Ultrasound surveillance of ectatic abdominal aortas

Gender-specific Predicted Normal Aortic Size and Its Consequences of the Population-Based Prevalence of Abdominal Aortic Aneurysms

BACKGROUND

To investigate if a relative-size-index of the abdominal aortic diameter influences the prevalence estimates of abdominal aortic dilatations compared to absolute diameters.

METHODS

Cross-sectional study. Participants from the Viborg Vascular Screening Trial, Viborg Women Cohort, and the Viborg Screening Program. Through multivariate linear regression analyses, 2 gender-specific prediction-equations were developed based upon body-surface area and age. The definitions of absolute and relative size of aortic ectasies were 25-29 mm and 1.25-1.49× individual-predicted size (IPS), abdominal aortic aneurysm (AAA) 30 mm and 1.5× IPS, and large repair-recommendable AAA ≥55 mm or ≥ 2.75× IPS, respectively.

RESULTS

Nineteen thousand two hundred and sixty nine males (69.6 years) and 2,426 females (67.1 years) attended the population- and ultrasound-based screening studies for AAA. The mean peak systolic abdominal anterior-posterior inner to inner diameter was 19.1 mm (±5.3 mm) and 16.6 mm (±2.8 mm) (P < 0.001) in males and females, respectively. Body surface area showed the strongest correlation with aortic diameters in both males (r = 0.19, P < 0.001) and females (r = 0.17, P < 0.001). Age correlated significantly with size, but only in males (r = 0.03, P < 0.001). The prevalence in men of absolute size-defined and relative size index-defined screening-detected aortic ectasies, AAAs and repair-recommendable AAAs were: 5.9% and 9.5% (P < 0.001), 3.3% and 4.2% (P < 0.001) and 9.9% and 15.2% (P = 0.004), respectively. Prevalence in females of absolute-size-defined and relative-size-index-defined screening-detected aortic ectasies, AAAs and repair-recommendable AAAs were 1.2% and 5.8% (P < 0.001), 0.5% and 1.3% (P = 0.003) and 0.0% and 23.1% (P = 0.553), respectively.

CONCLUSIONS

Despite statistical differences, ultrasound-based absolute diameters to detect AAA seem acceptable in men. In females, poor agreements were noticed concerning all 3 categories of aneurysms, indicating that the current absolute diagnostic cut-points do not reflect female anatomy.

Editor's Choice - Risk of Rupture and All Cause Mortality of Abdominal Aortic Ectasia: A Systematic Review and Meta-Analysis

OBJECTIVE

To clarify the natural history of abdominal aortic ectasia (AAE) measuring 25 - 29 mm in maximum diameter, and to determine the optimal follow up based on the growth, risk of rupture, and overall mortality of AAE.

DATA SOURCES

MEDLINE, Web of Science Core Collection, and Google Scholar.

REVIEW METHODS

This was a systematic review and meta-analysis of AAE in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, Web of Science Core Collection, and Google Scholar were searched, with the help of a health sciences librarian, up to 11 August 2021. Studies with longitudinal outcomes of AAE (prevalence, annual growth rate, aneurysmal enlargement, rupture, aneurysm related death, and all cause mortality) were included. Meta-analyses were conducted with a random effects model RESULTS: Twelve studies describing a total of 8 369 patients were eligible. The prevalence at population based settings was 3.2% (95% confidence interval [CI] 2.4 - 4.0); annual growth rate was 0.82 mm/year (95% CI 0.20 - 1.45). The estimated risks of aortic diameters exceeding 30 mm and 55 mm in five years were 45.0% (95% CI 28.5 - 61.5) and 0.3% (95% CI 0 - 0.6) respectively, while those beyond five years were 70.2% (95% CI 46.9 - 93.6) and 5.2% (95% CI 2.2 - 8.2). The rates of rupture and aneurysm related death were minimal until five years (0.1% and 0.1%, respectively) and beyond (0.4% and 0.2%, respectively). Overall mortality was 7.5% (95% CI 3.9 - 11.0) and 17.3% (95% CI 9.5 - 25.1) up to and beyond five years. Overall mortality from three studies showed no statistical difference between AAE and aneurysms (hazard ratio 0.62, 95% CI 0.32 - 1.21; p = .16). Cancer (35.0%) and cardiovascular diseases (31.9%) were major causes of death.

