In fact, most of these issues have been raised by the reviewers and unfortunately none of them have a straightforward answer. With regard to the first question, NORS went "live" in April 2010 and our analysis ended in February 2010, predating the NORS changes. Data from April 2010 to 2012 are currently not available. Evaluating the effect of NORS would therefore require further approval from NHSBT and a newly powered statistical analysis but we agree that it would be a useful exercise. Data about grade and experience of the recovery surgeon, the second issue, represent another problem we faced. Surgeon grade was not stored electronically in the NHSBT database for that time period, and surgeon experience is equally difficult to assess from the NHSBT data. Each recovery center has the responsibility to assign organ recovery to a particular surgeon. We assumed they had completed their training but we had no way of confirming this. In addition, the number of organ recoveries alone is not the only parameter that will determine whether a damaged organ will be used. It is equally important to have experience in organ implantation and certain centers may take more 'risk' depending on the size of their program. Furthermore, currently in the UK, a large number of recovery surgeons (fellows) did not train in the UK and assessing their seniority was not possible. Data collection at implanting centers represented another problem and the "damage rate" in the paper might indeed be an underestimation. However, damaged organs not used were reported, so we can assume that only minor injuries might have been missed. With respect to the authenticity of the damage reported, we assumed that the reporting was honest. In the event of the recovery surgeon not being honest, then we might suspect that the implanting surgeon has also not been honest, perhaps attributing a bench-work damage to the recovery. We had no way of assessing this. We think it would be more productive to encourage damage reporting from everyone, with the knowledge that damage happens, and reporting improves the chance of transplant success. In reply to the last question, can adequacy of perfusion be a good parameter to assess a recovery? The scenario where a poorly perfused kidney recovered from a 70-year-old DCD donor with a 3-hour agonal phase, a 1-hour functional warm ischemic time and a 12-hour cold ischemic time-can we really blame it on the recovery surgeon? Unfortunately we are not able to provide all the answers but we do agree that there is a need to continue efforts to improve the quality of procurement data.
