Infusion of Hypertonic Saline into the Lung Parenchyma during Radiofrequency Ablation of the Lungs with Multitined Expandable Electrodes:Results Using a Porcine Model

The present study was performed to clarify the effect of hypertonic saline infusion into the lung parenchyma on radiofrequency ablation (RFA) of the lungs. A total of 20 ablation zones were created in 3 pigs. The ablation zones were divided into 3 groups. Group 1 (n6) consisted of ablation zones created by applying smaller radiofrequency (RF) power without saline infusion;group 2 (n5) zones were created by applying greater RF power without saline infusion;and group 3 (n9) zones were created by applying greater RF power with saline infusion. The techniques of saline infusion included administration of hypertonic saline 1ml before RFA, followed by continuous administration at a rate of 1ml/min during the first 2min after the initiation of RFA. The ablation parameters and coagulation necrosis volumes were compared among the groups. Group 3 had a tendency toward smaller mean impedance than group 1 (p0.059) and group 2 (p0.053). Group 3 showed significantly longer RF application time than group 2 (p0.004) and significantly greater maximum RF power than group 1 (p0.001) and group 2 (p0.004). Group 3 showed significantly larger coagulation necrosis volume (mean, 1,421mm3) than group 2 (mean, 858mm3, p0.039) and had a tendency toward larger necrosis volume than group 1 (mean, 878mm3, p0.077). Although this small study had limited statistical power, hypertonic saline infusion during RFA appeared to enlarge coagulation necrosis of the lung parenchyma.