CT of the ilio-femoral arteries using direct aortic contrast injection: proof of feasibility in patients screened towards percutaneous aortic valve replacement

PRINCIPLES: Transfemoral aortic valve implantation (TAVI) is a promising treatment modality for selected patients with severe symptomatic aortic stenosis. Peripheral access via the femoral and iliac artery is an important issue, limiting this technique's applicability in patients suffering from peripheral arterial disease. Multislice computed tomography (MSCT) reliably identifies patients with suitable peripheral access. However, MSCT involves an additional contrast dye burden in patients often suffering from renal failure. In this study, the feasibility of direct-aortic-contrast-injection for MSCT was investigated, aiming to reduce total contrast load. METHODS: Patients undergoing evaluation for TAVI underwent an aortogram including iliac and femoral arteries. In 7 selected patients with questionable peripheral access, MSCT was performed by advancing a pigtail catheter to the level of L2, followed by direct injection of 15-20 ml of contrast mixed with an equal volume of saline. This injection was followed by an injection of 40 ml of saline. Scanning was initiated 4 seconds after starting the contrast injection. All MSCT scans were obtained using a 64 slice scanner. RESULTS: In all 7 patients, except one, the distal aorta, iliac and femoral arteries where adequately imaged to allow reliable assessment of peripheral access for TAVI. Of the 7 patients evaluated, 2 were rejected for TAVI based on the information of the MSCT using direct-aortic-contrast-injection. Limitations of the technique may be an underestimation of the arterial diameter due to spasms at the puncture site. CONCLUSION: MSCT using direct-aortic-contrast-injection for assessment of peripheral access for TAVI is feasible and may provide good diagnostic images with a reduced volume of contrast.