Stent with anti-migration feature

A method of forming a stent, comprising:

• attaching a plurality of threaded mandrels to a central mandrel, the threaded mandrels aligned parallel to the central mandrel and spaced apart around a circumference of the central mandrel;
• wrapping a shape memory filament around a first threaded mandrel forming a first circumferential loop;
• extending the filament circumferentially to a second threaded mandrel adjacent the first threaded mandrel, and wrapping the filament around the second threaded mandrel forming a second circumferential loop;
• extending the filament circumferentially to and wrapping the filament around successive adjacent threaded mandrels, forming additional loops;
• when the filament is extended back to the first threaded mandrel, moving the filament longitudinally and again wrapping the filament around the first threaded mandrel to form an additional loop;
• continuing the extending and wrapping of the filament circumferentially around each threaded mandrel, moving longitudinally along the threaded mandrels, thereby forming a series of longitudinally spaced apart loops on each threaded mandrel;
• heat setting the shape memory filament;
• removing the threaded mandrels;
• starting with the first circumferential loop, drawing each circumferential loop through a longitudinally adjacent loop along the central mandrel to form a stent;
• and removing the stent from the central mandrel.