Preservation of Porcine Donation after Circulatory Death (DCD) Liver by Perfusion and Orthotopic Liver Transplantation
June 14th, 2024
This protocol outlines the methodology of establishing a porcine model utilizing variable temperature-controlled Machine Perfusion (MP) for the preservation of the donor liver, followed by orthotopic liver transplantation (OLTx). It aims to promote the success rate of OLTx using donor donation after circulatory death (DCD) liver and establish a stable model.
Machine perfusion technology has advanced the preservation of donor liver quality, especially for extended criteria livers. By continuously pumping oxygen and nutrients via a centrifugal pump and oxygenator, it remains organ activity and monitors liver function, improving preservation time and transportation success rates. The main challenges in using machine perfusion for donor livers are replicating liver conditions with sophisticated equipments and skilled operations.
Limitations in post site DCD liver models includes deterioration in liver quality, storage duration, and anhepatic phase, leading to lower success rates in experimental models. To overcome challenges, we have developed a machine profusion device with variable temperature control, and we find such containers to stand the liver preservation while minimizing ischemic damage. These advancements enhance the success of our post site liver transplant model, and to promote further percutaneous use of machine profusion.
Begin the procedure on an anesthetized pig placed in a supine position on a surgical table by performing a midline laparotomy extended laterally to the right on the disinfected skin. Carefully dissect the hepatic artery and portal vein from the surrounding tissue. Then mobilize the celiac axis, and trace it to the abdominal aorta.
Dissect the abdominal aorta and the inferior vena cava to facilitate blood collection. Sequentially, cannulate the abdominal aorta and inferior vena cava. Collect the blood into acid citrate dextrose bags for subsequent use, then fit the portal vein with a specific catheter.
Next, excise the liver from the animal after inducing cardiac arrest. Preserve a section of abdominal aorta tissue for arterial cannulation. Place the liver in a sterile organ bag on ice.
Ligate all distal arterial branches of the liver before cannulating the common bile duct. Connect the catheter of the portal vein and abdominal aorta to a machine perfusion device. Perfuse the liver with 1.5 liters of perfusion solution.
Set the perfusion temperature to four degrees Celsius and time to eight hours, then set the perfusion parameters so that the hepatic artery is under pressure control of 25 millimeters of mercury, and the portal vein is under flow control of 200 milliliters per minute. While the device is in the normal thermic machine perfusion mode, increase the system's temperature to 37 degrees Celsius before priming it. Transfer the porcine donor liver into the device once it has been warmed for 10 minutes.
Set the arterial profusion pressures and the portal vein profusion. Increase the portal vein perfusion pressure to 0.75 milliliters per minute per gram after the first hour. After removing the donor liver from the device, insert a catheter into the portal vein to perfuse it sequentially via the portal vein catheter.
Next, insert a specialized catheter into the portal vein of the recipient liver, and ligate the catheter to secure it to the matching catheter on the donor portal vein With double-armed four zero monofilament polypropylene sutures, perform an end-to-end anastomosis of the suprahepatic cava. Connect both ends of the portal vein with matching cannulas to restore blood flow. After removing the clamp from the suprahepatic cava, perform an end-to-end anastomosis of the inferior vena cava with four zero monofilament polypropylene sutures.
Flush the donor hepatic artery with 10 milliliters of heparinized saline, and posit an additional bulldog clamp distally to prevent back bleeding. Finally, after removing the portal vein catheter, anastomosis the portal vein with a four zero monofilament polypropylene suture.
Overview
This protocol outlines the methodology of establishing a porcine model utilizing variable temperature-controlled Machine Perfusion (MP) for the preservation of the donor liver, followed by orthotopic liver transplantation (OLTx). It aims to promote the success rate of OLTx using donor donation after circulatory death (DCD) liver and establish a stable model.
Key Study Components
Area of Science
- Neuroscience
- Transplantation Biology
- Organ Preservation Techniques
Background
- Machine perfusion technology enhances donor liver quality preservation.
- Challenges include replicating liver conditions and skilled operations.
- Deterioration in liver quality affects success rates in DCD liver models.
- Innovations in machine perfusion devices are necessary to minimize ischemic damage.
Purpose of Study
- To establish a porcine model for liver preservation and transplantation.
- To improve the success rates of OLTx using DCD livers.
- To develop a stable model for future research.
Methods Used
- Variable temperature-controlled Machine Perfusion (MP).
- Continuous pumping of oxygen and nutrients via a centrifugal pump.
- Monitoring of liver function during preservation.
- Development of a machine perfusion device to enhance preservation.
Main Results
- Improved preservation time and transportation success rates for donor livers.
- Enhanced liver quality through advanced machine perfusion techniques.
- Successful establishment of a porcine model for OLTx.
- Minimized ischemic damage during liver preservation.
Conclusions
- The developed MP device significantly enhances liver preservation.
- Successful implementation of the porcine model for future studies.
- Potential for broader applications of machine perfusion in transplantation.
Frequently Asked Questions
Executive Industry Relevance
Preservation of DCD livers using variable temperature-controlled machine perfusion addresses a critical bottleneck in transplant research by reducing ischemic injury and extending organ viability. This approach enhances predictive confidence in preclinical liver transplantation models, supporting translational continuity from preservation innovation to clinical application. Improved model fidelity enables more reliable evaluation of preservation strategies and surgical techniques for enterprise R&D portfolios.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables mechanistic de-risking of preservation-induced injury in DCD livers.
- Supports functional validation of perfusion parameters and device settings.
- Facilitates hypothesis testing on ischemia mitigation and viability thresholds.
Screening & Assay Development
- Provides a validated large animal system for quantitative viability assessment.
- Standardizes preservation and transplantation workflows for reproducibility.
- Generates robust data for screening preservation solutions and perfusion protocols.
Translational & Preclinical Research
- Aligns preclinical models with clinical transplantation challenges for DCD livers.
- Enables risk-adjusted evaluation of new preservation technologies.
- Supports continuity from ex vivo preservation to in vivo transplantation outcomes.
Pipeline & Workflow Integration
This method integrates into the discovery-to-preclinical continuum by bridging ex vivo preservation research with in vivo transplantation validation in a large animal model.
- Discovery Biology: Advances understanding of ischemic injury mechanisms and preservation efficacy.
- Screening: Delivers quantitative viability and function metrics for protocol comparison.
- Analytics: Enables measurement of preservation duration, perfusion parameters, and post-transplant outcomes.
- Translational Research: Provides a clinically relevant model for evaluating new preservation devices and techniques.
- Enterprise Reuse: Establishes a reusable platform for iterative testing of preservation and transplantation innovations.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in preservation and transplantation outcomes.
- Operational Value: Standardizes workflows and enhances reproducibility across studies.
- Strategic Value: Informs go/no-go decisions for preservation technology advancement.
- Portfolio Impact: Reduces late-stage biological risk and supports prioritization of high-value innovations.
Implementation Considerations
- Requires expertise in large animal surgery and perfusion device operation.
- Demands access to advanced perfusion instrumentation and monitoring systems.
- Necessitates cross-team standardization of preservation and transplantation protocols.
- Adaptation may be needed for different animal models or device configurations.
- Limitations include technical complexity and resource intensity of large animal studies.
