1
|
Li B, Li G, Liu J, Sun H, Wen C, Yang Y, Qiao A, Liu J, Liu Y. Deep-learning-based real-time individualization for reduce-order haemodynamic model. Comput Biol Med 2024; 174:108476. [PMID: 38636328 DOI: 10.1016/j.compbiomed.2024.108476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 03/18/2024] [Accepted: 04/11/2024] [Indexed: 04/20/2024]
Abstract
The reduced-order lumped parameter model (LPM) has great computational efficiency in real-time numerical simulations of haemodynamics but is limited by the accuracy of patient-specific computation. This study proposed a method to achieve the individual LPM modeling with high accuracy to improve the practical clinical applicability of LPM. Clinical data was collected from two medical centres comprising haemodynamic indicators from 323 individuals, including brachial artery pressure waveforms, cardiac output data, and internal carotid artery flow waveforms. The data were expanded to 5000 synthesised cases that all fell within the physiological range of each indicator. LPM of the human blood circulation system was established. A double-path neural network (DPNN) was designed to input the waveforms of each haemodynamic indicator and their key features and then output the individual parameters of the LPM, which was labelled using a conventional optimization algorithm. Clinically collected data from the other 100 cases were used as the test set to verify the accuracy of the individual LPM parameters predicted by DPNN. The results show that DPNN provided good convergence in the training process. In the test set, compared with clinical measurements, the mean differences between each haemodynamic indicator and the estimate calculated by the individual LPM based on the DPNN were about 10 %. Furthermore, DPNN prediction only takes 4 s for 100 cases. The DPNN proposed in this study permits real-time and accurate individualization of LPM's. When facing medical issues involving haemodynamics, it lays the foundation for patient-specific numerical simulation, which may be beneficial for potential clinical application.
Collapse
Affiliation(s)
- Bao Li
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China
| | - Guangfei Li
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China.
| | - Jincheng Liu
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China
| | - Hao Sun
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China
| | - Chuanqi Wen
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China
| | - Yang Yang
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China
| | - Aike Qiao
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China
| | - Jian Liu
- Department of Cardiology, Peking University People's Hospital, Beijing, China
| | - Youjun Liu
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China
| |
Collapse
|
2
|
Xiong Z, Wang X, Yan Y, Liu Z, Luo X, Zheng T. A new computational fluid dynamics based noninvasive assessment of portacaval pressure gradient. J Biomech 2024; 167:112086. [PMID: 38615481 DOI: 10.1016/j.jbiomech.2024.112086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 03/27/2024] [Accepted: 04/04/2024] [Indexed: 04/16/2024]
Abstract
Accurate assessment of portacaval pressure gradient (PCG) in patients with portal hypertension (PH) is of great significance both for diagnosis and treatment. This study aims to develop a noninvasive method for assessing PCG in PH patients and evaluate its accuracy and effectiveness. This study recruited 37 PH patients treated with transjugular intrahepatic portosystemic shunt (TIPS). computed tomography angiography was used to create three dimension (3D) models of each patient before and after TIPS. Doppler ultrasound examinations were conducted to obtain the patient's portal vein flow (or splenic vein and superior mesenteric vein). Using computational fluid dynamics (CFD) simulation, the patient's pre-TIPS and post-TIPS PCG was determined by the 3D models and ultrasound measurements. The accuracy of these noninvasive results was then compared to clinical invasive measurements. The results showed a strong linear correlation between the PCG simulated by CFD and the clinical invasive measurements both before and after TIPS (R2 = 0.998, P < 0.001 and R2 = 0.959, P < 0.001). The evaluation accuracy of this noninvasive method reached 94 %, and the influence of ultrasound result errors on the numerical accuracy was found to be marginal if the error was less than 20 %. Furthermore, the information about the hemodynamic environment in the portal system was obtained by this numerical method. Spiral flow patterns were observed in the portal vein of some patients. In a conclusion, this study proposes a noninvasive numerical method for assessing PCG in PH patients before and after TIPS. This method can assist doctors in accurately diagnosing patients and selecting appropriate treatment plans. Additionally, it can be used to further investigate potential biomechanical causes of complications related to TIPS in the future.
Collapse
Affiliation(s)
- Zhuxiang Xiong
- Department of Mechanics, College of Architecture & Environment, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park / Yibin Institute of Industrial Technology, Yibin 644000, China
| | - Xiaoze Wang
- Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yuling Yan
- Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zhan Liu
- Department of Mechanics, College of Architecture & Environment, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park / Yibin Institute of Industrial Technology, Yibin 644000, China
| | - Xuefeng Luo
- Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Tinghui Zheng
- Department of Mechanics, College of Architecture & Environment, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park / Yibin Institute of Industrial Technology, Yibin 644000, China; West China Information Center, Sichuan University, Chengdu 610065, China.
| |
Collapse
|
3
|
Wang T, Yong Y, Ge X, Wang J. A computational model-based study on the feasibility of predicting post-splenectomy thrombosis using hemodynamic metrics. Front Bioeng Biotechnol 2024; 11:1276999. [PMID: 38274008 PMCID: PMC10808826 DOI: 10.3389/fbioe.2023.1276999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 10/30/2023] [Indexed: 01/27/2024] Open
Abstract
For portal hypertensive patients with splenomegaly and hypersplenism, splenectomy is an effective surgery to relieve the complications. However, patients who have undergone splenectomy often suffer from portal venous system thrombosis, a sequela that requires prophylaxis and timely treatment to avoid deterioration and death. The aim of this study is to investigate the feasibility of predicting post-splenectomy thrombosis using hemodynamic metrics based on computational models. First, 15 portal hypertensive patients who had undergone splenectomy were enrolled, and their preoperative clinical data and postoperative follow-up results were collected. Next, computational models of the portal venous system were constructed based on the preoperative computed tomography angiography images and ultrasound-measured flow velocities. On this basis, splenectomy was mimicked and the postoperative area of low wall shear stress (ALWSS) was simulated for each patient-specific model. Finally, model-simulated ALWSS was statistically compared with the patient follow-up results to investigate the feasibility of predicting post-splenectomy thrombosis using hemodynamic metrics. Results showed that ALWSS could predict the occurrence of post-splenectomy thrombosis with the area under the receiver operating characteristic curve (AUC) equal to 0.75. Moreover, statistical analysis implied that the diameter of the splenic vein is positively correlated with ALWSS (r = 0.883, p < 0.0001), and the anatomical structures of the portal venous system also influence the ALWSS. These findings demonstrated that the computational model-based hemodynamic metric ALWSS, which is associated with the anatomorphological features of the portal venous system, is capable of predicting the occurrence of post-splenectomy thrombosis, promoting better prophylaxis and postoperative management for portal hypertensive patients receiving splenectomy.
Collapse
Affiliation(s)
- Tianqi Wang
- School of Gongli Hospital Medical Technology, University of Shanghai for Science and Technology, Shanghai, China
- School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Yan Yong
- College of Science, University of Shanghai for Science and Technology, Shanghai, China
| | - Xinyang Ge
- College of Mathematical Medicine, Zhejiang Normal University, Jinhua, China
| | - Jitao Wang
- Department of Hepatobiliary Surgery, Xingtai Institute of Cancer Control, Xingtai, China
| |
Collapse
|
4
|
Torres Rojas AM, Lorente S. Liver fibrosis emulation: Impact of the vascular fibrotic alterations on hemodynamics. Comput Biol Med 2023; 166:107563. [PMID: 37852110 DOI: 10.1016/j.compbiomed.2023.107563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/10/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023]
Abstract
The liver circulatory system comprises two blood supply vascular trees (the hepatic artery and portal venous networks), microcirculation through the hepatic capillaries (the sinusoids), and a blood drainage vascular tree (the hepatic vein network). Vasculature changes due to fibrosis -located predominantly at the microcirculation level- lead to a marked increase in resistance to flow causing an increase in portal pressure (portal hypertension). Here, we present a liver fibrosis/cirrhosis model. We build on our 1D model of the healthy hepatic circulation, which considers the elasticity of the vessels walls and the pulsatile character of blood flow and pressure, and recreate the deteriorated liver vasculature due to fibrosis. We emulate altered sinusoids by fibrous tissue (stiffened, compressed and splitting) and propose boundary conditions to investigate the impact of fibrosis on hemodynamic variables within the organ. We obtain that the sinusoids stiffness leads to changes in the amplitude and shape of the blood flow and pressure waveforms but not in their mean value. For the compressed and splitting sinusoids, we observe significant increases in the mean value and amplitude of the pressure waveform in the altered sinusoids and in the portal venous network. In other words, we obtain the portal hypertension clinically observed in fibrotic/cirrhotic patients. We also study the extent of the spreading fibrosis by performing the structural fibrotic changes in an increasingly number of sinusoids. Finally, we calculate the portal pressure gradient (PPG) in the model and obtain values in agreement with those reported in the literature for fibrotic/cirrhotic patients.
