The treatment decisions are not simple, since each choice has its own trade-offs. How the benefits and trade-offs are valued varies across different patients, and, therefore, the right treatment decision needs to include greater patient participation. This starts with better communication of the probabilities associated with the outcomes of each option in terms that can be understood by patients. Equally important is helping the patients clarify their own treatment goals, as well as legitimizing patients' partnership in the decision-making process. Tools (e.g., decision aids) to achieve shared decision-making, are lacking in this area of medicine. We propose to investigate the impact of such decision aids on patient satisfaction and the outcomes of cerebral aneurysm coiling and clipping.