Basic Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 14, 2017; 23(18): 3279-3286
Published online May 14, 2017. doi: 10.3748/wjg.v23.i18.3279
Wall shear stress in portal vein of cirrhotic patients with portal hypertension
Wei Wei, Yan-Song Pu, Xin-Kai Wang, An Jiang, Rui Zhou, Yu Li, Qiu-Juan Zhang, Ya-Juan Wei, Bin Chen, Zong-Fang Li
Wei Wei, Yu Li, Zong-Fang Li, National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, the Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
Yan-Song Pu, An Jiang, Rui Zhou, Qiu-Juan Zhang, Ya-Juan Wei, Shaanxi Provincial Clinical Research Center for Hepatic and Splenic Diseases, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
Xin-Kai Wang, Bin Chen, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, Shaanxi Province, China
Author contributions: Wei W and Pu YS contributed equally to this work; Wei W, Pu YS and Li ZF designed the research; Jiang A, Zhou R, Li Y, Zhang QJ and Wei YJ collected the clinical data; Wang XK and Chen B contributed to the computational fluid dynamics remodeling; Wei W and Pu YS analyzed the data; Wei W and Li ZF wrote the paper.
Supported by the Program for Changjiang Scholars and Innovative Research Team in Universities, No. PCSIRT-1171; National Natural Science Foundation of China, No. 81270504; Fundamental Research Funds for the Central Universities, No. xjj20100209.
Institutional review board statement: This study was reviewed and approved by the Institutional Review Board of The Second Affiliated Hospital of Xi’an Jiaotong University.
Conflict-of-interest statement: All authors declare 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 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: Zong-Fang Li, MD, PhD, Professor, National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, No. 157 Xiwu Road, Xi’an 710004, Shaanxi Province, China. lzf2568@gmail.com
Telephone: +86-29-87679508 Fax: +86-29-87678634
Received: December 28, 2016
Peer-review started: December 30, 2016
First decision: January 19, 2017
Revised: February 3, 2017
Accepted: March 3, 2017
Article in press: March 3, 2017
Published online: May 14, 2017
Abstract
AIM

To investigate wall shear stress (WSS) magnitude and distribution in cirrhotic patients with portal hypertension using computational fluid dynamics.

METHODS

Idealized portal vein (PV) system models were reconstructed with different angles of the PV-splenic vein (SV) and superior mesenteric vein (SMV)-SV. Patient-specific models were created according to enhanced computed tomography images. WSS was simulated by using a finite-element analyzer, regarding the blood as a Newtonian fluid and the vessel as a rigid wall. Analysis was carried out to compare the WSS in the portal hypertension group with that in healthy controls.

RESULTS

For the idealized models, WSS in the portal hypertension group (0-10 dyn/cm2) was significantly lower than that in the healthy controls (10-20 dyn/cm2), and low WSS area (0-1 dyn/cm2) only occurred in the left wall of the PV in the portal hypertension group. Different angles of PV-SV and SMV-SV had different effects on the magnitude and distribution of WSS, and low WSS area often occurred in smaller PV-SV angle and larger SMV-SV angle. In the patient-specific models, WSS in the cirrhotic patients with portal hypertension (10.13 ± 1.34 dyn/cm2) was also significantly lower than that in the healthy controls (P < 0.05). Low WSS area often occurred in the junction area of SV and SMV into the PV, in the area of the division of PV into left and right PV, and in the outer wall of the curving SV in the control group. In the cirrhotic patients with portal hypertension, the low WSS area extended to wider levels and the magnitude of WSS reached lower levels, thereby being more prone to disturbed flow occurrence.

CONCLUSION

Cirrhotic patients with portal hypertension show dramatic hemodynamic changes with lower WSS and greater potential for disturbed flow, representing a possible causative factor of PV thrombosis.

Keywords: Portal hypertension, Wall shear stress, Portal vein system, Distribution, Disturbed flow

Core tip: For portal hypertension, idealized portal vein (PV) modeling showed a significantly lower wall shear stress (WSS) in both sides of the PV and the occurrence of disturbed flow in the left wall of the PV. In addition, greater risk of disturbed flow was found for smaller PV-splenic vein (SV) angle and larger superior mesenteric vein-SV angle. In patient-specific models, WSS in cirrhotic patients with portal hypertension was markedly lower than that in healthy controls and disturbed flow was more likely to occur in the portal hypertension patients.