Untreated unruptured aneurysm: Natural history at long-term

Although the diagnosis of unruptured intracranial aneurysm (IA) has become more frequent, its natural history and management still remain controversial. A better comprehension of its evolution could optimize our therapeutic strategies. The aim of our study was to evaluate, in a cohort of patients with untreated unruptured IA based on the proposition of multidisciplinary staff meetings, the proportion of bleeding, death and cardiovascular events during a long-term prospective follow-up.

This longitudinal study concerned a series of patients with unruptured IA collected over a period of 8 years (2006-2014) identified from a prospectively collected database including all patients with unruptured IA discussed during multidisciplinary staff meetings in the neurosurgery department at Rouen University Hospital. Clinical endpoints were the rupture rate, incidence of death or occurrence of noticeable pathological event defined by any event leading to death, admission to the intensive care unit or challenging the vital prognosis.

After a mean follow-up delay of 46.9±18.7 months, the IA remained stable in 73 patients (98.6%) out of 74. The rate of rupture per aneurysm year of follow-up was 0.3%, the rate of cardiovascular events was 2.1% and the death rate was 2.8% per year of follow-up.

In this study, we emphasize the important incidence of adverse events in these patients, which has to be taken into account before proposing a prophylactic IA exclusion. The low incidence of IA rupture confirmed the decision of conservative treatment made during a multidisciplinary staff meeting.