LAUSR

Editor We read with interest the excellent study by Heylen et al.1. The authors concluded that we must keep donor nephrectomy time in kidneys donated after circulatory death (DCD) as short as possible with efficient cooling to improve outcome. Subsequently, three additional time intervals may also contribute to impaired outcome in DCD kidneys; the agonal phase, and bench time in the donor and transplant hospitals. During the agonal phase, donor organs perfusion and oxygenation may be suboptimal. Hypoxia and hypotension during the agonal phase have an impact on kidney ischaemia– reperfusion injury and complications in DCD kidney transplantation2. Allen et al.3 showed that area under the curve for systolic blood pressure was predictive of delayed graft function, and the slope of oxygen saturation during the first 10 min after extubation was associated with graft failure. Different bench practices in donor and transplant hospitals could have an influence on kidney outcome. Ideally, during benching, the donor kidney should be submerged in cold preservation fluid4. However, with deviations in preservation methods, the kidney can be exposed to additional warm ischaemia time. This is particularly important during multiorgan retrieval, where liver and pancreas will be benched first, rewarming the donor kidneys unless properly cooled. The same applies in vascular reconstruction in the donor kidney. The kidney will be handled and consequently warm up. Surprisingly, there is almost no literature on kidney temperature during benching. A recent study monitoring the temperature of donor livers observed an increase in temperature between the end of retrieval and packing of the organ, and from the back table to reperfusion, with a maximum of 20 ∘C5. This crucial information, which is lacking in the literature, will help in understanding and determining what impact every time frame within the donation and transplantation process has on kidney outcome. E. van Straalen and R. C. Minnee Division of HPB and Transplant Surgery, Department of Surgery, Erasmus MC University Medical Center, Rotterdam, The Netherlands