Collapse
Affiliation(s)
- Aimee M Torres Rojas
- Mechanical Engineering Department, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA.
| | - Sylvie Lorente
- Mechanical Engineering Department, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA
| |
Collapse
|
5
|
Wang T, Ge X, Li X, Liu T, Liang F, Zhou Z. A 0D-3D multi-scale model of the portal venous system coupled with the entire cardiovascular system applied to predict postsplenectomy hemodynamic metrics. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38083238 DOI: 10.1109/embc40787.2023.10340121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Splenectomy is a common surgery for portal hypertensive patients with splenomegaly. Although splenectomy is able to effectively relieve the complications of portal hypertension, it also increases the risk of portal venous system thrombosis remarkably. Previous studies demonstrated that the hemodynamic metrics of the portal venous system could be employed in predicting the risk of postsplenectomy thrombosis, and 3D models were utilized to simulate the blood flow in the portal venous system. Aiming to reflect the global effect of splenectomy and better simulate the hemodynamic metrics, in this study, a 0D-3D multi-scale model of the portal venous system coupled with the entire cardiovascular system was constructed based on population-averaged data in combination with patient-specific preoperative clinical measurements. The pre- and postoperative global blood flows as well as the variations were calculated successfully, and the flow field and time-averaged wall shear stress of the portal venous system were simulated. The model-simulated spatial distributions of the hemodynamic metrics in the portal venous system were comparable with the regions suffering from thrombosis after splenectomy. These results imply that the present model could reflect the reallocation of the blood flow in the splanchnic circulation after splenectomy and simulate the hemodynamic metrics of the portal venous system, which would promote the more accurate risk stratification of postsplenectomy thrombosis and improve the patient-specific postoperative management.Clinical Relevance- The computational model developed by the present study provides a feasible scheme for simulating postsplenectomy hemodynamic metrics of the portal venous system more accurately, which would benefit the risk prediction and prophylaxis of portal venous system thrombosis for portal hypertensive patients receiving splenectomy.
Collapse
|
6
|
Qiu Y, Tai Y, Lei J, Zeng Y, Wu H, Li K. Modelling the liver region as porous media to noninvasively measure portal vein pressure gradient (PPG) with numerical methods. J Biomech 2023; 155:111660. [PMID: 37285779 DOI: 10.1016/j.jbiomech.2023.111660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 05/11/2023] [Accepted: 05/23/2023] [Indexed: 06/09/2023]
Abstract
Portal hypertension is the initial and main consequence of liver cirrhosis. Currently the diagnosis relies on invasive and complex operation. This study proposed a new computational method in computational fluid dynamics (CFD) analysis to noninvasively measure the portal pressure gradient (PPG) by considering the liver region as porous media to account for the patient-specific liver resistance. Patient-specific computational models based on the CT scan images and the ultrasound (US) velocity measurement was established. The results show that the PPG derived from CFD analysis is in great agreement with clinical measured data (23.93 mmHg vs 23 mmHg). Validation of the numerical method and was performed by post-TIPS PPG measurement (10.69 mmHg vs 11 mmHg). Then the range of porous media parameters is investigated in a validation group of three patients. The computational method proposed in this study is promising in more accurately measuring the PPG noninvasively.
Collapse
Affiliation(s)
- Yue Qiu
- Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China; West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China; Med-X Center for Informatics, Sichuan University, Chengdu, Sichuan 610041, PR China; West China Hospital-SenseTime Joint Lab, Chengdu, Sichuan 610041, PR China
| | - Yang Tai
- Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Jianguo Lei
- Med-X Center for Informatics, Sichuan University, Chengdu, Sichuan 610041, PR China; West China Hospital-SenseTime Joint Lab, Chengdu, Sichuan 610041, PR China
| | - Yi Zeng
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Hao Wu
- Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China.
| | - Kang Li
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China; Med-X Center for Informatics, Sichuan University, Chengdu, Sichuan 610041, PR China; West China Hospital-SenseTime Joint Lab, Chengdu, Sichuan 610041, PR China.
| |
Collapse
|
7
|
Rojas AMT, Lorente S. 1D-model of the human liver circulatory system. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 238:107612. [PMID: 37224726 DOI: 10.1016/j.cmpb.2023.107612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/27/2023] [Accepted: 05/15/2023] [Indexed: 05/26/2023]
Abstract
BACKGROUND AND OBJECTIVE Blood flow rate and pressure can be measured in vivo by invasive and non-invasive techniques in the large vessels of the hepatic vasculature, but it is not possible to do so along the entire liver circulatory system. Here, we develop a novel 1D model of the liver circulatory system to obtain the hemodynamic signals from macrocirculation to microcirculation with a very low computational cost. METHODS The model considers structurally well-defined elements that constitute the entire hepatic circulatory system, the hemodynamics (the temporal-dependence of the blood flow rate and pressure), and the elasticity of the vessel walls. RESULTS Using flow rate signals from in vivo measurements as inputs in the model, we obtain pressure signals within their physiological range of values. Furthermore, the model allows to get and analyze the blood flow rate and pressure signals along any vessel of the hepatic vasculature. The impact of the elasticity of the different model components on the inlet pressures is also tested. CONCLUSIONS A 1D model of the entire blood vascular system of the human liver is presented for the first time. The model allows to obtain the hemodynamic signals along the hepatic vasculature at a low computational cost. The amplitude and shape of the flow and pressure signals has hardly been studied in the small liver vessels. In this sense, the proposed model is a useful non-invasive exploration tool of the characteristics of the hemodynamic signals. In contrast to models that partially address the hepatic vasculature or those using an electrical analogy, the model presented here is made entirely of structurally well-defined elements. Future works will allow to directly emulate structural vascular alterations due to hepatic diseases and studying their impact on pressure and blood flow signals at key locations of the vasculature.
Collapse
Affiliation(s)
- Aimee M Torres Rojas
- Mechanical Engineering Department, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA
| | - Sylvie Lorente
- Mechanical Engineering Department, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA.
| |
Collapse
|
8
|
Nguyen VL, Misawa A, Obara H. An electrical analog permeability model assessing fluid flow in a decellularized organ. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 237:107595. [PMID: 37192592 DOI: 10.1016/j.cmpb.2023.107595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/27/2023] [Accepted: 05/09/2023] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND OBJECTIVE In recellularization, cell-seeding efficiency refers to the uniform distribution of cells across the decellularized organ, which should be enhanced to ensure effective functioning. During cell seeding, flow dynamics influence the distribution of cells because the driving force of cell movement is the fluid force. However, after decellularization, because of flow permeability through the vessel wall, the fluid pressure and velocity in the vessels of vascular trees are significantly reduced compared with those in the native organ, which might affect cell seeding efficiency. Therefore, it is necessary to assess the flow characteristics in the vessels of decellularized organs to select appropriate seeding conditions. Although electrical analog models have been widely used to investigate the flow distribution in organs, current models do not reflect the permeable conditions. This study proposes a model to extend the conventional electrical analog model to simulate the flow characteristics in decellularized organs. METHODS A resistor reflecting permeable flow was added to the original electrical analog model to describe the permeable conditions in the decellularized organs. Decellularization and pressure drop measurements of the kidney were also conducted for model development, calibration, and validation. The developed model was then applied to a decellularized kidney to reveal changes in flow characteristics. RESULTS The resistance calculation of permeable flow was determined for each generation of vascular trees. The coefficient of permeability can be indicated by the measured flow exiting through the outlet or the pressure drop across the decellularized organ. The developed permeability model had a qualitative and quantitative agreement with the experimental data without calibration. The results of the permeability model for the decellularized kidney indicated significant reductions of up to 70% in the flow rate and pressure of the organ compared to the native kidney. CONCLUSIONS The developed model can simulate the flow characteristics in each individual vessel of decellularized organs. The results from the model can be used to assess the optimal flow rate condition for the cell seeding process.
