Caliber of the common bile duct: effect of cholecystectomy and other factors in a ultrasonographic study of 8534 patients

Utilizing CT to identify clinically significant biliary dilatation in symptomatic post-cholecystectomy patients: when should we be worried?

PURPOSE

To determine a reliable threshold common duct diameter on CT, in combination with other ancillary CT and clinical parameters, at which the likelihood of pathology requiring further imaging or intervention is increased in post-cholecystectomy patients.

METHODS

In this IRB approved retrospective study, two attending radiologists independently reviewed CT imaging for 118 post-cholecystectomy patients, who were subsequently evaluated with MRCP, ERCP, or EUS, prompted by findings on the CT and clinical status. Measurements of the common duct (CD) were obtained at the porta hepatis, distal duct, and point of maximal dilation on axial and coronal CT scans. Patients were grouped by whether they required intervention after follow-up imaging. Pertinent baseline lab values and patient demographics were reviewed.

RESULTS

Of the 118 post-cholecystectomy patients, 38 patients (31%) required intervention, and 80 patients (69%) did not require intervention after follow-up imaging. For both readers, axial and coronal CD diameters were significantly higher in the 'intervention required' vs 'no intervention' groups at all locations (p value < 0.05). There was good to excellent inter-reader agreement at all locations (ICC 0.68-0.92). Pertinent baseline lab values including AST (p = 0.043), ALT (p = 0.001), alkaline phosphatase (p = 0.0001), direct bilirubin (p = 0.011), total bilirubin (p = 0.028), and WBC (p = 0.043) were significantly higher in the 'intervention required' group. CD thresholds of 8 mm yielded the highest sensitivities (76-95%), and CD thresholds of 12 mm yielded the highest specificities (65-78%). CD combined with bilirubin levels increased sensitivity and specificity, compared to using either feature alone.

CONCLUSION

Dilated CD on CT combined with bilirubin levels increases the sensitivity and specificity for identifying patients needing intervention. We recommend that a post-cholecystectomy patient who presents with a CD diameter > 10 mm on CT and elevated bilirubin levels should undergo further clinical and imaging follow-up.

Sonographic measurement of normal common bile duct diameter and associated factors at the University of Gondar comprehensive specialized hospital and selected private imaging center in Gondar town, North West Ethiopia

Background

The biliary tree is a three-dimensional system of channels that bile flows from the hepatocytes to the gallbladder and to the intestine. Size of the common bile duct (CBD) is a predictor of biliary obstruction and, therefore, its measurement is an important component of biliary system evaluation. Factors like age, height, weight, BMI, previous cholecystectomy, drugs, and type of imaging modality affect CBD diameter, but the duct significantly dilated due to obstructive biliary pathology.

Objective

To measure the normal CBD diameter and its association with age, sex, and anthropometric measurement at the University of Gondar Comprehensive Specialized Hospital and selected private imaging center, Gondar town, Northwest Ethiopia, 2019.

Methods and materials

Institutional based cross-sectional study was conducted on 206 subjects without any history of hepatobiliary abnormality. The CBD measured at the proximal part just caudal to the porta hepatis. Descriptive analysis, student t-test, one way ANOVA, correlation and both bivariable and multivariable linear regression analysis were implemented. In bivariable linear regression variables with p-value, less than 0.2 were selected for multivariable analysis and in multivariable linear regression analysis variables with P-Value less than 0.05 were considered as statistically significant.

Results

The mean age of the study participants was 39.4 (range 18–87). The mean diameter of the CBD was 3.64mm 95%CI (3.52, 3.77), which ranges from 1.8 to 5.9 mm, with 65% of the participant having CBD diameter less than 4mm. The diameter of CBD significantly associated with age with a linear trend. The mean diameter in a rural area was greater than subjects living in an urban area. Independent t-test showed no statistically significant difference in CBD diameter between male and female subjects.

Conclusion

The lower limit of the CBD diameter for this study was similar to most of the studies, but the upper limit was found to be slightly lower. The diameter was significantly associated with age along the linear trend and it was progressively increased from the lower age group onwards. The diameter of CBD did not show statistically significant association with any of the anthropometric measurement.

Association between common bile duct diameter and abdominal aorta calcium score

BACKGROUND AND OBJECTIVE

There is evidence of association between aging and increase in the normal upper limit of the common bile duct (CBD) diameter. As aging is a documented risk factor for atherosclerosis, and the possible effect that atherosclerosis can have on the CBD diameter via affecting its smooth muscle contractility and blood flow, we decided to determine the association between CBD diameter and atherosclerosis in the abdominal aorta (AA).

METHODS

A total of 99 asymptomatic patients (53 males and 46 females; age range of 18-88 years) without history of cholecystectomy who underwent abdominal contrast-enhanced CT scan were included. The CBD diameter was measured. The atherosclerosis of AA was quantified by Agatston score.

RESULTS

Mean (± SD) CBD diameter was 6.14 (± 1.95) mm; range = 2.4-12.7 mm. Agatston score was 0 in 59 patients. In the remaining 40 patients, median (interquartile range, IQR) Agatston score was 497.5 (2026.3). Mean (± SD) CBD diameter in patients with Agatston score > 0 was 7.39 (± 2.07) mm compared to 5.29 (± 1.32) mm in patients without calcification plaque (P < 0.001). A moderate correlation was seen between CBD diameter and Agatston score (ρ = 0.43; P = 0.005).

CONCLUSION

Although the exact cause of increased CBD diameter with advancing age is not understood, a general atherosclerotic process which occurs with aging may affect smooth muscle of the CBD. Whether an upper limit for normal CBD should be defined or not when evaluating dilated CBD for patients with subclinical or clinical atherosclerosis needs further studies.