The futility of surveillance for old and small aneurysms

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.

Editor's Choice - Systematic Review and Meta-Analysis of Contemporary Abdominal Aortic Aneurysm Growth Rates

OBJECTIVE

To evaluate the contemporary growth rate of small abdominal aortic aneurysms (AAAs) in view of recent epidemiological changes, such as decreasing smoking rates and establishment of population screening programmes.

DATA SOURCES

MEDLINE, CENTRAL, PsycINFO, Web of Science Core Collection, and OpenGrey databases.

REVIEW METHODS

Systematic review following the PRISMA guidelines. In October 2021, databases were queried for studies reporting on AAA growth rates published from 2015 onwards. The primary outcome was contemporary AAA growth rates in mm/year. Data were pooled in a random effects model meta-analysis, and heterogeneity was assessed through the I2 statistic. GRADE assessment of the findings was performed. The protocol was published in PROSPERO (CRD42022297404).

RESULTS

Of 8 717 titles identified, 43 studies and 28 277 patients were included: 1 241 patients from randomised controlled trials (RCTs), 23 941 from clinical observational studies, and 3 095 from radiological or translational research studies. The mean AAA growth rate was 2.38 mm/year (95% CI 2.16 - 2.60 mm/year; GRADE = low), with meta-regression analysis adjusted for baseline diameter showing an increase of 0.08 mm/year (95% CI 0.024 - 0.137 mm/year; p = .005) for each millimetre of increased baseline diameter. When analysed by study type, the growth rate estimated from RCTs was 1.88 mm/year (95% CI 1.69 - 2.06 mm/year; GRADE = high), while it was 2.31 mm/year (95% CI 1.95 - 2.67 mm/year; GRADE = moderate) from clinical observational studies, and 2.85 mm/year (95% CI 2.44 - 3.26 mm/year; GRADE = low) from translational and radiology based studies (p < .001). Heterogeneity was high, and small study publication bias was present (p = .003), with 27 studies presenting a moderate to high risk of bias. The estimated growth rate from low risk studies was 2.09 mm/year (95% CI 1.87 - 2.32; GRADE = high).

CONCLUSION

This study estimated a contemporaneous AAA growth rate of 2.38 mm/year, being unable to demonstrate any clinically meaningful AAA growth rate reduction concomitant with changed AAA epidemiology. This suggests that the RESCAN recommendations on small AAA surveillance are still valid. However, sub-analysis results from RCTs and high quality study data indicate potential lower AAA growth rates of 1.88 - 2.09 mm/year, findings that should be validated in a high quality prospective registry.

Outcomes of octogenarians receiving aortic repair

OBJECTIVE

Abdominal aortic aneurysm (AAA) repair is recommended for aneurysms greater than 5.5 cm in men and 5 cm in women. Because AAA is more common among the elderly, we sought to evaluate contemporary practices of elective AAA repair and 2-year postoperative outcomes in octogenarians.

METHODS

We identified octogenarians undergoing elective AAA repair in the Vascular Quality Initiative from 2012 to 2019. We included patients undergoing endovascular (EVAR) and open (OAR) aortic repair. Demographics and comorbid conditions were compared between patient groups. Frailty was calculated using previously published methods. Patients with frailty scores above the 75th percentile of the operative cohort were considered high frailty. The primary outcome was 1- and 2-year mortality. Secondary outcomes included postoperative complications. Standard statistical methods were utilized. Cox proportional hazard models were used to identify factors that affect mortality.

