Ultrasonographic dimensions of the common bile duct in Chinese children: results of 343 cases.

BACKGROUND: At present, the diagnostic criteria of congenital cholangiectasis are still vague. PURPOSE: The aim of this study was to assess the diameter references of the common bile duct (CBD) in pediatric population in different age groups with ultrasound. METHODS: The diameter of the common bile duct was measured with ultrasound in 343 Chinese Han children aged 1 day to 14 years (mean: 3.2 years, median: 2.8 years) who were all free of hepatic and biliary tract disease. The ultrasound records, gender, and age were collected for reviewed analysis. RESULTS: A total of 343 children were included, and the CBD was clearly detected in 322 cases (93.9%). The mean diameter of this population was 1.58 ± 0.70 mm. (ranging from 0.4 to 4.4mm). Spearman correlation analysis showed that the diameter of CBD was positively associated with age (r=0.573, P<0.001). The percentile method demonstrated that the diameter references of CBD was as follows: ≤ 1 years: ≤ 2.26 mm; ≤ 4 years: ≤ 2.99 mm; ≤ 7 years: ≤ 3.03 mm; and ≤ 14 years: ≤ 4.10mm. CONCLUSIONS: There was a close correlation between CBD width and the age. The range of CBD widths in each age group will be helpful in the diagnosis of biliary dilatation in childhood.

Indicial response functions of growth and remodeling of common bile duct postobstruction.

Biliary duct obstruction is an important clinical condition that stems from cholelithiasis, the neoplasm in the wall or, most commonly, gallbladder stones. The objective of this study is to understand the structural and mechanical remodeling of the common bile duct (CBD) postobstruction. Porcine CBD was ligated near the duodenum that increased the duct's pressure from 6.4 to 18.3 cmH(2)O in the first 12 h and to 30.7 cmH(2)O after 32 days. The remodeling process was studied after 3 h, 12 h, 2 days, 8 days, and 32 days (n = 5 in each group) after obstruction. One additional animal in each group was sham operated. At each scheduled time, the time course of change of morphometry (diameter, length, wall thickness, etc.) and mechanical properties (stress, strain, etc.) was documented. It was found that the diameter increased by about threefold and the wall thickness of the CBD doubled in the 32-day group compared with the sham group (P < 0.001). The stress and strain increased initially with increase in pressure but recovered to near the control values by day 32 due to the structural and mechanical adaptations. Hence, the net effect of the structural and mechanical remodeling is to restore the stress and strain to their homeostatic values. Furthermore, the strain recovers more rapidly and more completely than stress. Finally, the remodeling data were expressed mathematically in terms of indicial response functions (IRF), i.e., change of a particular feature of a CBD in response to a unit step change of the pressure. The IRF approach provides a quantitative description of the remodeling process in the CBD.

Ultrasonographic study on the growth and dimensions of healthy children and adults organs.

We measured by ultrasound the spleen, the kidneys, the pancreas in 323 children (age 0-12), the thyroid in 60 children of same age range, and all these organs in 180 adults (in adults we measured additionally the testis, the gallbladder and the choledochus). Children and adults were all healthy, without evidence of pathologies potentially involving these organs. The children have been selected looking at clinical and hematological parameters, while the adults have been selected among a military population, that is the most significant sample of healthy young adults. We measured the length, the transversal diameter and the thickness of the spleen, kidneys, pancreas, testis and thyroid, the diameter of the choledochus and the maximum length of the gallbladder (pre and post stimulus). We found a good correlation between age and dimensions for pancreas, kidneys and spleen in children, representing the progressive growth of these organs. Our data represent an assessment of the normal dimensions of these organs in vivo by means of ultrasound, and therefore they are an useful tool to discriminate pathologically enlarged or reduced organs, both in children and in adults.

Common bile duct in children: sonographic dimensions.

PURPOSE: To determine the normal caliber and rate of growth of the extrahepatic biliary ducts in the pediatric population. MATERIALS AND METHODS: The diameter of the common bile duct was measured with sonography in 173 children aged 1 day to 13 years (mean, 6.0 years; median, 5.0 years) who were examined for reasons other than hepatic or biliary tract disease. Results were subjected to regression analysis and compared with similar measurements of the extrahepatic portal vein and hepatic artery. The size of the gallbladder was subjectively estimated as distended, moderately full, and contracted. Differences in the diameter of the common bile duct in these three groups were evaluated with the Mann-Whitney U test. RESULTS: The average diameter of the common bile duct in this population was 1.27 mm +/- 0.67 (< 3.3 mm in all patients and < 1.2 mm in children aged 3 months or less). The slope of the curve describing the growth of the common bile duct was relatively flat, similar to that of the hepatic artery and half that of the portal vein. There was a significant difference in the diameter of the common bile duct between patients with distended gallbladders and those with contracted gallbladder (P = .02). CONCLUSION: The pediatric common bile duct is significantly smaller than adult norms; it is a distensible structure responsive to fluctuations in prandial bile flow.

Postnatal development of the brush cells in the common bile duct of the rat.

The postnatal development of brush cells in the distal segment of the common bile duct of the rat was examined with respect to cell number and immunoreactivity for liver fatty acid-binding protein (L-FABP). The brush cells, distinguishable from the principal cells by scanning electron microscopy, first appeared in the common bile duct 4 weeks after birth. They showed a remarkable increase in number, with a sex difference in time, i.e., between 8 and 12 weeks in the male and between 10 and 14 weeks in the female. In both sexes, the frequency of brush cells reached approximately 30% of total epithelial cells by 16 weeks and remained constant until 40 weeks of age. Cells with positive immunoreactivity for L-FABP first appeared in small numbers at 8 weeks. Immuno-electron microscopy revealed that all immunoreactive cells were brush cells. They increased in number gradually from 16 to 40 weeks with no sex difference. At 40 weeks, the immunoreactive cells reached approximately 7.5% of total epithelial cells, corresponding to one-fourth of the number of brush cells. These results indicate that the occurrence of the brush cell population in the common bile duct is a late event in the postnatal development of the rat and that its functional maturation progresses with aging.

The development of the glands of the common bile duct.

The number of glands at a constant level within the wall of the common bile duct was measured in the foetus, infant, child and adult. The number of glandular acini increases from foetal life to reach a maximum within the 1st year of life. Thereafter it remains remarkably constant. This is in contrast to the lumen and wall of the common bile duct which only reaches adult proportions in adult life. Conversely, the density of acini within the wall of the common bile duct is at a peak in early foetal life and decreases progressively throughout infancy and childhood.