Devices for vessel debulking with radiofrequency ablation

A tissue modification device for modifying a target tissue within a vascular stent, the tissue modification device comprising:

• an elongate body;
• a tissue modification structure on a distal end of the elongate body, the tissue modification structure comprising:
• an expandable support;
• and
• an electrode array carried by the expandable support, the electrode array having at least a first and a second electrically isolated zones positioned circumferentially around the expandable support;
• wherein, when expanded, the expandable support is configured to advance the electrode array into contact with the target tissue within the vascular stent;
• and
• wherein the tissue modification device is configured to deliver at least a first tissue modifying energy field from the first electrically isolated zone when a first electrical current is supplied to the electrode array, and optionally to deliver a second tissue modifying energy field from the second electrically isolated zone when a second electrical current is supplied to the electrode array.