7022 One uniform endosonographic layer reflects a thin subserosal adipose tissue of the normal gallbladder wall.

Abstract

Introduction and aim: Endoscopic ultrasonography (EUS) plays a major role in diagnosis of the gallbladder lesions. The normal gallbladder wall has been demonstrated to consist of 3 layers on EUS images. It is generally accepted that the 2nd and the 3rd layers include the muscularis propria and subserosal fibrous tissue, and the subserosal adipose tissue, respectively. However these 3 layers cannot be seen in some normal gallbladder by EUS images. Therefore this study was aimed to clarify the cause of these 2 different EUS images seen normal gallbladder by histological study of the gallbladder wall performed simultaneously. Materials and methods: Gallbladder specimens from 12 autopsy cases without biliary tract disorders, 6 with the three EUS layers (goup A) and 6 with one uniform layer (group B), were enrolled in this study. Two needles were stabbed into the gallbladder wall from the mucosa to perform EUS and histological study for the same area of the specimen. For this study an Olympus GFUMQ 240 with a frequency of 7.5MHz was used. Results: Histology of the specimens were summarized in the table. The thickness of the muscularis propria and fibrous layer showed no significant differences between group A and B. While the thickness of the adipose layer of group B was determined to be one half of group A. Conclusions: This study indicates that the one uniform layer seen in normal gallbladder on EUS images reflects a thin subserosal adipose layer.