A stent is provided with arms for positioning the stent between two passageways. The stent may also be a stent-graft with a transition between a covered portion and an uncovered portion that is positioned relative to the junction between the two passageways. The arms are self-expanding and are biased outward from the tubular wall of the stent structure. The arms engage the wall of the first passageway around the junction to the second passageway to position a portion of the stent in the first passageway and another portion of the stent in the second passageway.