Systematic Reviews
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Jun 16, 2021; 13(6): 170-183
Published online Jun 16, 2021. doi: 10.4253/wjge.v13.i6.170
Anatomic variations of the intra-hepatic biliary tree in the Caribbean: A systematic review
Shamir O Cawich, Alexander Sinanan, Rahul R Deshpande, Michael T Gardner, Neil W Pearce, Vijay Naraynsingh
Shamir O Cawich, Alexander Sinanan, Vijay Naraynsingh, Department of Clinical Surgical Sciences, University of the West Indies, St Augustine 000000, Trinidad and Tobago
Rahul R Deshpande, Department of Surgery, Manchester Royal Infirmary, Manchester M13 9WL, United Kingdom
Michael T Gardner, Department of Anatomy, University of the West Indies, Kingston KIN7, Jamaica
Neil W Pearce, Department of Surgery, Southampton University NHS Trust, Southampton SO16DP, Southampton, United Kingdom
Author contributions: Cawich SO and Sinanan A designed and coordinated the study; Gardner MT, Pearce NW and Deshpande RR performed experiments, acquired and analyzed data; Cawich SO, Gardner MT, Sinanan A, Pearce NW and Deshpande RR interpreted the data; Cawich SO and Gardner MT wrote the manuscript; all authors approved the final version of the article.
Conflict-of-interest statement: There are no conflicts of interest to disclose.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
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: Shamir O Cawich, FACS, Professor, Department of Clinical Surgical Sciences, University of the West Indies, St. Augustine Campus, St Augustine 000000, Trinidad and Tobago. socawich@hotmail.com
Received: January 25, 2021
Peer-review started: January 25, 2021
First decision: March 1, 2021
Revised: March 15, 2021
Accepted: May 20, 2021
Article in press: May 20, 2021
Published online: June 16, 2021
Processing time: 136 Days and 4 Hours
Abstract
BACKGROUND

In the classic descriptions of the human liver, the common hepatic duct forms at the confluence of left and right hepatic ducts. Many authors have documented variations in the intra-hepatic ductal system, but to the best of our knowledge there has been no report on bile duct variations in Caribbean populations.

AIM

To evaluate the variations in bile duct anatomy using magnetic resonance cholangiography (MRC) in unselected patients at a major hepatobiliary referral centre in the Eastern Caribbean. Knowledge of the intra-hepatic biliary anatomy is important to optimize service delivery for any physician treating liver and biliary disorders.

METHODS

This study was carried out at a tertiary referral hospital for hepatobiliary diseases in the Eastern Caribbean. We retrospectively evaluated magnetic resonance cholangiograms in 152 consecutive patients at this facility over a two-year period from April 1, 2017 to March 31, 2019. Two consultant radiologists experienced in MRC interpretation reviewed all scans and described biliary anatomy according to the Huang’s classification. A systematic review of published studies was performed and relevant data were extracted in order to calculate the global prevalence of each biliary variant. The variants in our population were compared to the global population.

RESULTS

There were 152 MRCs evaluated in this study in 86 males and 66 females. There were 109 (71.7%) persons with “classic” biliary anatomy (type A1) and variants were present in 43 (28.3%) persons. There was no statistical relationship between the presence of anatomic variants and gender or ethnicity. We encountered the following variants: 29 (19.1%) type A2, 7 (4.6%) type A3, 6 (3.95%) type A4, 0 type A5 and a single variant (quadrification) that did not fit the classification system. Compared to the global prevalence, our population had a significantly greater occurrence of A1 anatomy (71.7% vs 62.6%; P = 0.0227) and A2 trifurcations (19.1% vs 11.5%; P = 0.0069), but a significantly lower incidence of A3 variants (4.61% vs 11.5%; P = 0.0047).

CONCLUSION

There are significant differences in intra-hepatic biliary anatomy in this unselected Eastern Caribbean population compared to global statistics. Specifically, persons of Caribbean descent have a greater incidence of Huang A2 trifurcations and a lower incidence of Huang A3 variants.

Keywords: Liver; Variant; Biliary; Duct; Intra-hepatic; Aberrant; Trifurcation, Bifurcation

Core Tip: Many authors have documented variations in the intra-hepatic ductal system, but to the best of our knowledge there has been no report on bile duct variations in Caribbean populations. In the unselected Eastern Caribbean population, 71.7% of persons have normal intra-hepatic biliary anatomy. Variant anatomy in this population occurs with the following frequencies: A2 (19.1%), A3 (4.6%) and A4 (3.95%).