System for treating occlusions in body lumens

A system for treating an occlusion within a body lumen comprising:

• an insulated wire, the insulated wire having a helically coiled portion near a distal end thereof, and with a distal tip of the insulated wire having a portion of the insulation removed to define an electrode;
• an elongated central electrode with a distal end thereof being received within the helically coiled portion of the insulated wire;
• an insulated tube located about the distal end of the central electrode and within the helically coiled portion of the insulated wire, wherein an annular space is defined between an outer surface of the insulated tube and an inner surface of the helically coiled portion to define a fluid lumen for supplying conductive fluid to the distal tip during use;
• and
• a tubular outer shell covering the coiled portion of the insulated wire, and with proximal ends of the insulated wire and the central electrode being connectable to terminals of an electrical pulse generator, where the system is configured so that when voltage pulses are applied to the central electrode and the insulated wire, a series of cavitation bubbles are created between the electrode of the insulated wire and the central electrode and wherein as the distal tip of the insulated wire is worn away during use, the electrode of the insulated wire moves towards the proximal end of the insulated wire.