“Honey Pot”-Like Lesion Formation: Impact of Catheter Contact Angle on Lesion Formation by Novel Diamond-embedded Temperature-controlled Ablation Catheter in a Porcine Experimental Model

Background Novel diamond-embedded catheter enables precise temperature-controlled ablation. However, the effects of contact angle on lesion formation of this catheter are poorly understood. Objective This study evaluated lesion formation using the temperature-controlled ablation catheter embedded with diamond at different angles in a porcine experimental model. Methods We used freshly sacrificed porcine hearts, and radiofrequency catheter ablation was performed at 50 watts for 15 s at an upper-temperature setting of 60°C. The contact force (5, 10, and 30 g) and catheter contact angles (30°, 45°, and 90°) were changed in each set (n = 13 each). The surface width, maximum lesion width, lesion depth, surface area, distance from the distal edge to the widest area, and impedance drop were evaluated. Results The surface width and maximum lesion width were longer at 30° than at 90° (p<0.05). There were no significant differences in the lesion depth by catheter angle except at 30 g. The surface area was larger at 30° than at 90° (p<0.05). The distance from the distal edge to the widest area was longer at 30° than at 90° (p<0.05). There were no significant differences in the impedance drop according to the catheter angle. Conclusion With the diamond-embedded temperature-controlled ablation catheters, the lesion width increased at a shallower contact angle, whereas the lesion depth did not. The surface area also increased at a shallower contact angle. This catheter created a large ablation lesion on the proximal side of the catheter, which looked like a “Honey pot.”