Collapse
Affiliation(s)
- Van Lap Nguyen
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan; Faculty of Mechanical Engineering, Thuyloi University, 175 Tay Son, Dong Da, Hanoi, Vietnam.
| | - Akari Misawa
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Hiromichi Obara
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| |
Collapse
|
9
|
Liu B, Yue Z, Cui T, Zhao H, Wang L, Fan Z, Wu Y, Meng M, Zhang K, Jiang L, Ding H, Zhang Y, Liu F. Innovative angiography: a new approach to discover more hepatic vein collaterals in patients with cirrhotic portal hypertension. BMC Gastroenterol 2023; 23:144. [PMID: 37165348 PMCID: PMC10173554 DOI: 10.1186/s12876-023-02792-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 04/27/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND The hemodynamics of patients with cirrhosis and portal hypertension are complex and variable. We aimed to investigate differences in venous pressures determined by innovative angiography and conventional angiography using balloon occlusion of the hepatic veins in patients with alcoholic cirrhosis and portal hypertension. METHODS A total of 134 patients with alcoholic cirrhosis who fulfilled the inclusion criteria from June 2017 to June 2020 were included. During transjugular intrahepatic portosystemic shunt, conventional and innovative angiography were performed, and venous pressures were measured. A paired t-test and Pearson's correlation coefficient were used for analysis. RESULTS Conventional and innovative hepatic angiography detected lateral branches of the hepatic vein in 26 (19.4%) and 65 (48.5%) cases, respectively (P < 0.001). Innovative angiography detected a total of 65 patients with lateral shunts, of whom 37 (56.9%) had initial shunts. The average wedged hepatic venous pressure and portal venous pressure of the initial lateral branches were 21.27 ± 6.66 and 35.84 ± 7.86 mmHg, respectively, with correlation and determination coefficients of 0.342 (P < 0.05) and 0.117, respectively. The mean hepatic venous pressure gradient and portal pressure gradient were 9.59 ± 7.64 and 26.86 ± 6.78 mmHg, respectively, with correlation and determination coefficients of 0.292 (P = 0.079) and 0.085, respectively. CONCLUSIONS Innovative angiography reveals collateral branches of the hepatic veins more effectively than conventional angiography. Hepatic vein collateral branches are the primary factors leading to underestimation of wedged hepatic venous pressures and hepatic venous pressure gradients, with the initial hepatic vein collateral branches resulting in the most severe underestimations.
Collapse
Affiliation(s)
- Bowen Liu
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, No.10 Tieyi Road, Yangfangdian Street, Haidian District, Beijing, 100038, China
| | - Zhendong Yue
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, No.10 Tieyi Road, Yangfangdian Street, Haidian District, Beijing, 100038, China
| | - Ting Cui
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, No.10 Tieyi Road, Yangfangdian Street, Haidian District, Beijing, 100038, China
| | - Hongwei Zhao
- Department of Interventional Therapy, Beijing Tongren Hospital, Capital Medical University, Beijing, 100005, China
| | - Lei Wang
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, No.10 Tieyi Road, Yangfangdian Street, Haidian District, Beijing, 100038, China
| | - Zhenhua Fan
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, No.10 Tieyi Road, Yangfangdian Street, Haidian District, Beijing, 100038, China
| | - Yifan Wu
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, No.10 Tieyi Road, Yangfangdian Street, Haidian District, Beijing, 100038, China
| | - Mingming Meng
- Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, China
| | - Ke Zhang
- Department of General Surgery, Beijing Ditan Hospital, Capital Medical University, Beijing, 100102, China
| | - Li Jiang
- Department of General Surgery, Beijing Ditan Hospital, Capital Medical University, Beijing, 100102, China
| | - Huiguo Ding
- Department of Gastroenterology, Beijing YouAn Hospital, Capital Medical University, Beijing, 100069, China
| | - Yuening Zhang
- Department of Gastroenterology, Beijing YouAn Hospital, Capital Medical University, Beijing, 100069, China
| | - Fuquan Liu
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, No.10 Tieyi Road, Yangfangdian Street, Haidian District, Beijing, 100038, China.
| |
Collapse
|
10
|
Sala L, Golse N, Joosten A, Vibert E, Vignon-Clementel I. Sensitivity Analysis of a Mathematical Model Simulating the Post-Hepatectomy Hemodynamics Response. Ann Biomed Eng 2023; 51:270-289. [PMID: 36326994 PMCID: PMC9832106 DOI: 10.1007/s10439-022-03098-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
Recently a lumped-parameter model of the cardiovascular system was proposed to simulate the hemodynamics response to partial hepatectomy and evaluate the risk of portal hypertension (PHT) due to this surgery. Model parameters are tuned based on each patient data. This work focuses on a global sensitivity analysis (SA) study of such model to better understand the main drivers of the clinical outputs of interest. The analysis suggests which parameters should be considered patient-specific and which can be assumed constant without losing in accuracy in the predictions. While performing the SA, model outputs need to be constrained to physiological ranges. An innovative approach exploits the features of the polynomial chaos expansion method to reduce the overall computational cost. The computed results give new insights on how to improve the calibration of some model parameters. Moreover the final parameter distributions enable the creation of a virtual population available for future works. Although this work is focused on partial hepatectomy, the pipeline can be applied to other cardiovascular hemodynamics models to gain insights for patient-specific parameterization and to define a physiologically relevant virtual population.
Collapse
Affiliation(s)
- Lorenzo Sala
- Inria Saclay Ile-de-France, 91120 Palaiseau, France
| | - Nicolas Golse
- Université Paris-Saclay, Inserm Physiopathogénèse et traitement des maladie du foie, UMR-S 1193, 94800 Villejuif, France
| | - Alexandre Joosten
- Université Paris-Saclay, Inserm Physiopathogénèse et traitement des maladie du foie, UMR-S 1193, 94800 Villejuif, France
| | - Eric Vibert
- Université Paris-Saclay, Inserm Physiopathogénèse et traitement des maladie du foie, UMR-S 1193, 94800 Villejuif, France
| | | |
Collapse
|
11
|
Yin K, Wang X, Zheng T. Computational hemodynamic analysis for optimal stent position in the transjugular intrahepatic portosystemic shunt procedure. J Biomech 2022; 143:111303. [PMID: 36126502 DOI: 10.1016/j.jbiomech.2022.111303] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/02/2022] [Accepted: 09/09/2022] [Indexed: 11/27/2022]
Abstract
Transjugular intrahepatic portosystemic shunt (TIPS) is an effective treatment for portal hypertension (PH). The current study aimed to investigate the effect of stent position on post-TIPS hemodynamic performance using computational fluid dynamics. Patient-specific pre- and post-TIPS models were reconstructed from CT images of two patients, then virtual TIPS models were created by shifting the portal vein (PV) entry site of the stent. Although there were marginal differences the effects of left-sided and right-sided TIPS on post-TIPS portal pressure and shunting flow, right-sided TIPS resulted in a greater proportion of superior mesenteric vein (SMV) flow diverting to stents compared to that for left-sided TIPS. The results also demonstrated that the nearer the entry site of stent to the portal venous bifurcation, the greater and more stable the shunting blood flow. These results suggest that the entry site of the stent should be as close to the portal vein bifurcation as possible during TIPS. TIPS on the right branch of the portal vein may be more likely to result in post-TIPS hepatic encephalopathy than that on the left branch.
