Renal function changes after fenestrated endovascular aneurysm repair

Abstract

Limited data exist regarding the effect of fenestrated endovascular aneurysm repair (fEVAR) on renal function. We performed a comprehensive analysis of acute and chronic renal function changes in patients after fEVAR. This study included patients undergoing fEVAR at two institutions between September 2012 and March 2015. Glomerular filtration rate was estimated using the Modification of Diet in Renal Disease formula with serum creatinine levels obtained during the study period. Acute and chronic renal dysfunction was assessed using the RIFLE (Risk, Injury, Failure, Loss, End-stage renal disease) criteria and the chronic kidney disease (CKD) staging system, respectively. fEVAR was performed in 110 patients for juxtarenal or paravisceral aortic aneurysms, with a mean follow-up of 11.7months. A total of 206 renal stents were placed, with a mean aneurysm size of 62.9mm (range, 45-105mm) and a mean neck length of 4.1mm. Primary renal stent patency was 97.1% at the latest follow-up. Moderate kidney disease (CKD stage ≥ 3) was present in 51% of patients at baseline, with a mean preoperative glomerular filtration rate of 60.0± 19.6mL/min/1.73m2. Acute kidney injury occurred in 25 patients (22.7%), although 15 of these (60%) were classified as having mild dysfunction. During follow-up, 59 patients (73.7%) were found to have no change or improved renal disease by CKD staging, and 19 (23.7%) had a CKD increase of one stage. Two patients were noted to have end-stage renal failure requiring hemodialysis. Clinically significant renal dysfunction was noted in 21 patients (26.2%) at the latest follow-up. Freedom from renal decline at 1year was 76.1% (95% confidence interval, 63.2%-85.0%). Surrogate markers for higher operative complexity, including operating time (P= .001), fluoroscopy time (P< .001), contrast volume (P= .017), and blood loss (P= .002), served as dependent risk factors for acute kidney injury, although though no independent predictors were identified. Age (P= .008) was an independent risk factor for long-term decline, whereas paradoxically, baseline kidney disease (P= .032) and longer operative times (P= .014) were protective of future renal dysfunction. Acute and chronic renal dysfunction both occur in approximately one-quarter of patients after fEVAR; however, most of these cases are classified as mild according to consensus definitions of renal injury. The presence of mild or moderate baseline kidney disease should not preclude endovascular repair in the juxtarenal population. Routine biochemical analysis and branch vessel surveillance remain important aspects of clinical follow-up for patients undergoing fEVAR.