Mannitol is routinely used during partial nephrectomies due to its renoprotective properties. With minimally invasive techniques, the need for mannitol has been questioned. Robotic-assisted laparoscopic partial nephrectomy (RALPN) has been shown to decrease warm ischemia time, which may potentially minimize the benefit of mannitol. To date, no prospective, randomized, controlled trials have investigated the use of mannitol in only robotic procedures. We hypothesize that the intraoperative mannitol use during RALPN provides no statistically significant benefit for post-operative renal function outcomes. We conducted a randomized, controlled, double-blinded, single surgeon, prospective study to assess renal function after RALPN. Patients were randomized into a control group with intravenous normal saline infusion prior to clamping of the vessels or to an experimental group with an infusion of mannitol. Estimated glomerular filtration rate (eGFR) were obtained prior to the surgery as well as post operatively at 24 h, 1 week, and 30 days. Preoperative eGFR showed no statistical differences between the groups and evaluation of median percent change in eGFR after surgery did not indicate a statistical difference between the groups after RALPN. After prospective analysis of the change in post-operative renal function of randomized groups who received 12 g of mannitol following RALPN, we determined that infusion of mannitol does not provide significant improvement of maintenance of renal functions after RALPN. Based on our results, we recommend discontinuing routine use of mannitol during RALPN.
Keywords: Mannitol; Partial nephrectomy; Prospective; Renal cell carcinoma; Renal mass.