An embodiment of the invention provides a prosthesis delivery system comprising a delivery catheter having an expandable member and a prosthesis carried over the expandable member. The prosthesis includes a radially expandable scaffold section and at least two anchors extending axially from an end thereof; and means for capturing at least the anchors to prevent the anchors from divaricating from the expandable member as the catheter is advanced through a patient's vasculature.