Contrast Strategy In Fenestrated EndoVascular Aneurysm Repair Randomized Control Trial

The primary objective of this study is to evaluate whether a contrast reduction strategy, utilizing carbon dioxide (CO2) as the preferred arterial visualization agent during fenestrated endovascular aneurysm repair (FEVAR) when feasible, decreases the postoperative incidence of acute kidney injury (AKI) compared to standard iodine contrast medium administration in patients undergoing FEVAR for abdominal aortic aneurysms. This objective addresses the clinically significant problem of contrast-induced nephrotoxicity, a common complication following endovascular procedures that can lead to increased morbidity and prolonged hospitalization.

The secondary objectives include:

• Percentage of patients developing AKI stage 1 and above according to KDIGO criteria
• Technical success rate of the repair procedure
• Image quality assessment during the intervention
• Radiation exposure quantification
• Detection rate of endoleaks
• Incidence of adverse events
• Quality of life assessment before and after the procedure up to 3 years
• Recovery status at day 2 and cognitive function at 1 month
• Clinical success of the repair during follow-up period
• Incidence of chronic kidney disease up to 3 years
• Need for reinterventions to maintain clinical success
• Survival up to 3 years

The sponsor did not provide information regarding the total number of participants enrolled in this clinical trial. The study population includes both **male** and **female** subjects aged 18 years and older, comprising adults and elderly individuals. Participants are patients scheduled for elective **fenestrated endovascular aortic repair (FEVAR)** of **juxtarenal** or **pararenal abdominal aortic aneurysms** within six months, utilizing a customized fenestrated endograft based on stainless steel stents and polyester graft. Female participants of childbearing potential are required to have a negative pregnancy test at enrollment and must use highly effective contraceptive methods throughout the trial duration. All participants must provide written informed consent prior to enrollment. The trial does not include vulnerable populations.

This clinical trial investigates a contrast reduction strategy during fenestrated endovascular aneurysm repair (FEVAR) for patients with abdominal aortic aneurysm. The study is designed as a randomized controlled trial to compare a strategy aimed at reducing exposure to iodine contrast media by preferentially using carbon dioxide to visualize arteries during the procedure when possible, versus the standard care approach. The trial is classified as a Phase IV clinical trial. The primary objective is to determine whether the contrast reduction strategy decreases the postoperative incidence of acute kidney injury following FEVAR of abdominal aortic aneurysms compared to standard practice.

The trial will utilize three iodine contrast media products administered as solution for injection: iohexol, iomeprol, and iodixanol. The maximum daily dose and maximum total dose for each contrast agent is 300 ml millilitres, with a maximum treatment period of 1 day. All active substances are of chemical origin.

Eligible participants must be at least 18 years old and scheduled for elective FEVAR of juxtarenal or pararenal aortic aneurysm within six months using a customized fenestrated endograft based on stainless steel stents and polyester graft. Written informed consent is required prior to enrollment. Female participants of childbearing potential must provide a negative pregnancy test and use highly effective birth control methods throughout the trial duration.

The primary endpoint is the incidence of patients developing acute kidney injury, defined as RIFLE stage R (Risk) and above during the early postoperative period according to the RIFLE classification. Secondary endpoints include multiple assessments of kidney function, success of surgery, intraoperative imaging quality, adverse events, quality of life, survival, chronic kidney disease progression, and reintervention rates. Kidney function will be evaluated using both RIFLE and KDIGO classifications based on serum creatinine assessment and urinary output. Quality of life will be measured using the EQ-5D-5L instrument at multiple timepoints, and the Swedish Quality of Recovery Scale will be administered at day 2 postoperatively. Cognitive function will be assessed using the Montreal Cognitive Assessment before the procedure and at 1 month.

