities, and costs for each decision arm were derived from literature. Results: At a given rupture rate, incremental effectiveness varied linearly with coprevalence of AAA and IA. For an assumed rupture rate of 5%/year, screening was effective for coprevalence &gt;6.8% (top graph) and was cost-effective for coprevalence &gt;7.7%. The incremental cost-effectiveness ratio (ICER) favored screening (ICER=$54,193/QALY) at a 7.8% coprevalence and dropped to $27,841.50/QALY at 8.8% coprevalence. Our model was sensitive to IA rupture rate as well as coprevalence (bottom graph). Conclusion: Our model suggests the cost-effectiveness of screening for IA in patients with AAA, below the accepted societal threshold of an ICER $60,000/QALY at a coprevalence ≥7.8% and IA rupture rate ≥5%. These are plausible assumptions for this genetically high-risk population. Further prospective study is warranted to establish coprevalence of AAA and IA, rupture rates, and determine the benefit of dedicated screening.

Screening for Abdominal Aortic Aneurysm in 65-Year-old Men Remains Cost-effective with Contemporary Epidemiology and Management

The epidemiology and management of abdominal aortic aneurysms (AAA) has changed significantly, with lower prevalence, increased longevity of patients, increased use of endovascular aneurysm repair (EVAR), and improved outcome. The clinical and health economic effectiveness of one-time screening of 65-year-old men was assessed within this context. One-time ultrasound screening of 65-year-old men (invited) versus no screening (control) was analysed in a Markov model. Data on the natural course of AAA (risk of repair and rupture) was based on randomised controlled trials. Screening detected AAA prevalence (1.7%), surgical management (50% EVAR), repair outcome, costs, and long-term survival were based on contemporary population-based data. Incremental cost-efficiency ratios (ICER), absolute and relative risk reduction for death from AAA (ARR, RRR), numbers needed to screen (NNS), and life-years gained were calculated. Annual discounting was 3.5%. In base case at 13-years follow-up the ICER was €14,706 per incremental quality-adjusted life-year (QALY); ARR was 15.1 per 10,000 invited, NNS was 530, and QALYs gained were 56.5 per 10,000 invited. RRR was 42% (from 0.36% in control to 0.21% in invited). In a lifetime analysis the ICER of screening decreased to €7,570/QALY. The parameters with highest impact on the cost-efficiency of screening in the sensitivity analysis were the prevalence of AAA (threshold value <0.5%) and degree of incidental detection in the control cohort. In the face of recent changes in the management and epidemiology of AAA, screening men for AAA remains cost-effective and delivers significant clinical impact.

Ultrasound Measurement for Abdominal Aortic Aneurysm Screening: A Direct Comparison of the Three Leading Methods

Ultrasound (US) is non-invasive and cost-effective for screening abdominal aortic aneurysms (AAAs) but there is no universally accepted method to measure the aortic diameter. This study evaluates the accuracy, reproducibility, and repeatability of three methods: inner-to-inner (ITI), leading-to-leading edge (LTL), and outer-to-outer (OTO). The secondary objective of this study was to determine whether aneurysm size or grade of operator had any effect on either intra- or inter-observer variability. Fifty static US images were measured by six assessors (2 vascular radiologists, 2 interventional radiology trainees, and 2 sonographers) on two separate occasions 6 weeks apart. Repeatability and reproducibility were calculated and compared with computed tomography (CT) as the gold standard. All three methods have high repeatability and reproducibility when static images are used. The inter-observer reproducibility coefficients between assessors were 0.48cm, 0.35cm, and 0.34cm for ITI, LTL and OTO, respectively. The intra-observer repeatability coefficients between assessors were 0.30cm, 0.20cm, and 0.19cm for ITI, LTL and OTO, respectively. The mean difference between CT and OTO, LTL, and ITI was 1mm, 3mm, and 5mm, respectively (all underestimations) (p<.0001). US consistently underestimates aortic size when compared with CT, with ITI demonstrating the greatest underestimation (on average 5mm). In the UK, this underestimation by the NHS Abdominal Aortic Aneurysm screening programme reduces the sensitivity of the screening test and may impact on the way in which vascular specialists interpret the findings of the screening programme.

