Sonographic measurement of normal common bile duct diameter and associated factors at the University of Gondar Comprehensive Specialized Hospital and one private imaging center in Gondar town, Northwest Ethiopia

Abstract

Abstract Background: Common bile duct (CBD) is formed by the union of the cystic duct to the common hepatic duct at various location. It transports bile from the liver to the duodenum and back to the gallbladder if the sphincter of oddi is closed. The CBD is a normal distensible structure composed of fibro-elastic tissue with little or no muscular support. The size of the CBD is a predictor of biliary obstruction and, therefore, its measurement is an important component of biliary system evaluation. Objective: The aim of this study was to determine the normal CBD diameter and assess its association with age, sex, and anthropometry. Methods and Materials: Institutional based cross-sectional study was conducted to determine the normal range of CBD diameter and associated factor at the University of Gondar Comprehensive Specialized Hospital and one private imaging center in Gondar town. The data were entered into an Epi-info version 7.2.0.1, exported and analyzed using SPSS Statistics software version 20. In bivariable linear regression variables with p-value, less than 0.2 were selected for multi-variable analysis and in multivariable linear regression analysis variables with P-Value less than 0.05 were considered as statistically significant. Results: A total of 206 subjects comprising 93(45.1%) male and 113(54.9%) female with mean age, height, weight, body mass index of 39.4year, 1.63 meter, 57.8 Kg, and 21.6 Kg/m², respectively were studied. Of the study participants, 86 (41.7%) were from rural and 120(58.3%) were from urban. The mean CBD diameter was 3.64 mm with 95% CI (3.52, 3.77). CBD diameter significantly associated with age along the linear trend. The mean diameter of the CBD in rural area was greater than those subjects living in urban area. There was no statistically significant difference in CBD diameter between male and female subject. The diameter of the CBD hardly demonstrated a significant association with anthropometric measurement. Conclusion: The present study revealed that the age of the study subjects had a statistically significant association with the diameter of the CBD and it was progressively increased from the lower age group onward along with a linear trend. The diameter of the CBD did not show statistically significant association with the anthropometric measurement. Keyword; Common bile duct, Common bile duct diameter, Ethiopia, Ultrasound