Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN 55455, USA.
Division of Solid Organ Transplantation, Department of Surgery, University of Minnesota, Minneapolis, MN, USA.
J R Soc Interface. 2023 Oct;20(207):20230444. doi: 10.1098/rsif.2023.0444. Epub 2023 Oct 25.
Partial liver resections are routinely performed in living donor liver transplantation and to debulk tumours in liver malignancies, but surgical decisions on vessel reconstruction for adequate inflow and outflow are challenging. Pre-operative evaluation is often limited to radiological imaging, which fails to account for post-resection haemodynamic alterations. Substantial evidence suggests post-surgical increase in local volume flow rate enhances shear stress, signalling hepatic regeneration, but excessive shear stress has been postulated to result in small for size syndrome and liver failure. Predicting haemodynamic alterations throughout the liver is particularly challenging due to the dendritic architecture of the vasculature, spanning several orders of magnitude in diameter. Therefore, we developed a mathematical lumped parameter model with realistic heterogeneities capturing inflow/outflow of the human liver to simulate acute perfusion alterations following surgical resection. Our model is parametrized using clinical measurements, relies on a single free parameter and accurately captures established perfusion characteristics. We quantify acute changes in volume flow rate, flow speed and wall shear stress following variable, realistic liver resections and make comparisons with the intact liver. Our numerical model runs in minutes and can be adapted to patient-specific anatomy, providing a novel computational tool aimed at assisting pre- and intra-operative surgical decisions for liver resections.
部分肝切除术在活体供肝移植和肝脏恶性肿瘤减瘤术中常规进行，但血管重建以确保充分的流入和流出的手术决策具有挑战性。术前评估通常仅限于影像学检查，但无法考虑术后血液动力学改变。大量证据表明，术后局部体积流量的增加会增强剪切应力，从而提示肝再生，但过高的剪切应力被认为会导致小肝综合征和肝功能衰竭。由于血管呈树突状结构，直径跨越几个数量级，因此预测整个肝脏的血液动力学改变特别具有挑战性。因此，我们开发了一个具有现实异质性的数学集中参数模型，用于模拟手术切除后急性血流灌注改变。我们的模型使用临床测量进行参数化，依赖于单个自由参数，并准确捕捉已建立的血流特征。我们定量分析了不同现实肝切除术后体积流量率、流速和壁面剪切应力的急性变化，并与完整肝脏进行了比较。我们的数值模型在几分钟内运行，可以适应患者特定的解剖结构，为肝切除术的术前和术中手术决策提供了一种新的计算工具。
