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.
