Effect of renal insufficiency on outcome following infrarenal aortic surgery.

BACKGROUND: This study reviewed the effect of preoperative renal insufficiency on outcome following elective infrarenal aortic surgery.
METHODS: The charts of 210 consecutive patients undergoing aortic surgery (occlusive disease, 15%; aneurysmal disease, 78%; or combined disease, 7%) from 1990 to 1995 were categorized into three groups based on preoperative creatinine ([Cr] group 1 Cr < 1.5, n = 171; group 2 Cr 1.5 to 1.7, n = 22; and group 3 Cr > or = 1.8, n = 17) and calculated creatinine clearance ([CrCl] CrCl > 45 mL/min, n = 162 versus CrCl < 45 mL/min, n = 48). Patients with renal artery stenosis or those who required suprarenal cross clamping or emergency procedures were excluded. Differences in postoperative intensive care unit (ICU) stay, ventilator days, dialysis dependence, morbidity, and, mortality were compared.
RESULTS: Patients in groups 2 and 3 had an increased incidence of postoperative dialysis dependence (group 2 9%, group 3 8%) when compared with patients in group 1 (group 1: 0%, P < 0.05). Patients in the CrCl > 45 group had a lower mortality rate when compared with patients with a CrCl < 45 (CrCl > 45 0.6% versus CrCl < 45 8%, P <0.05) a lower incidence of dialysis (0% versus 7%, P <0.05), and a lower incidence of postoperative serum creatinine elevation from baseline (CrCl > 45 8% versus CrCl < 45 18%, P <0.05). There was no significant difference in morbidity, ICU stay, or ventilator days between the groups. Upon regression analysis, preoperative CrCl but not Cr was predictive of postoperative mortality (P <0.05). Serum Cr was more predictive than CrCl of impaired renal function postoperatively.
CONCLUSIONS: Preoperative CrCl is more accurate than Cr as a predictor of postoperative mortality. Patients with preoperative CrCl < 45 mL/minute who undergo elective aortic surgery have a significant increase in postoperative cardiac-related mortality and dialysis.