Biopsy and tract ablation

The device for biopsy tract ablation consists of two components: an insulation sheath and an RF applicator connected to a cable (Figure 1). The insulation sheath was made of stainless steel and was coated with a polyester film. The insulation sheath was 13 cm long and the outer diameter was 17-gauge. The monopolar RF applicator was made of stainless steel without coating. The RF applicator was 15 cm long and the active tip length was 2 cm when combined with the insulation sheath. A thermocouple was embedded within the tip of the RF applicator. A cable with a connector that delivers energy and receives thermal information connects the RF applicator to the generator (VIVA RFA System, STARmed). Procedures were performed on an inpatient basis. Grounding pads were attached to the bilateral thighs. Local anesthesia with lidocaine was performed. Sedative medications during the procedure were not used. The procedure was performed in the following order (Figure 2): (a) insert 18-gauge biopsy gun (Acecut, TSK Laboratory, Japan) into the insulation sheath, (b) target and sample hepatic mass under ultrasound guidance, (c) pull the biopsy gun out leaving behind the insulation sheath (one additional sampling was performed by reinserting the biopsy gun through the insulation sheath), (d) insert the RF applicator into the insulation sheath and (e) apply RF energy for tract ablation . During tract ablation, the power of RF energy was adjusted between 40 W and 60 W to maintain the temperature at the tip of the applicator at 70–80°C.

Device for biopsy tract ablation.

Process of biopsy and tract ablation. (a) insert biopsy gun into the insulation sheath, (b) target and sample hepatic mass under ultrasound guidance, (c) pull the biopsy gun out leaving behind the insulation sheath, (d) insert the RF applicator into the insulation sheath and (e) apply RF energy for tract ablation.