Abstract: A device for modifying blood flow through a target artery of a patient is described. A method for treating obesity in a patient includes positioning the device in a first artery to decrease blood flow through a second artery causing hypoperfusion to a gastrointestinal organ serviced by the second artery, and interfering with gastrointestinal function to induce weight loss. A system for placement of a blood flow modification device within a first artery to gradually reduce blood flow to a second target artery while maintaining blood flow to the first artery is also provided. The device may be modifiable after treatment to restore or increase blood flow to the artery.