Collapse
Affiliation(s)
- Keli Yin
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park / Yibin Institute of Industrial Technology, Yibin 644000, China.
| | - Xiaoze Wang
- Department of Gastroenterology and Hepatology, Sichuan University-University of Oxford Huaxi Joint Centre for Gastrointestinal Cancer, West China Hospital, Sichuan University, Chengdu, China.
| | - Tinghui Zheng
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China; Med-X Center for Informatics, Sichuan University, Chengdu 610041, China.
| |
Collapse
|
12
|
Predicting the risk of postsplenectomy thrombosis in patients with portal hypertension using computational hemodynamics models: A proof-of-concept study. Clin Biomech (Bristol, Avon) 2022; 98:105717. [PMID: 35834965 DOI: 10.1016/j.clinbiomech.2022.105717] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/05/2022] [Accepted: 07/06/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND The high incidence of thrombosis in the portal venous system following splenectomy (a frequently adopted surgery for treating portal hypertension in patients with splenomegaly and hypersplenism) is a critical clinical issue. The aim of this study was to address whether quantification of postsplenectomy hemodynamics has potential value for assessing the risk of postsplenectomy thrombosis. METHODS Computational models were constructed for three portal hypertensive patients treated with splenectomy based on their preoperative clinical data to quantify hemodynamics in the portal venous system before and after splenectomy, respectively. Each patient was followed up for three or five months after surgery and examined with CT to screen potential thrombosis. FINDINGS The area ratio of wall regions exposed to low wall shear stress was small before splenectomy in all patients, which increased markedly after splenectomy and exhibited enlarged inter-patient differences. The largest area ratio of low wall shear stress and most severe flow stagnation after splenectomy were predicted for the patient suffering from postsplenectomy thrombosis, with the wall regions exposed to low wall shear stress corresponding well with the CT-detected distribution of thrombus. Further analyses revealed that postoperative hemodynamic characteristics were considerably influenced by the anatomorphological features of the portal venous system. INTERPRETATION Postoperative hemodynamic conditions in the portal venous system are highly patient-specific and have a potential link to postsplenectomy thrombosis, which indicates that patient-specific hemodynamic studies may serve as a complement to routine clinical assessments for refining risk stratification and postoperative patient management.
Collapse
|
13
|
Correlation between hepatic venous pressure gradient and portal venous pressure gradient in hepatitis B cirrhosis with different hepatic veins anatomy. Eur J Radiol 2022; 155:110463. [DOI: 10.1016/j.ejrad.2022.110463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 07/14/2022] [Accepted: 08/03/2022] [Indexed: 11/18/2022]
|
14
|
Taebi A, Janibek N, Goldman R, Pillai R, Vu CT, Roncali E. The Impact of Injection Distance to Bifurcations on Yttrium-90 Distribution in Liver Cancer Radioembolization. J Vasc Interv Radiol 2022; 33:668-677.e1. [PMID: 35301128 PMCID: PMC9156550 DOI: 10.1016/j.jvir.2022.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 02/22/2022] [Accepted: 03/06/2022] [Indexed: 01/26/2023] Open
Abstract
PURPOSE To model the effect of the injection location on the distribution of yttrium-90 (90Y) microspheres in the liver during radioembolization using computational simulation and to determine the potential effects of radial movements of the catheter tip. MATERIALS AND METHODS Numerical studies were conducted using images from a representative patient with hepatocellular carcinoma. The right hepatic artery (RHA) was segmented from contrast-enhanced cone-beam computed tomography scans. The blood flow was investigated in the trunk of the RHA using numerical simulations for 6 injection position scenarios at 2 sites located at a distance of approximately 5 and 20 mm upstream of the first bifurcation (RHA diameters of approximately 4.6 mm). The 90Y delivery to downstream vessels was calculated from the simulated hepatic artery hemodynamics. RESULTS Varying the injection location along the RHA and across the vessel cross-section resulted in different simulated microsphere distributions in the downstream vascular bed. When the catheter tip was 5 mm upstream of the bifurcation, 90Y distribution in the downstream branches varied by as much as 53% with a 1.5-mm radial movement of the tip. However, the catheter radial movement had a weaker effect on the microsphere distribution when the injection plane was farther from the first bifurcation (20 mm), with a maximum delivery variation of 9% to a downstream branch. CONCLUSIONS An injection location far from bifurcations is recommended to minimize the effect of radial movements of the catheter tip on the microsphere distribution.
Collapse
Affiliation(s)
- Amirtaha Taebi
- Department of Agricultural and Biological Engineering, Mississippi State University
| | - Nursultan Janibek
- Department of Mechanical and Aerospace Engineering, University of California Davis
| | - Roger Goldman
- Department of Radiology, University of California Davis
| | - Rex Pillai
- Department of Radiology, University of California Davis
| | | | - Emilie Roncali
- Department of Radiology, University of California Davis,Department of Biomedical Engineering, University of California Davis
| |
Collapse
|
15
|
Li Z, Chen Y, Zeng X, Stephen S, Li Y, Li H, Dong L, He T, Zhang S, Yang P, Jiang W, Fan H. Clinical and hemodynamic insights into the use of internal iliac artery balloon occlusion as a prophylactic technique for treating postpartum hemorrhage. J Biomech 2021; 129:110827. [PMID: 34736088 DOI: 10.1016/j.jbiomech.2021.110827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/02/2021] [Accepted: 10/16/2021] [Indexed: 11/19/2022]
Abstract
Recently, the effectiveness of internal iliac artery balloon occlusion (IIABO) for treating postpartum hemorrhage caused by pernicious placenta previa (PPP) has been questioned. We conducted a retrospective analysis and hemodynamic simulation to assess the IIABO's effectiveness. The retrospective analysis involved 480 patients with PPP, among which 288 underwent IIABO treatment and the remaining 192 were used as controls. Blood loss and preoperative indicators were recorded, and multiple regression analysis was applied to test the effect of preoperative indicators on blood loss. Hemorrhage mechanisms were simulated using a numerical model. Results suggested that no significant difference in blood loss (1836 ± 1440 ml vs. 1784 ± 1647 ml, p = 0.22) was observed between the two groups. In addition, preoperative indicators, including age, weight, gestational age, gravidity, parity, blood type, anemia, or diabetes, were not associated with blood loss. In the simulation, after the intra-iliac artery was blocked, blood loss was caused by a reversed flow in the intrapelvic arteries, uterine veins, and uterine venules. The ratio of the time-averaged hemorrhage velocity (TAHV) in the balloon group to that in the control group was lower than that obtained in a clinical study (13.0% vs. 88.9%); in the presence of collateral circulation, blood loss occurred from collateral circulation and uterine venules after IIABO intervention, and the TAHV was 60%-90% that of the control group, which was closer to the clinical results (88.9%). These results suggest that IIABO cannot effectively treat postpartum hemorrhage because of the collateral circulation and reversed flow in the uterine venules.
Collapse
Affiliation(s)
- Zhongyou Li
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Yu Chen
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China; Medical Big Data Center, Sichuan University, Chengdu 610041, China.
| | - Xiaoxi Zeng
- Medical Big Data Center, Sichuan University, Chengdu 610041, China
| | - Salerno Stephen
- Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA
| | - Yi Li
- Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA
| | - Huafeng Li
- West China Second Hospital, Sichuan University, Chengdu 610041, China.
| | - Lihua Dong
- Department of Anatomy, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Teng He
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Shihong Zhang
- West China Second Hospital, Sichuan University, Chengdu 610041, China
| | - Pei Yang
- West China Second Hospital, Sichuan University, Chengdu 610041, China
| | - Wentao Jiang
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Haidong Fan
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| |
Collapse
|
16
|
Gomes J, Kong J, Kurc T, Melo ACMA, Ferreira R, Saltz JH, Teodoro G. Building robust pathology image analyses with uncertainty quantification. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 208:106291. [PMID: 34333205 DOI: 10.1016/j.cmpb.2021.106291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND OBJECTIVE Computerized pathology image analysis is an important tool in research and clinical settings, which enables quantitative tissue characterization and can assist a pathologist's evaluation. The aim of our study is to systematically quantify and minimize uncertainty in output of computer based pathology image analysis. METHODS Uncertainty quantification (UQ) and sensitivity analysis (SA) methods, such as Variance-Based Decomposition (VBD) and Morris One-At-a-Time (MOAT), are employed to track and quantify uncertainty in a real-world application with large Whole Slide Imaging datasets - 943 Breast Invasive Carcinoma (BRCA) and 381 Lung Squamous Cell Carcinoma (LUSC) patients. Because these studies are compute intensive, high-performance computing systems and efficient UQ/SA methods were combined to provide efficient execution. UQ/SA has been able to highlight parameters of the application that impact the results, as well as nuclear features that carry most of the uncertainty. Using this information, we built a method for selecting stable features that minimize application output uncertainty. RESULTS The results show that input parameter variations significantly impact all stages (segmentation, feature computation, and survival analysis) of the use case application. We then identified and classified features according to their robustness to parameter variation, and using the proposed features selection strategy, for instance, patient grouping stability in survival analysis has been improved from in 17% and 34% for BRCA and LUSC, respectively. CONCLUSIONS This strategy created more robust analyses, demonstrating that SA and UQ are important methods that may increase confidence digital pathology.