RESULTS

The frequency of AAA repair in octogenarians has remained stable. Of all aortic operations, 21.4% were performed on octogenarians; 9735 (23.3% of 41,712) EVAR and 755 (10.3% of 7325) OARs. Among octogenarian patients, 42.0% of EVARs were under size thresholds: 48.3% males ≤5.5 cm diameter and 21.5% females ≤5.0 cm diameter compared with 18.8% OARs: 23.4% males and 10.7% females. Additionally, 25.6% had high frailty scores. Among octogenarians, 1- and 2-year mortality was 9.3% ± 0.3% and 14.8% ± 0.4% for EVAR and 15.2% ± 1.3% and 18.9% ± 1.5% for OAR patients, respectively (P < .01). In-hospital mortality rate was higher after OAR (0.87% EVAR vs 7.55% OAR; P < .01) and differed with frailty (EVAR, low frailty 0.2% vs high frailty 1.7%; OAR, low frailty 2.3% vs high frailty 15.6%). For EVAR, patient factors associated with mortality included heart failure (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.06-1.25; P = .001) and dialysis (HR, 1.71; 95% CI, 1.13-2.59; P = .012). For OAR, coronary artery disease (HR, 1.55; 95% CI, 0.98-2.44; P = .062) was associated with mortality. Statin use was protective of mortality for all patients (EVAR: HR, 0.68; 95% CI, 0.60-0.78; P < .01): OAR: HR, 0.58; 95% CI, 0.37-0.92; P = .020). Among octogenarians, high frailty was independently associated with 2-year mortality (EVAR: HR, 3.36; 95% CI, 2.62-4.31; P < .01 and OAR: HR, 2.35; 95% CI, 1.09-5.10; P = .030).

CONCLUSIONS

Nationally, a large portion of elective AAA repair in octogenarians is performed below recommended size thresholds, one-quarter of whom are frail with poor long-term 2-year mortality rates. High 2-year mortality following AAA repair in this age group exceeds the published risk of rupture for 5- to 5.5-cm AAA, suggesting that increase in the size threshold of elective repair among octogenarians should be explored.

The natural history of large abdominal aortic aneurysms in patients without timely repair

OBJECTIVE

Contemporary data on the natural history of large abdominal aortic aneurysms (AAAs) in patients undergoing delayed or no repair are lacking. In this study, we examine the impact of large AAA size on the incidence of rupture and mortality.

METHODS

From a prospectively maintained aneurysm surveillance registry, patients with an unrepaired, large AAA (≥5.5 cm in men and ≥5.0 cm in women) at baseline (ie, index imaging) or who progressed to a large size from 2003 to 2017 were included, with follow-up through March 2020. Outcomes of interest obtained by manual chart review included rupture (confirmed by imaging/autopsy), probable rupture (timing/findings consistent with rupture without more likely cause of death), repair, reasons for either no or delayed (>1 year after diagnosis of large AAA) repair and total mortality. Cumulative incidence of rupture was calculated using a nonparametric cumulative incidence function, accounting for the competing events of death and aneurysm repair and was stratified by patient sex.

RESULTS

Of the 3248 eligible patients (mean age, 83.6 ± 9.1 years; 71.2% male; 78.1% white; and 32.0% current smokers), 1423 (43.8%) had large AAAs at index imaging, and 1825 progressed to large AAAs during the follow-up period, with a mean time to qualifying size of 4.3 ± 3.4 years. In total, 2215 (68%) patients underwent repair, of which 332 were delayed >1 year; 1033 (32%) did not undergo repair. The most common reasons for delayed repair were discrepancy in AAA measurement between surgeon and radiologist (34%) and comorbidity (20%), whereas the most common reasons for no repair were patient preference (48%) and comorbidity (30%). Among patients with delayed repair (mean time to repair, 2.6 ± 1.8 years), nine (2.7%) developed symptomatic aneurysms, and an additional 11 (3.3%) ruptured. Of patients with no repair, 94 (9.1%) ruptured. The 3-year cumulative incidence of rupture was 3.4% for initial AAA size 5.0 to 5.4 cm (women only), 2.2% for 5.5 to 6.0 cm, 6.0% for 6.1 to 7.0 cm, and 18.4% for >7.0 cm. Women with AAA size 6.1 to 7.0 cm had a 3-year cumulative incidence of rupture of 12.8% (95% confidence interval, 7.5%-19.6%) compared with 4.5% (95% confidence interval, 3.0%-6.5%) in men (P = .002).

CONCLUSIONS

In this large cohort of AAA registry patients over 17 years, annual rupture rates for large AAAs were lower than previously reported, with possible increased risk in women. Further analyses are ongoing to identify those at increased risk for aneurysm rupture and may provide targeted surveillance regimens and improve patient counseling.