Review Reports - The Role of Normothermic Machine Perfusion in Extended Criteria Donor Grafts: A New Direction in Liver Graft Assessment and Preservation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This is a very well organized and comprehensive study that focuses on a very interesting topic. The real problem with such studies is that liver transplant centers have not found shared criteria on the characteristics that livers must have before deciding to use MP. Only in this case would the data from the different existing studies be comparable.

So I have only one question: What are the characteristics of the livers treated in these analyzed studies, did they have common discard criteria? Unfortunately, if the only criterion was of being discarded by the centers, this is not enough because the reasons could be multiple.

In the paper I read discarded for "standard criteria" or "traditional" criteria but what's the definition of "standard" and "traditional" ? What are the standard or traditional liver discard criteria?

I would probably add this aspect to the limitations of the study.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The use of NMPs in transplantology is now a reality in most transplant centers and much has already been written on the subject, but it certainly remains an interesting topic. Since this is a review some points should be better described:

- the mechanism of action of NMP especially to justify the advantage over scs. As it is known this goes through different key points (ATP restoration, inflammatory and immune response etc). In the paper it seems described superficially.

- when we talk about perfusion machines we speak about preservation, viability assessment, but also reconditioning techniques. although it is not the main topic I think it is appropriate to mention it given that there have been described strategies to improve outcome even in ECDs (e.g., macrosteatosis)

Comments on the Quality of English Language

can be improved and especially should be avoid several repetitions specially in the introduction