Collapse
Affiliation(s)
- Jeremias Gomes
- Department of Computer Science, University of Brasília, Brasília, Brazil
| | - Jun Kong
- Biomedical Informatics Department, Emory University, Atlanta, USA; Department of Biomedical Engineering, Emory-Georgia Institute of Technology, Atlanta, USA; Department of Mathematics and Statistics, Georgia State University, Atlanta, USA
| | - Tahsin Kurc
- Biomedical Informatics Department, Stony Brook University, Stony Brook, USA; Scientific Data Group, Oak Ridge National Laboratory, Oak Ridge, USA
| | - Alba C M A Melo
- Department of Computer Science, University of Brasília, Brasília, Brazil
| | - Renato Ferreira
- Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Joel H Saltz
- Biomedical Informatics Department, Stony Brook University, Stony Brook, USA
| | - George Teodoro
- Department of Computer Science, University of Brasília, Brasília, Brazil; Biomedical Informatics Department, Stony Brook University, Stony Brook, USA; Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
| |
Collapse
|
17
|
Wang J, Liu D, Qi X. A step forward to predict the risk of post-hepatectomy portal hypertension. J Hepatol 2021; 75:249-250. [PMID: 33667510 DOI: 10.1016/j.jhep.2021.02.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 02/22/2021] [Indexed: 12/13/2022]
Affiliation(s)
- Jitao Wang
- CHESS Center, Institute of Portal Hypertension, The First Hospital of Lanzhou University, Lanzhou, China; CHESS Working Party, Xingtai Institute of Cancer Control, Xingtai People's Hospital, Xingtai, China
| | - Dengxiang Liu
- CHESS Working Party, Xingtai Institute of Cancer Control, Xingtai People's Hospital, Xingtai, China.
| | - Xiaolong Qi
- CHESS Center, Institute of Portal Hypertension, The First Hospital of Lanzhou University, Lanzhou, China.
| |
Collapse
|
18
|
Machine Learning-Based Pulse Wave Analysis for Early Detection of Abdominal Aortic Aneurysms Using In Silico Pulse Waves. Symmetry (Basel) 2021. [DOI: 10.3390/sym13050804] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
An abdominal aortic aneurysm (AAA) is usually asymptomatic until rupture, which is associated with extremely high mortality. Consequently, the early detection of AAAs is of paramount importance in reducing mortality; however, most AAAs are detected by medical imaging only incidentally. The aim of this study was to investigate the feasibility of machine learning-based pulse wave (PW) analysis for the early detection of AAAs using a database of in silico PWs. PWs in the large systemic arteries were simulated using one-dimensional blood flow modelling. A database of in silico PWs representative of subjects (aged 55, 65 and 75 years) with different AAA sizes was created by varying the AAA-related parameters with major impacts on PWs—identified by parameter sensitivity analysis—in an existing database of in silico PWs representative of subjects without AAAs. Then, a machine learning architecture for AAA detection was trained and tested using the new in silico PW database. The parameter sensitivity analysis revealed that the AAA maximum diameter and stiffness of the large systemic arteries were the dominant AAA-related biophysical properties considerably influencing the PWs. However, AAA detection by PW indexes was compromised by other non-AAA related cardiovascular parameters. The proposed machine learning model produced a sensitivity of 86.8 % and a specificity of 86.3 % in early detection of AAA from the photoplethysmogram PW signal measured in the digital artery with added random noise. The number of false positive and negative results increased with increasing age and decreasing AAA size, respectively. These findings suggest that machine learning-based PW analysis is a promising approach for AAA screening using PW signals acquired by wearable devices.
Collapse
|
19
|
Wang T, Zhou Z, Liang F. Influences of Anatomorphological Features of the Portal Venous System on Postsplenectomy Hemodynamic Characteristics in Patients With Portal Hypertension: A Computational Model-Based Study. Front Physiol 2021; 12:661030. [PMID: 33912074 PMCID: PMC8072460 DOI: 10.3389/fphys.2021.661030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
Splenectomy, as an effective surgery for relieving complications caused by portal hypertension, is often accompanied by a significantly increased incidence of postoperative thrombosis in the portal venous system (PVS). While the underlying mechanisms remain insufficiently understood, the marked changes in hemodynamic conditions in the PVS following splenectomy have been suggested to be a potential contributing factor. The aim of this study was to investigate the influences of the anatomorphological features of the PVS on hemodynamic characteristics before and after splenectomy, with emphasis on identifying the specific anatomorphological features that make postoperative hemodynamic conditions more clot-promoting. For this purpose, idealized computational hemodynamics models of the PVS were constructed based on general anatomical structures and population-averaged geometrical parameters of the PVS. In the models, we incorporated various anatomorphological variations to represent inter-patient variability. The analyses of hemodynamic data were focused on the spatial distribution of wall shear stress (WSS) and the area ratio of wall regions exposed to low WSS (ALS). Obtained results showed that preoperative hemodynamic conditions were comparable among different models in terms of space-averaged WSS and ALS (all were small) irrespective of the considerable differences in spatial distribution of WSS, whereas, the inter-model differences in ALS were significantly augmented after splenectomy, with the value of ALS reaching up to over 30% in some models, while being smaller than 15% in some other models. Postoperative ALS was mainly determined by the anatomical structure of the PVS, followed by some morphogeometrical parameters, such as the diameter and curvature of the splenic vein, and the distance between the inferior mesenteric vein and splenoportal junction. Relatively, the angles between tributary veins and trunk veins only had mild influences on ALS. In addition, a marked increase in blood viscosity was predicted after splenectomy, especially in regions with low WSS, which may play an additive role to low WSS in initiating thrombosis. These findings suggest that the anatomical structure and some morphogeometrical features of the PVS are important determinants of hemodynamic conditions following splenectomy, which may provide useful clues to assessing the risk of postsplenectomy thrombosis based on medical imaging data.
Collapse
Affiliation(s)
- Tianqi Wang
- State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Zunqiang Zhou
- Department of Surgery, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Fuyou Liang
- State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China
- Key Laboratory of Hydrodynamics (Ministry of Education), School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China
- World-Class Research Center “Digital Biodesign and Personalized Healthcare,” Sechenov First Moscow State Medical University, Moscow, Russia
| |
Collapse
|
20
|
Golse N, Joly F, Combari P, Lewin M, Nicolas Q, Audebert C, Samuel D, Allard MA, Sa Cunha A, Castaing D, Cherqui D, Adam R, Vibert E, Vignon-Clementel IE. Predicting the risk of post-hepatectomy portal hypertension using a digital twin: A clinical proof of concept. J Hepatol 2021; 74:661-669. [PMID: 33212089 DOI: 10.1016/j.jhep.2020.10.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/25/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Despite improvements in medical and surgical techniques, post-hepatectomy liver failure (PHLF) remains the leading cause of postoperative death. High postoperative portal vein pressure (PPV) and portocaval gradient (PCG), which cannot be predicted by current tools, are the most important determinants of PHLF. Therefore, we aimed to evaluate a digital twin to predict the risk of postoperative portal hypertension (PHT). METHODS We prospectively included 47 patients undergoing major hepatectomy. A mathematical (0D) model of the entire blood circulation was assessed and automatically calibrated from patient characteristics. Hepatic flows were obtained from preoperative flow MRI (n = 9), intraoperative flowmetry (n = 16), or estimated from cardiac output (n = 47). Resection was then simulated in these 3 groups and the computed PPV and PCG were compared to intraoperative data. RESULTS Simulated post-hepatectomy pressures did not differ between the 3 groups, comparing well with collected data (no significant differences). In the entire cohort, the correlation between measured and simulated PPV values was good (r = 0.66, no adjustment to intraoperative events) or excellent (r = 0.75) after adjustment, as well as for PCG (respectively r = 0.59 and r = 0.80). The difference between simulated and measured post-hepatectomy PCG was ≤3 mmHg in 96% of cases. Four patients suffered from lethal PHLF for whom the model satisfactorily predicted their postoperative pressures. CONCLUSIONS We demonstrated that a 0D model could correctly anticipate postoperative PHT, even using estimated hepatic flow rates as input data. If this major conceptual step is confirmed, this algorithm could change our practice toward more tailor-made procedures, while ensuring satisfactory outcomes. LAY SUMMARY Post-hepatectomy portal hypertension is a major cause of liver failure and death, but no tool is available to accurately anticipate this potentially lethal complication for a given patient. Herein, we propose using a mathematical model to predict the portocaval gradient at the end of liver resection. We tested this model on a cohort of 47 patients undergoing major hepatectomy and demonstrated that it could modify current surgical decision-making algorithms.
