In this MEDICA-tradefair.com interview, PD Dr. Nathanael Raschzok, MD, talks about the application of machine perfusion, explains the differences between methods, and discusses the organs that could benefit from this technique in the future. He also rates its importance in organ transplantation considering the shortage of donor organs.
Dr. Raschzok, you use machine perfusion to precondition donor organs for transplantation. What does this entail?
Dr. Nathanael Raschzok: Machine perfusion in organ transplantation is not a new technique, especially when it comes to abdominal organ transplantation. The first liver transplantations already tried the process. However, machine perfusion was put on the back burner because it was and still is efficient, cost-effective, and easy to use a cold storage solution in organ preservation.
Nearly fifteen years ago, hypothermic machine perfusion became the international gold standard in kidney transplantation. It means organs are typically connected to the perfusion device at the removal center, flushed with a cold preservative solution, and then delivered to the transplant center. I intentionally said international gold standard because for various reasons, it is not the standard in Germany, though the technique has been checked and validated in studies.
There are many exciting developments as it pertains to kidney research. Our hospital compares cold versus warm perfusion in a prospective randomized clinical trial (NCT04644744). With cold (hypothermic) machine perfusion, the organ is flushed with a cold preservative solution. Warm (normothermic) machine perfusion uses a solution with a different configuration containing a hemoglobin-based oxygen carrier. These are typically red blood cells from donors, allowing the oxygenation of organs. They are metabolically active, if supplied with blood or flushed at 37 °C, the postulation being this improves the post-transplant outcome.
We have also seen a similar trend in liver projects over the last ten years. First, hypothermic machine perfusion with a preservative solution was established. In a next step, hypothermic oxygenated machine perfusion ("HOPE") was introduced in liver transplantation. It was primarily developed and used to prepare so-called marginal donor organs. These are organs from donors with limiting criteria or pre-existing conditions that are expected to deliver poorer transplantation results compared to standard organ procurement. Last but not least, the move from hypothermic towards normothermic machine perfusion was made as this is an international practice that is applied in Germany and in clinical trials at our clinical facility.