Asymptomatic Intracranial Aneurysms in the Elderly: Long-Term Clinical and Radiologic Follow-Up of 193 Consecutive Patients

Background: Evidence is lacking regarding the role of radiologic surveillance for asymptomatic intracranial aneurysms (AIAs) in the elderly (≥65 years). We sought to establish if long-term clinical and radiologic observation is warranted for older patients with AIAs. Methods: A retrospective cohort of 193 consecutive patients with 255 AIAs were clinically and radiologically observed between January 2011 and January 2019. The primary end points were documented aneurysm growth, subarachnoid hemorrhage, or definitive treatment with microsurgical clipping or endovascular coiling. Baseline patient and aneurysm characteristics were obtained. Univariate and multivariate comparisons were performed. Results: Aneurysm growth was observed in 8 patients (4.2%) at a median follow-up of 58.2 months (interquartile range, 38.4–78.5 months). The median aneurysm size at initial diagnosis was 3.5 mm (interquartile range, 2.2–5 mm). Aneurysms larger than 7 mm selected for surveillance were noted in 37 patients (19.2%). The growth rate was estimated at 0.2 mm per person-year. At the end of the study period, 175 patients (90.7%) were alive, 6 (3.1%) were lost to follow-up, and 12 (6.2%) died of unrelated causes. During the 1025.2 person-years follow-up, no patient had experienced subarachnoid hemorrhage, and none required definitive treatment. The presence of aneurysmal bleb (odds ratio, 6.02; 95% confidence interval, 1.15–31.43; P = 0.033) and multiple intracranial aneurysms (odds ratio, 10.98; 95% confidence interval, 1.27–94.91; P = 0.029) were associated with growth. Conclusions: AIAs in older patients deemed suitable for conservative management do not require robust follow-up. The current study suggests a potential role for closer surveillance for patients with multiple intracranial aneurysms or aneurysms with bleb morphology.