CONCLUSION

AAE carries minimal risk of aneurysm related lethal events during the first five years, but a similar overall mortality risk as abdominal aortic aneurysm. Cancer and cardiovascular diseases are leading causes of death in patients with AAE.

Tailor-Made Tapering Grafts for Large-Neck Aorta

Patients having a large aortic neck poses a challenge in abdominal aortic aneurysm surgery both in endovascular and open aneurysm repair, sometimes necessitating paravisceral or thoracoabdominal aneurysm repair which carries considerable perioperative risk. Here, we describe techniques of using a tailor-made tapering graft in open surgery that can be adjusted for large neck morphology. This technique helps avoid discrepancies between the proximal aorta and graft, and postoperative acute kidney injury by clamping at lower levels. The conscientious use of this technique in selected patients realizes satisfactory outcomes both in the short term and midterm in the demanding anatomy of large aortic necks.

The value of evaluating the abdominal aorta in patients <50 years of age presenting for abdominal ultrasound

INTRODUCTION

Practitioners of US routinely include a survey of the abdominal aorta during abdominal US in accordance with international guidelines. Such practice is of uncertain value in younger patients.

METHODOLOGY

This study was a retrospective review of 2000 abdominal US examinations which included visualisation of the aorta in patients <50 years of age. Patient demographics and referral details were recorded, and US images and reports were reviewed for the presence of aortic and periaortic pathology.

RESULTS

The most common indications for US were abdominal pain (1337, 44%), deranged liver function tests (453, 15%), nausea and/or vomiting (229, 8%), elevated inflammatory markers (146, 5%), pancreatitis (134, 4%) and pyrexia (127, 4%). Fewer than half (977, 49%) of the reports contained a comment regarding the aorta. Aortic pathology was reported in 2 (0.1%) cases. Both were reported as aortic ectasia and both represented a false-positive diagnosis. One male patient had a known abdominal aortic aneurysm with endovascular aortic repair. No new aortic aneurysms were found. All cases of atherosclerotic disease were ignored, and none were reported. Periaortic pathology was encountered on 1 patient, but this was known. No case of new periaortic pathology was detected.

CONCLUSION

Routine and indiscriminate imaging of the abdominal aorta during abdominal US in patients <50 years of age is not evidence based. No new case of abdominal aortic aneurysm or new para-aortic pathology was detected, all cases of atherosclerosis were ignored, and two false-positive diagnoses of aortic ectasia were made.

Primary Care Screening for Abdominal Aortic Aneurysm: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Ruptured abdominal aortic aneurysms (AAAs) have mortality estimated at 81%.

OBJECTIVE

To systematically review the evidence on benefits and harms of AAA screening and small aneurysm treatment to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed (publisher supplied only), Database of Abstracts of Reviews of Effects, and Cochrane Central Register of Controlled Trials for relevant English-language studies published through September 2018. Surveillance continued through July 2019.

STUDY SELECTION

Trials of AAA screening benefits and harms; trials and cohort studies of small (3.0-5.4 cm) AAA treatment benefits and harms.

DATA EXTRACTION AND SYNTHESIS

Two investigators independently reviewed abstracts and full-text articles and extracted data. The Peto method was used to pool odds ratios (ORs) for AAA-related mortality, rupture, and operations; the DerSimonian and Laird random-effects model was used to pool calculated risk ratios for all-cause mortality.

MAIN OUTCOMES AND MEASURES

AAA and all-cause mortality; AAA rupture; treatment complications.

