A stent is adapted for deployment at a preselected site in a duct within the body of a patient to inhibit the lumen of the duct at that site from narrowing to a point that resists passage through the lumen. The stent is a generally cylindrical open-ended element having a perforated self-supporting sidewall of substantially uniform thickness adapted to be selectively expanded radially when the stent is to be deployed, to engage the wall of the duct and to resist radial contraction under forces exerted on said sidewall by the wall of the duct in the region of the engagement. The sidewall has greater rigidity in the midsection of the length of the cylindrical element and greater flexibility at each end thereof, by virtue of its having a composite design of different patterns, each pattern being a network of interconnected links with openings therebetween that determine the relative rigidity and flexibility of the sidewall along the length of the cylindrical element. The links may be sized to produce the differences in relative rigidity and flexibility along the length of the sidewall, and the sizing may undergo an abrupt or a continuous change between the midsection and each end of the cylindrical element. For sizing, the links may exhibit a decrease in width from the midsection to either end of the cylindrical element. Where the duct is a blood vessel with side branches emanating from the lumen of the main vessel, at least some of the openings between links in the midsection of the sidewall may be sized to enable access to the side branches from the lumen of the stent when the stent is deployed at the selected site in the main vessel.