Related Experiment Video
Updated: May 17, 2026
Laparoscopic Common Bile Duct Exploration in Patients with a Previous History of Biliary Tract Surgery
Published on: February 10, 2023
Extrahepatic bile duct measurement by using transabdominal ultrasound in Japanese adults: multi-center prospective
Takao Itoi1, Terumi Kamisawa, Hideki Fujii
1Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo, 160-0023, Japan, itoi@tokyo-med.ac.jp.
Background:
In adults, less than 10-mm bile duct has idiomatically been recognized as "non-dilated bile duct" though there was no obvious evidence. The aim of this study was to prospectively examine the maximum inner diameter of extrahepatic bile duct (MDEBD) in consecutive adults.
Methods:
Transabdominal ultrasound (US) was performed to measure the MDEBD of 8840 cases (4420 male) in five institutions. The frequency of ultrasound probe ranged from 3.5 to 5 MHz.
Results:
The mean diameter of MDEBD was 4.5 ± 1.4 mm (range 1-14 mm). The relationship between the MDEBD and age was shown as follows: MDEBD = 2.83 + 0.03 × age. Multiple regression analysis was analyzed between 6 groups and significant α level is 0.008 in this analysis. In all age groups but 20s and 30s, there was statistically significant MDEBD among each age group (p < 0.0001). Mean, mode value and median MDEBD is increasing according to the age as follows: 20s: 3.9 ± 1.0 mm, 30s: 3.9 ± 1.2 mm, 40s: 4.3 ± 1.2 mm, 50s: 4.6 ± 1.3 mm, 60s: 4.9 ± 1.4 mm, >70s: 5.3 ± 1.6 mm.
Conclusion:
The present study revealed that MDEBD positively correlates with age. Therefore, when we examine the presence of dilation of the bile duct, our calculating formula appears to be suitable for accurate evaluation.
