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World J Hepatol. Jan 27, 2015; 7(1): 28-32
Published online Jan 27, 2015. doi: 10.4254/wjh.v7.i1.28
Hagen-Poiseuille’s law: The link between cirrhosis, liver stiffness, portal hypertension and hepatic decompensation
Gerond Lake-Bakaar, Muneeb Ahmed, Amy Evenson, Alan Bonder, Salomao Faintuch, Vinay Sundaram
Gerond Lake-Bakaar, Muneeb Ahmed, Amy Evenson, Alan Bonder, Salomao Faintuch, Vinay Sundaram, Liver Tumor Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, United States
Author contributions: Lake-Bakaar G was responsible for the original conception and preparation of the manuscript; Ahmed M, Evenson A, Bonder A, Faintuch S and Sundaram V individually contributed equally to the work applying their areas of specialty to the core hypothesis and researching articles for the work; all authors approved the final version of the manuscript.
Conflict-of-interest: The authors do not have any conflicts of interest.
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: Gerond Lake-Bakaar, MD, PhD, Liver Tumor Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 110 Francis Street, Suite 7A-055, Boston, MA 02215, United States. glakebak@bidmc.harvard.edu
Telephone: +1-617-6329838 Fax: +1-617-6329820
Received: June 19, 2014
Peer-review started: June 20, 2014
First decision: July 10, 2014
Revised: November 5, 2014
Accepted: November 17, 2014
Article in press: November 19, 2014
Published online: January 27, 2015
Processing time: 205 Days and 5.8 Hours
Abstract

The onset of hepatic decompensation in cirrhosis heralds an accelerated downhill course with poor outcome. The sole predictor of this decompensation in cirrhosis is increased hepatic vein to portal vein gradient hepatic venous pressure gradient (HVPG). Surrogate markers of liver function or hepatic reserve appear to be less relevant. The hepatic sinusoids become less elastic and more rigid as liver fibrosis and cirrhosis progress. We propose that the Hagen-Poiseuille’s law, which applies to rigid, but not elastic vessels, determines the pressure-flow characteristics in the sinusoids. In the rigid cirrhotic liver, HVPG rises dramatically with any change in net surface area or radius, r4 of the vasculature that follows surgical resection. This review relates liver stiffness to the risk of decompensation in patients with cirrhosis. The liver has a unique dual blood supply comprising a low pressure portal vein and high pressure hepatic artery. We compare the complexity of autoregulation in the normal elastic liver with that in the rigid cirrhotic liver. Therapeutic modalities to reduce portal pressure may reduce the risk of hepatic decompensation and improve outcomes in cirrhosis.

Keywords: Portal hypertension; Liver stiffness; Hagen-Poiseuille’s law

Core tip: Unlike the elastic normal liver, hepatic sinusoidal vessels become progressively more rigid with advancing cirrhosis and thus subject to Hagen-Poiseuille’s law. Thereafter, pressure gradient is inversely proportional to the fourth power of vessel radius, r4. Surgical resection reduces liver volume and thus net diameter of sinusoids, without reducing hepatic blood inflow. The net reduction in r, at the same flow rates increases pressure gradient by a factor r4 and likely accounts for the poor outcomes in patients with cirrhosis and established portal hypertension. Reducing hepatic venous pressure gradient reduction as part of the management of cirrhosis may reduce the risk of decompensation.