Multi-modality ablation device

An instrument for ablation of tissue, the instrument comprising:

• a body having at least one surface for contacting a tissue surface, the at least one surface being substantially planar, and a heat exchanger;
• an ultrasonic transducer disposed in the body for generating ultrasonic energy and directing at least a portion of the ultrasonic energy to the tissue surface, the ultrasonic transducer being operatively connected to an ultrasonic generator;
• at least one radio-frequency electrode disposed on the at least one surface for directing radio frequency energy to the tissue surface, the at least one radio-frequency electrode being operatively connected to a power source;
• a tissue thickness measuring means for measuring a thickness of the tissue to be ablated;
• and
• one or more switches for selectively coupling at least one of the ultrasonic transducer to the ultrasonic generator and the at least one radio-frequency electrode to the power source based on a measured thickness of the tissue, wherein the heat exchanger cools at least one of the ultrasonic transducer, the at least one radio-frequency electrode, and the tissue surface.