A tissue resection apparatus is provided which includes an outer tube with a helical coil disposed on a distal end. The coil is provided with a first electrode. A central tube has a distal edge profile comprising one or more surface segments. One of the surface segments includes a second electrode. The central tube is slidably disposed within the outer tube and positioned such that second electrode opposes at least a portion of the first electrode. A cutting tube is slidably disposed within the central tube and includes a cutting edge.