Intact Cost-effectiveness of Screening for Abdominal Aortic Aneurysms in Sweden

Intact Cost-effectiveness of Screening for Abdominal Aortic Aneurysms in Sweden

Experiences of Screening for Abdominal Aortic Aneurysm—In and Out on Five Minutes

Background: The purpose of AAA screening is to prevent rupture and mortality. Screening for life-threatening diseases is a double-edged sword. The aim of this study is to describe 65-year-old men’s experiences of health related quality of life and anxiety after screening for Abdominal Aortic Aneurysm, and experiences of information and reasons for not participating. Methods: 368 men answered Short Form 36 (SF-36), and anxiety and depression scale (HAD). 72 telephone interviews were conducted with the participants and 77 with those who declined to take part in the screening programme. Results: The SF-36 domains of Physical Function and Role limitations due to emotional health problems were significantly better for men who had undergone screening compared to a matched population. Compared to non-smokers, smokers had lower values in the SF-36 domains of general health perceptions, social functioning, role limitations due to emotional health problems and mental health. 80% of patients did not experience any form of anxiety/panic in connection with the screening invitation. Of the men who did not participate, 56% stated that they would like to be screened or had already undergone the examination. Conclusion: The men who underwent the investigation were healthier in some of the SF-36 domains than the general population. The participants did not experience any great anxiety before the screening and despite the short duration of the examination.

State-of-the-art aortic imaging: Part II - applications in transcatheter aortic valve replacement and endovascular aortic aneurysm repair

Transcatheter aortic valve replacement (TAVR) as well as thoracic and abdominal endovascular aortic repair (TEVAR and EVAR) rely on accurate pre- and postprocedural imaging. This review article discusses the application of imaging, including preprocedural assessment and measurements as well as postprocedural imaging of complications. Furthermore, the exciting perspective of computational fluid dynamics (CFD) based on cross-sectional imaging is presented. TAVR is a minimally invasive alternative for treatment of aortic valve stenosis in patients with high age and multiple comorbidities who cannot undergo traditional open surgical repair. Given the lack of direct visualization during the procedure, pre- and peri-procedural imaging forms an essential part of the intervention. Computed tomography angiography (CTA) is the imaging modality of choice for preprocedural planning. Routine postprocedural follow-up is performed by echocardiography to confirm treatment success and detect complications. EVAR and TEVAR are minimally invasive alternatives to open surgical repair of aortic pathologies. CTA constitutes the preferred imaging modality for both preoperative planning and postoperative follow-up including detection of endoleaks. Magnetic resonance imaging is an excellent alternative to CT for postoperative follow-up, and is especially beneficial for younger patients given the lack of radiation. Ultrasound is applied in screening and postoperative follow-up of abdominal aortic aneurysms, but cross-sectional imaging is required once abnormalities are detected. Contrast-enhanced ultrasound may be as sensitive as CTA in detecting endoleaks.

Secondary aortoduodenal fistula following endovascular repair of inflammatory abdominal aortic aneurysm due to Streptococcus anginosus infection: A case report and literature review

INTRODUCTIONAortoenteric fistula is a rare but very serious complication of both surgical and endovascular abdominal aortic reconstruction. Since the advent of endovascular abdominal aortic aneurysm repair (EVAR), 20 cases of aortoduodenal fistula associated with aortic stent grafts have been reported.1 However, only a handful has been reported following inflammatory abdominal aortic aneurysm repair. It most commonly presents with bleeding, usually from the upper gastro-intestinal tract. With recent advances in the screening, diagnosis and management of abdominal aortic aneurysms either surgically or through an endovascular approach, the diagnosis of an aortoduodenal fistula in patients with gastro-intestinal bleeding must be suspected and excluded. PRESENTATION OF CASEWe describe a case of secondary aortoduodenal fistula that occurred two and a half years following endovascular stent graft repair of an inflammatory abdominal aortic aneurysm. We also outline the emergency correction plan and the attempts at repair. DISCUSSIONThis case defies the general concept that patients with inflammatory abdominal aortic aneurysms are relatively immune to rupture. Although the presence of a peri-aneurysm thick inflammatory membrane decreases the possibility of rupture, these patients are more susceptible to other related complications such as aorto-enteric and aorto-caval fistulas.2 This case also demonstrates the peculiar presence of Streptococcus anginosus as the pathological organism leading to graft infection and subsequent fistula, as opposed to enterococci which are often found in endograft infection. CONCLUSIONAorto-enteric fistulas are associated with a grave prognosis. Early diagnosis is crucial and extra vigilance should be taken in cases of inflammatory AAA.

