Technical and operative factors in infrarenal aortic reconstruction and their effect on the glomerular filtration rate in the immediate postoperative period and 6 months later.

ABSTRACT

Renal failure is an important cause of postoperative morbidity and mortality in infrarenal aortic reconstruction. Several mechanisms for this postoperative renal dysfunction have been suggested. However, biochemical testing of renal function is insensitive since it shows only gross renal changes. This study examined prospectively the effects of the technical and operative factors on renal function using radionuclide tests. The authors measured the total Glomerular Filtration Rate (GFR) using 51Cr-EDTA clearance in 59 patients undergoing elective infrarenal aortic reconstruction. We also examined the individual kidneys using 99mTc-DTPA renography and 99mTc-DMSA renal scanning. Renal scanning gives the percentage of function of each kidney, while renography gives a graphic assessment of individual renal perfusion and clearance. All tests were carried out preoperatively, 2 weeks postoperatively and 6 months later. Twelve technical factors including aortic cross clamping time, type of aortic anastomosis, forced diuresis, division of left renal vein and various others were recorded to study their effect on the GFR and the individual kidney function. The effect on renal function of these operative factors has not previously been described. GFR showed no change in the immediate postoperative period. Six months later GFR decreased, the mean decrease was 9 ml/min. (P = 0.007 Wilcoxon rank). Some of our patients showed an increased GFR, a phenomenon that was recognised recently. None of the factors studied, except division of the left renal vein, had any effect on the changes in the GFR in the immediate postoperative period or 6 months later.