A self-expandable stent (1) formed of a flexible, part-tubular body (2), anchoring portions (3) extending from each end of the body (2) and an array (4) of holes or perforations (40, 41, 42) through the body (2) and anchoring portions (3). The body (2) includes an open side (20) and a pair of axial edges (21) extending along a longitudinal axis (L) of the stent (1). The body (2) also includes a central portion (5) and a pair of axial edge portions (6) joining the central portion (5) to the axial edges (21). The central portion (5) of the body (2) is invertible from a relaxed, part-tubular condition to a flexed, inverted part-tubular condition in which the axial edges (21) overlap or converge toward one another for insertion and release in a lumen (TR, TET) to expand, bear against and support a wall of the lumen (TR, TET).