Selecting the Best Gastric Anatomical Place for Biopsy to Detect Helicobacter Pylori in Iranian Morbid Obese Patients.

Background: Obesity and Helicobacter pylori (H. pylori) infection are public health problems in the world and Iran. This study aimed to indicate the anatomical place with the most accurate results for H. pylori. According to gastric mapping, this study will be able to evaluate the prevalence of H. pylori based on the pathology of gastric mapping and the accuracy of the antral rapid urease test (RUT) based on endoscopic findings.

Methods: In this cross-sectional study, upper digestive endoscopy and gastric pathology were studied in 196 obese patients candidates for bariatric surgery. Statistical analyses were performed using a t-test and Chi-square/fisher's exact test to compare the groups. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and odds ratio (OR) were used to compare RUT and pathological H. pylori test of each of the six areas of the stomach. We set a positive test of the pathology of 6 regions of the stomach as our gold standard (in this study).

Results: The most common area of the stomach for pathological findings of H. pylori were incisura (116, 59.2%), greater curvature of the antrum (115, 58.3%), lesser curvature of the antrum (113, 57.7%), lesser curvature of the corpus (112, 57.1%), greater curvature of the corpus (111, 56.6%) and cardia (103, 52.6%). The prevalence of H. pylori was 58.2% (114 cases) and 61.2% (120 cases) with RUT and gastric pathology, respectively. Mild, moderate, and severe infection of H. pylori in cardia (58, 29.6%), greater and lesser curvature of the antrum (61, 31.1%), and greater curvature of the antrum (37, 18.9%) had the highest percentages of incidence comparing to other sites of the stomach, respectively. The most sensitive area for pathologic biopsy was incisura (96.6%, 95% confidence interval: 91.7, 98.7).

Conclusion: According to the highest sensitivity, PLR, NPV, and pathological findings of H. pylori in accordance with the lowest NLR in the incisura compared with other parts of the stomach, it is highly recommended to take the biopsy from the incisura instead of other anatomical places of stomach for detecting H. pylori specifically if our strategy is taking only one biopsy.