Evaluating Radiofrequency Ablation in Pigs

Previous literature reported that the number of lumbar vertebrae in pigs was 6-7 (25 (link)). The experimental animal in this study was the Bama miniature pig, and each pig had six lumbar vertebrae. RFA was performed in L1, L2, L3, L4, and L5 vertebrae of six Bama miniature pigs, and L5 vertebra was not ablated as control group. The ablation parameters were set as power 35W, temperature 70 °C, active tip 1cm, and ablation time 20 minutes. Thermocouples were placed in the spinal canal, the pedicle hole, and the anterior edge of the vertebra to monitor the temperature in real time. MR imaging (GE, 3.0T discovery, MR750) was performed on 0, 7, and 14 days after RFA. The scanning sequences were T1-weighted and T2-weighted. In T1-weighted and T2-weighted images, the longest diameter of RFA was measured.
The three groups of pigs were euthanized at three separate time points, and then the lumbar vertebrae were taken out. A high-precision hard tissue slicer was used to cut the vertebrae to obtain a complete cross-section of the vertebral body. The thickness of the section was about 2 mm. The maximum diameter of ablation range of gross specimens was measured. Then the special embedding box was used for embedding, ethylene diamine tetraacetic acid (EDTA) was used for decalcification, and the decalcification of samples was observed regularly. Finally, HE and TUNEL were used to evaluate the range of RFA. According to the effective range of HE staining, the maximum diameter of RFA was measured.