Background: Endovascular abdominal aortic aneurysm repair involves manipulation of the aorta around the renal arteries. Fenestrated grafts involve the direct cannulation, stenting and injecting of contrast into the renal arteries. These procedures may be associated with an acute post-operative creatinine rise.
Methods: We retrospectively examined data from all endovascular aortic repairs at our institution from 2005 to 2009, where contrast dosage had been recorded. Renal impairment was defined as a 25% increase in creatinine during the 5-day postoperative period. Univariable analysis was undertaken for a number of likely predictors, including: age, contrast dosage, preoperative creatinine, graft type (fenestrated or standard), diabetes mellitus, hypertension, hypercholesterolaemia, ischaemic heart disease, aspirin therapy, statins therapy, non-steroidal anti-inflammatory drug use, preoperative N-acetyl-cysteine and intravenous pre-hydration. Multivariable analysis was then applied to variables with a univariable P-value of < 0.05.
Results: We identified 106 consecutive cases, with complete data for 102. Twenty per cent of patients developed renal impairment (22/102). Contrast dose (P = 0.043) and fenestrated grafts (P = 0.006) were identified as significant risk factors for post-operative creatinine increase (P = 0.043). Multivariable analysis demonstrated that fenestrated grafts were a risk factor independent of contrast dosage (P < 0.05).
Conclusions: Patients who received a fenestration graft (P < 0.01) and increased contrast dose (P < 0.05) were at a significant increased risk of a 25% post-operative creatinine rise. The risk of fenestration grafts persisted when multivariable regression was performed to control for contrast dosage (P < 0.05). Other variables investigated were not found to be significant in this study.