Re: Massimiliano Spaliviero, Nicholas E. Power, Katie S. Murray, et al. Intravenous Mannitol Versus Placebo During Partial Nephrectomy in Patients with Normal Kidney Function: A Double-blind, Clinically-integrated, Randomized Trial. Eur Urol 2018;73:53-9

Intraoperative Intravenous Mannitol Administration Failed to Provide Added Value on Renal Functional Preservation After Partial Nephrectomy in Patients with Chronic Kidney Disease: A Matched Cohort Study

Background: Previous randomized-controlled trials have demonstrated that intraoperative intravenous mannitol administration shows no added value on renal functional preservation after partial nephrectomy (PN) in patients with normal renal function. However, the renoprotective effect of mannitol has not been fully evaluated in patients with preoperative chronic kidney disease (CKD). Materials and Methods: This was a retrospective cohort study with propensity score matching. Patients with a preoperative estimated glomerular filtration rate (eGFR) of <60 mL/minute/1.73 m² undergoing PN were enrolled in the study between January 2012 and December 2019 in Peking University First Hospital. Participants were divided into two groups: patients who received 25 g of mannitol (group M+) or not (group M-). The primary endpoint was the decreased rate of eGFR at the 6-month follow-up. Results: A total of 244 patients were included in the analysis. After propensity score matching, 80 patients remained in each group. The percentage of decrease from baseline eGFR at postoperative 6-month follow-up showed no difference between the two patient groups (median 11.1 [interquartile range 5.3-25.3] in group M+ vs 12.2 [4.7-21.3] in group M-, median difference -0.7 [95% confidence interval -4.6 to 3.1]; p = 0.704). Postoperative acute kidney injury, renal replacement therapy during hospitalization, postoperative complications, incidence of >20% decrease from baseline eGFR at 6 months, and dialysis at 6 months showed no difference between the two patient groups. Conclusions: A 25 g dose of mannitol administration during PN failed to provide added value on renal functional preservation in CKD patients.

Phase III Trial of Intravenous Mannitol Versus Placebo During Nephron-sparing Surgery: Post Hoc Analysis of 3-yr Outcomes

Our recently reported phase III trial demonstrated that patients undergoing nephron-sparing surgery (NSS) with an estimated glomerular filtration rate (eGFR) of ≥45 ml/min/1.73 m2 who received mannitol had no improvement in renal function at 6 mo compared with those who received placebo. Some authors have suggested that benefit is restricted to subgroups, such as those with comorbidities. We assessed whether preoperative eGFR, or other patient and surgical factors modified the effect of mannitol on postoperative outcomes at 6 mo and with extended follow-up. We also assessed whether mannitol was associated with differences in long-term GFR years after surgery. No significant difference between the mannitol or placebo groups (mean eGFR difference: 1.4; 95% confidence interval: -2.6, 5.3; p = 0.5) was found in the 134 patients with known eGFR at 3 yr after NSS. At both 6 mo and 3 yr, the effect of mannitol was not significantly modified by patient or surgical factors including preoperative eGFR. In summary, we validated our original trial conclusions by finding that intraoperative use of mannitol does not improve either short- or long-term renal function in patients undergoing NSS. Specifically, there is no evidence that comorbidities, including lower preoperative eGFR, modify the effect of mannitol. PATIENT SUMMARY: Use of mannitol at the time of partial nephrectomy does not improve either short- or long-term renal function even in patients with comorbidities, including lower preoperative renal function. The routine use of intraoperative mannitol should be discontinued.