Benefits and Role of Carbon Dioxide Angiography in Case of Misalignment Between Fenestration and Target Vessel During Fenestrated Endovascular Aneurysm Repair

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 ImpactCO2 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.

Renal Benefits of CO2 as a Contrast Media for EVAR Procedures: New Perspectives on 1 Year Outcomes

BACKGROUND AND OBJECTIVES

Endovascular aneurism repair (EVAR) is a minimally invasive alternative to open surgery for the treatment of abdominal aortic aneurysm. Iodine contrast medium (ICM) is considered the gold standard, at the high price of related nephrotoxicity and allergic reactions. Carbon dioxide (CO2) has been suggested as an alternative non-nephrotoxic contrast media agent. We aimed to evaluate the safety and the renal impact of the administration of CO2, compared with ICM in EVAR procedures.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

We retrospectively reviewed data of patients who underwent EVAR at the Vascular Surgery Department of the Sant'Orsola Hospital in Bologna. Estimated glomerular filtration rate (eGFR) was evaluated before intervention, immediately after and at 12 months.

RESULTS

In total, 22 patients received CO2 and low-dose ICM (CO2 Group) and 22 received standard ICM (Control Group), matched for clinical characteristics and renal function at the time of procedure. Pre and post-operative renal function values (eGFR) were compared between the two groups: in the immediate post-operative the group treated with CO2 and low-dose ICM globally showed a slight improvement in renal function (mean eGFR +5.10%±3.2), meanwhile the group treated with standard dose of ICM presented a significant worsening of renal function compared with pre-procedure values (mean eGFR -9.65%±4). Incidence of post-contrast acute kidney injury (PC-AKI) was 9% in the CO2 group vs 27% in the Control group. At 12 months, the renal impairment was significantly greater in the ICM group than in the CO2 group (mean eGFR decrease -19.2%±11.1 and -7.40%±3.5, respectively).

CONCLUSIONS

Administration of either CO2 alone or along with low-dose ICM showed to be safer than full-dose ICM alone, lowering the incidence of PC-AKI in patients undergoing EVAR. Unexpectedly, our study revealed also a significant worsening of renal function in patients treated with standard dose of ICM in 1-year follow-up, introducing the concept that acute renal damage caused by ICM could elicit a chronic injury process that affect long-term renal outcomes.

CLINICAL IMPACT

Evaluating the safety and the renal impact of the administration of CO2, compared to Iodinate Contrast Medium, in EVAR procedures represents a first step in order to further tayloring medical procedures on patients characteristics. Our findings can guide the clinicians and surgeons in the procedures choice, not considering only the immediate effect of ICM on renal function but also the potential long-term effects.

Fenestrated endovascular aortic repair of a superior mesenteric artery aneurysm using carbon dioxide angiography and intravascular ultrasound

Superior mesenteric artery aneurysms are rare; however, current guidelines suggest they all require repair due to the high rupture and mortality rates, and endovascular repair is an effective management strategy. Iodinated contrast traditionally used in endovascular repair can cause significant complications, including severe allergic reactions and contrast-induced nephropathy in patients with chronic renal disease. Therefore, other imaging methods should be used during endovascular procedures to reduce these risks. We describe a unique and innovative approach using carbon dioxide angiography and intravascular ultrasound during fenestrated endovascular repair of an uncommon superior mesenteric artery aneurysm in a patient with severe contrast allergies.