Retrospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Dec 27, 2020; 12(12): 1289-1298
Published online Dec 27, 2020. doi: 10.4254/wjh.v12.i12.1289
Incidental biliary dilation in the era of the opiate epidemic: High prevalence of biliary dilation in opiate users evaluated in the Emergency Department
Monique T Barakat, Subhas Banerjee
Monique T Barakat, Divisions of Adult and Pediatric Gastroenterology and Hepatology, Stanford University Medical Center, Stanford, CA 94305, United States
Subhas Banerjee, Division of Gastroenterology and Hepatology, Stanford University Medical Center, Stanford, CA 94304, United States
Author contributions: Barakat MT and Banerjee S were involved in conception and design of the study as well as collection, analysis and interpretation of the data in collaboration with the Stanford University Statistics Consulting Service; Barakat MT and Banerjee S were involved in drafting and critical revision of the article for important intellectual content; Banerjee S granted final approval of the article.
Institutional review board statement: This study was approved by the Stanford University Institutional Review Board (Protocol No. 41605), with associated HIPPA and Consent Waivers.
Informed consent statement: Informed consent signature not required from patients for this retrospective cohort study, per terms of Institutional Review Board (IRB) protocol approval.
Conflict-of-interest statement: The authors have no conflicts of interest related to this study.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Subhas Banerjee, MD, Professor, Division of Gastroenterology and Hepatology, Stanford University Medical Center, 300 Pasteur Drive, Stanford, CA 94304, United States. subhas.banerjee@stanford.edu
Received: August 2, 2020
Peer-review started: August 2, 2020
First decision: September 30, 2020
Revised: October 12, 2020
Accepted: October 30, 2020
Article in press: October 30, 2020
Published online: December 27, 2020
Processing time: 137 Days and 14 Hours
Abstract
BACKGROUND

Biliary dilation is frequently related to obstruction; however, non-obstructive factors such as age and previous cholecystectomy have also been reported. In the past two decades there has been a dramatic increase in opiate use/dependence and utilization of cross-sectional abdominal imaging, with increased detection of biliary dilation, particularly in patients who use opiates.

AIM

To evaluate associations between opiate use, age, cholecystectomy status, ethnicity, gender, and body mass index utilizing our institution’s integrated informatics platform.

METHODS

One thousand six hundred and eighty-five patients (20% sample) presenting to our Emergency Department for all causes over a 5-year period (2011-2016) who had undergone cross-sectional abdominal imaging and had normal total bilirubin were included and analyzed.

RESULTS

Common bile duct (CBD) diameter was significantly higher in opiate users compared to non-opiate users (8.67 mm vs 7.24 mm, P < 0.001) and in patients with a history of cholecystectomy compared to those with an intact gallbladder (8.98 vs 6.72, P < 0.001). For patients with an intact gallbladder who did not use opiates (n = 432), increasing age did not predict CBD diameter (r2 = 0.159, P = 0.873). Height weakly predicted CBD diameter (r2 = 0.561, P = 0.018), but weight, body mass index, ethnicity and gender did not.

CONCLUSION

Opiate use and a history of cholecystectomy are associated with CBD dilation in the absence of an obstructive process. Age alone is not associated with increased CBD diameter. These findings suggest that factors such as opiate use and history of cholecystectomy may underlie the previously-reported association of advancing age with increased CBD diameter. Further prospective study is warranted.

Keywords: Biliary dilation; Opiate; Narcotic; Endoscopic ultrasound; Endoscopic retrograde cholangiopancreatography; Bile duct

Core Tip: What is current knowledge? Biliary dilation is often related to an obstructing process. Non-obstructive factors such as age and prior cholecystectomy have also been associated with biliary dilation. Rates of opiate use have dramatically increased within the United States over the past two decades. There has also been a dramatic increase in utilization of cross-sectional abdominal imaging over the past two decades What is new here. Opiate use is associated with biliary dilation in the absence of an obstructive process. Increasing opiate use and increasing utilization of imaging are resulting in increased incidental detection of biliary dilation leading to increased referrals for endoscopic workup. Contrary to conventionally held views, our study indicates that age alone is not associated with increased bile duct diameter. Increasing probability of opiate use and cholecystectomy with advancing age may underlie the previously-reported association of advancing age with increased bile duct diameter. Height is weakly associated with increased bile duct diameter, consistent with an organ scaling effect.