Effect of saline on temperature controlled Radiofrequency ablation

Saline for enhancement of lesion size has been demonstrated for constant power radiofrequency systems using saline irrigation of the treatment area. The data for temperature-controlled systems and non-irrigation applications of saline are limited. Data from a human clinical trial using a low-power, temperature-controlled radiofrequency system for treatment of the base of tongue demonstrated a correlation between the amount of electrolyte fluid injected into the treatment area and positive treatment outcome. This study investigates the effects of electrolyte solutions on lesion volume and energy delivery time using a low-power, temperature-controlled radiofrequency system in an ex vivo setting. Lesions were formed at set temperature and energy (85degreesC, 750 Joules), in bovine tongue. Varying amounts of saline, local anesthetic, or a mixture of the two, were used to simulate the in vivo situation. Lesion volumes increased with the amount of fluid injected, with saline having a greater effect than the local anesthesia or the mixture of the two. Fluid injection had a more variable effect on time. Both saline and local anesthesia alone decreased time with increased volume, but the change was not significant. Comparisons of the similarities and differences between the ex vivo and in vivo data are discussed.