Potential benefits and harms of offering ultrasound surveillance to men aged 65 years and older with a subaneurysmal (2.5-2.9 cm) infrarenal aorta

Abstract

Objective: The objective of this review was to perform a rapid evidence summary to determine the prevalence of subaneurysmal aortic aneurysms, growth rates, and risk factors that modulate growth in average-risk men aged 65 years and older. Secondary objectives were to evaluate benefits and harms of lifelong ultrasound (US) surveillance and treatment outcomes for any large aneurysms that develop in the screened population.

Methods: We searched multiple databases (eg, Ovid MEDLINE, Embase Classic and Embase, and the Cochrane Library) on February 16, 2016. Using a liberal accelerated method, two reviewers screened titles and abstracts for relevance and subsequently screened full-text studies. General study characteristics (eg, country, study design, number of participants) and data (eg, number of men with subaneurysmal aortas, quality of life [QoL], mortality) were extracted. One reviewer performed data extraction and risk of bias assessments, and a second reviewer verified 100% of studies. Any disagreements were resolved by consensus.

Results: The search identified 37 relevant studies ranging in size from 3 to 52,690 participants. Prevalence of subaneurysmal aortas ranged from 1.14% to 8.53%, and 55% to 88% of these men progressed to a 3.0-cm aneurysm by 5 years of follow-up. Risk factors for growth included the infrarenal aortic diameter at age 65 years, having a subaneurysmal aorta at age 65 years, and current smoking. The 36-Item Short Form Health Survey was the most commonly used tool to measure QoL, and QoL was typically lower in people with abdominal aortic aneurysm. Anxiety and depression levels did not differ significantly between comparison groups in any studies. Four studies reported on the number of men whose aorta was subaneurysmal on initial US who went on to surgery. Overall, 10% (57/547) of men initially measuring in the subaneurysmal range progressed to abdominal aortic aneurysm >5.4 cm and received elective surgery; 1% (6/547) received emergency surgery because of a ruptured aorta. Among those who did, mortality rates were much lower for elective (9.5%) vs emergency surgery (50%). Risk of bias was usually low for studies measuring prevalence and moderate and high for studies measuring psychological harms of screening and harms and benefits of surgery. Overall, using the Grading of Recommendations Assessment, Development, and Evaluation framework as guidance, the quality of the evidence was generally very low.

Conclusions: Because of the limited evidence and the low quality of the existing evidence, it is not possible to determine confidently whether men with abdominal aortas measuring 2.5 to 2.9 cm should be observed in a lifelong US surveillance program.