Large Population Multi-Center Study of Small Unruptured Intracranial Aneurysms in Prospective Cohorts: Initial Sac Morphology and Longitudinal Outcome

Most intracranial aneurysms (IA) that present unruptured at the clinic remain stable over time with no measurable change or symptoms, if left untreated. But a few do grow larger and occasionally rupture. The ability to preemptively identify aneurysms that will become unstable over time (i.e., those that will grow and/or rupture) can result in timely intervention for these few patients while avoiding unnecessary treatment for countless others [1]. Previous reports assessing potential factors including by our group [2–4] have been confined to comparing geometric and/or biomechanical indices of aneurysms between populations that presented with ruputred lesions from those that presented with unruptured lesions. But, such indices (that discriminate rupture ‘status’) need not necessarily distinguish unruptured aneurysms that fork toward growth and/or rupture over a period of time from those that remain stable over time. Further, the physician’s dilemma to treat or not to treat presents itself mostly only in small aneurysms (< 7mm).