Tissue severing devices with sliding support and methods

A tissue severing device comprising:

• a handle;
• a tube member including an elongated tube having a tube member proximal end extending into the handle and a tube member distal end opposite the tube member proximal end, the tube member defining a tube member lumen that extends through the tube member proximal end to the tube member distal end and defining a tube member axis;
• an inner member including an elongated body having an inner member proximal end extending through the tube member lumen and into the handle and an inner member distal end opposite the inner member proximal end, the inner member being operable to be received within the tube member lumen;
• a cutting element including a cutting element proximal end and a cutting element distal end opposite the cutting element proximal end, the cutting element proximal end extending into the inner member distal end, the cutting element distal end extending from the inner member distal end,
• the tube member distal end being operable to move distally over and receive the inner member distal end and the inner member distal end therein, and the tube member distal end being operable to move in a proximal direction to expose the cutting element distal end;
• and
• a slidable support ribbon operable for supporting the inner member distal end in a curved position when the inner member distal end is at least partially exposed by the withdrawal of the tube member distal end, the slidable support ribbon comprising an elongated body including a slidable support ribbon proximal end and a slidable support ribbon distal end opposite the slidable support ribbon proximal end, the slidable support ribbon proximal end extending through the tube member lumen from about the tube member proximal end to about the tube member distal end and adjacent the inner member, the slidable support ribbon distal end positioned adjacent the inner member distal end and the cutting element distal end.