Collapse
Affiliation(s)
- Nicolas Golse
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France; Université Paris-Saclay, INSERM, Physiopathogénèse et Traitement des Maladies du Foie, UMR-S 1193; INRIA, Centre de Recherche de Paris, 2 rue Simone Iff, Paris 75012, France.
| | - Florian Joly
- INRIA, Centre de Recherche de Paris, 2 rue Simone Iff, Paris 75012, France; Université de la Sorbonne, CNRS, Université de Paris, Laboratoire Jacques-Louis Lions (LJLL), F-75005 Paris, France
| | - Prisca Combari
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France
| | - Maïté Lewin
- Department of Radiology, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France
| | - Quentin Nicolas
- INRIA, Centre de Recherche de Paris, 2 rue Simone Iff, Paris 75012, France
| | - Chloe Audebert
- INRIA, Centre de Recherche de Paris, 2 rue Simone Iff, Paris 75012, France; Université de la Sorbonne, CNRS, Université de Paris, Laboratoire Jacques-Louis Lions (LJLL), F-75005 Paris, France; Université de la Sorbonne, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire de Biologie Computationnelle et Quantitative UMR 7238, F-75005 Paris, France
| | - Didier Samuel
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France; Université Paris-Saclay, INSERM, Physiopathogénèse et Traitement des Maladies du Foie, UMR-S 1193
| | - Marc-Antoine Allard
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France; Université Paris-Saclay, INSERM, Physiopathogénèse et Traitement des Maladies du Foie, UMR-S 1193
| | - Antonio Sa Cunha
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France; Université Paris-Saclay, INSERM, Physiopathogénèse et Traitement des Maladies du Foie, UMR-S 1193
| | - Denis Castaing
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France; Université Paris-Saclay, INSERM, Physiopathogénèse et Traitement des Maladies du Foie, UMR-S 1193
| | - Daniel Cherqui
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France; Université Paris-Saclay, INSERM, Physiopathogénèse et Traitement des Maladies du Foie, UMR-S 1193
| | - René Adam
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France; INSERM, Unit 985, Villejuif, 94800, France
| | - Eric Vibert
- Department of Surgery, Paul-Brousse Hospital, Assistance Publique Hôpitaux de Paris, Centre Hépato-Biliaire, Villejuif, 94800, France; Université Paris-Saclay, INSERM, Physiopathogénèse et Traitement des Maladies du Foie, UMR-S 1193
| | | |
Collapse
|
21
|
Wang T, Liang F, Li L, Zhang W, Wang G, Wang J, Zhang C, Qi X. A computational model-based study on the exchangeability of hepatic venous pressure gradients measured in multiple hepatic veins. Med Eng Phys 2020; 84:28-35. [PMID: 32977920 DOI: 10.1016/j.medengphy.2020.07.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 07/21/2020] [Accepted: 07/26/2020] [Indexed: 12/28/2022]
Abstract
Hepatic venous pressure gradient (HVPG) is a hemodynamic index widely used for evaluating the severity of portal hypertension. Theoretically, HVPG can be measured in any of the three major (i.e., right, middle and left) hepatic veins (HVs); however, it remains unclear whether HVPGs measured in different HVs are exchangeable, and if not, what factors cause inter-HV HVPG differences? In consideration of the potential limitations of invasive in vivo measurements, we employed a computational model implemented in conjunction with stochastic parameter sampling to simulate and compare HVPG measurements in multiple HVs under various sinusoidal portal hypertensive conditions. Results demonstrated that HVPGs measured in the right and middle HVs were basically exchangeable, whereas those in the left HV were relatively lower due primarily to the smaller proportion of hepatic venous flow through the left HV compared with that through the right or middle HV. Moreover, it was found that hepatic vein-to-vein shunts (HVVS) led to a marked augmentation of inter-HV HVPG differences and significant underestimation of portal pressure gradient with HVPG. These findings suggest that understanding the distribution of hepatic venous flow and status of HVVS is essential for selecting a proper HV for implementing HVPG measurement in clinical practice.
Collapse
Affiliation(s)
- Tianqi Wang
- School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Fuyou Liang
- School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Key Laboratory of Hydrodynamics (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Lei Li
- CHESS Center, Institute of Portal Hypertension, The First Hospital of Lanzhou University, Lanzhou 73000, China
| | - Wen Zhang
- Department of Interventional Radiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Guangchuan Wang
- Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, China
| | - Jitao Wang
- Department of Hepatobiliary Surgery, Affiliated Xingtai People's Hospital of Hebei Medical University, Xingtai 054001, China
| | - Chunqing Zhang
- Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, China
| | - Xiaolong Qi
- CHESS Center, Institute of Portal Hypertension, The First Hospital of Lanzhou University, Lanzhou 73000, China
| |
Collapse
|
22
|
Taebi A, Pillai RM, S. Roudsari B, Vu CT, Roncali E. Computational Modeling of the Liver Arterial Blood Flow for Microsphere Therapy: Effect of Boundary Conditions. Bioengineering (Basel) 2020; 7:E64. [PMID: 32610459 PMCID: PMC7552664 DOI: 10.3390/bioengineering7030064] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 12/11/2022] Open
Abstract
Transarterial embolization is a minimally invasive treatment for advanced liver cancer using microspheres loaded with a chemotherapeutic drug or radioactive yttrium-90 (90Y) that are injected into the hepatic arterial tree through a catheter. For personalized treatment, the microsphere distribution in the liver should be optimized through the injection volume and location. Computational fluid dynamics (CFD) simulations of the blood flow in the hepatic artery can help estimate this distribution if carefully parameterized. An important aspect is the choice of the boundary conditions imposed at the inlet and outlets of the computational domain. In this study, the effect of boundary conditions on the hepatic arterial tree hemodynamics was investigated. The outlet boundary conditions were modeled with three-element Windkessel circuits, representative of the downstream vasculature resistance. Results demonstrated that the downstream vasculature resistance affected the hepatic artery hemodynamics such as the velocity field, the pressure field and the blood flow streamline trajectories. Moreover, the number of microspheres received by the tumor significantly changed (more than 10% of the total injected microspheres) with downstream resistance variations. These findings suggest that patient-specific boundary conditions should be used in order to achieve a more accurate drug distribution estimation with CFD in transarterial embolization treatment planning.
