Computerized tomography angiography by direct intra-aortic low volume contrast injection in patients being evaluated for EVAR.

Background Computerized tomography angiography is an important tool for endovascular repair of abdominal aortic aneurysm planning. This study aimed to evaluate the utility of computerized tomography angiography using direct intra-aortic injection of low volume of iodinated contrast in patients being considered for endovascular repair of abdominal aortic aneurysm. Design A 5F high-flow angiographic catheter was positioned in the mid-thoracic aorta through femoral percutaneous access. Computerized tomography angiography was performed with image acquisition starting simultaneously with power injection of 10 mL of iopamidol 76% diluted with normal saline to 50 mL, at 6 mL/s through the angiographic catheter. Aortic enhancement was assessed with a circular region-of-interest within the aorta. Values ≥150 HU were considered adequate. Results Nine patients with abdominal aortic aneurysm and chronic renal dysfunction underwent computerized tomography angiography with intra-arterial contrast injection for endovascular repair of abdominal aortic aneurysm planning. Mean age 78.8 ± 5.0 years, mean baseline creatinine 1.8 ± 0.4 mg/dL and mean glomerular filtration rate 36.8 ± 4.2 mL/min. Adequate computerized tomography angiography aortic enhancement was obtained in all cases (mean intra-aortic density: 300.4 ± 72.8 HU). The total contrast volume used for the computerized tomography angiography and the endovascular repair of abdominal aortic aneurysm combined was 30.0 ± 21.4 mL. Seventy-five percent of the patients received ≤30 mL of contrast. No significant renal function deterioration occurred (creatinine clearance pre- and post-procedure 36.8 ± 4.2 mL/min versus 38.6 ± 6.1 mL/min, p = 0.32). Successful endovascular repair of abdominal aortic aneurysm was achieved in eight patients. One patient underwent open treatment based on computerized tomography angiography information. No endoleak or aneurysm growth occurred (median follow-up: 121 days (range 36-1242)). Conclusion Direct intra-aortic injection of low volume of iodinated contrast provides adequate and reproducible pattern of aortic enhancement on computerized tomography angiography. The computerized tomography angiography so acquired can be used for endovascular repair of abdominal aortic aneurysm limiting the total volume of iodinated contrast required.