RESULTS

Fifty studies (N = 323 279) met inclusion criteria. Meta-analysis of population-based randomized clinical trials (RCTs) estimated that a screening invitation to men 65 years or older was associated with a reduction in AAA-related mortality over 12 to 15 years (OR, 0.65 [95% CI, 0.57-0.74]; 4 RCTs [n = 124 926]), AAA-related ruptures over 12 to 15 years (OR, 0.62 [95% CI, 0.55-0.70]; 4 RCTs [n = 124 929]), and emergency surgical procedures over 4 to 15 years (OR, 0.57 [95% CI, 0.48-0.68]; 5 RCTS [n = 175 085]). In contrast, no significant association with all-cause mortality benefit was seen at 12- to 15-year follow-up (relative risk, 0.99 [95% CI 0.98-1.00]; 4 RCTs [n = 124 929]). One-time screening was associated with significantly more procedures over 4 to 15 years in the invited group compared with the control group (OR, 1.44 [95% CI, 1.34-1.55]; 5 RCTs [n = 175 085]). Four trials (n = 3314) of small aneurysm surgical treatment demonstrated no significant difference in AAA-related mortality or all-cause mortality compared with surveillance over 1.7 to 12 years. These 4 early surgery trials showed a substantial increase in procedures in the early surgery group. For small aneurysm treatment, registry data (3 studies [n = 14 424]) showed that women had higher surgical complications and postoperative mortality compared with men.

CONCLUSIONS AND RELEVANCE

One-time AAA screening in men 65 years or older was associated with decreased AAA-related mortality and rupture rates but was not associated with all-cause mortality benefit. Higher rates of elective surgery but no long-term differences in quality of life resulted from screening.

Risk of developing an abdominal aortic aneurysm after ectatic aorta detection from initial screening

OBJECTIVE

Current abdominal aortic aneurysm (AAA) surveillance guidelines lack any follow-up recommendations after initial abdominal aortic screening diameter of less than 3.0 cm. Some reports have demonstrated patients with late AAA formation and late ruptures after initial ultrasound screening detection of patients with an aortic diameter of 2.5 to 2.9 cm (ectatic aorta). The purpose of this study was to determine ectatic aorta prevalence, AAA development, rupture risk, and risk factor profile in patients with detected ectatic aortas in a AAA screening program.

METHODS

A retrospective chart review of all patients screened for AAA from January 1, 2007, to December 31, 2016, within a regional health care system was conducted. Screening criteria were men 65 to 75 years of age that smoked a minimum of 100 cigarettes in their lifetime. An ectatic aorta was defined as a maximum aortic diameter from 2.5 to 2.9 cm. An AAA was defined as an aortic diameter of 3 cm or greater. Patients screened with ectatic aortas who had subsequent follow-up imaging of the aorta with a minimum of 1-year follow-up were analyzed for associated clinical and cardiovascular risk factors. All data were collected through December 3,/2018. A logistic regression of statistically significant variables from univariate and χ² analyses were performed to identify risks associated with the development of AAA from an initially diagnosed ectatic aorta. A Cox proportional hazard model was used to assess survival data. A P value of less than .05 was considered statistically significant.

RESULTS

From a screening pool of 19,649 patients, 3205 (16.3%) with a mean age of 72.1 ± 5.3 years were identified to have an ectatic aorta from January 1, 2007, to December 31, 2016. The average screening ectatic aortic diameter was 2.6 ± 0.1 cm. There were 672 patients (21.0%) with a mean age of 73.0 ± 5.7 years who received subsequent imaging for other clinical indications and 193 of these patients (28.7%) with ectatic aortas developed an AAA from the last follow-up scan (4.2 ± 2.5 years). The average observation length of all patients was 6.4 ± 2.9 years. No ruptures were reported, but 27.8% of deaths were of unknown cause. One patient had aortic growth to 5.5 cm or greater (0.15%). Larger initial screening diameter (P < .01), presence of chronic obstructive pulmonary disease (P < .01), and active smoking (P = .01) were associated with AAA development.

CONCLUSIONS

Patients with diagnosed ectatic aortas from screening who are active smokers or have chronic obstructive pulmonary disease are likely to develop an AAA.

