Anti-inflammatory signaling during ex vivo liver perfusion improves the preservation of pig liver grafts before transplantation.

Normothermic ex vivo liver perfusion (NEVLP) improves graft preservation by avoiding cold ischemia injury. We investigated whether the protective effects of NEVLP can be further improved by applying strategies targeted on reducing the activation of proinflammatory cytokines during perfusion. Livers retrieved under heart-beating conditions were perfused for 4 hours. Following the preservation period, a pig liver transplantation was performed. In group 1 (n = 5), anti-inflammatory strategies (alprostadil, n-acetylcysteine, carbon monoxide, sevoflurane, and subnormothermic temperature [33°C]) were applied. This was compared with a perfused control group (group 2) where livers (n = 5) were perfused at 37°C without anti-inflammatory agents, similar to the setup used in current European clinical trials, and to a control group preserved with static cold storage (group 3). During 3-day follow-up, markers of reperfusion injury, bile duct injury, and liver function were examined. Aspartate aminotransferase (AST) levels during perfusion were significantly lower in the study versus control group at 1 hour (52 ± 6 versus 162 ± 86 U/L; P = 0.01), 2 hours (43 ± 5 versus 191 ± 111 U/L; P = 0.008), and 3 hours (24 ± 16 versus 218 ± 121 U/L; P = 0.009). During perfusion, group 1 versus group 2 had reduced interleukin (IL) 6, tumor necrosis factor α, and galactosidase levels and increased IL10 levels. After transplantation, group 1 had lower AST peak levels compared with group 2 and group 3 (1400 ± 653 versus 2097 ± 1071 versus 1747 ± 842 U/L; P = 0.47) without reaching significance. Bilirubin levels were significantly lower in group 1 versus group 2 at day 1 (3.6 ± 1.5 versus 6.60 ± 1.5 µmol/L; P = 0.02) and 3 (2 ± 1.1 versus 9.7 ± 7.6 µmol/L; P = 0.01). A trend toward decreased hyaluronic acid, as a marker of improved endothelial cell function, was observed at 1, 3, and 5 hours after reperfusion in group 1 versus group 2. Only 1 early death occurred in each group (80% survival). In conclusion, addition of anti-inflammatory strategies further improves warm perfused preservation. Liver Transplantation 22 1573-1583 2016 AASLD.

Normothermic ex vivo liver perfusion using steen solution as perfusate for human liver transplantation: First North American results.

The European trial investigating normothermic ex vivo liver perfusion (NEVLP) as a preservation technique for liver transplantation (LT) uses gelofusine, a non-US Food and Drug Administration-approved, bovine-derived, gelatin-based perfusion solution. We report a safety and feasibility clinical NEVLP trial with human albumin-based Steen solution. Transplant outcomes of 10 human liver grafts that were perfused on the Metra device at 37 °C with Steen solution, plus 3 units of erythrocytes were compared with a matched historical control group of 30 grafts using cold storage (CS) as the preservation technique. Ten liver grafts were perfused for 480 minutes (340-580 minutes). All livers cleared lactate (final lactate 1.46 mmol/L; 0.56-1.74 mmol/L) and produced bile (61 mL; 14-146 mL) during perfusion. No technical problems occurred during perfusion, and all NEVLP-preserved grafts functioned well after LT. NEVLP versus CS had lower aspartate aminotransferase and alanine aminotransferase values on postoperative days 1-3 without reaching significance. No difference in postoperative graft function between NEVLP and CS grafts was detected as measured by day 7 international normalized ratio (1.1 [1-1.56] versus 1.1 [1-1.3]; P = 0.5) and bilirubin (1.5; 1-7.7 mg/dL versus 2.78; 0.4-15 mg/dL; P = 0.5). No difference was found in the duration of intensive care unit stay (median, 1 versus 2 days; range, 0-8 versus 0-23 days; P = 0.5) and posttransplant hospital stay (median, 11 versus 13 days; range, 8-17 versus 7-89 days; P = 0.23). Major complications (Dindo-Clavien ≥ 3b) occurred in 1 patient in the NEVLP group (10%) compared with 7 (23%) patients in the CS group (P = 0.5). No graft loss or patient death was observed in either group. Liver preservation with normothermic ex vivo perfusion with the Metra device using Steen solution is safe and results in comparable outcomes to CS after LT. Using US Food and Drug Administration-approved Steen solution will avoid a potential regulatory barrier in North America. Liver Transplantation 22 1501-1508 2016 AASLD.