title: Simultaneous use of endoscopic resection and radiofrequency ablation is not  safe in an esophageal porcine model.
abstract: 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.
authors.affiliation: Department of Gastroenterology and Hepatology, St Antonius hospital, Amsterdam, The Netherlands.
authors.forename: L Alvarez
authors.initials: LA
authors.lastname: Herrero
authors.forename: F G I
authors.initials: FG
authors.lastname: van Vilsteren
authors.forename: M
authors.initials: M
authors.lastname: Visser
authors.forename: S L
authors.initials: SL
authors.lastname: Meijer
authors.forename: M I
authors.initials: MI
authors.lastname: van Berge Henegouwen
authors.forename: J J G H M
authors.initials: JJ
authors.lastname: Bergman
authors.forename: B L A M
authors.initials: BL
authors.lastname: Weusten
mesh_terms: D000818:Animals; D001471:Barrett Esophagus / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects* / Q000379:methods; D003131:Combined Modality Therapy; D004938:Esophageal Neoplasms / Q000601:surgery*; D004939:Esophageal Perforation / Q000453:epidemiology / Q000209:etiology*; D004940:Esophageal Stenosis / Q000453:epidemiology / Q000209:etiology*; D004945:Esophagoscopy / Q000009:adverse effects* / Q000379:methods; D023421:Models, Animal; D012306:Risk; D013552:Swine; D016896:Treatment Outcome