US Patent 7037345 Medical stent with variable coil and related methods

A medical stent includes a first section which includes a first material, defines a lumen, and includes a first coil completing more than one revolution. The first coil revolves about and is coaxial with an axis, expanding and opening as it revolves from the origin of the first coil. A second section of the stent includes a second material, defines a lumen, and includes a second coil completing at least one revolution. A third section defines a lumen and is located between the first and second sections. The third section includes a co-extrusion of the first and second materials. One of the first or second sections is harder than the other section.