Medical devices for implantation in a body vessel, and methods of using and making the same, are provided. A medical device includes a support frame having struts and a weakened frame portion, and a remodelable material tensionably attached to the support frame. The weakened frame portion has a first configuration in which the support frame has a first outward radial force and a second configuration in which the support frame has a second, lesser outward radial force. The remodelable material restricts expansion of the frame from a radially compressed configuration to a radially expanded configuration when the weakened frame portion is in the first configuration. The remodelable material can form one or more valve leaflets adapted to regulate fluid flow in a body vessel, such as a vein.