Radiofrequency ablation of liver tumors: A novel needle perfusion technique enhances efficiency

Aims: Usually, the ablation is time-consuming due to charring around the electrodes. We hypothesize that an open saline perfusion might help to overcome this problem and allow faster ablations.

Methods: 159 liver tumors were treated during 95 sessions of mainly ultrasound assisted RFA with the same generator and the same expandable RFA-needle.Fifty-four tumors were treated according to the proposed manufacturer's protocol and compared with 105 tumors treated according to the novel saline perfusion protocol. The ablation procedure was performed until a tissue temperature of at least 100°C was reached at every electrode tip for at least 5 minutes. All the patients were followed up with contrast enhanced computed tomography (CT) at regular intervals. Local hepatic recurrence was defined as radiologic and/or histologic evidence of viable tumor in the ablated liver area.

Results: Both study groups were comparable.The median follow-up was more than two years in both groups. The median RFA time was significantly reduced from 18.9 minutes in the group without needle perfusion to 8.0 minutes in the group with needle perfusion (p<0.001). The local recurrence rate at the RFA site was tendentially higher in the non-perfusion group than in the perfusion group (9.6% vs. 5.8%). No recurrence occurred at the ablation site of tumors smaller than 3cm in either group.

Conclusions: The perfusion of an expandable radiofrequency needle with 0.9% saline solution significantly accelerates the ablation procedure of liver tumors without compromising the oncosurgical result.