Long-term fate of renal function after open surgery for juxtarenal and pararenal aortic aneurysm.

BACKGROUND

Although the indications for endovascular aneurysm repair for abdominal aortic aneurysm have been expanding, our primary strategy for pararenal and juxtarenal abdominal aortic aneurysm (P/JRAA) is open surgery (OS). One consequence of OS for P/JRAA is transient renal ischemia owing to renal artery clamping, which can be followed by acute kidney injury (AKI). Prior studies referred to the impact of renal ischemia on AKI, but they have rarely evaluated longer-term renal function. This study focused on a chronic renal decline (CRD) during follow-up.

METHODS

A retrospective review of our series of P/JRAA treated with OS from 2007 to 2015. Patients on hemodialysis at the time of surgery were excluded. Preoperative renal function was estimated using the chronic kidney disease (CKD) staging system. Postoperative AKI was defined by the RIFLE criteria (Risk, Injury, Failure, Loss of function, End-stage renal disease). CRD was defined as progression in CKD stage or estimated glomerular filtration rate (eGFR) decline of >20%.

RESULTS

Among 451 elective OS, 111 underwent repair for P/JRAA. Three patients were excluded because of preoperative hemodialysis. Consequently, 108 patients were enrolled. Preoperatively, 41 patients (38.0%) had CKD stage 3 (eGFR < 60 mL/min/1.73 m). Eight patients (7.2%) were in stage 4 (eGFR < 30 mL/min/1.73 m). Proximal clamping was supraceliac (6 patients), suprarenal (34 patients), and inter-renal (68 patients). The median renal ischemic time was 33 minutes. The left renal vein was divided in 24 patients. Fourteen renal arteries in 14 patients were revascularized. Cold renal perfusion was applied in 11 patients. One in-hospital death was excluded from these analyses. AKI was observed in 20 patients (18.7%). One patient required temporary hemodialysis. During a median renal function follow-up for 24.5 months (interquartile range, 3.34-48.4), 17 patients (15.9%) had CRD. One patient required hemodialysis 5 years after surgery. In univariate analysis, CKD stages 3 and 4 were significant predictors for CRD (P = .014 and P < .001, respectively). Cold renal perfusion was associated with a higher risk of CRD (P = .047). On multivariate analysis, preoperative CKD stage 3 (hazard ratio, 4.22; 95% confidence interval, 1.10-16.3; P = .036) and stage 4 (hazard ratio, 59.72; 95% confidence interval, 10.13-352.0; P < .001) were identified as risk factors. In patients with CKD stage ≤2, the estimated freedom from CRD at 5 years was 96.6 ± 3.4%.

CONCLUSIONS

CKD stage ≥3 was a significant risk for CRD after OS for P/JRAA. Renal artery clamping seemed innocuous for patients with a preoperative eGFR of ≥60 mL/min/1.73 m in terms of CRD. No significant impact of left renal vein division on CRD was confirmed.