To the Editor
We read with interest the research report by Stoker et al, which demonstrated superior outcomes when normothermic machine perfusion (NMP) was used for deceased donor liver transplantation. While the study justifies the use of NMP, real-world challenges exist which prevent a full conversion away from static cold storage technique for this procedure.
First, cost and resources must be considered. The use of NMP is estimated to add $25,000 to $50,000 USD per case. A major hospital system that performs between 100 and 200 liver transplant cases in a year could face an increased cost of $2.5 to $10 million annually when incorporating NMP. Maintaining a procured liver via NMP requires continuous monitoring and hourly blood draws, adding to the cost and resources required to train and retain a critical care nurse who needs to be available day and night. Given that the benefits of NMP appear to diminish 30 minutes after reperfusion of the transplanted liver, hospital leadership may be reticent to incorporate NMP equipment and personnel into their budget.
Next, patients have more hemodynamic stability when NMP is utilized, but these demonstrated benefits are either small or transient. Assessment of long-term outcomes, such as 1-year mortality or quality of recovery, appears to be a research opportunity in which data is currently lacking. Intermediate outcomes, such as vasopressor use or blood transfusion requirement, are easy to measure, but do not demonstrate its lasting impact on a patient or the hospital ecosystem. An analogous subspecialty in which similar research challenges arise is regional anesthesia and pain medicine; studies may tout reduction in pain scores or opioid consumption, but long-term functional outcomes are either equivocal or not yet studied. As NMP becomes more commonplace, the ethics of patient autonomy is worth discussion. Often, the coordination required to prepare a patient for liver transplant is so complex that it is rare for a surgeon to have a thorough discussion with the patient about the quality of the specific organ that will be used. History shows that some details of transplant allocation may be deemed unimportant to patients and their families, but ultimately these details may affect patient decision-making. In the future, patients may ask to only receive their liver transplant with NMP-treated organs. Will leadership within the United Network of Organ Sharing (UNOS) be amenable to allowing patients to make these decisions? If NMP organs are clearly superior, what are the ethics of using traditional static cold storage for a liver transplant patient who suffers from hepatic encephalopathy and cannot make medical decisions for themselves?