Normal common bile duct in adult

Abstract               Background: Ultrasonically diameter of common bile duct has been identified at porta hepatis and evaluation done. Size is of the common bile duct is important to diagnose obstruction by internal calculus or tumor from external. Method: 103 (51 male and 52 females) normal adults were included in the study group. Sonologist measured the diameter of common bile duct at porta hepatis and documented. Parameters like age, height, weight and body surface area were correlated with common bile duct. Results: Mean diameter of portal vein was observed 9.20 mm. Though no correlation was identified with any parameters such as height, and body surface area but it is in the same accord to previous studies. Conclusion: Ultrasonic evaluation of common bile duct is important, valuable and diagnostic in most of the biliary disorders such as cholelithiasis and obstruction in jaundice. No parameter like age, height or weight has any impact on size of diameter of common bile duct

Key Word: bile duct.

INTRODUCTION

Common bile Duct is formed by the union of common hepatic duct and cystic duct just below the porta hepatis. Common bile duct opens on the major papilla in the posteromedial wall of the duodenum.¹ Common bile duct is dilated in case of cholelithiasis, jaundice with obstruction.² Evaluation of common bile duct can be done by various radiological procedures. But ultrasound is safe, simple non-invasive method in hepatobiliary diseases ultrasound is first line of investigation.³ In jaundiced patients, ultrasound is the main to identify the biliary tract disease to distinguish dilated from non-dilated biliary ducts. Thus diameter of common bile is important ultrasonic measure in the evaluation of hepatobiliary disorders.⁴

AIMS AND OBJECTIVES

To evaluate the measurements of diameter of common bile duct at porta hepatis. Measurements are correlated with the: age, sex, height, weight and body surface area.

MATERIALS AND METHOD

Selection of cases: 103 cases (51 males and 52 females) were included in the study group. After examining the abdomen by ultrasound expert, if no hepatobiliary, portal vein pathology is detect then the case is included in the study. Diameter of common bile duct at porta hepatis is noted in millimetres. Other parameters height in meters and weight in kilogram were noted. And then using the formula given below for Body surface area is calculated: A= W^0.425 X H^0.725 X 71.84(constant) Sq.M. A is body surface area in square meters, W is weight in kilogram Kg, His height in meters⁵ All 103 cases were correlated with the parameters such as age, weight and height.

Ultrasound scan: The patient had to fast a minimum of eight hours before the examination so that bowel gas get limited and gall bladder was not contracted. The examination of abdomen was done in supine and in oblique position with the transducer of 3.5 MHz. To conduct the proper ultrasound without any fallacy of abdomen, the patient were called in the morning on empty stomach. Because bowels are relatively empty. History, clinical examination was correlated with the ultrasound observation. As per standard procedure, scan was undertaken in supine position from midline from above downwards and left to right. Particular site of interest can be seen by real time sonography. Standard oblique view were taken of liver, pancreas, etc. Porta hepatis is viewed in longitudinal scan and diameter of common bile duct is measured.³

RESULT

Table 1: Mean values and standard deviation of variables

The mean age was 34.94 years with standard deviation of 12.96 years. 95% Confidence limit of age are 31.96-37.92 yrs The mean height was 5.25 feet with standard deviation of 0.39 feet. 95% Confidence limit of height are 5.13-5.33 feet. The mean weight was 51.79 Kg.with standard deviation of 11.39 Kg. 95% Confidence limit of weight are 49.53 - 54.05Kg

Table 2

Mean measurements of the diameter of common bile at porta hepatis in different age group, Mean Diameter of portal vein in age group 18-30 years (48 cases) was found to be 3.2 mm, Mean Diameter of portal vein in age group 31-40 years (25 cases) was found to be 3.5 mm, Mean Diameter of portal vein in age group 41-50 years (15 cases) was found to be 3.4 mm, Mean Diameter of portal vein in age group 51-60 years (11cases) was found to be 3.5 mm, Mean Diameter of portal vein in age group 61-70 years (2 cases) was found to be 3.0 mm, Mean Diameter of portal vein in age group 71-80 years (11) cases was found to be 4.0 mm (Table/Fig 2)

