Hemodynamic analyses of the portal vein flow changes using MRI, focusing on post-hepatectomy liver regeneration and small-for-size syndrome.

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20947
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0905:Surgery of the organs maintaining homeostasis and related fields
• Research Institution: Kyoto University
• Principal Investigator: OSHIMA Yu 京都大学, 医学研究科, 客員研究員 (50911830)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 肝切除 / 門脈血行動態 / 肝再生 / 過小グラフト症候群 / wall shear stress

Outline of Final Research Achievements

The study aimed to analyze the relationship between portal vein hemodynamics and liver regeneration after hepatectomy and to elucidate the mechanisms of small-for-size syndrome using 3D non-cine phase contrast MRI and fluid dynamics analyses. Firstly, portal vein hemodynamic parameters were measured in 70% hepatectomy models that follows the normal liver regeneration process, and their relationship with liver regeneration were evaluated. Subsequently, we examined the association between portal vein hemodynamic parameters and 90% hepatectomy models that exhibit small-for-size syndrome.
Currently, we are evaluating the relationship between portal vein hemodynamic parameters, cytokines, and growth factors in the context of the liver regeneration process. Additionally, we are attempting to analyze the hemodynamic parameters that either induce or impair liver regeneration.

Free Research Field

消化器外科

Academic Significance and Societal Importance of the Research Achievements

肝切除後の相対的な門脈血流量増加が肝再生を誘導する一方で、血管内皮細胞への過大な力学的刺激が肝再生を障害し、過小グラフト症候群発生のリスクとなる。しかし、これまで門脈血行動態の詳細な評価は困難であったため、門脈血行動態と肝再生との関係や、過小グラフト症候群の病態はいまだ十分に解明されていない。
本研究により、ラット肝切除術後の血行動態パラメーター(血流量、血流速度、壁せん断応力など)を定量的に評価することが可能となった。今後は肝疾患や肝臓外科治療の小動物モデルにおいて、門脈血行動態変化と肝再生との関係や、過小グラフト症候群の病態を解明することに応用できると考えられる。