Basic Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplant. Jun 18, 2021; 11(6): 231-243
Published online Jun 18, 2021. doi: 10.5500/wjt.v11.i6.231
Surgical relevance of anatomic variations of the right hepatic vein
Shamir O Cawich, Vijay Naraynsingh, Neil W Pearce, Rahul R Deshpande, Robbie Rampersad, Michael T Gardner, Fawwaz Mohammed, Roma Dindial, Tanzilah Afzal Barrow
Shamir O Cawich, Vijay Naraynsingh, Fawwaz Mohammed, Department of Surgery, University of the West Indies, St Augustine 000000, Trinidad and Tobago
Shamir O Cawich, Vijay Naraynsingh, Fawwaz Mohammed, Department of Surgery, Port of Spain General Hospital, Port of Spain 000000, Trinidad and Tobago
Neil W Pearce, University Surgical Unit, Southampton General Hospital, Southampton SO16 6YD, United Kingdom
Rahul R Deshpande, Department of Surgery, Manchester Royal Infirmary, Manchester M13 9WL, United Kingdom
Robbie Rampersad, Department of Radiology, University of the West Indies, St. Augustine 000000, Trinidad and Tobago
Robbie Rampersad, Roma Dindial, Tanzilah Afzal Barrow, Department of Radiology, Port of Spain General Hospital, Port of Spain 000000, Trinidad and Tobago
Michael T Gardner, Section of Anatomy, Basic Medical Sciences, University of the West Indies, Kingston 000000, Jamaica
Tanzilah Afzal Barrow, Department of Radiology, University of the West Indies, St Augustine 000000, Trinidad and Tobago
Author contributions: Cawich SO, Gardner MT and Mohammed F designed and coordinated the study; Naraynsingh V, Barrow TA, Dindial R and Rampersad R performed experiments, acquired and analyzed data; Cawich SO, Gardner MT, Mohammed F, Naraynsingh V, Barrow TA, Dindial R and Deshpande RR and Pearce NW interpreted the data; Cawich SO and Gardner MT wrote the manuscript; all authors approved the final version of the article.
Institutional review board statement: The study was reviewed by the institutional board and deemed exempt as it was an observational study on images already obtained during patient care and no changes in clinical management were made due to study protocols.
Conflict-of-interest statement: The authors declare that they have no competing interests.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at TT.liver.surgery@gmail.com. All data are anonymized and risk of identification is low.
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 Surgery, University of the West Indies, St Augustine Campus, St Augustine 000000, Trinidad and Tobago. socawich@hotmail.com
Received: February 9, 2021
Peer-review started: February 9, 2021
First decision: March 17, 2021
Revised: March 18, 2021
Accepted: May 20, 2021
Article in press: May 20, 2021
Published online: June 18, 2021
Processing time: 122 Days and 23.7 Hours
Abstract
BACKGROUND

Variations in the anatomy of hepatic veins are of interest to transplant surgeons, interventional radiologists, and other medical practitioners who treat liver diseases. The drainage patterns of the right hepatic veins (RHVs) are particularly relevant to transplantation services.

AIM

The aim was to identify variations of the patterns of venous drainage from the right side of the liver. To the best of our knowledge, there have been no reports on RHV variations in in a Caribbean population.

METHODS

Two radiologists independently reviewed 230 contrast-enhanced computed tomography scans performed in 1 year at a hepatobiliary referral center. Venous outflow patterns were observed and RHV variants were described as: (1) Tributaries of the RHV; (2) Variations at the hepatocaval junction (HCJ); and (3) Accessory RHVs.

RESULTS

A total of 118 scans met the inclusion criteria. Only 39% of the scans found conventional anatomy of the main hepatic veins. Accessory RHVs were present 49.2% and included a well-defined inferior RHV draining segment VI (45%) and a middle RHV (4%). At the HCJ, 83 of the 118 (70.3%) had a superior RHV that received no tributaries within 1 cm of the junction (Nakamura and Tsuzuki type I). In 35 individuals (29.7%) there was a short superior RHV with at least one variant tributary. According to the Nakamura and Tsuzuki classification, there were 24 type II variants (20.3%), six type III variants (5.1%) and, five type IV variants (4.2%).

CONCLUSION

There was significant variation in RHV patterns in this population, each with important relevance to liver surgery. Interventional radiologists and hepatobiliary surgeons practicing in the Caribbean must be cognizant of these differences in order to minimize morbidity during invasive procedures.

Keywords: Liver; Variant; Hepatic; Vein; Anomaly; Venous, Drainage, Vena cava

Core Tip: There were variations in right hepatic vein (RHV) anatomy in 61% of unselected persons in the eastern Caribbean. They included proximal confluence (61%), accessory RHVs (49.2%), hepatocaval junction variants (29.7%), both dorsal and ventral segment VIII veins entering middle hepatic vein (28%), and absent segment VII tributaries (4.2%). The Nakamura and Tsuzuki classification included type I hepatocaval junction variants in 83 individuals (70.3%), type II in 24 (20.3%), type III in 6 (5.1%), and type IV variants in five (4.2%). Knowledge of the anatomic variations of the RHV are particularly important to optimize transplantation services.