Outcomes of Sub-threshold Abdominal Aortic Aneurysms Undergoing Surveillance in Patients Aged 85 Years or Over

Objective: Despite an increasing elderly population there is limited evidence regarding the surveillance and management of small abdominal aortic aneurysms (AAAs) in octogenarians. This study investigated outcomes of patients aged ≥85 years undergoing AAA surveillance to identify whether discontinuation of surveillance might be safe. Methods: This was a retrospective cohort study of all patients aged 85 years undergoing surveillance with a small (30–54 mm) AAA between January 2007 and November 2017. Patients were stratified depending on aneurysm diameter at index (<40 mm, 40–50 mm, > 50 mm). A threshold of 55 mm was used to decide intervention in all patients. Subsequent management of threshold aneurysms, aneurysm related and all cause mortality were also collected. Results: One hundred and one patients were included (88 male, mean diameter at index 45 mm, median follow up 56.0 months). The majority of patients (72.3%) undergoing surveillance had not reached threshold at the end of follow up. Only one patient in the <40 mm group developed a threshold aneurysm, compared with five (11.6%) and 22 (75.9%) in the 40–50 mm and >50 mm groups, respectively (p < .0001). Of the 28 patients reaching threshold, eight (28.6%) underwent surgical repair (5 standard endovascular, one complex endovascular, and two open). Twenty-six (25.7%) patients died during follow up, with cardiorespiratory pathologies being the leading cause of death. Only three aneurysm related deaths were observed, including two fatal ruptures and one death following repair from an infected stent graft (all in the >50 mm index group). Conclusion: The present data suggests that discontinuation of aneurysm surveillance in patients aged 85 years with aneurysms < 40 mm might be safe. In patients with a larger aneurysm or those approaching threshold, early assessment of fitness for surgery may prevent unnecessary surveillance. The decision to treat aneurysms reaching threshold is complex but is appropriate in selected patients.