A system for supporting or dilating a body vessel includes a balloon catheter with a shaft having a delivery lumen in communication with an interior of the balloon. The balloon includes holes formed in the outer wall of the balloon. Additional or daughter balloons are delivered through the delivery lumen into the cavity of the balloon and through the holes into engagement with the holes. The daughter balloons are inflatable to seal against the holes, and the main balloon is subsequently inflatable when sealed by the daughter balloons. The daughter balloons may be delivered to branch vessels to provide support in addition to the inflation of the main balloon. The system may include preloaded wires extending through the delivery lumen and through the holes, and the daughter balloons can be delivered over the wires to the desired location.