Techniques to Ameliorate the Impact of Second Warm Ischemic Time on Kidney Transplantation Outcomes

Anastomosing the renal artery and vein in transplant recipients without a cooling mechanism exposes the kidney to temperatures exceeding the metabolic threshold (15°C to 18°C), at which the protective effects of renal hypothermia are lost. This anastomotic time, or second warm ischemic time, can be deleterious to graft outcomes, especially if it is prolonged. Techniques to ameliorate organ warming prior to reperfusion have been designed, and range from simpler surface cooling techniques, to organ immersion in bags of ice slush, and the application of ‘jackets’ that incorporate their own internal cooling mechanism. The efficacy of these methods with respect to the minimization of kidney temperature prior to reperfusion and subsequent effects on graft outcomes are discussed using clinical and experimental data, in the setting of open, laparoscopic, and robotic kidney transplantation. •A prolonged anastomotic time beyond 35–45 minutes negatively affects kidney function post-transplantation.•The effects of this can potentially be countered by cooling the kidney during anastomoses such that its temperature is maintained less than the metabolic threshold.•Cooling mechanisms include ice bags for organ immersion, surface cooling methods, and/or specifically designed kidney cooling jackets.•There is some clinical evidence for the use of the ice bag technique, however, kidney cooling jackets have currently only been used in the experimental setting.