Syuhei Yoshimoto1, Shinji Torai1, Masaki Yoshioka1, Soichi Nadahara1, Eiji Kobayashi2. 1. SCREEN Holdings Co., Ltd, Kyoto, Japan. 2. SCREEN Holdings Co., Ltd, Kyoto, Japan; Department of Organ Fabrication, Keio University School of Medicine, Tokyo, Japan. Electronic address: organfabri@keio.jp.
Abstract
BACKGROUND: To solve the serious donor shortage, the demand is increasing for developing a new method to use the marginal donors, including donors after cardiac death (DCD). Continuous machine perfusion from ex vivo to in situ is a novel technique to overcome warm ischemia during organ grafting as an ischemia-free transplantation. Herein, we tested orthotopic and heterotopic ischemia-free liver transplantation in pigs and evaluated the perfusion characteristics of DCD grafts from ex vivo preservation to implantation. MATERIALS AND METHODS: The demonstration of ischemia-free transplantation was conducted using both orthotopic and heterotopic transplantation models. Warm ischemia time (WIT) was set at 60 minutes or 120 minutes in the DCD models. Recipients were humanely killed 3 days after transplant. Flow rates of portal vein and hepatic artery were set to 0.06 to 0.15 mL/min/g and 0.04 to 0.06 mL/min/g for the liver weight ratio, respectively. RESULTS: Under the stable perfusion rate by machine perfusion, the average hepatic artery pressure of the liver graft after a WIT of 120 minutes was approximately 80 mm Hg higher than after WIT of 60 minutes. The recipient with liver graft of WIT of 60 minutes could not survive overnight. In heterotopic model, the recipient with 1 hour DCD liver survived until humanely killed. CONCLUSIONS: The results of pressure monitoring in our DCD liver graft model indicate that pressures are influenced not only by thrombus formation but also by postmortem rigidity at 2 hours after cardiac death.
BACKGROUND: To solve the serious donor shortage, the demand is increasing for developing a new method to use the marginal donors, including donors after cardiac death (DCD). Continuous machine perfusion from ex vivo to in situ is a novel technique to overcome warm ischemia during organ grafting as an ischemia-free transplantation. Herein, we tested orthotopic and heterotopic ischemia-free liver transplantation in pigs and evaluated the perfusion characteristics of DCD grafts from ex vivo preservation to implantation. MATERIALS AND METHODS: The demonstration of ischemia-free transplantation was conducted using both orthotopic and heterotopic transplantation models. Warm ischemia time (WIT) was set at 60 minutes or 120 minutes in the DCD models. Recipients were humanely killed 3 days after transplant. Flow rates of portal vein and hepatic artery were set to 0.06 to 0.15 mL/min/g and 0.04 to 0.06 mL/min/g for the liver weight ratio, respectively. RESULTS: Under the stable perfusion rate by machine perfusion, the average hepatic artery pressure of the liver graft after a WIT of 120 minutes was approximately 80 mm Hg higher than after WIT of 60 minutes. The recipient with liver graft of WIT of 60 minutes could not survive overnight. In heterotopic model, the recipient with 1 hour DCD liver survived until humanely killed. CONCLUSIONS: The results of pressure monitoring in our DCD liver graft model indicate that pressures are influenced not only by thrombus formation but also by postmortem rigidity at 2 hours after cardiac death.