Donor's Therapeutic Hypothermia vs Normothermia in Kidney Transplantation: A Meta-analysis of Randomized Controlled Trials

Luccas Marcolin Miranda ^1* Pedro Emanuel Carneiro De Lima ² Nathalia De Carvalho Dias Miranda ³ Giovanna Zaniolo Margraf ¹ Juliano Riella ⁴

• ¹ Pontifical Catholic University of Parana, Curitiba, Brazil
• ² Federal University for Latin American Integration, Foz do Iguaçu, Brazil
• ³ Bahiana School of Medicine and Public Health, Salvador, Brazil
• ⁴ Department of Surgery, School of Medicine, Emory University, Atlanta, United States

Introduction: The shortage of organs remains one of the most challenging global problems nowadays. Donor’s therapeutic hypothermia was suggested to decrease kidney delayed graft function (DGF) when compared to normothermia in previous trials, but the role of such intervention is still controversial. To assess this, we performed a systematic review and meta-analysis of randomized clinical trials (RCTs) investigating the benefits of donor hypothermia in DGF rate and Graft Failure. Methods: MEDLINE, Embase, and Cochrane databases were systematically searched for studies of deceased organ donors who underwent hypothermia or normothermia prior to kidney transplantation. Statistical analysis was performed using R Studio version 3.6. Heterogeneity was assessed using I² statistics and a Baujat Plot. Results: Four different RCTs were analyzed, including more than 3000 recipients. Donor hypothermia was associated with a lower, but not statistically significant, rate of DGF (RR 0.87; 95% CI 0.71-1.08; P = .21) and graft failure (RR 0.70; 95% CI 0.45-1.10; P = .12). When analyzing only expanded criteria donors, a significantly lower rate of DGF was observed in the hypothermia-treated group (RR 0.65; 95% CI 0.47-0.89; P = .008). Sensitivity analysis identified one study as an outlier, probably due to protocol deviation. When excluded from the analysis, a significant reduction in DGF rate was observed among the hypothermia-treated group when compared normothermia (RR 0.80; 95% CI 0.67-0.94; P = .007). Conclusion: Our meta-analysis could not find a statistical difference between donor therapeutic hypothermia and normothermia in preventing DGF or Graft Failure. However, these results may be influenced by outliers and the limitations of included studies. Further studies are needed to clarify the role of donor hypothermia in kidney transplantation. If proven beneficial, it could be a promising alternative to sites where preservation techniques are limited, such as low-income countries.