Trends in the management and outcomes of kidney transplantation for autosomal dominant polycystic kidney disease.

Background. Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disorder leading to end-stage renal failure. The objective of this study was to evaluate a longitudinal experience of kidney transplantation for ADPKD. Methods. A single center retrospective review of patients undergoing kidney transplantation was conducted, with comparisons across two time periods: early (02/2000–04/2007, n = 66) and late (04/2007–08/2012, n = 67). Results. Over the 13.5-year study period, 133 patients underwent transplantation for ADPKD. Overall, no significant difference between the early and late group with regard to intraoperative complications, need for reoperation, readmissions within 30 days, delayed graft function, and mortality was noted. There was a trend towards increase in one-year graft survival (early 93.1% versus late 100%, P = 0.05). In the early group, 67% of recipients had undergone aneurysm screening, compared to 91% of recipients in the late group (P < 0.001). Conclusions. This study demonstrates consistent clinical care with a trend towards improved rates of one-year graft survival. Interestingly, we also note a significantly higher use of cerebral imaging over time, with the majority that were detected requiring surgical intervention which may justify the current practice of nonselective radiological screening until improved screening criteria are developed.

Aortic aneurysm screening in a high-risk population: a non-contrast computed tomography study in korean males with hypertension.

Background and ObjectivesScreening strategies for aortic aneurysm (AA) according to risk factors and ethnicity are controversial. This study explored the prevalence of AA and determined whether screening is necessary in a population of multiple risk factors.Subjects and MethodsFrom June, 2012 to April, 2013, 542 consecutive elderly (≥65 years) male hypertensive patients without a history of AA were prospectively enrolled. After excluding 15 patients (2.8%) with aortic valve surgery, 30 patients (5.5%) with suboptimal computed tomography (CT) images, the remaining 496 patients (age 73±5 years) comprised the study population. Maximal diameters of the thoracic and abdominal aorta were measured using non-contrast CT.ResultsThe prevalence of thoracic AA (TAA, diameter ≥40 mm) and abdominal AA (AAA, diameter ≥30 mm) was 36.5% (181/496) and 6.0% (30/496), respectively. In the multivariate logistic regression analysis, determinants for TAA were age {odds ratio (OR) 1.059, 95% confidence interval (CI) 1.018-1.101, p=0.005}, dyslipidemia (OR 0.621, 95% CI 0.418-0.923, p=0.018), body surface area (OR 11.92, 95% CI 2.787-50.97, p=0.001), diastolic blood pressure (OR 1.029, 95% CI 1.009-1.049, p=0.004) and AAA (OR 3.070, 95% CI 1.398-6.754, p=0.005). In contrast, AAA was independently associated with dysplipidemia (OR 2.792, 95% CI 1.091-7.143, p=0.032), current/past smokerfs (OR 4.074, 95% CI 1.160-14.31, p=0.028), and TAA (OR 3.367, 95% CI 1.550-7.313, p=0.002).ConclusionThe prevalence of AA was significant and TAA was more prevalent than AAA in elderly Korean males with hypertension. Future research should establish distinct screening strategies for TAA and AAA according to risk factors and ethnicity.

Reliability of aortic aneurysm screening measurements.

