THE EFFECT OF INFRARENAL AORTIC RECONSTRUCTION ON GLOMERULAR-FILTRATION RATE AND EFFECTIVE RENAL PLASMA-FLOW

Compromised patients with aortic disease are vulnerable to various complications from aortic reconstruction. These complications are related to changes in systemic haemodynamics during aortic cross-clamping, which leads to cardiac stress and alteration in regional bloodflow to different organs. One of the most important postoperative complications is renal failure which is associated with a high mortality rate. Circulatory alterations within the kidney must play a role in the pathogenesis of renal dysfunction that may follow infrarenal aortic cross-clamping and reconstruction. To study the effects of abdominal aortic reconstruction on renal function and perfusion, we measured prospectively the glomerular filtration rate (GFR, n = 59), effective renal plasma flow (ERPF, n = 38) and left ventricular ejection fraction (LVEF, n = 38) in patients undergoing elective infrarenal aortic reconstruction. Radionuclide techniques were used. The three parameters were measured at three time points: preoperatively, postoperatively and 6 months after surgery. The LVEF was measured in order to reflect the patient's cardiac status and pre-renal perfusion, We also measured the three parameters in two control groups of patients: a group of patients undergoing major colonic surgery and a group of patients with arterial disease under conservative management. Six months after surgery the GFR had decreased in 67% of aortic reconstruction patients. Overall GFR in the aortic reconstruction group decreased by a mean of 9 ml min-1 (p = 0.007). This was associated with a decrease in the ERPF in 48.5% of patients. The mean decrease in ERPF in the aortic reconstruction group was 74 ml min-1 (p = 0.05). The LVEF was unchanged. These changes were not apparent in the immediate postoperative period. Both control groups were unchanged indicating that the findings are specific to the aortic reconstruction patients.