Effect of remote ischaemic preconditioning on renal protection in patients undergoing laparoscopic partial nephrectomy: a blinded' randomised controlled trial

Objective To evaluate whether remote ischaemic preconditioning (RIPC) reduces renal injury in patients undergoing laparoscopic partial nephrectomy (LPN). Patients and methods In all, 82 patients undergoing LPN were randomly assigned to either the RIPC or control group, with 40 and 38 patients, respectively completing 6-months follow-up. RIPC was conducted after induction of anaesthesia, which consisted of three 5-min cycles of right lower limb ischaemia and 5min of reperfusion during each cycle. The primary outcome was the absolute change in glomerular filtration rate (GFR) of the affected kidney by renal scintigraphy from baseline to 6 months. The secondary outcomes included urinary retinol-binding protein (RBP) levels measured at 24 and 48h, serum creatinine, and estimated GFR (eGFR) at 1 and 6 months, and changes in GFR by renal scintigraphy. Results There were no differences in the change of GFR of the affected kidney at 6 months, while it was significantly decreased by 15.0% in the control group vs 8.8% in the RIPC group at 1 month (P = 0.034). The urinary RBP levels increased 8.4-fold at 24h in the control group compared with a lower increase of 3.9-fold in the RIPC group (P < 0.001). There were no differences in the serum creatinine level or eGFR at 1 and 6 months between the two groups. Conclusions In patients undergoing LPN, RIPC using transient lower limb ischaemia may reduce renal impairment in the short term, but failed in the longer term despite a non-significant trend in favour of RIPC. These novel data support the need for a larger study of RIPC during LPN surgery.