Epicardial linear electroporation ablation and lesion size

Background: Electroporation can be used as a nonthermal method to ablate myocardial tissue. However, like with all electrical ablation methods, determination of the energy supplied into the myocardium enhances the clinically required controllability over lesion creation.

Objective: To investigate the relationship between the magnitude of epicardial electroporation ablation and the lesion size using an electrically isolating linear suction device.

Methods: In 5 pigs (60-75 kg), the pericardium was opened after medial sternotomy. A custom linear suction device with a single 35 × 6-mm electrode inside a 42-mm-long and 7-mm-wide plastic suction cup was used for electroporation ablation. Single cathodal applications of 30, 100, or 300 J were delivered randomly at 3 different epicardial left ventricular sites. Coronary angiography was performed before ablation, immediately after ablation, and after 3 months survival. Lesion size was measured histologically after euthanization.

Results: The mean depth of 30, 100, and 300 J lesions was 3.2 ± 0.7, 6.3 ± 1.8, and 8.0 ± 1.5 mm, respectively (P = .0003). The mean width of 30, 100, and 300 J lesions was 10.1 ± 0.8, 15.1 ± 1.5, and 17.1 ± 1.3 mm, respectively (P<.0001). Significant tissue shrinkage was observed at the higher energy levels. No luminal arterial narrowing was observed after 3 months: 2.3 ± 0.3 mm vs 2.3 ± 0.4 mm (P = .85).

Conclusion: The relationship between the amount of electroporation energy delivered through a linear suction device with a single linear electrode and the mean myocardial lesion size is significant in the absence of major adverse events or permanent damage to the coronary arteries.