The tissue ablation device includes a tissue ablation probe having an elongated probe shaft and electrodes carried by the distal end of the probe shaft. The device further comprises a cannula with a central lumen extending along a longitudinal axis for removably receiving the probe shaft. The cannula further comprises concentric inner and outer tubes extending along the longitudinal axis, wherein the outer is tube is translatable relative to the inner tube. The inner and outer tubes further comprise inner and outer apertures, respectively, that are aligned by translating the outer tube. When the inner and outer apertures are aligned, electrodes are deployed through the inner and outer apertures. One method includes introducing a cannula and a tissue ablation probe to a tissue site and operating the tissue ablation probe and the cannula to deploy the electrodes and ablate tissue.
