A mechanism can include a step feature guidewire having a guidewire with aproximalend, a distal end, and a diameter. A self-expanding element can be disposedapproximate to thedistal end of the guidewire and can have at least two states which include acontracted diameterand an expanded diameter. The self-expanding element can be expandable underits inherentproprieties, based at least on its original shape and the nature of thematerials that make up theelement. Further, the expanded diameter can be approximately 70% to 280% ofthe guidewirediameter. While the guidewire is designed for passing through a body lumenwhile treating apatient, the expanded diameter is less than any body lumen diameter theguidewire isdetermined to pass through.
