The benefit of combined carbon dioxide automated angiography and fusion imaging in preserving perioperative renal function in fenestrated endografting

Background: Contrast-induced nephropathy is a possible adverse event in fenestrated endovascular aneurysm repair (FEVAR). Automated carbon dioxide (CO2) angiography has been proposed as an alternative to iodinated contrast medium (ICM) for standard endovascular aneurysm repair; however, its use in FEVAR has not yet been investigated. The aim of this study was to analyze the possibility of reducing the amount of procedural ICM during FEVAR by combining CO2 with intraprocedural three-dimensional preoperative computed tomography angiography images overlaid on two-dimensional live fluoroscopy images (fusion imaging [FI]). Methods: Between January and April 2018, juxtarenal and pararenal abdominal aortic aneurysms and type IV thoracoabdominal aortic aneurysms undergoing FEVAR with a CO2 + FI protocol were prospectively collected and compared with FEVAR cases treated with standard procedural imaging (ICM + FI) between June and December 2017. Preoperative, intraoperative, and postoperative data were analyzed. Amount of ICM, procedure and fluoroscopy time, total radiation dose (dose-area product), endoleaks, and technical success (defined as absence of type I or type III endoleak and target visceral vessel patency at completion angiography) were assessed. The 30-day renal function worsening (estimated glomerular filtration rate reduction >25% of the preoperative value) and 6-month reinterventions were also considered. Analysis was done by Fisher exact and Mann-Whitney tests. Results: Forty-five patients were enrolled, 15 (33%) managed by CO2 + FI and 30 (67%) by ICM + FI. The two groups were homogeneous in their clinical, anatomic, and endograft features. Median ICM administration was significantly lower in CO2 + FI compared with ICM + FI (41 mL [interquartile range (IQR), 26 mL] vs 138.5 mL [IQR, 88 mL]; P = .001). There was no difference in median procedure time, fluoroscopy time, and dose-area product between CO2 + FI and ICM + FI. Intraoperative type I or type III endoleak detection was similar (P = 1) in CO2 + FI (7%) and ICM + FI (7%), with immediate repair and technical success achieved in all cases. Early type II endoleak did not differ in the two groups (CO2 + FI, 27%; ICM + FI, 20%; P = .7). Postoperative renal function deteriorated in two patients (13%) in the CO2 + FI group vs eight patients (27%) in the ICM + FI group (P = .04). The median increase of postoperative creatinine concentration was smaller in the CO2 + FI group than in the ICM + FI group (0.09 mg/dL [IQR, 0.03 mg/dL] vs 0.3 mg/dL [IQR, 0.4 mg/dL]; P = .04). The median hospitalization time was shorter in the CO2 + FI group (5 days [IQR, 1 day] vs 8 days [IQR, 4 days]; P = .002). No reintervention was necessary at 30-day and 6-month follow-up in either group. Conclusions: CO2 + FI is safe and effective in FEVAR and allows the amount of ICM to be significantly reduced, leading to shorter hospitalization time and better renal function preservation at 30 days. Technical success, procedure and fluoroscopy time, radiation dose, and 6-month reinterventions are comparable with those of the standard ICM imaging protocol for FEVAR. Based on this preliminary experience, CO2 + FI may be proposed as an effective tool to reduce the overall amount of procedural ICM, with consequent benefits on perioperative renal function.