Successful transplantation of porcine liver grafts following 48-hour normothermic preservation.

Current cold storage organ preservation technique fails to preserve marginal donor grafts sufficiently. Evidence from large animal experiments suggests superiority of normothermic machine preservation of liver allografts. Long-term organ preservation using normothermic perfusion might not only allow organ viability assessment before transplantation, but also provide the means for further organ modifications under physiologic conditions. Previous research has shown that porcine livers can be transplanted successfully after normothermic preservation of 20 hours. In the present study we investigate whether similar methodology is capable of further extending the safe limit to 48 hours. In this study, livers from White Landrace pigs were preserved by normothermic, oxygenated sanguineous perfusion. After a 48-hour period of preservation, livers were transplanted into recipient pigs and followed for 5 days. Outcome parameters measured included markers of synthetic and metabolic liver function as well as hepatocellular injury and blood gas analysis during perfusion and follow-up. Histological assessment of morphological liver integrity was performed. All livers showed sustained bile production and metabolic activity throughout the preservation period. Low levels of hepatocellular damage were found. Following transplantation all liver grafts revealed excellent graft function and death-censored graft survival was 100%. Porcine livers were transplanted successfully following 48 hours normothermic machine preservation

Perfusion flows during 46 hours of normothermic perfusion.

<p>(A) portal flow ± SD, (B) hepatic artery flow ± SD, (C) IVC flow ± SD. Perfusate flows were measured in-line using ultrasonic flow probes.</p

Markers of cellular injury.

<p>ALT, CRP, Bilirubin and GGT measured in perfusate during normothermic machine perfusion ± SD.</p

Mean pressures during 46 hours of normothermic perfusion.

<p>Control was achieved by regulation of pump speed and inflow to portal venous blood reservoir to keep values within physiologic range. Portal pressure was based on the principle of autoregulation. (A) Portal pressure ± SD, (B) Arterial pressure ± SD, (C) IVC pressure ± SD. All pressures were measured in-line showing little variation between livers. (n = 4).</p

Perfusion flows during 46 hours of normothermic perfusion.

<p>(A) portal flow ± SD, (B) hepatic artery flow ± SD, (C) IVC flow ± SD. Perfusate flows were measured in-line using ultrasonic flow probes.</p

pH and base excess during normothermic organ preservation.

<p>Acid—base homeostasis was sustained until the end of organ preservation solely dependent on autoregulation of the perfused liver.</p

Animal survival and graft survival.

<p>Animal survival and graft survival censored for death with functioning graft.</p

Mean bile secretion during normothermic organ preservation.

<p>During normothermic perfusion all livers produced clear, viscous bile. Secretion started within two hours of perfusion and was sustained until the end of the preservation period. (n = 4).</p

Histological appearance of liver parenchyma.

<p>(A) Biopsy at baseline (following donor hepatectomy), (B) Biopsy taken after 48 hours of organ preservation by normothermic machine perfusion, (C) post-mortem biopsy after five days of recipient follow-up.</p

Post-transplant markers of cellular injury.

<p>(A) ALT (U/l), (B) bilirubin (mg/dl)*, (C) total protein (mg/dl) measured in serum during 5 days of follow-up after orthotropic liver transplantation ± SD. *In one pig autopsy revealed an anastomotic leak from the common bile duct. Serum levels of bilirubin were increased to above 20 mg/dl. Bilirubin data from this pig were excluded.</p