Peri-Operative Mortality and Survival After Repair of Abdominal Aortic Aneurysm in Advanced Age Patients: A National Study from the Norwegian Registry for Vascular Surgery Focused on Nonagenarians

Objective: Treatment of abdominal aortic aneurysm (AAA) in nonagenarians has become more frequent. This national observational cohort study aimed to investigate peri-operative mortality and survival after AAA surgery in nonagenarians in Norway.

Methods: All AAA repairs registered in the Norwegian Registry for Vascular Surgery from 2015 to 2021 were identified and stratified into nonagenarians > 90 years old (n = 77), octogenarians 80 - 89 years old (n = 1 362), and patients < 80 years old (n = 4 590). The patient characteristics and comorbidities were recorded, and the 30 and 90 day mortality rates were calculated. Kaplan-Meier analysis was performed to obtain the estimated median survival and survival curves.

Results: In the nonagenarians, the 30 day mortality rates were 2.5% in asymptomatic patients, 33.3% in symptomatic patients, and 59.1% in the patients with a ruptured AAA (rAAA). The estimated median survival (years) were 3.3 (95% confidence interval [CI] 1.95 - 4.59) for asymptomatic AAA, 2.9 (interquartile range [IQR] 2.82, 5.80) for symptomatic AAA, and 0.1 for rAAA (IQR 0.01, 3.04). For nonagenarians surviving the first 90 days, the estimated median survival (years) were 4.2 (95% CI 2.56 - 5.88) for asymptomatic AAA, 3.4 (IQR 2.86, 5.80) for symptomatic AAA, and 3.8 (IQR 1.49, 4.85) for rAAA. The 90 day mortality rates were 100.0%, 80.0%, and 62.5% for asymptomatic, symptomatic, and rAAA, respectively, after open surgical repair (OSR), and 5.1%, 10.0%, and 50.0%, respectively, after endovascular aortic repair (EVAR).

Conclusion: Peri-operative mortality and survival results after AAA surgery in nonagenarians support treatment of selected asymptomatic patients. The 90 day survivors had an expected survival of more than three years, enabling balanced decision making regarding surgical vs. conservative treatment options in this challenging cohort. EVAR is the treatment method of choice for AAA in nonagenarians because most of them would probably live longer untreated than if treated by OSR.