Unruptured intracranial aneurysms in patients over 80 years: natural history and management implications

Purpose: Patients over the age of 80 years when diagnosed with an unruptured intracranial aneurysm (UIA) pose unique decision-making challenges due to shortened life-expectancy and increased risk of treatment. Thus, we investigated the risk of rupture and survival of a consecutive series of patients who were diagnosed with an UIA after the age of 80 years. Methods: Data of consecutive patients with an UIA were reviewed, and patients were included in our study if they were first evaluated for a UIA by the senior author during their ninth decade of life. Outcomes were aneurysm rupture and overall survival after diagnosis. Survival was estimated from a Kaplan-Meier survival curve. Incidence of risk factors was compared to a population of patients less than 65 years who were seen by the senior author over the same time period. Results: Eighty-three patients who were over 80 years when diagnosed with a UIA were included in this study. In our population, there is a risk of rupture of 3.2% per patient-year. One-, three-, and five-year survival rates for our population were estimated to be 92, 64, and 35%, respectively. When compared to patients under 65 years diagnosed with a UIA, “over 80” patients had a significantly higher incidence of hypertension, and a significantly lower incidence of smoking history and familial aneurysm history. Conclusions: In our study population, UIAs greater than 7 mm carry a non-negligible risk of rupture of 3.2% per patient-year, and further studies investigating the risk-to-benefit ratio of treatment in this population are warranted.