Prognostic value of D-dimer and markers of coagulation for stratification of abdominal aortic aneurysm growth

Abdominal aortic aneurysm (AAA) is associated with high morbidity and mortality and is an established cause of unbalanced hemostasis. A number of hemostatic biomarkers have been associated with AAA; however, the utility of hemostatic biomarkers in AAA diagnosis and prognosis is unclear. The aim of the present study was to characterize the potential prognostic value of D-dimer and markers of altered hemostasis in a large cohort of patients with AAAs characterized by either fast or slow aneurysm growth (frequency matched for baseline diameter) and subaneurysmal dilations. We measured plasma concentrations of thrombin-antithrombin (TAT) complex, platelet factor 4 (PF4), and D-dimer in 352 patients with either fast-growing AAAs (>2 mm/y), slow-growing AAAs (<2 mm/y), subaneurysmal aortic dilations, or nonaneurysmal aortas. Plasma D-dimer and TAT were significantly elevated in both AAA and subaneurysmal dilation patients compared with controls. Individuals with D-dimer levels ≥500 ng/mL had 3.09 times the odds of subaneurysms, 6.23 times the odds of slow-growing AAAs, and 7.19 times the odds of fast-growing AAAs than individuals with D-dimer level <500 ng/mL. However, no differences in D-dimer concentration were noted between fast- and slow-growing aneurysms. Plasma D-dimer and TAT were strong independent predictors of AAA growth rate with multivariate analysis revealing a 500-ng/mL increase in D-dimer or 1-µg/mL increase in TAT led to additional 0.21-mm and 0.24-mm changes in aortic diameter per year, respectively. Rising levels of plasma TAT, in addition to D-dimer, may predict disease progression and aneurysm growth in patients with AAA or subaneurysmal dilation.

Prevalence and natural history of and risk factors for subaneurysmal aorta among 65-year-old men

Background: The aims of this study were to determine the prevalence of screening-detected subaneurysmal aorta (SAA), i.e. an aortic diameter of 2.5-2.9 cm, its associated risk factors, and natural history among 65-year-old men. Methods: A total of 14,620 men had their abdominal aortas screened with ultrasound and completed a health questionnaire containing information on smoking habits and medical history. They were categorized based on the aortic diameter: normal aorta (<2.5 cm; n = 14,129), SAA (2.5-2.9 cm; n = 258), and abdominal aortic aneurysm (AAA) (≥3.0 cm; n = 233). The SAA-group was rescanned after 5 years. Associated risk factors were analyzed. Results: The SAA-prevalence was 1.9% (95% confidence interval 1.7%-2.1%), with 57.0% (50.7%-63.3%) expanding to ≥3.0 cm within 5 years. Frequency of smoking, coronary artery disease, hypertension, hyperlipidemia, and claudication were significantly higher in those with SAA and AAA compared to those with normal aortic diameter. Current smoking was the strongest risk factor for SAA (odds ratio [OR] 2.8; P < 0.001) and even stronger for AAA (OR 3.6; P < 0.001). Men with SAA expanding to AAA within 5 years presented pronounced similarities to AAA at baseline. Conclusions: Men with SAA and AAA presented marked similarities in the risk factor profile. Smoking was the strongest risk factor with an incremental association with disease severity, and disease progression. This indicates that SAA and AAA may have the same pathophysiological origin and that SAA should be considered as an early stage of aneurysm formation. Further research on the cost-effectiveness and potential benefits of surveillance as well as smoking cessation and secondary cardiovascular prevention in this subgroup is warranted.

Editor's Choice - Influence of Proximal Aortic Neck Diameter on Durability of Aneurysm Sealing and Overall Survival in Patients Undergoing Endovascular Aneurysm Repair. Real World Data from the Gore Global Registry for Endovascular Aortic Treatment (GREAT)

OBJECTIVES

Aortic neck diameter is an independent anatomical feature that is poorly understood, yet potentially linked to proximal seal failure and adverse outcome following standard EVAR. The aim of this study was to assess whether large proximal aortic neck (LAN) diameter is associated with adverse outcome using prospectively collected individual patient data from The Global Registry for Endovascular Aortic Treatment (GREAT).

