Comparative evaluation of intragastric bile acids and hepatobiliary scintigraphy in the diagnosis of duodenogastric reflux

Abstract

AIM: To assess the diagnostic value of a combination of intragastric bile acids and hepatobiliary scintigraphy in the detection of duodenogastric reflux (DGR).

METHODS: The study contained 99 patients with DGR and 70 healthy volunteers who made up the control group. The diagnosis was based on the combination of several objective arguments: a long history of gastric symptoms (i.e., nausea, epigastric pain, and/or bilious vomiting) poorly responsive to medical treatment, gastroesophageal reflux symptoms unresponsive to proton-pump inhibitors, gastritis on upper gastrointestinal (GI) endoscopy and/or at histology, presence of a bilious gastric lake at > 1 upper GI endoscopy, pathologic 24-h intragastric bile monitoring with the Bilitec device. Gastric juice was aspirated in the GI endoscopy and total bile acid (TBA), total bilirubin (TBIL) and direct bilirubin (DBIL) were tested in the clinical laboratory. Continuous data of gastric juice were compared between each group using the independent-samples Mann-Whitney U-test and their relationship was analysed by Spearman’s rank correlation test and Fisher’s linear discriminant analysis. Histopathology of DGR patients and 23 patients with chronic atrophic gastritis was compared by clinical pathologists. Using the Independent-samples Mann-Whitney U-test, DGR index (DGRi) was calculated in 28 patients of DGR group and 19 persons of control group who were subjected to hepatobiliary scintigraphy. Receiver operating characteristic curve was made to determine the sensitivity and specificity of these two methods in the diagnosis of DGR.

RESULTS: The group of patients with DGR showed a statistically higher prevalence of epigastric pain in comparison with control group. There was no significant difference between the histology of gastric mucosa with atrophic gastritis and duodenogastric reflux. The bile acid levels of DGR patients were significantly higher than the control values (Z: TBA: -8.916, DBIL: -3.914, TBIL: -6.197, all P < 0.001). Two of three in the DGR group have a significantly associated with each other (r: TBA/DBIL: 0.362, TBA/TBIL: 0.470, DBIL/TBIL: 0.737, all P < 0.001). The Fisher’s discriminant function is followed: Con: Y = 0.002TBA + 0.048DBIL + 0.032TBIL - 0.986; Reflux: Y = 0.012TBA + 0.076DBIL + 0.089TBIL - 2.614. Eighty-four point zero five percent of original grouped cases were correctly classified by this method. With respect to the DGR group, DGRi were higher than those in the control group with statistically significant differences (Z = -5.224, P < 0.001). Twenty eight patients (59.6%) were deemed to be duodenogastric reflux positive by endoscopy, as compared to 37 patients (78.7%) by hepatobiliary scintigraphy.

CONCLUSION: The integrated use of intragastric bile acid examination and scintigraphy can greatly improve the sensitivity and specificity of the diagnosis of DGR.

Keywords: Duodenogastric reflux, Diagnosis, Intragastric bile acids, Hepatobiliary scintigraphy

Core tip: The study results suggest that total bile acid is the most important factor of the bile acids to determine duodenogastric reflux (DGR) by using a variety of statistical methods. Using the receiver operator curve, we found the hepatobiliary scintigraphy is better than the examination of gastric juice in the diagnosis of DGR. From this study, the biggest revelation is that we can research other medical problems particularly using many statistical methods.