Abstract
Tissue charring during radio frequency (RF) therapy causes an impedance rise and prevents further tissue heating from occurring, thereby limiting the size of lesions that can be created. The ability to create very large lesions would provide minimally invasive treatment options for deep tissue left ventricular arrythmias and otherwise-untreatable large liver tumors. Adding convection as a method of heat transfer by injecting saline at the RF electrode site acts to both clamp the electrode/tissue interface temperature and carry energy deeper into the tissue. We have developed a RF system that uses both conduction and convection simultaneously to both enhance the amount of heat transfer and prevent or greatly delay the onset of charring. Here we confirm the heat transfer augmentation of convection with experimental results in skeletal muscle, liver, and myocardium.
A New Approach to Ultrasound Guided Radio-Frequency Needle Placement