Collapse
Affiliation(s)
- Amirtahà Taebi
- Department of Biomedical Engineering, University of California Davis, One Shields Ave., Davis, CA 95616, USA
| | - Rex M. Pillai
- Department of Radiology, University of California Davis, 4860 Y Street, Suite 3100, Sacramento, CA 95817, USA; (R.M.P.); (C.T.V.)
| | | | - Catherine T. Vu
- Department of Radiology, University of California Davis, 4860 Y Street, Suite 3100, Sacramento, CA 95817, USA; (R.M.P.); (C.T.V.)
| | - Emilie Roncali
- Department of Biomedical Engineering, University of California Davis, One Shields Ave., Davis, CA 95616, USA
| |
Collapse
|
23
|
Comparison of Instantaneous Wave-Free Ratio (iFR) and Fractional Flow Reserve (FFR) with respect to Their Sensitivities to Cardiovascular Factors: A Computational Model-Based Study. J Interv Cardiol 2020; 2020:4094121. [PMID: 32508540 PMCID: PMC7240797 DOI: 10.1155/2020/4094121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/18/2020] [Accepted: 02/27/2020] [Indexed: 02/06/2023] Open
Abstract
While coronary revascularization strategies guided by instantaneous wave-free ratio (iFR) are, in general, noninferior to those guided by fractional flow reserve (FFR) with respect to the rate of major adverse cardiac events at one-year follow-up in patients with stable angina or an acute coronary syndrome, the overall accuracy of diagnosis with iFR in large patient cohorts is about 80% compared with the diagnosis with FFR. So far, it remains incompletely understood what factors contribute to the discordant diagnosis between iFR and FFR. In this study, a computational method was used to systemically investigate the respective effects of various cardiovascular factors on FFR and iFR. The results showed that deterioration in aortic valve disease (e.g., regurgitation or stenosis) led to a marked decrease in iFR and a mild increase in FFR given fixed severity of coronary artery stenosis and that increasing coronary microvascular resistance caused a considerable increase in both iFR and FFR, but the degree of increase in iFR was lower than that in FFR. These findings suggest that there is a high probability of discordant diagnosis between iFR and FFR in patients with severe aortic valve disease or coronary microcirculation dysfunction.
Collapse
|
24
|
Roncali E, Taebi A, Foster C, Vu CT. Personalized Dosimetry for Liver Cancer Y-90 Radioembolization Using Computational Fluid Dynamics and Monte Carlo Simulation. Ann Biomed Eng 2020; 48:1499-1510. [PMID: 32006268 PMCID: PMC7160004 DOI: 10.1007/s10439-020-02469-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 01/25/2020] [Indexed: 12/14/2022]
Abstract
Yttrium-90 (Y-90) transarterial radioembolization uses radioactive microspheres injected into the hepatic artery to irradiate liver tumors internally. One of the major challenges is the lack of reliable dosimetry methods for dose prediction and dose verification. We present a patient-specific dosimetry approach for personalized treatment planning based on computational fluid dynamics (CFD) simulations of the microsphere transport combined with Y-90 physics modeling called CFDose. The ultimate goal is the development of a software to optimize the amount of activity and injection point for optimal tumor targeting. We present the proof-of-concept of a CFD dosimetry tool based on a patient's angiogram performed in standard-of-care planning. The hepatic arterial tree of the patient was segmented from the cone-beam CT (CBCT) to predict the microsphere transport using multiscale CFD modeling. To calculate the dose distribution, the predicted microsphere distribution was convolved with a Y-90 dose point kernel. Vessels as small as 0.45 mm were segmented, the microsphere distribution between the liver segments using flow analysis was predicted, the volumetric microsphere and resulting dose distribution in the liver volume were computed. The patient was imaged with positron emission tomography (PET) 2 h after radioembolization to evaluate the Y-90 distribution. The dose distribution was found to be consistent with the Y-90 PET images. These results demonstrate the feasibility of developing a complete framework for personalized Y-90 microsphere simulation and dosimetry using patient-specific input parameters.
Collapse
Affiliation(s)
- Emilie Roncali
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
| | - Amirtahà Taebi
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Cameron Foster
- Department of Radiology, UC Davis Medical Center, Sacramento, CA, 95817, USA
| | - Catherine Tram Vu
- Department of Radiology, UC Davis Medical Center, Sacramento, CA, 95817, USA
| |
Collapse
|
25
|
Golse N, Joly F, Nicolas Q, Vibert E, Line PD, Clementel IV. Partial orthotopic liver transplantation in combination with two-stage hepatectomy: A proof-of-concept explained by mathematical modeling. Clin Biomech (Bristol, Avon) 2020; 73:195-200. [PMID: 32035308 DOI: 10.1016/j.clinbiomech.2020.01.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/21/2020] [Accepted: 01/28/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Resection And Partial Liver Segment 2/3 Transplantation with Delayed total hepatectomy (RAPID) includes total hepatectomy in 2 steps with small graft transplantation at first stage. To avoid graft portal hyperperfusion, portal vein pressure monitoring is required after revascularization and right portal vein clamping. To date, portal flow modulation has not been reported but simulating hemodynamics in RAPID patients would be useful to anticipate these procedures. Our team developed hemodynamic 0D modeling; we aimed to assess if this mathematical model could be accurately used in the RAPID setting. METHODS The modified 0D model was retrospectively tested on 3 patients. We compared our estimated portal vein pressures and portocaval gradients to those intraoperatively measured, as indication to modulate portal flow relies on these measures. FINDINGS Portal pressures measured after right portal vein clamping (end of RAPID procedure) in patients 1, 2 and 3 were respectively of 14, 16 and 12 mmHg while the simulated pressures were of 13.1, 14.8 and 11.5 mmHg (p = 0.25). Portocaval gradients measured after right portal vein clamping in the 3 patients were respectively of 10, 11 and 7 mmHg while the simulated gradients were of 9.9, 11.6 and 8.3 mmHg (p = 0.5). INTERPRETATION We succeeded to predict portal vein pressures and portocaval gradients after RAPID. This promising report demonstrates that 0D simulation could be a useful tool for human decision-making. Moreover, such a patient-specific model could be of importance if we transpose RAPID experience to hepatocellular carcinoma bearing cirrhotics, a population with high probability of portal hypertension after RAPID.
Collapse
Affiliation(s)
- Nicolas Golse
- Department of Surgery, Hepato-Biliary Centre in Paul Brousse Hospital, Assistance Publique Hôpitaux de Paris, Villejuif 94800, France; INSERM, Unit 1193, Villejuif 94800, France; Inria, centre de recherche de Paris, 2 rue Simone Iff, Paris 75012, France.
| | - Florian Joly
- Inria, centre de recherche de Paris, 2 rue Simone Iff, Paris 75012, France
| | - Quentin Nicolas
- Inria, centre de recherche de Paris, 2 rue Simone Iff, Paris 75012, France
| | - Eric Vibert
- Department of Surgery, Hepato-Biliary Centre in Paul Brousse Hospital, Assistance Publique Hôpitaux de Paris, Villejuif 94800, France; INSERM, Unit 1193, Villejuif 94800, France
| | - Pal Dag Line
- Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Norway
| | | |
Collapse
|
26
|
Yu H, Bartlett A, Hunter P, Ho H. Computational simulations for the hepatic arterial buffer response after liver graft transplantation from an adult to a child. Med Eng Phys 2020; 75:49-52. [DOI: 10.1016/j.medengphy.2019.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 09/28/2019] [Accepted: 11/04/2019] [Indexed: 12/12/2022]
|
27
|
Lin YQ, Jiang B, Li HQ, Jin CX, Wang H. Application of the Hepatic Transit Time (HTT) in Evaluation of Portal Vein Pressure in Gastroesophageal Varices Patients. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2019; 38:2305-2314. [PMID: 30609088 DOI: 10.1002/jum.14924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 12/03/2018] [Accepted: 12/09/2018] [Indexed: 06/09/2023]
Abstract
OBJECTIVES To analyze the clinical significance of using hepatic transit time (HTT) to evaluate portal vein pressure in gastroesophageal varices patients. METHODS For the observation group, we enrolled 50 gastroesophageal varices patients who had received esophagogastric variceal embolization in our hospital between January 2015 and February 2018. Patients without liver disease populated the control group and were recruited during the same time period. All patients underwent contrast-enhanced sonography. In the observation group, free portal pressure (FPP) was detected during esophagogastric variceal embolization with ultrasound guidance. Differences in hepatic artery-hepatic vein transit time (HA-HVTT), portal vein-hepatic vein transit time (PV-HVTT), and parenchyma-hepatic vein transit time (PA-HVTT) were compared between groups. Correlations between HA-HVTT, PV-HVTT, PA-HVTT, and FPP in the observation group were analyzed using the Pearson coefficient and linear regression analysis. RESULTS HA-HVTT (t = 5.078; P < .001), PV-HVTT (t = 12.163; P < .001), and PA-HVTT (t = 2.649; P = .009) within the observation group were significantly lower than those of the control group. The areas under the curve of HTT were 0.771 (HA-HVTT), 0.951 (PV-HVTT), and 0.652 (PA-HVTT), and the sensitivity and specificity of PV-HVTT at 7.99 seconds were 86.0% and 88.0%, respectively. The HA-HVTT (r = -0.799; P < .001), PV-HVTT (r = -0.554; P < .001), and PA-HVTT (r = -0.735; P < .001) negatively correlated to FPP in the observation group. Linear regression analysis showed y = -0.410x + 7.254 (HA-HVTT and FPP), y = -0.335x + 4.983 (PV-HVTT and FPP), and y = -0.566x + 4.997 (PA-HVTT and FPP) in the observation group. CONCLUSION Compared with the control patients, the HTT of patients with portal hypertension-esophagogastric varices was significantly shorter, and showed an inverse relationship with FPP.
