EURURO Vol. 73 No. 1

60 148

Platinum Priority – Editorial
Referring to the article published on pp. 53–59 of this issue
Should Urologists Abandon the Use of Mannitol During Partial
Nephrectomy?
Paras H. Shah, Bradley C. Leibovich
Department of Urology, Mayo Clinic, Rochester, MN, USA
Partial nephrectomy (PN) is the preferred surgical approach
for clinically localized renal tumors as enhanced preserva-
tion of kidney function is achieved in the context of
equivalent cancer control An increase in the incidental
detection of small renal masses coupled with the realization
that oncologic efficacy is at least equivalent for partial and
radical nephrectomy and bolstered by the now
widespread availability of minimally-invasive surgical plat-
forms has accelerated the adoption of PN As a major
impetus of PN is to decrease the risk of postoperative
chronic kidney disease (CKD), considerable effort has been
undertaken to understand modifiable risk factors which
influence nephron damage, among which renal ischemia is
considered paramount . Mannitol, an osmotic diuretic, is
widely used during PN as it is thought to mitigate the
adverse effects of ischemia by both increasing renal blood
flow and acting as a free radical scavenger . Nevertheless,
existing evidence supporting a clinical benefit of mannitol
during PN is of low methodologic quality.
In this month's issue of European Urology, Spaliviero et al
report their results from a randomized clinical trial
comparing the use of 12.5 g of intravenous mannitol versus
placebo on renal functional outcomes after elective PN. The
authors demonstrate that intraoperative administration of
12.5 g of mannitol within 30 min of hilar clamping does not
alter the trajectory of functional decline after PN, as
observed values between groups with respect to percent
change and absolute estimated glomerular filtration rate
(eGFR), as well as differential renal function on renal
scintigraphy, did not differ at postoperative 6-mo follow-up.
Based on this level 1 evidence, the authors assert that the
routine administration of mannitol prior to hilar clamping
should be discontinued. The study was well executed; it is
appropriately reported as per CONSORT guidelines, ran-
domization procedures are clearly explained, treatment
allocation was double-blinded, and the outcome measures
are objective and clinically meaningful. We congratulate the
authors for completing a trial to address this issue. Despite
the strengths of their work, several aspects of the study
design warrant closer attention.
The mannitol dose of 12.5 g used in this study is
considered low by current standards. Although authors
base their dose selection on two animal studies which
demonstrate efficacy at 0.25 g/kg , they acknowledge
that a dose of 25 g is more commonly utilized in
contemporary practice, as it would correspond to an
appropriate weight-based dose for a 100-kg patient.
An international survey of 92 high-volume urologic centers
further supports the preferential use of higher doses, with
approximately 50% of providers administering 25 g of
mannitol versus only 30% using 12.5 g . The authors
postulate that higher doses of mannitol may also be
ineffective by referencing a randomized trial which noted
no difference in 3-mo postoperative eGFR utilizing 50 g of
mannitol during cadaveric renal transplantation ;
however, extrapolating a lack of benefit during cadaveric
transplantation, where kidneys often experience hours of
cold ischemia and postoperative function may be influ-
enced by organ rejection, should be done with caution.
Although the authors correctly identify a lack of high-
quality evidence to inform the use of doses higher than
12.5 g during PN, such doses are routinely used, and the
present study does not directly refute a potential benefit
from such dosing.
Additionally, the current study primarily enrolled
patients with normal preoperative renal function, none of
available at
journal homepage:
DOI of original article:
* Corresponding author. Mayo Clinic, 200 First Street South West, Rochester, MN 55905, USA. Tel. +1 507 284 2511; Fax:+1 507 284 4951.
E-mail address: (B.C. Leibovich).
0302-2838/© 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.