The aim of this feasibility study was to assess the impact that image processing of abdominal aortic ultrasound (US) images had on the intra-observer reliability of the diameter measurement. The study compared variability between inner-to-inner (ITI), outer-to-outer (OTO) and outer-to-inner (OTI) wall diameter measurements and their resilience to image processing. Three US images of transverse abdominal aortas were manipulated in 13 different ways using functions from Image J software (National Institutes of Health, Bethesda, MD, USA). Blinded measurements were performed of the aortic diameters from each image; this was repeated for ITI, OTO and OTI. Profiles of each image were produced and sets of rules developed to provide detailed instructions as to where, on the profile, the callipers should be placed to correspond with the actual image. The reliability of the diameter measurements compared to the original diameter measurement was least affected by adjusting the brightness and contrast of the US images (better than ± 1.5 mm). Using the functions 'Sharpen' and 'Find Edges' created the largest difference (up to -5 mm). The ITI measurements had the widest spread of variability, whereas the OTI measurements proved to be the most repeatable and resilient to image processing. This study suggests the precision of the measurements can be kept within satisfactory levels even after image manipulation. It also showed the most reliable measuring guideline was OTI, in contrast to the guideline currently used by the NHS Abdominal Aortic Aneurysm Screening Programme. Further research is needed to transfer the findings into the clinical setting of the National Screening Programme to increase its reliability.

Reliability of the measurement of the abdominal aortic diameter by novice operators using a pocket-sized ultrasound system

Despite favorable results of randomized studies and several guidelines, screening for abdominal aortic aneurysm is poorly implemented in most countries. In order to implement an effective abdominal aortic aneurysm screening programme, training of physicians other than cardiovascular imaging specialists is necessary. Also, the use of pocket-sized ultrasound systems seems an appealing alternative to conventional echography machines for large-scale screening. To test the hypothesis that, after a short period of specific training with a pocket-sized ultrasound system, novice operators could reliably measure the abdominal aortic diameter. We assessed the agreement between abdominal aortic diameter measurements from novice operators using a pocket-sized ultrasound system and experts using conventional machines. After focused training of novice operators, the abdominal aortic diameter was independently measured at least four times: by two experts using conventional ultrasound, by one expert using a pocket-sized ultrasound system and by at least one novice operator using the pocket-sized system; each operator was blinded to the others. The aortic diameters of 56 patients were measured. The intraclass correlation coefficients between the four sets of measurement were all>0.91 and the mean difference between the measurements was negligible (<1mm). The interoperator variability for experts using conventional machines versus novices using pocket-sized machines was ≤ 4mm in 92.0% of cases. No learning curve over time was noted. In order to screen for abdominal aortic aneurysm, the abdominal aortic diameter can be accurately measured by non-specialist physicians with pocket-sized ultrasound devices after a short period of training.

Risk Factors Associated with the Diagnosis of Abdominal Aortic Aneurysm in Patients Screened at a Regional Veterans Affairs Health Care System

An active abdominal aortic aneurysm (AAA) screening program at a regional Veterans Affairs (VA) health system identifies patients at risk for AAA. The purpose of this study is to evaluate unique risk factors associated with the AAA diagnosis upon AAA screening examination to identify the most at risk patients for AAA. Data were extracted from a regional VA health care system to identify patients who underwent AAA screening within a 3-year period. An aortic diameter ≥3.0cm was defined as an AAA. Patient risk factors included age, body mass index, total cholesterol, estimated glomerular filtration rate (eGFR), statin use, and active smoking status; the presence of hypertension, diabetes, coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), or peripheral vascular disease (PVD) was also evaluated. Risk factors were compared in a multivariate analysis between patients with AAA and patients with a normal aorta. A total of 6,142 patients (mean ± SD age: 72.7±5.3years) were screened for AAA between January 2007 and December 2009. A total of 469 patients (7.6%) with AAA were identified. The following risk factors were significantly associated with a diagnosis of AAA: age >75years (39.6% vs. 28.9%; P<0.001), prevalence of CAD (43.1% vs. 28.5%; P<0.001), COPD (26% vs. 11.4%; P<0.001), PVD (37.3% vs. 7.7%; P<0.001), eGFR <60mL/min (36.7% vs. 24.3%; P<0.001), and current smoking (23.2% vs. 15.3%; P<0.001). The risk factors significantly associated with normal aortic size were the presence of diabetes (18.6% vs. 27.4%; P<0.001) and total cholesterol ≥200mg/dL (10.4% vs. 15%; P=0.04). The diagnosis of AAA in a large screening study is typically identified in patients who are at high risk for cardiovascular disease. The presence of diabetes is a major cardiovascular risk factor that is more associated with normal aorta when compared to patients with the AAA diagnosis. Total cholesterol ≥200mg/dL was associated with decreased AAA risk, and renal insufficiency was associated with increased AAA risk.