BACKGROUND: The overall rate of renal complications after surgery on the suprarenal aorta remains high. Possible mechanisms are, a reduction and maldistribution of renal blood flow, activation of the renin-angiotensin system, and the release of various mediators. In this study, changes in renal blood flow, local renal perfusion, the oxygen extraction ratio, and in renal function by furosemide following supraceliac aortic cross clamping and unclamping were observed.

METHODS: A total of 13 mongrel dogs were divided into two groups; a control group (n = 7), and a furosemide group (n = 6). For aortic cross clamping the supraceliac aorta was exposed and a doppler flowmeter probe was placed on the left renal artery. A thermal diffusion microprobe was also inserted in the renal parenchyme to measure local renal perfusion. Sixty minutes after aortic cross clamping, systemic hemodynamic data, renal blood flow, and local renal perfusion were measured. These parameters were also repeatedly measured at 1, 2, 3, 4, 5, and 6 hours after unclamping. Biomarkers of renal dysfunction and injury (renin activity, creatinine, and Cystatin-C) were measured.

RESULTS: No differences were observed between the two groups in terms of renal blood flow, local renal perfusion, and oxygen extraction ratio. Renal blood flow and perfusion did not recover to the baseline level after unclamping in either group. Plasma renin activity significantly reduced in the furosemide group 3 hours after clamping, but serum creatinine, and Cystatin-C concentrations were similar in the tow groups.

CONCLUSIONS: We conclude that the administration of furosemide after supraceliac aortic unclamping to improve renal function is not effective in experimental dogs.