Effects of Short-Term Normothermic and Subnormothermic Perfusion After Cold Preservation on Liver Transplantation From Donors After Cardiac Death.

BACKGROUND: Liver transplantation from donors after cardiac death (DCD) could increase the pool of organs. We previously reported that oxygenated subnormothermic (20°C-25°C) ex vivo liver perfusion (SELP) improved the graft viability in rats. This study aimed to compare the effectiveness of SELP and normothermic (37°C) ex vivo liver perfusion (NELP) after cold storage (CS) in DCD liver grafts. METHODS: Male Wistar rats were used, and grafts were retrieved 30 minutes after cardiac arrest. We performed oxygenated NELP and SELP with a Krebs-Henseleit buffer for different time points and durations: Group 0, donation performed from heart-beating donors (control); Group 1 (DCD group), donation performed from DCD donors with no treatments; Group 2, NELP performed before CS (30 minutes); Group 3, NELP performed after CS (30 minutes); Group 4, SELP performed after CS (30 minutes); Group 5, SELP performed after CS (60 minutes); and Group 6, SELP performed after CS (90 minutes). After 15 minutes of incubation at room temperature, the grafts were reperfused under normothermic conditions for 60 minutes as a model of liver transplantation. RESULTS: No significant differences in body and liver weight were observed between all groups. In the SELP after CS groups, even 30 minutes of perfusion improved bile production, tumor necrosis factor-α, and interleukin-1ß significantly compared with the DCD group (P < .05), comparable with NELP groups. CONCLUSION: SELP rescued DCD livers from ischemia-reperfusion injury the same as the normothermic perfusion before or after CS groups. SELP after CS is more convenient than normothermic perfusion; hence, this technique may increase the organ pool.

Risks of Living Donor Liver Transplantation Using Small-For-Size Grafts.

BACKGROUND: In living donor liver transplantation (LDLT), a graft-to-recipient weight ratio (GRWR) of under 0.8 is recognized as the critical graft size. Our aim was to compare the survival rates of recipients with small-for-size grafts (SFSG: GRWR <0.8), normal-sized grafts (NSG), and large-for-size grafts (LFSG: GRWR ≥ 3.5) and to investigate the mortality risk with SFSG. METHODS: Between 1991 and April 2019, we performed 188 LDLT surgeries. Recently, we added splenectomy when portal vein pressure is high (>17 mm Hg) to interrupt the splenic bloodstream. We divided all LDLT cases retrospectively into 3 groups: an SFSG group (n = 22), NSG group (n = 154), and LFSG group (n = 12). We investigated the survival rates in these groups. Furthermore, we divided the SFSG group into 2 subgroups: an SFSG with splenectomy (SFSG+S) group (n = 7) and an SFSG without splenectomy group. We investigated the occurrence rates of lethal complications such as portal vein thrombosis, hepatic artery thrombosis, and hepatic vein thrombosis. RESULTS: The 5-year survival rate in the SFSG group was significantly lower (52.8%) than in the other groups (NSG: 84.5%; LFSG: 83.3%), but that of the SFSG+S group was similar (80.0%) to that of other groups. There was no difference in the occurrence of postoperative complications such as portal vein thrombosis, hepatic artery thrombosis, or hepatic vein thrombosis between the SFSG+S group and other groups. CONCLUSIONS: Graft survival of LDLT using SFSG+S was as good as that of normal-sized grafts. Reducing portal vein pressure was important for SFSG.

Cytoprotective Effects of Mesenchymal Stem Cells During Liver Transplantation From Donors After Cardiac Death in Swine.

BACKGROUND: Liver transplantation from donors after cardiac death (DCDs) can increase the pool of available organs. Recently, mesenchymal stem cells (MSCs) have been used to treat various diseases. Some studies have reported that MSCs improve the outcome of liver transplantation from DCDs in mice. The aim of this study was to evaluate the cytoprotective effects and safety of MSC transplantation on liver grafts from DCDs in swine. METHODS: For the MSCs, we used swine adipose-derived stem cells (ADSCs). Landrace swine were divided into 3 groups (n = 5) as follows: 1. the heart-beating (HB) group, from which liver grafts were retrieved and transplanted; 2. the DCD group, from which liver grafts were retrieved 10 minutes after apnea-induced cardiac arrest and transplanted; and 3. the ADSC group, from which liver grafts were retrieved as with the DCD group, transplanted, and then infused with 1.0 × 107 ADSCs 2 hours after reperfusion. RESULTS: In the HB group, all 5 recipients survived for >7 days, whereas all 5 recipients in the DCD group died within 24 hours after transplantation. In the ADSC group, 3 recipients survived for >7 days, whereas 2 recipients died within 4 days after transplantation. The survival rate was significantly higher in the ADSC group than in the DCD group. CONCLUSIONS: MSCs could protect the function of liver grafts from warm ischemia-reperfusion injury and improve the viability of DCD liver grafts.