METHODS

A total of 3166 consecutive patients, from 78 global centres, receiving Gore Excluder stent grafts for infrarenal abdominal aortic aneurysm repair between 2011 and 2017 were included. Patient demographics, biometrics, operative details, and clinical outcome were analysed. Patients were divided into two groups: normal baseline proximal aortic neck (NAN) diameter (<25 mm on computed tomography aortography), and LAN (≥25 mm). Clinical follow up (including imaging) was available for 76.5% of patients 5 years post-intervention. Primary endpoints analysed were Type IA endoleak and any aortic re-intervention up to 5 years post-procedure. A composite endpoint of Type IA endoleak, re-intervention, aortic rupture, or aortic related mortality was also assessed.

RESULTS

A total of 1977 (62.4%) patients were classified NAN and 1189 (37.6%) were LAN. Immediate technical success was achieved in 3164 out of 3166 (>99.9%) of cases. Freedom from Type IA endoleak was achieved in 99.3% at 1 year and 97.3% at 5 years (lower in LAN vs. NAN: 96.8% [CI 93.7-98.4] vs. 98.6% [CI 94.5-99.6], p = .007). Freedom from aortic re-intervention was 93.7% at 1 year and 83.2% at 5 years (78.6% [CI 66.0-87.0] LAN vs. 86.0% [CI 81.8-89.3] NAN, p = .11). Freedom from primary composite endpoint was 95.9% at 1 year and 84.9% at 5 years (81.3% [CI 69.2-89.0] LAN vs. 87.0% [CI 81.6-91.0] NAN, p = .066). Five year survival was lower in the LAN group; 64.6% (CI 50.1-75.7) vs. 76.5% (CI 70.7-81.3), p = .03).

CONCLUSION

LAN is associated with delayed Type IA endoleak occurrence and lower overall survival.

Insights and Clinical Implications from the pELVIS Registry for the Treatment of Aneurysms Involving the Iliac Bifurcation

The pErformance of iLiac branch deVIces for aneurysmS (pELVIS) Registry is the largest retrospective analysis of prospectively collected data on the use of iliac branch devices (IBD) for the treatment of iliac and aortoiliac aneurysms. It shows the feasibility of the technique with good short- and mid-term results. The most common anatomical challenge for IBD use is the presence of aneurysmal deterioration of the internal iliac arteries (IIA). Experience acquired in the registry treating concomitant aneurysmal lesions of the IIA provides significant information on the performance of IBDs for this specific clinical presentation. Treatment of isolated aneurysms in the common iliac artery without extension to the infrarenal aorta showed favourable results with lower costs, and lower use of irradiation and contrast media. Overall, the relatively low procedure-related complications and repeat interventions show broad applicability of the technique. Further analysis is required to evaluate the longstanding performance of IBD.

Coronary Artery Disease as a Relevant Risk Factor in Screening of Abdominal Aortic Ectasia and Aneurysm

BACKGROUND

The aim of this study was to investigate the prevalence of abdominal aortic aneurysm (AAA) and abdominal aortic ectasia (AAE) in coronary artery disease (CAD) patients in a multicenter setting to obtain significant data to establish an AAA screening program in our departments.

METHODS

Between January and September 2016, 500 patients with suspected or diagnosed CAD planned for coronary angiography or coronary artery bypass graft (CABG) underwent a sonographic examination of the infrarenal abdominal aorta to diagnose AAA or AAE. We calculated the prevalence of AAA and AAE in patients diagnosed of CAD and investigated factors potentially associated with the occurrence of AAA.

RESULTS

The overall prevalence in all grades of CAD for AAE was 35.1% and for AAA 5.4%. In patients with three-vessel CAD, the prevalence of AAE was 34% and of AAA 6.8%. Significant correlation was found between the three-vessel CAD and AAA (p = 0.039). The logistic regression analysis showed significant correlation between AAA and age > 65 years (p = 0.05). The multivariate analysis of risk factors and CAD revealed significant correlations between one-vessel CAD and arterial hypertension (AH) (p = 0.004) and age > 65 years (p = 0.001) as well as between three-vessel CAD and AH (p = 0.01), peripheral artery disease (p = 0.01), and age > 65 years (p = 0.03).

