"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: The purpose of this study was to evaluate lesion formation using the temperature-controlled ablation catheter embedded with diamond at different angles in a porcine experimental model.

Methods: Freshly sacrificed porcine hearts were used. Radiofrequency catheter ablation was performed at 50 W for 15 seconds at an upper temperature setting of 60°C. The contact force (5g, 10g, 30g) and catheter contact angles (30°, 45°, 90°) were changed in each set (n = 13 each). Surface width, maximum lesion width, lesion depth, surface area, distance from the distal edge to the widest area, and impedance drop were evaluated.

Results: Surface width and maximum lesion width were longer at 30° than at 90° (P <.05). There were no significant differences in the lesion depth by catheter angle except at 30g. Surface area was larger at 30° than at 90° (P <.05). Distance from the distal edge to the widest area was longer at 30° than at 90° (P <.05). There were no significant differences in impedance drop according to catheter angle.

Conclusion: With diamond-embedded temperature-controlled ablation catheters, lesion width increased at a shallower contact angle, whereas lesion depth did not. 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."