Review
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 28, 2018; 24(12): 1285-1298
Published online Mar 28, 2018. doi: 10.3748/wjg.v24.i12.1285
Review article: Update on current and emergent data on hepatopulmonary syndrome
Ioannis Goulis, Maria Vlachou, George Giannakoulas, Evangelos Cholongitas, Stergios Soulaidopoulos
Stergios Soulaidopoulos, Ioannis Goulis, Fourth Department of Internal Medicine, Hippokration General Hospital, Medical School of Aristotle University of Thessaloniki, Thessaloniki 54642, Greece
Evangelos Cholongitas, First Department of Internal Medicine, Laiko General Hospital, Medical School of National and Kapodistrian University of Athens, Athens 11527, Greece
George Giannakoulas, Maria Vlachou, Department of Cardiology, AHEPA University Hospital, Medical School of Aristotle University of Thessaloniki, Thessaloniki 54621, Greece
Author contributions: Cholongitas E conceived of and designed the study; Soulaidopoulos S, Vlachou M and Giannakoulas G finished the data acquisition; Soulaidopoulos S and Vlachou M performed the data analysis and interpretation; Soulaidopoulos S and Cholongitas E drafted the manuscript; Goulis I, Cholongitas E, and Giannakoulas G made critical revision of the manuscript.
Conflict-of-interest statement: The authors have no financial or other conflicts of interest related to the submitted manuscript to declare.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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/
Correspondence to: Evangelos Cholongitas, MD, PhD, Associate Professor, First Department of Internal Medicine, Medical School of National & Kapodistrian University of Athens, Laiko General Hospital, Agiou Thoma 17, Athens 11527, Greece. cholongitas@yahoo.gr
Telephone: +30-6936-378903 Fax: +30-2310-992940
Received: January 9, 2018
Peer-review started: January 10, 2018
First decision: February 5, 2018
Revised: February 18, 2018
Accepted: March 7, 2018
Article in press: March 7, 2018
Published online: March 28, 2018
Processing time: 75 Days and 13.7 Hours
Abstract

Hepatopulmonary syndrome (HPS) is a frequent pulmonary complication of end-stage liver disease, characterized by impaired arterial oxygenation induced by intrapulmonary vascular dilatation. Its prevalence ranges from 4% to 47% in patients with cirrhosis due to the different diagnostic criteria applied among different studies. Nitric oxide overproduction and angiogenesis seem to be the hallmarks of a complicated pathogenetic mechanism, leading to intrapulmonary shunting and ventilation-perfusion mismatch. A classification of HPS according to the severity of hypoxemia has been suggested. Contrast-enhanced echocardiography represents the gold standard method for the detection of intrapulmonary vascular dilatations which is required, in combination with an elevated alveolar arterial gradient to set the diagnosis. The only effective treatment which can modify the syndrome’s natural history is liver transplantation. Although it is usually asymptomatic, HPS imparts a high risk of pretransplantation mortality, independently of the severity of liver disease, while there is variable data concerning survival rates after liver transplantation. The potential of myocardial involvement in the setting of HPS has also gained increasing interest in recent research. The aim of this review is to critically approach the existing literature of HPS and emphasize unclear points that remain to be unraveled by future research.

Keywords: Hepatopulmonary syndrome; Liver cirrhosis; Liver transplantation; Portal hypertension; Contrast echocardiography

Core tip: Hepatopulmonary syndrome (HPS) constitutes a relatively frequent complication of end-stage liver disease, characterized by impairment of arterial oxygenation. The only effective treatment is liver transplantation, improving hypoxemia. While there are controversial data regarding HPS prognosis before and after liver transplantation, the question remains whether HPS constitutes an independent factor of morbidity, providing HPS patients priority for liver transplantation. Furthermore, possible associations with myocardial function, which could support the utility of echocardiographical parameters as markers of HPS, remain yet to be established.