CONCLUSION

Our results confirm, that in comparison to other data, the prevalence of AAA in patients with CAD is high. Thus, it is recommended to include patients with CAD, especially elderly patients with three-vessel CAD, in future AAA screening programs.

Circulating Vascular Basement Membrane Fragments are Associated with the Diameter of the Abdominal Aorta and Their Expression Pattern is Altered in AAA Tissue

OBJECTIVE

Abdominal aortic aneurysm (AAA) is characterised by enhanced proteolytic activity, and extracellular matrix (ECM) remodelling in the vascular wall. Type IV and XVIII collagen/endostatin are structural proteins in vascular basement membrane (VBM), a specialised ECM structure. Here the association between plasma levels of these collagens with the aortic diameter and expansion rate is studied, and their expression in aortic tissue characterised.

METHODS

This was a retrospective population based cohort study. Type IV and XVIII collagen/endostatin were analysed in plasma by ELISA assay in 615 men, divided into three groups based on the aortic diameter: 1) normal aorta ≤ 25 mm, 2) sub-aneurysmal aorta (SAA) 26-29 mm, and 3) AAA ≥ 30 mm. Follow up data were available for 159 men. The association between collagen levels and aortic diameter at baseline, and with the expansion rate at follow up were analysed in ordinal logistic regression and linear regression models, controlling for common confounding factors. Tissue expression of the collagens was analysed in normal aorta (n = 6) and AAA (n = 6) by immunofluorescence.

RESULTS

Plasma levels of type XVIII collagen/endostatin (136 ng/mL [SD 29] in individuals with a normal aorta diameter, 154 ng/ml [SD 45] in SAA, and 162 ng/ml [SD 46] in AAA; p = .001) and type IV collagen (105 ng/mL [SD 42] normal aorta, 124 ng/ml [SD 46] SAA, and 127 ng/ml [SD 47] AAA; p = .037) were associated with a larger aortic diameter. A significant association was found between the baseline levels of type XVIII/endostatin and the aortic expansion rate (p = .035), but in the multivariable model, only the initial aortic diameter remained significantly associated with expansion (p = .005). Altered expression patterns of both collagens were observed in AAA tissue.

CONCLUSION

Plasma levels of circulating type IV and XVIII collagen/endostatin increase with AAA diameter. The expression pattern of VBM proteins is altered in the aneurysm wall.

ADAB2IPgenotype: sex interaction is associated with abdominal aortic aneurysm expansion

A faster expansion rate of abdominal aortic aneurysm (AAA) increases the risk of rupture. Women are at higher risk of rupture than men, but the mechanisms underlying this increased risk are unknown. We investigated whether genetic variants that influence susceptibility for AAA (CDKN2A-2B,SORT1,DAB2IP,LRP1andLDLR) are associated with AAA expansion and whether these associations differ by sex in 650 patients with AAA (mean age 70±8 years, 17% women) enrolled in the Mayo Clinic Vascular Disease Biorepository. Women had a mean aneurysm expansion 0.41 mm/year greater than men after adjustment for baseline AAA size. In addition to baseline size, mean arterial pressure (MAP), non-diabetic status,SORT1-rs599839[G] andDAB2IP-rs7025486[A] were associated with greater aneurysm expansion (all p<0.05). The associations of MAP and rs599839[G] were similar in both sexes, while the associations of baseline size, pulse pressure (PP) and rs7025486[A] were stronger in women than men (all p-sexinteraction≤0.02). A three-way interaction of PP*sex* rs7025486[A] was noted in a full-factorial analysis (p=0.007) independent of baseline size and MAP. In the high PP group (≥median), women had a mean growth rate 0.68 mm/year greater per [A] of rs7025486 than men (p-sexinteraction=0.003), whereas there was no difference in the low PP group (p-sexinteraction=0.8). We demonstrate that variantsDAB2IP-rs7025486[A] andSORT1-rs599839[G] are associated with AAA expansion. The association of rs7025486[A] is stronger in women than men and amplified by high PP, contributing to sex differences in aneurysm expansion.

