Background: Thoracoabdominal aortic aneurysm open surgery is accompanied by a significant incidence of renal failure due to renal ischemia. The effect of remote ischemic preconditioning (RIPC) in renal ischemia/reperfusion (IR) injury during a thoracoabdominal aortic aneurysm open repair approach was examined on an animal model.
Materials and methods: Three groups of rats underwent the following operations respectively: (a) Sham operation in control group; (b) Renal IR injury produced by subphrenic aortic cross-clamping (45/45 min IR), in IR group; (c) The same renal IR injury following RIPC produced by a brief occlusion of the infrarenal aorta (15/15 min IR) in RIPC group. Levels of lactate, base excess, and malondialdehyde (MDA) were measured in selective blood samples from the left renal vein, while levels of MDA were measured in samples of kidney tissues.
Results: Renal blood base excess was significantly reduced in IR and RIPC groups as compared to sham group, but it was significantly higher in RIPC compared to the IR group (-7.69 +/- 0.62 versus -15.15 +/- 0.86, P < 0.001). Renal blood lactate was significantly increased in both IR and RIPC groups as compared to the sham group, but it was significantly lower in RIPC group compared to IR group (6.76 +/- 0.19 versus 11.99 +/- 0.33, P < 0.001). Renal blood MDA was increased in both IR and RIPC groups compared to the sham group, but it was significantly less compared in the RIPC group compared to IR group (1.55 +/- 0.38 versus 2.94 +/- 0.16, P = 0.002). Finally, kidney tissue MDA was increased in both IR and RIPC groups versus sham group, but it was significantly lower in RIPC group compared to the IR group (5.92 +/- 0.82 versus 13.98 +/- 2.41, P = 0.005).
Conclusions: RIPC induced by a temporary infrarenal aortic occlusion decreased the IR renal injury caused by subphrenic aortic cross-clamping.