Abstract and Introduction
Background and Aim: Common endoscopic findings in stomachs with Helicobacter pylori infections include antral nodularity, thickened gastric folds, and visible submucosal vessels. These findings are suggestive but not diagnostic of H. pylori infection. Magnifying endoscopy can reveal more precisely the abnormal mucosal patterns in an H. pylori-infected stomach; however, it requires more training, expertise, and time. We aimed to establish a new classification for predicting H. pylori-infected stomachs by non-magnifying standard endoscopy alone.
Methods: A total of 617 participants who underwent gastroscopy were prospectively enrolled from August 2011 to January 2012. We performed a careful close-up examination of the corpus at the greater curvature maintaining a distance ≤ 10 mm between the endoscope tip and the mucosal surface. We classified gastric mucosal patterns into four categories: normal regular arrangement of collecting venules (numerous minute red dots), mosaic-like appearance (type A; swollen areae gastricae or snakeskin appearance), diffuse homogenous redness (type B), and untypical pattern (type C; irregular redness with groove) to predict H. pylori infection status.
Results: The frequencies of H. pylori infection in patients with a normal regular arrangement of collecting venules pattern and types A, B, and C patterns were 9.4%, 87.7%, 98.1%, and 90.9%, respectively. The sensitivity, specificity, and positive and negative predictive values of all abnormal patterns for prediction of H. pylori infection were 93.3%, 89.1%, 92.3%, and 90.6%, respectively. The overall accuracy was 91.6%.
Conclusions: Careful close-up observation of the gastric mucosal pattern with standard endoscopy can predict H. pylori infection status.
Gastroscopic biopsy-based tests such as the rapid urease test, histological examination, and culture have been widely used to diagnose Helicobacter pylori infection. Many investigators have attempted to categorize the endoscopic findings characteristic of a H. pylori-infected stomach. In 2002, Japanese endoscopists found that collecting venules, seen as numerous minute red dots in the gastric corpus, were a characteristic finding in the normal stomach without H. pylori infection using both standard and magnifying endoscopy. This finding was termed "regular arrangement of collecting venules" (RAC). Although magnifying endoscopy provides more precise information concerning the network of collecting venules, it is not available in all endoscopy units, and its use requires training under an experienced supervisor.
The endoscopic findings of an H. pylori-infected stomach were erythema, erosions, antral nodularity, thickened gastric folds, and visible submucosal vessels. However, these findings are not a reliable method of diagnosis because of their low sensitivity and specificity.[3–6] Recently, Taiwanese endoscopists performed a study using close-up observation between the endoscopic tip and the gastric mucosa and found the "mosaic pattern" in the corpus mucosa. This method is a more sensitive and specific way to determine H. pylori infection status. They classified gastric mucosal patterns into two categories (normal RAC and abnormal mosaic pattern). However, the classification was insufficient to predict all H. pylori infections. We used four categories: a normal RAC and three abnormal patterns including mosaic-like appearance (type A), diffuse homogenous redness (type B), and untypical pattern (type C) to predict a H. pylori-infected stomach.
We performed a large-scale study to evaluate the diagnostic accuracy of H. pylori infection status with our own new endoscopic classification system using non-magnifying standard endoscopy. The aims of our study were to (i) establish a new classification for the H. pylori-infected stomach using four categories: a normal RAC pattern and three types of abnormal mucosal patterns (types A, B, and C); (ii) investigate the association between gastric mucosal patterns and severity of gastritis; (iii) determine the clinical features and other endoscopic appearance associated with H. pylori infection; and (iv) validate inter- and intraobserver agreement in the assessment of endoscopic patterns.
J Gastroenterol Hepatol. 2013;28(2):279-284. © 2013 Blackwell Publishing