Long Term Outcome of Screen Detected Sub-Aneurysmal Aortas in 65 Year Old Men: a Single Scan After Five Years Identifies Those at Risk of Needing AAA Repair

Predictors of abdominal aortic aneurysm progression in men with small infrarenal aortic diameters at screening

OBJECTIVE

Screening for abdominal aortic aneurysm (AAA) defined as an infrarenal aortic diameter (IAD) of ≥30 mm reduces mortality, but managing patients with diameters of 25 to 29 mm is debated. Incorporating body surface area into the diagnostic criteria may improve the identification of those at risk of developing treatment-requiring aneurysms in this group. In a previous study, we defined a relative AAA as an IAD ≥150% larger than expected, with the normal diameter calculated using body surface area as a scaling factor. This study aimed to determine if this criterion could identify those at risk of aneurysmal development among patients with aortic diameter of 25 to 29 mm at screening.

METHODS

A cohort study was conducted on men with abdominal aortic diameters of 25 to 29 mm at AAA screening in Malmö, Sweden, with a median follow-up of 9.9 years. Growth rates were compared between the relative aneurysm group and the nonrelative aneurysm group using a linear mixed-effects model to account for both fixed and random effects. Time and hazard ratio to reach 40 mm, a marker of significant aneurysmal progression, were assessed using a log-rank test and a Cox proportional hazards model, both adjusted for smoking status and diabetes.

RESULTS

In a cohort of 270 men, three developed AAAs ≥55 mm. The baseline growth rate was 0.1 mm/year (95% confidence interval [CI], 0.0-0.3). Growth rates were increased by 0.4 mm/year (95% CI, 0.0-0.7) in the relative aneurysm group, and by 0.4 mm/year (95% CI, 0.2-0.7) in smokers. The median time to reach an IAD of ≥40 mm was 11.5 years for relative aneurysms and was not reached for those without, with a significant difference shown by a log-rank test stratified for smoking (P = .009). Hazards ratio to reach an IAD of ≥40 mm for relative aneurysms was 2.77 (95% CI, 1.34-5.74; P = .006) compared with those without.

CONCLUSIONS

In men with diameters of 25 to 29 mm at screening for AAAs, the use of an individualized diagnostic criterion, based on height and weight, could identify those with increased aneurysm growth and a significantly shorter time to reach 40 mm compared with baseline. The relative aortic diameter, beyond the absolute diameter, seemed to be important for aneurysmal development. However, the differences were likely too small to warrant changes in clinical practice, highlighting the need for further research to establish clinical relevance.

Whole aorta imaging shows increased risk for thoracic aortic aneurysms and dilatations in relatives of abdominal aortic aneurysm patients

OBJECTIVE

For relatives of abdominal aortic aneurysm (AAA) patients, guidelines recommend abdominal imaging aimed at early detection and management of AAA, and do not include screening for thoracic aortic aneurysms (TAA). We aimed to investigate if TAA occur in undiagnosed relatives of patients with AAA without a known genetic susceptibility for aneurysms, similar to families with identified genetic susceptibilities for aneurysms like in Marfan and Loeys-Dietz syndrome, where both AAAs and TAAs occur.

METHODS

Relatives of patients with AAA were invited for noncontrast whole aorta computed tomography (CT) screening. Systematic measurements of the CT scans were used to detect aneurysms and dilatations. Classification into familial and nonfamilial was based on reported family histories. In addition, aneurysm gene panel testing of AAA index cases was used for the classification of high vs unknown genetic risk (high genetic risk: familial aneurysm or a pathogenic/likely pathogenic (P/LP) in an aneurysm gene; unknown genetic risk: no family history or P/LP).

RESULTS

Whole aorta imaging of 301 relatives of 115 index patients with AAA with noncontrast CT scans showed a 28-fold increase in TAAs in relatives (1.7% [P < .001] vs the age-adjusted population) and a high frequency of thoracic dilatations in 18% of the relatives. Thoracic aneurysms and dilatations in relatives occurred even when index patients were unaware of familial aneurysms. AAA was increased in the relatives compared with the age-adjusted population (8%; P < .001).

CONCLUSIONS

An increased risk for thoracic aneurysms and dilatations was detected by whole aorta imaging of relatives of index patients with AAA, even when index patients were unaware of familial aneurysms. These results indicate still unknown shared genetic susceptibilities for thoracic and abdominal aneurysms. Therefore, imaging of the whole aorta of relatives of all abdominal aneurysm patients, will improve early detection of aortic aneurysms in relatives of all patients with AAA.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Eleven-Year Outcomes of a Screening Project for Abdominal Aortic Aneurysm (AAA) in 65-Year-Old Men

Objective

Since 2011, the Department of Vascular Surgery at Oslo University Hospital has offered screening for abdominal aortic aneurysm (AAA) to 65-year-old men living in Oslo, Norway. The aim of this study was to evaluate the effect of the screening project on AAA-related mortality and rupture and repair rates in the screened population.

Methods

This cohort study included men that participated in AAA screening at the Department of Vascular Surgery at Oslo University Hospital in the period May 2011 to September 2019. All men with screen-detected AAA (aortic diameter ≥30 mm) and subaneurysmal aortic dilatation (aortic diameter 25-29 mm) were included. A stratified (1:1 with the subaneurysm group), randomized selection of men with normal aortic diameter (<25 mm) upon screening was also included. The follow-up data on events (ruptures, repairs, and deaths) after screening were collected retrospectively from patient electronic medical records at Oslo University Hospital, the National Population Register and the Norwegian Cause of Death Registry (CoDR).

Results

In total, 2048 men were included, with a median follow-up time of 7.1 years (IQR 3.8). Among men with screen-detected AAA, 0.6% died of AAA-related causes (0.9 AAA-related deaths per 1000 person-years). The rupture rate was 0.3% among men with screen-detected AAA or subaneurysmal aortic dilatation, giving an incidence of 0.5 ruptures per 1000 person-years. The overall repair rate in the AAA group was 20.6% (36.1 repairs per 1000 person-years) and 0.6% (0.9 repairs per 1000 person-years) in the subaneurysm group.

Conclusion

In a population screened for AAA, the incidence of rupture and the AAA-related mortality was very low. Almost one-fifth of the participants with screen-detected AAA underwent elective repair, representing a group that might have presented with rupture if untreated. These results indicate that screening is valuable in preventing AAA rupture and AAA-related mortality.

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.