Background
/Aims: The aims of this study were to determine the H. pylori re-infection rate in patients that underwent endoscopic mucosal resection (EMR) due to a gastric adenoma and gastric adenocarcinoma, and to define the correlation between H. pylori re-infection and the presence of metachronous lesions. Methods: An endoscopic examination with a biopsy was performed at six months, 12 months, and every year thereafter to determine if H. pylori re-infection occurred and if metachronous lesions were present in patients that had undergone EMR (EMR group). At least a three-year follow-up examination was performed, and patients with an on-site recurrent lesion were excluded. The re-infection rate was compared to the rate in patients with peptic ulcers (control group). Results: Six patients (24%) among the 25 patients included in this study had H. pylori re-infection, an indication of a high re-infection rate as compared to the rate in patients with peptic ulcers (p=0.03). Two patients (33.3%) who were re-infected with H. pylori had metachronous lesions (p=0.009). Conclusions: Determination of the H. pylori status during a follow-up study after EMR is essential and re-eradication therapy is recommended in patients with H. pylori re-infection to prevent metachronous lesions. (Korean J Gastrointest Endosc 2008;36: 257-261)