An expandable stent comprising a tubular body made up of a plurality of separated tubular elements (1) arranged along a common longitudinal axis. Each tubular element (1) comprises a plurality of rhombic-shaped closed cell elements (2) joined by circumferentially extending linking members (3). The closed cell elements (2) are expandable to allow the tubular elements, and hence the stent itself, to expand. In the direction of the longitudinal axis of the stent, the extremities of each of the closed cell elements has an enlarged loop (30) with waisted portions (33) which allow the tubular elements to interlock to create a stable structure, at least when in the unexpanded condition.