Plasma D-dimer as a predictor of the progression of abdominal aortic aneurysm

Essentials D-dimer could provide important information about abdominal aortic aneurysm (AAA) progression. The greatest diameter of the infrarenal aorta and the value of plasma D-dimer were determined. AAA progression is correlated with increasing plasma D-dimer levels. The increasing value of plasma D-dimer could be a predictor of aneurysm progression.

SUMMARY

Background The natural course of abdominal aortic aneurysm (AAA) is mostly asymptomatic and unpredictable. D-dimer could provide potentially important information about subsequent AAA progression. Objectives The aims of this study were to establish the relationship between the progression of an abdominal aortic aneurysm (AAA) and plasma D-dimer concentration over a 12-month period and determine the value of plasma D-dimer in patients with sub-aneurysmal aortic dilatation. Patients/Methods This was a prospective observational study that involved 33 patients with an AAA, 30 patients with sub-aneurysmal aortic dilatation and 30 control subjects. The greatest diameter of the infrarenal aorta, which was assessed by ultrasound, and the value of plasma D-dimer were determined for all subjects at baseline assessment, as well as after 12 months for those with an AAA. Results A positive correlation was found between the diameter of an AAA and plasma D-dimer concentration at the baseline and the control measurement stages. There was a strong positive correlation between AAA progression and increasing plasma D-dimer concentration over a 12-month period. Among patients with sub-aneurysmal aortic dilatation (n = 30), the value of plasma D-dimer was higher compared with matched controls (n = 30). Conclusions There is a strongly positive correlation between AAA progression and increasing plasma D-dimer concentration. The value of plasma D-dimer is higher in patients with sub-aneurysmal aortic dilatation than in control subjects.

A multi-locus genetic risk score for abdominal aortic aneurysm

BACKGROUND

We investigated whether a multi-locus genetic risk scores (GRS) was associated with presence and progression of abdominal aortic aneurysm (AAA) in a case - control study.

METHODS AND RESULTS

The study comprised of 1124 patients with AAA (74 ± 8 years, 83% men, 52% of them with a maximal AAA size ≤ 5 cm) and 6524 non-cases (67 ± 11 years, 58% men) from the Mayo Vascular Disease Biorepository. AAA was defined as infrarenal abdominal aorta diameter ≥ 3.0 cm or history of AAA repair. Non-cases were participants without known AAA. A GRS was calculated using 4 SNPs associated with AAA at genome-wide significance (P ≤ 10(-8)). The GRS was associated with the presence of AAA after adjustment for age, sex, cardiovascular risk factors, atherosclerotic cardiovascular diseases and family history of aortic aneurysm: odds ratio (OR, 95% confidence interval, CI) 1.06 (1.04-1.09, p < 0.001). Adding GRS to conventional risk factors improved the association of presence of AAA (net reclassification index 14%, p < 0.001). In a subset of patients with AAA who had ≥ 2 imaging studies (n = 651, mean (SE) growth rate 2.47 (0.11) mm/year during a mean time interval of 5.41 years), GRS, baseline size, diabetes and family history were each associated with aneurysm growth rate in univariate association (all p < 0.05). The estimated mean aneurysm growth rate was 0.50 mm/year higher in those with GRS > median (5.78) than those with GRS ≤ median (p = 0.01), after adjustment for baseline size (p < 0.001), diabetes (p = 0.046) and family history of aortic aneurysm (p = 0.02).

CONCLUSIONS

A multi-locus GRS was associated with presence of AAA and greater aneurysm expansion.

Does a normal screening ultrasound of the abdominal aorta reduce the likelihood of rupture in emergency department patients?

