BACKGROUND: The incidence of renal insufficiency is reported about 18-27% during the thoracoabdominal aneurysm surgery. The possible mechanisms are reduction and maldistribution of renal blood flow, activation of renin angiotensin system, release of various mediators. In this study, we observed the effect of nicardipine, one of the calcium channel blockers that commonly used, on the systemic hemodynamics and the renal fuctions. METHODS: A total of 13 mongrel dogs were divided into two groups: control group (C, n = 7), nicardipine administration group (N, n = 6). After brachial arterial and Swan-Ganz catheterization, midline abdominal incision was made. For the aortic cross clamping the supraceilac aorta was exposed and the doppler flowmeter probe was placed on the left renal artery. The thermal diffusion microprobe was inserted in the renal parenchyme to measure local renal perfusion. At sixty minutes after aortic cross clamping, systemic hemodynamic data, renal blood flow and local renal perfusion were measured and at 1, 2, 3, 4, 5 and 6 hours after unclamping the same parameters were measured. RESULTS: There were no differences on renal blood flow, renal perfusion and oxygen extraction ratio between two groups. The renal blood flow and renal perfusion did not recover to the baseline level after unclamping in both groups. The plasma renin activity, serum creatinine concentration and cystatin-c did not show any difference between groups respectively. CONCLUSIONS: We concluded that the administration of nicardipine after supraceliac aortic unclamping to improve the renal function was not effective in experimental dogs.
Aneurysm ; Animals ; Aorta ; Calcium Channel Blockers ; Catheterization, Swan-Ganz ; Constriction* ; Creatinine ; Dogs* ; Flowmeters ; Hemodynamics* ; Incidence ; Nicardipine* ; Oxygen ; Perfusion ; Plasma ; Renal Artery ; Renal Circulation ; Renal Insufficiency ; Renin ; Renin-Angiotensin System ; Thermal Diffusion

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.
Animals ; Aorta ; Aortic Aneurysm ; Biomarkers ; Constriction* ; Creatinine ; Dogs* ; Flowmeters ; Furosemide* ; Hemodynamics ; Oxygen ; Perfusion ; Plasma ; Renal Artery ; Renal Circulation ; Renin ; Renin-Angiotensin System ; Thermal Diffusion