Mannitol has no impact on renal function after open partial nephrectomy in solitary kidneys

Mannitol has been administered during partial nephrectomy as a renal protective agent for ischemic damage. However, we do not have any high-level clinical evidence of its effectiveness. The aim of the present study was to evaluate the effect of mannitol during open partial nephrectomy by comparing the postoperative renal function of patients who received it and those who did not. We retrospectively reviewed the records of 55 patients who underwent open partial nephrectomy for renal cancer in a solitary kidney from January 1990 to December 2012, and who were followed up postoperatively for at least 6 months. Of the 55 patients, mannitol was given to 20 patients (group M+) and not to the other 35 patients (group M-). We compared not only the postoperative estimated glomerular filtration rate, but also its decrease rate and the incidence of acute kidney injury requiring dialysis in the two groups. There were no significant differences in perioperative patient characteristics between the two groups. Mannitol made no significant difference in both the postoperative estimated glomerular filtration rate and its decrease rate at any point within 6 months of the postoperative period. The incidence of acute kidney injury requiring dialysis was one (5.0%) in group M+ and two (5.7%) in group M-. These findings suggest that there might be no advantage from the administration of mannitol during open partial nephrectomy.