Microwave Antenna Probe Having a Deployable Ground Plane

A surgical ablation probe, comprising:

• a cannula having a proximal end and a distal end;
• a shaft slidably disposed within the cannula and having at least a stowed position and a deployed position;
• an inner conductor coaxially disposed within the shaft and extending from a distal end thereof to form a needle electrode;
• and
• a deployable ground plane electrode assembly disposed about a distal end of the shaft, wherein when the shaft is in a stowed position, the deployable ground plane electrode is substantially contained within the cannula, and when the shaft is in a deployed position the deployable ground plane electrode extends substantially radially from a distal end of the shaft.

A method of using a surgical ablation system, comprising:

• positioning an ablation probe at an operative site, wherein the ablation probe includes a cannula having therein a deployable ground plane antenna and a distal needle electrode;
• deploying the ground plane antenna and distal needle electrode;
• delivering electrosurgical energy to tissue via the needle electrode to facilitate the insertion of the needle electrode into tissue;
• inserting the needle electrode into tissue;
• delivering ablation energy to tissue via the needle electrode;
• withdrawing the needle electrode from tissue;
• retracting the ground plane antenna into the cannula;
• and
• removing the ablation probe from the operative site.