The Revolutions of Helicobacter Pylori Infection, Bacterial Density, and Histological Features After Antrectomy

The eradication of H pylori is known to reduce the recurrence rate of peptic ulcer and gastric inflammation. But it is still not clear about the prevalence of HP infection in patients after surgical interventions when the micro-environment had been changed. Since biliary enterogastric reflux is suggested to inhibit the growth of HP, we will investigate in a prospective study the effect of partial gastrectomy on the influence of HP infection incidence.

Patients with previous distal gastrectomy will be prospectively evaluated as study group. Same number of patients with the same indication of endoscopy evaluations and without previous gastrectomy will be established as a normal control group for H pylori infection rate comparison. All patients in study and control groups who had previously received H pylori eradication therapy will be excluded. Three gastric biopsy specimens were collected from each patient for histological analysis. Patients with a pre-operative biopsy, operative specimen revealing H pylori colonization or a positive serum H pylori IgG will be indicated previous H pylori infection and will be assessed the percentage of spontaneous clearance of HP infection. A positive bile staining will indicate biliary enterogastric reflux. This assessment will be made by two investigators, and disagreements will be resolved by joint discussion to reach a consensus. Tissue sections stained with hematoxylin and eosin and the Giemsa stain will be examined by pathologist who was unaware of the endoscopy findings. Density of HP in the tissue and histological gastritis activity and intestinal metaplasia will be graded as normal (0), mild (1), moderate (2) and severe (3) based on the Sydney system. Follicular gastritis will be based on the absence (0) or presence (1) of lymphoid follicules and lymphoid with germinal center (2).

The primary end point will be the change of infection rate on HP after distal gastrectomy procedure comparing the normal control. The secondary end point will assess the correlation between the duration of the antrectomy, the operative procedure, the severity of bile reflux with the inhibition of HP growth. Finally, this study will be base on histopathological features with the density of HP, the grading of gastritis activity, intestinal metaplasia and follicular gastritis.