A stent (1) comprising a tubular frame (2) comprising a first end (3) and a second end and a longitudinal axis (4) therebetween. The frame (2) comprises a plurality of struts (9) defining a generally cylindrical portion comprising a longitudinally extending helical fin (11) protruding radially inwardly and having a helix angle. The angle, relative to the longitudinal axis (4), of at least some of the struts (9) in the helical fin (11) is substantially aligned with the helix angle of the helical fin (11).