A comparison of renal function between open and endovascular aneurysm repair in patients with baseline chronic renal insufficiency.

OBJECTIVE: Endovascular aneurysm repair (EVAR) is rapidly becoming the predominant technique for repair of abdominal aortic aneurysms. Results from current studies, however, are conflicting on the effect of EVAR on renal function compared with standard open repair. Furthermore, data for open repair in patients with baseline renal insufficiency suggests worse outcomes, including renal function. This analysis compared the effects of open repair vs EVAR on renal function in patients with baseline renal insufficiency.
METHODS: We reviewed our records for patients with preoperative chronic renal insufficiency (serum creatinine, 1.5 mg/dL) who underwent open repair or EVAR between 1999 and 2004. The same group of vascular surgeons at a single institution performed aneurysm repair on 98 patients: 46 open (37 men, 9 women) and 52 EVAR (50 men, 2 women). Preoperative, postoperative, and follow-up serum creatinine and creatinine clearance were compared, as was the development of postoperative renal impairment (increase in serum creatinine >30%).
RESULTS: Serum creatinine and creatinine clearance were not statistically different between the open and EVAR groups during any time period studied. Likewise when comparing the magnitude of change in serum creatinine in patients between the postoperative and follow-up times with preoperative values, no significant differences existed between the open and EVAR groups. When the change in serum creatinine over time within each group was compared, however, the open group had a significant increase in serum creatinine postoperatively (2.43 +/- 1.20 vs 2.04 +/- 0.64, P = .012), which returned to baseline during follow-up (1.96 +/- 0.94, P = .504). Although serum creatinine in the EVAR group increased compared with preoperative values of 2.04 +/- 0.55 (postoperative, 2.27 +/- 1.04; follow-up, 2.40 +/- 1.37), this failed to reach statistical significance for the postoperative (P = .092) or follow-up (P = .081) periods. A similar pattern was noted in creatinine clearance. Postoperative renal impairment was noted in 13 open (28%) and 15 EVAR patients (29%) and was not statistically different between groups. Overall, two patients (4.3%) from the open group and four (7.7%) from the EVAR group required hemodialysis; one in the EVAR group required permanent hemodialysis. This difference was not statistically significant (P = .681).
CONCLUSIONS: Open and endovascular repair of abdominal aortic aneurysms in patients with pre-existent renal insufficiency can be performed safely with preservation of renal function. In contrast to previous reports, no significant differences existed between open repair and EVAR in postoperative alterations in renal function. Although a significant increase in serum creatinine develops in patients with renal insufficiency postoperatively with open repair, this appears to be transient, and preoperative renal dysfunction alone should not exclude either approach. After EVAR, patients with pre-existing renal insufficiency continue to be at risk for progressive renal dysfunction, and protective measures should be taken to preserve renal function in this patient population.