Collapse
Affiliation(s)
- Yuan-Qiang Lin
- Department of Ultrasound, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Bo Jiang
- Department of General Surgery, Nanhu Hospital, China-Japan Union Hospital, Jilin University, Changchun, China
| | - He-Qun Li
- Department of Ultrasound, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Chun-Xiang Jin
- Department of Ultrasound, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Hui Wang
- Department of Ultrasound, China-Japan Union Hospital, Jilin University, Changchun, China
| |
Collapse
|
28
|
Ma R, Hunter P, Cousins W, Ho H, Bartlett A, Safaei S. Anatomically based simulation of hepatic perfusion in the human liver. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3229. [PMID: 31368204 DOI: 10.1002/cnm.3229] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 06/19/2019] [Accepted: 06/19/2019] [Indexed: 06/10/2023]
Abstract
Liver structures of a healthy subject are digitised and segmented from computed tomography (CT) images, and hepatic perfusion is modelled in the hepatic artery and portal vein of the healthy subject with structured tree-based outflow boundary conditions. This self-similar structured tree is widely used in the literature, eg, blood flow simulation in larger systemic arteries and cerebral circulation, and is used in this study to model the effect of the smaller hepatic arteries and arterioles, as well as the smaller hepatic portal veins and portal venules. Physiologically reasonable results are obtained. Since the structured tree terminates at the size of the microvasculature system in liver lobules, the structured tree boundary condition will enable the proposed organ-level model of hepatic arterial flow to be easily connected to tissue-level models of liver lobules. Blood flow in the hepatic vein is also modelled in this subject with three-element Windkessel model as outflow boundary conditions. The benefit of integrating the perfusion in all hepatic vascular vessels is that it helps us analyse some complicated clinical phenomenon more efficiently, eg, one possible application is to obtain the portal pressure gradient (PPG) to help examine the reliability of hepatic venous pressure gradient (HVPG) as an indirect measure of portal pressure. Moreover, since four to six generations of hepatic vessels, which are sufficient for liver classification analysis, were employed in the model, this study is setting the computational foundation of a potentially handy surgical tool.
Collapse
Affiliation(s)
- Renfei Ma
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Peter Hunter
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | | | - Harvey Ho
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Adam Bartlett
- Department of Surgery, University of Auckland, Auckland, New Zealand
- Liver Research Unit, Auckland City Hospital, Auckland, New Zealand
| | - Soroush Safaei
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
29
|
Qi X, Berzigotti A, Cardenas A, Sarin SK. Emerging non-invasive approaches for diagnosis and monitoring of portal hypertension. Lancet Gastroenterol Hepatol 2019; 3:708-719. [PMID: 30215362 DOI: 10.1016/s2468-1253(18)30232-2] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/13/2018] [Accepted: 06/25/2018] [Indexed: 02/08/2023]
Abstract
Clinically significant portal hypertension is associated with an increased risk of developing gastro-oesophageal varices and hepatic decompensation. Hepatic venous pressure gradient measurement and oesophagogastroduodenoscopy are the gold-standard methods for assessing clinically significant portal hypertension (hepatic venous pressure gradient ≥10 mm Hg) and gastro-oesophageal varices, respectively. However, invasiveness, cost, and feasibility limit their widespread use, especially if repeated and serial evaluations are required to assess the efficacy of pharmacotherapy. Although new techniques for non-invasive portal pressure measurement have been pursued for many decades, only recently have new tools been assessed and validated for larger clinical application. This Review focuses on the recent advances in non-invasive approaches for the diagnosis and serial monitoring of portal hypertension and varices for clinical practice.
Collapse
Affiliation(s)
- Xiaolong Qi
- CHESS Group, Hepatic Hemodynamic Lab, Institute of Hepatology, Nanfang Hospital, Southern Medical University, Guangzhou, China; CHESS Frontier Center, Lanzhou University, Lanzhou, China.
| | - Annalisa Berzigotti
- Hepatology Group, Swiss Liver Center, University Clinic for Visceral Surgery and Medicine, Inselspital, University of Bern, Bern, Switzerland
| | - Andres Cardenas
- GI/Liver Unit, Institute of Digestive Diseases and Metabolism, Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Shiv Kumar Sarin
- Department of Hepatology, Institute of Liver and Biliary Sciences, New Delhi, India
| |
Collapse
|
30
|
Gomes J, Barreiros W, Kurc T, Melo ACMA, Kong J, Saltz JH, Teodoro G. Sensitivity analysis in digital pathology: Handling large number of parameters with compute expensive workflows. Comput Biol Med 2019; 108:371-381. [PMID: 31054503 DOI: 10.1016/j.compbiomed.2019.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 02/28/2019] [Accepted: 03/07/2019] [Indexed: 12/19/2022]
Abstract
Digital pathology imaging enables valuable quantitative characterizations of tissue state at the sub-cellular level. While there is a growing set of methods for analysis of whole slide tissue images, many of them are sensitive to changes in input parameters. Evaluating how analysis results are affected by variations in input parameters is important for the development of robust methods. Executing algorithm sensitivity analyses by systematically varying input parameters is an expensive task because a single evaluation run with a moderate number of tissue images may take hours or days. Our work investigates the use of Surrogate Models (SMs) along with parallel execution to speed up parameter sensitivity analysis (SA). This approach significantly reduces the SA cost, because the SM execution is inexpensive. The evaluation of several SM strategies with two image segmentation workflows demonstrates that a SA study with SMs attains results close to a SA with real application runs (mean absolute error lower than 0.022), while the SM accelerates the SA execution by 51 × . We also show that, although the number of parameters in the example workflows is high, most of the uncertainty can be associated with a few parameters. In order to identify the impact of variations in segmentation results to downstream analyses, we carried out a survival analysis with 387 Lung Squamous Cell Carcinoma cases. This analysis was repeated using 3 values for the most significant parameters identified by the SA for the two segmentation algorithms; about 600 million cell nuclei were segmented per run. The results show that significance of the survival correlations of patient groups, assessed by a logrank test, are strongly affected by the segmentation parameter changes. This indicates that sensitivity analysis is an important tool for evaluating the stability of conclusions from image analyses.
Collapse
Affiliation(s)
- Jeremias Gomes
- Department of Computer Science, University of Brasília, Brazil
| | | | - Tahsin Kurc
- Biomedical Informatics Department, Stony Brook University, Stony Brook, USA; Scientific Data Group, Oak Ridge National Laboratory, Oak Ridge, USA
| | - Alba C M A Melo
- Department of Computer Science, University of Brasília, Brazil
| | - Jun Kong
- Biomedical Informatics Department, Emory University, Atlanta, USA; Department of Biomedical Engineering, Emory-Georgia Institute of Technology, Atlanta, USA; Department of Mathematics and Statistics, Georgia State University, Atlanta, USA
| | - Joel H Saltz
- Biomedical Informatics Department, Stony Brook University, Stony Brook, USA
| | - George Teodoro
- Department of Computer Science, University of Brasília, Brazil; Biomedical Informatics Department, Stony Brook University, Stony Brook, USA.
| |
Collapse
|