Treatment of gastric dysplasia and metaplasia by endoscopic radiofrequency ablation: a feasibility study

Abstract

INTRODUCTION: Patients with pre-neoplastic gastric lesions including intestinal metaplasia (IM) and dysplasia are at increased risk of developing gastric cancer. Endoscopic radiofrequency ablation (RFA) has been successfully used in the eradication of dysplasia and IM associated with Barrett's esophagus. We tested the feasibility of using RFA for the treatment of dysplasia and IM in the stomach. METHODS: Patients who had histologically confirmed gastric dysplasia or IM were recruited. All patients had H. pylori eradicated prior to RFA. Gastroscopy was performed by high definition endoscope with narrow band imaging and chromoendoscopy. Gastric pre-neoplastic lesions should be endoscopically visible, well defined and not raised. Ablation was performed using a HALO90 catheter (Covidien GI Solutions) attached to gastroscope and conducted under direct visualization until the target gastric mucosal lesions were treated. All procedures were performed on an outpatient basis under intravenous sedation. Endoscopy and RFA was repeated at 8 week intervals for a maximum of 3 sessions or when there were no further endoscopically visible lesions. All patients were followed up by endoscopy at 6 and 12 months post-RFA. During follow up examination, reference to previous tattoo marks and video-recordings were made to ensure accurate localization of previous RFA treated lesions. Areas suspicious for dysplasia and/or metaplasia were biopsied for histological examination. The primary outcome was the complete eradication of dysplasia and/or IM. The secondary outcome was improvement in grading of IM as stipulated in updated Sydney Classification. The histological assessment was made by two pathologists who were blinded to the sequences of the biopsy samples. RESULTS: A total of 12 patients were recruited (median age 73 years; 7 male). Four patients had low-grade dysplasia (LGD) and the remaining 8 patients had non-dysplastic IM at baseline. Up to the time of writing this abstract, a total of 25 treatment sessions were applied and 4 patients had completed 3 sessions of RFA. Nine patients, including 2 patients with LGD, had completed their 6-month follow up endoscopy and 5 patients had completed their 12-month follow up. Complete eradication of dysplasia was noted in both patients with LGD at baseline (100%). The severity of IM improved in 6 (67%) patients and the remaining 3 patients showed no interval changes on histology at 6-months. At 12-months, 3 (60%) patients had histological improvement in IM. Most patients tolerated the procedure well, except one patient who had a minor mucosal laceration of the cricopharyngeus during insertion of the catheter. CONCLUSION: Radiofrequency ablation successfully eradicated low-grade dysplasia of the stomach. Gastric IM persisted with RFA treatment, but most showed histological improvement on follow up.