Effect of Mannitol on Kidney Function After Kidney Transplantation: A Systematic Review and Meta-Analysis

Background: The effect of mannitol usage during kidney donation and kidney transplantation is still unclear. Therefore, we performed a systematic review and meta-analysis to research the difference in graft function between kidney grafts treated with and without mannitol. Methods: A literature search was performed in 5 databases and included 8 eligible studies out of 3570 references, which were included up to July 12, 2021. Relevant outcomes for analysis were graft survival, rejection, acute renal failure, delayed graft function, renal failure, creatinine clearance, diuresis, and serum creatinine. Results: Eight studies were identified, 1 study examining the effect of mannitol during kidney donation and 7 studies during kidney transplantation, of which 6 eligible for meta-analysis. A total of 1143 patients were included in these studies. The following outcome measures demonstrated significant differences in favor of mannitol usage compared with a control group: acute renal failure (risk ratio [RR], 0.45; 95% confidence interval [CI], 0.26–0.79; P < .01]) and delayed graft function (RR, 0.25; 95% CI, 0.08–0.77; P = 0.02 and RR, 0.69; 95% CI, 0.51–0.94; P = 0.94). Differences in other outcome parameters were not significant. Conclusions: This systematic review and meta-analysis suggested that the use of mannitol during kidney transplantation leads to lower incidence of acute renal failure and delayed graft function. For all other outcomes, no significant difference was found. Further research should be conducted on the use of mannitol during donor nephrectomy because of the limited availability of studies. Finally, for interpretation of the outcomes, the quality of the evidence should be taken into consideration and we emphasize the need for more up-to-date research.