Table 3

Mean measurements of the diameter of common bile duct in males of different group, Mean measurements of the diameter of common bile duct in males of different group, Mean measurements of the diameter of common bile duct in males of 18-30 age group (23 cases) is 3.0 mm, Mean measurements of the diameter of common bile duct in males of 31-40 age group (14 cases) is 3.6 mm ( Table/Fig 3)

Table 4

Mean measurements of the diameter of common bile duct in females of different group, The Mean measurements of the diameter of portal vein in females of different group, Mean measurements of the diameter of common bile duct in females 18-30 group (25 cases) is 3 mm, Mean measurements of the diameter of common bile duct in females 31-40 group (11 cases) is 3 mm, Mean measurements of the diameter of common bile duct in females 41-50 group (09 cases) is 3 mm, Mean measurements of the diameter of common bile duct in females 51-60 group (07 cases) is 4 mm (Table/Fig 4)

Table 5: Statistical significance of age with diameter of common bile duct

To test the association between pairs of variables, Pearson’s moment correlation coefficient was calculated.

AGE: Age and diameter of common bile duct at porta hepatis. The correlation coefficient was 0.16742 which at degrees of freedom was not significant (p> 0.05) Thus it is found that there is no significant association between age and diameter of common bile duct.

Table 6

Correlation of measurements of diameter of common bile duct with height ranging from 124 to -75 cm, Correlation of measurements of diameter common bile duct with height ranging from 124 to -75 cm(Table/Fig 6), Mean measurement of diameter of common bile duct in the group of 120-135 cm (cases 3)is 3 mm, Mean measurement of diameter of common bile duct in the group of 136-150 cm (cases 22)is 3.3 mm, Mean measurement of diameter of common bile duct in the group of 151-165 cm (cases 52 )is 3.4 mm, Mean measurement of diameter of common bile duct in the group of 166-180 cm (cases 26 )is 3.4 mm

Table 7: Statistical significance of height with diameter of common bile duct

Height: Height and diameter of common bile duct at porta hepatis. The correlation coefficient was 0.04635 which at degrees of freedom was not significant (p> 0.05).

Table 8:

Correlation of Mean measurements of diameter of common bile duct with weight of the individuals ranging from 32-83 Kg, Mean measurement of diameter of common bile duct in the group of 31-40 kg ( cases 21) is 3.2 mm, Mean measurement of diameter of common bile duct in the group of 41-50 kg ( cases 33) is 3.5 mm, Mean measurement of diameter of common bile duct in the group of 51-60 kg ( cases 28) is 3.3 mm, Mean measurement of diameter of common bile duct in the group of 61-70 kg ( cases 13) is 3.3 mm, Mean measurement of diameter of common bile duct in the group of 71-80 kg ( cases 7) is 3.7 mm (Table/ Fig 8)

Table 9:

Weight: Weight and diameter of common bile duct. The correlation coefficient was 0.02599 which at degrees of freedom was not significant (p> 0.05) statistically. (Table/Fig.9)

Table 10:

Correlation of Mean measurements of common bile duct with body surface area ranging from 1.05 to 1.88 sq.m, Mean measurement of diameter of common bile duct in the group 1.16-1.30 sq.m (cases 12) is 3.3 mm,Mean measurement of diameter of common bile duct in the group 1.31-1.45 sq.m (cases 29) is 3.4 mm, Mean measurement of diameter of common bile duct in the group 1.46-1.60 sq.m (cases 28) is 3.4 mm, Mean measurement of diameter of common bile duct in the group 1.61-1.75 sq.m (cases 21) is 3.5 mm, Mean measurement of diameter of common bile duct in the group 1.76-1.90 sq.m (cases 10) is 3.6 mm (Table/ Fig 10)

Table 11:

Body surface area (BSA): BSA and diameter of common bile duct. The correlation coefficient was 0.366 which at degrees of freedom was not significant (p> 0.05) statistically. (Table/Fig 11)

Table 12:

comparison of the Mean values of height, weight, body surface area, common bile duct in males and females,ean diameter of common bile duct in male is 3.37 mm. Mean diameter of common bile duct in female is Mean diameter of common bile duct in male is 3.37 mm.