The Relationship between Gallbladder Morphology Classified by Ultrasound and the Presence of Gallbladder Stones

Purpose: Although the factors and mechanisms behind the formation of gallbladder stones (gallstones) have been studied for many years, few investigations have focused on the relationship between gallbladder morphology and the presence of gallstones. Therefore, this study was performed to obtain this information by comparing the presence or absence of gallstones and type of gallstone with the different morphological types of gallbladders, to determine the factors most commonly linked to the presence of gallstones.Subjects and Methods: In total, we evaluated 144 subjects (78 men and 66 women; mean age, 75±13 years; range, 34–95 years) who underwent an abdominal ultrasound at our hospital to screen for gallstones, between April and October 2019. Gallbladder morphology was classified into pyriform, hourglass-shaped, and flexed types, and the presence or absence of gallstones was compared among these types. Gallstones were classified as large and small, and their prevalence was compared according to gallbladder morphology. The relationship between the presence or absence of gallstones and age, body mass index, diabetes, dyslipidemia, and gallbladder morphology was determined.Results and Discussion: Regarding gallbladder morphology, 97 subjects had the pyriform-type, 26 had the hourglass-type, and 21 had the flexed-type. Gallstones were found in 11, 5, and 12 subjects with pyriform, hourglass, and flexed types, respectively. Furthermore, subjects with a flexed-type gallbladder had a significantly higher prevalence（p＜0.001），which was thought to be related to bile congestion. No significant differences were observed in the prevalence of large or small gallstones among the gallbladder morphological types. Flexed-type gallbladder morphology was significantly associated with the presence of gallstones (odds ratio, 10.35; 95% confidence interval 3.42–31.32; p＜0.001).Conclusion: Flexed-type gallbladder was most significantly associated with the presence of gallstones, suggesting that gallbladder morphology determined by ultrasound is an indicator of the presence of gallstones.