INTRODUCTION

Abdominal aortic aneurysm (AAA) development is a multifactorial process that is more prevalent among people ≥65years of age. Major risk factors are obesity, male sex, history of smoking (at least 100 cigarettes in a person's lifetime), and history of AAA in a first-degree relative. The United States Preventative Task Force has recommended a one-time ultrasound screening for men aged 65-75years. Based on studies, negative results on a single ultrasound examination around the age of 65years appear to virtually exclude the risk for future AAA rupture or death. While ultrasonography (US) is the confirmatory study of choice, computed tomography (CT) can also be used in the diagnosis of AAA. The goal of this study is to determine if AAA rupture can reliably be excluded in individuals with abdominal pain who have had a normal caliber aorta on CT or US after the age of 65years.

MATERIALS AND METHODS

A retrospective study (approved by institutional review board) of emergency department (ED) patients in an urban academic center was performed. Subjects were included if they met the following criteria: age ≥65years; an initial CT or US as an ED patient, inpatient, or outpatient for any indication, which identified an abdominal aorta <3cm; and a second CT or US during an ED visit. The incidence of ruptured AAA on the second CT or US with a history of normal aortic caliber was identified.

RESULTS

During the study period, 606 subjects were enrolled. Demographic data are listed in Table 1. Three subjects (0.5%) exhibited an abnormal-sized aorta on ED evaluation. None of these three subjects had an AAA intervention. The average size of the abnormal aorta in these three subjects was 3.3cm (S.D. 0.17).

CONCLUSION

Based on these results, it appears that AAA and rupture may reliably be excluded in ED patients with abdominal pain who have previously had a normal caliber aorta on CT or US after the age of 65years. A prospective, multicenter study would help validate these findings.

Evaluation of the accuracy of aorta scan BVI 9600 in screening for abdominal aortic aneurysm

OBJECTIVES

Despite a decreasing incidence of abdominal aortic aneurysm (AAA), the cost-effectiveness of AAA ultrasound screening can be improved by reducing the screening costs and increasing the uptake rates. The BVI 9600 (BVI) is a promising tool for this purpose as it is inexpensive and can detect AAA without a trained operator. This study aims to investigate whether the BVI can be used to detect AAA for the purpose of a low-cost outreach screening approach.

METHODS

A total of 142 subjects had their abdominal aortae measured by five sonographers using the BVI and a conventional ultrasound machine. The examination included four anterior-posterior measurements at four equally spaced scanning locations from the xiphisternum to the umbilicus. The measurements produced by each machine were compared using Bland-Altman plots, followed by an analysis of the AAA detection performance.

RESULTS

The BVI measured the aortic diameter to within 0.88-1.56 cm of the true diameter, exceeding the 0.5 cm "clinically acceptable difference" (CAD). Its accuracy was poorer when measuring the aneurysmal aortae (mean difference -0.56 cm, variability 1.72 cm) than normal aortae (mean difference 0.02 cm, variability 0.76 cm). Nine out of 52 aneurysms were not detected due to undersizing measurement and non-visualization of the aortae.

CONCLUSIONS

At present, the BVI is not sufficiently accurate to detect AAA for screening purposes. A number of technical features require improvement.

Lower respiratory tract infection and rapid expansion of an abdominal aortic aneurysm: a case report

INTRODUCTION

The rate of abdominal aortic aneurysm expansion is related to multiple factors. There is some evidence that inflammation can accelerate aneurysm expansion. However, the association between pulmonary sepsis and rapid abdominal aortic aneurysm expansion is rarely reported.

CASE PRESENTATION

Here we present a case of a rapidly expanding abdominal aortic aneurysm in a 68-year-old Caucasian man with a concomitant lower respiratory tract infection and systemic sepsis requiring intensive monitoring and urgent endovascular intervention. Our patient had an uncomplicated post-operative recovery and a follow-up computed tomography scan at one month demonstrated no evidence of an endoleak.

CONCLUSION

This case highlights the potential association between pulmonary sepsis and rapid abdominal aortic aneurysm expansion. In such cases, a policy of frequent monitoring should be adopted to identify those patients requiring definitive management.