Abdominal Aortic Aneurysms in the Ageing: Outcomes of Aneurysm Surveillance in 85 Year Olds

Abstract

Introduction - By 2036 it is estimated that the number of people over the age of 85 years will double from present levels.1 This will have a profound impact on the management of complex vascular pathologies, such as abdominal aortic aneurysms (AAA). Despite this, the evidence relating to AAA surveillance was performed on patients aged less than 80 years and subsequently there is a paucity of evidence relating to the continued surveillance of this cohort.2 We aim to assess the outcomes of patients of 85 year olds who are under surveillance for small AAAs (3.0-5.5cm). Methods - A single-centre, retrospective analysis of all patients, aged 85 or over, undergoing active surveillance of small AAAs between January 2007-January 2018. Patients were stratified into four groups according to AAA diameter (<4.0, 4.0-4.5, 4.6-5.0, >5.0cm) at the age of 85 years (index scan), or older if first scan after this age. A comparison between the groups was performed to identify the rates of patients reaching threshold (>5.5cm), subsequent management and mortality (ruptured AAA and other cause mortality). Follow-up was continued from index scan to death or 01/01/2018 (whichever sooner). Results - 101 patients were identified (male=88) with a mean AAA diameter of 4.5cm (SD=0.92) at index scan. Mean follow-up was 1078 days (SD=739). 28 patients (27.7%) reached threshold size for repair, of which 8 (28.6%) underwent elective surgical repair. Of patients undergoing repair, 6(75%) had an AAA of >5cm at index scan. In patients with an AAA of <4.0cm at index, only 1 (3.4%) reached threshold and none underwent repair. Standard endovascular aneurysm repair was the modality of choice (62.5%). No patients underwent emergency repair. Comparison of outcomes between groups is shown in table 1. Overall mortality in the cohort was 26 (25.7%). Acute lower respiratory tract infection (42.3%) and cerebral vascular accident (23.1%) were the leading causes of death. Only 2 deaths occurred from ruptured AAAs (7.7%), both having an AAA of >5cm at index. No 30-day post-operative mortality was recorded.Table 1Comparison of patients reaching threshold and undergoing repairAneurysm diameter at aged 85 (cm)TotalTotal reaching threshold (% total)Surgical repair (% threshold)Mortality - ruptured aneurysm (% total)<4.0291 (3.4)0 (0.0)0 (0.0)4.0-4.5264 (15.4)1 (25.0)0 (0.0)4.6-5.0171 (5.9)1 (100)0 (0.0)>5.02922 (75.9)6 (27.3)2 (6.9) Open table in a new tab Conclusion - At the age of 85 years, it is very unlikely that patients with AAAs of <4cm will reach a threshold size for repair and discontinuation of surveillance can be considered. In our experience, the risk of death for a rupture in patients with AAAs 3.0-5.5cm at the age of 85 years remains relatively low and occurred only in patients with AAAs >5cm at index scan.