Simultaneous use of endoscopic resection and radiofrequency ablation is not safe in an esophageal porcine model

Radiofrequency ablation (RFA) is safe and effective for eradication of Barrett’s esophagus after endoscopic resection (ER) of neoplasia. Widespread ER, however, is likely to induce stenosis, hampering subsequent circumferential RFA. A ‘single step’ procedure with ER and circumferential RFA in the same session may avoid this problem. Two variants are possible: circumferential RFA of Barrett’s esophagus including the lesion followed by ER of the ablated lesion (‘RFA→ER’), or ER of the lesion directly followed by circumferential RFA of remaining Barrett’s esophagus including the resection wound (‘ER→RFA’). First aim was to evaluate perforation risk of ‘ER→RFA’ using increasing RFA energies. Second aim was to compare stenosis rate after ‘ER→RFA’ versus ‘RFA→ER’. In Experiment 1, 24 areas in six pigs underwent widespread ER directly followed by circumferential RFA with increasing energies (2 x 10, 2 x 12-6 x 12 J/cm(2)) in the esophagus. In Experiment 2, eight pigs each had four treatment areas randomized: ‘ER→RFA’, RFA alone, ER alone, and ‘RFA→ER’. No acute perforations occurred when ablating ER wounds. Two delayed perforations occurred: one in experiment 1, another in experiment n2 at the ‘ER→RFA’ area. The remaining seven pigs in experiment 2 showed stenosis in all ‘ER→RFA’ and ‘RFA→ER’ areas versus 5/7 RFA alone areas, and 0/7 ER alone areas. In conclusion, the ‘single step’ variant ‘ER→RFA’ is not safe in this porcine model and seems therefore not ethical to evaluate in humans at this stage. Given the high rate of stenosis after ‘RFA→ER’ and RFA alone, one might question the validity of the porcine model for this type of experiments.