Utilizing CO2 Cone Beam Computed Tomography for Post-Procedure Completion Control Following Fenestrated Endovascular Repair of Complex Aortic Aneurysm With a Standardized CO2 Protocol

Purpose: To assess the feasibility and efficacy of a standardized CO2 protocol and CO2 cone beam computed tomography (CBCT) for procedural completion in fenestrated endovascular aneurysm repair (FEVAR) of complex aortic aneurysms in patients with chronic kidney disease (CKD). Materials and Methods: Ten patients with complex aortic aneurysms and CKD (estimated glomerular filtration rate <90 ml/min) underwent FEVAR with custom-made fenestrated devices, using CO2 as the primary contrast agent. Procedures were conducted in a hybrid operating room following a standardized CO2 protocol with optimized injection parameters and visualization techniques to maximize CO2 imaging efficacy. CO2 CBCT was performed intraoperatively to verify stent graft deployment, bridging stent positioning, target vessel patency, and the presence of potential endoleaks. Results: All 10 procedures were completed successfully without intraoperative complications or CO2-related adverse effects. Completion CO2 CBCT provided clear visualization of visceral and renal vessels, and no significant endoleaks were detected. One procedure was entirely iodine contrast-free, while minimal iodine contrast was used in others to address diagnostic uncertainties. Postoperative renal function remained stable across all patients. Conclusion: CO2 CBCT is a feasible and effective alternative for completion imaging in complex FEVAR procedures for patients with CKD, potentially reducing the need for iodine contrast and the associated risk of nephropathy. A standardized CO2 protocol can enhance procedural safety. Further research with larger cohorts is needed to confirm these findings. Clinical Impact: CO2 serves as the preferred contrast medium for the endovascular treatment of patients with iodine contrast allergies or those afflicted with chronic kidney disease (CKD) to preserve further renal deterioration. Ensuring protection from potentially harmful substances is paramount during endovascular repair in such patients. Equally crucial is performing the procedure safely through a standardized protocol and confirming its accuracy upon completion. Nevertheless, the possibility of employing CO2 for cone beam computed tomography provides invaluable insights into procedural efficacy, thereby enhancing outcomes for CKD patients undergoing complex endovascular repair.