The estimated recruitment start date is January 1, 2026, with an estimated trial completion date of December 31, 2031. Participants will undergo baseline assessments preoperatively, followed by the FEVAR procedure. Postoperative evaluations will occur at discharge, day 2, 1 month, and annually up to 3 years. Follow-up visits will include clinical assessments, imaging studies (computed tomography), laboratory evaluations of renal function, quality of life questionnaires, and monitoring for adverse events. The expected length of participant involvement is up to 3 years following the surgical intervention. Early termination from the study may occur based on specific clinical conditions, though detailed criteria for early withdrawal are not specified in the available data.

The clinical trial utilizes three different iodine contrast media as experimental medications, all administered as part of the test treatment strategy during fenestrated endovascular aneurysm repair (FEVAR) procedures. These contrast agents are used to visualize arteries during the surgical intervention, with the study exploring a strategy aimed at reducing overall iodine contrast exposure by preferentially using carbon dioxide (CO2) when possible, compared to standard of care approaches.

Omnipaque contains iohexol as the active substance at a concentration of 180 mg iodine per milliliter. The medication is supplied as a solution for injection. The maximum daily dose is 300 milliliters, with a maximum total dose of 300 milliliters administered over a treatment period of 1 day. The product is manufactured by GE Healthcare BV and is authorized in Luxembourg.

Iomeron contains iomeprol as the active substance at a concentration of 150 mg iodine per milliliter. This medication is also formulated as a solution for injection. The dosing parameters match those of the other contrast agents, with a maximum daily dose of 300 milliliters and a maximum total dose of 300 milliliters administered during a single-day treatment period. The product is manufactured by Bracco Imaging S.p.A. and is authorized in Sweden.

Visipaque contains iodixanol as the active substance at a concentration of 270 mg iodine per milliliter. The pharmaceutical form is a solution for injection. The maximum daily dose is 300 milliliters, with a maximum total dose of 300 milliliters over a 1-day treatment period. This product is manufactured by GE Healthcare BV and is authorized in Luxembourg.

All three contrast media are administered via injection route during the FEVAR procedure. The active substances in all products are of chemical origin. The selection among these three iodine-based contrast agents may be determined by institutional preferences and availability, as all serve the same functional role within the trial's treatment strategy.

Efficacy will be assessed through multiple parameters evaluating kidney function, surgical outcomes, imaging quality, safety, patient-reported outcomes, and long-term clinical endpoints. The primary endpoint is the incidence of patients with acute kidney injury (AKI), defined as RIFLE stage R (Risk) and above during the early postoperative period according to the RIFLE classification (Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease) suggested in the reporting standards for complex aortic repair.

Secondary endpoints include kidney function assessed by the incidence of patients developing AKI stage 1 and above according to KDIGO classification, based on serum creatinine assessment and urinary output. Surgical success will be evaluated by the number and percentage of patients fulfilling the definitions of immediate technical and primary and secondary clinical successes calculated with life-tables, based on clinical and imaging endpoints at the fenestrated endovascular aneurysm repair (FEVAR) and computed tomography during follow-up at 1 month and yearly up to 3 years. Intraoperative imaging assessment will include image quality assessed by a 5-point Likert scale, incidence of detected endoleaks and their type, radiation exposure, and absorbed dose. The percentage of patients experiencing adverse events until discharge and adverse events of special interest up to 3 years after FEVAR will be documented by number, type, and severity.

Quality of life will be measured using the EQ-5D-5L instrument preoperatively, at discharge, at 1 month, and at 1, 2, and 3 years. The Swedish Quality of Recovery Scale (SwQoR) will be administered at day 2 postoperatively, and the Montreal Cognitive Assessment (MoCA) will be performed before the procedure and at 1 month. Survival up to 3 years will be calculated as the percentage of surviving patients. The percentage of patients whose cause of death is related to aortic repair and renal insufficiency up to 3 years after FEVAR will be determined. The percentage of patients with chronic kidney disease (CKD) stage 2 and above within 3 years, according to the National Kidney Foundation Kidney Disease Outcomes Quality Initiative classification, will be assessed based on estimated glomerular filtration rate (eGFR). The percentage of patients with worsening of CKD stage within 3 years according to the same classification will also be evaluated based on eGFR assessment. Reintervention rates will be monitored throughout the study period.