A radiofrequency ablation device includes an elongate cannula having a distal portion and a proximal portion and a lumen extending between the distal and proximal portions. The RF ablation device further includes an elongate tubular member disposed within the lumen of the elongate cannula, the elongate tubular member having a distal region and a proximal region, the elongate tubular member including a lumen extending between the distal and proximal portions. A sildable electrode member is disposed in the portion of the elongate cannula lumen located external to the elongate tubular member. As an alternative to the elongate tubular member, the electrode member may include a lumen. The lumen of the elongate tubular member (or electrode member) carries or vents gaseous vapor generated during the RF ablation process.
