Bipolar ablation is an innovative direction of catheter ablation technology. The aim of this study was to investigate the damaged area of bipolar radiofrequency ablation in vitro pigs' hearts under different conditions and to evaluate the effectiveness and safety. The bipolar radiofrequency ablation was performed in vitro pigs' hearts with a 4 mm bipolar electrode under different conditions at various combinations of the parameters (Distance: from 12 mm to 17 mm; Power: 30 w or 40 w; Time: from 20 s to 90 s; Temperature: 45°C or 60°C; Saline Perfusion: 0 ml/h, 1000 ml/h or 1500 ml/h). We measured the length, width, depth, connection rate and blasting rate of the connective ablation lesion and then evaluated the effectiveness and safety of connective ablation lesion. Numerical analysis showed that there was a positive correlation between the time, temperature and the length, depth, connection rate, blasting rate. There was a negative correlation between the power, perfusion and the depth, while other indexes were positively correlated with the power, perfusion. Distance and length were positively correlated, while other indexes were negatively correlated with the distance. Regression analysis showed that the infusion was not significantly correlated with the depth, connection rate, blasting rate. The temperature was not significantly correlated with the length, connection rate. Power and depth's correlation was not significant. When the parameter combination was 12 mm, 20 s, 30 w, 60°C, 1500 ml/h, the effectiveness and safety was optimum, with the mean lesion length being 19.89 ± 3.02 mm, the depth of an average being 3.50 ± 0.63 mm, the connection rate and the blasting rate being 100% and 13.9% respectively. The bipolar ablation in vitro pigs' hearts could form the most stable continuous damage.
Keywords: Bipolar ablation; cold saline perfusion; connective ablation; isolated pigs’ hearts.