New techniques in organ preservation and liver transplantation

Dr. Tolba reviews the history of solid organ transplantation and the outcomes of liver transplantation. Immunosuppressive therapy has improved the results enormously and new surgical techniques have been developed, such as split and living donor liver transplantation. As we can see in the headlines of major German newspapers, there is an alert regarding the lack of liver donors around the world. Spain has the record in donation rate, whereas Germany has the lowest rate (47 and 8 per 1 million people, respectively).

Better use of marginal liver allografts is urgently needed to cope with this problem.

Ischemia-reperfusion injury is still a major concern. Older donors and marginal organs (old and fatty livers) are being used, and they might be more susceptible to ischemia damages. The standard of care for grafts is cold storage, which causes hepatocellular injury and organ damage.

Machine perfusion techniques might be the future to avoid these problems. The first one was invented in 1935. Currently, there are normothermic and hypothermic preservation machines that reduce ischemia-reperfusion injury and decrease biliary complications after transplantation. It is, however, a very expensive and complicated technique.

Dr. Tolba explains both the normothermic and the hypothermic perfusion processes and the patophysiology behind oxygenated perfusion.

A randomized clinical trial with 46 cases (HOPE ECD-DBD), one of the first randomized trials on hypothermic perfusion, was conducted by his team. New preservation solutions were also developed by his team, focusing on the treatment of steatotic grafts. A fatty liver changes hepatocytes and diminishes the sinusoidal microcirculation.

Remote ischemic conditioning is another technique that can help reduce the damage to the graft by means of protective biochemical pathways.

In summary, ischemic-reperfusion injury is a major issue that might result in life-threatening short- and long-term complications. Different strategies, such as machine perfusion, are now available and under trial.