Long-Term Evaluation of Biliary Reflux After Experimental One-Anastomosis Gastric Bypass in Rats.

BACKGROUND: Controversy remains regarding biliary reflux after one-anastomosis gastric bypass (OAGB). The aim of this "pilot" study was to analyze biliary reflux and its potential long-term consequences on esogastric mucosae in OAGB-operated rats. METHODS: Diet-induced obese rats were subjected to OAGB (n = 10) or sham (n = 4) surgery and followed up for 16 weeks. Evolution of weight and glucose tolerance was analyzed. Bile acid concentration measurement, histological and qRT-PCR analysis were performed in the esogastric segments. RESULTS: Weight loss and glucose tolerance were improved after OAGB. Mean bile acid concentration was 4.2 times higher in the esogastric segments of OAGB rats (compared to sham). A foveolar hyperplasia of the gastro-jejunal anastomosis and an eosinophilic polynuclear cell infiltration were observed in OAGB rats. An esophageal hyper-papillomatosis was observed in both groups (OAGB = 50%, sham = 50%). qRT-PCR analysis showed no differences between OAGB and sham mRNA levels of Barrett's esophagus or esogastric carcinogenic-specific genes. No intestinal metaplasia, dysplasia, or cancer were observed after a 16-week follow-up. CONCLUSIONS: After a 16-week follow-up, this pilot study confirmed the good reproducibility of our OAGB rat model. OAGB rats had not developed any pre-cancerous or cancerous lesions. Further experimental studies with longer term follow-up are required.