Ferumoxytol-enhanced magnetic resonance angiography for endovascular aortic repair surveillance in a patient after renal transplant

Abstract

Endovascular aneurysm repair requires lifelong imaging surveillance, typically with contrast-enhanced computed tomography imaging. This poses risks to patients with end-stage renal disease. Ferumoxytol, a superparamagnetic iron-based nanoparticle with minimal nephrotoxicity, has emerged as an alternative contrast agent for magnetic resonance angiography in patients with renal impairment. We present a case of a patient with a failing renal transplant who underwent ferumoxytol-enhanced magnetic resonance angiography to further characterize an indeterminant etiology of continued aneurysm sac expansion to 10 cm, avoiding iodinated and gadolinium-based contrast while achieving high-quality imaging for endoleak detection.

Keywords: EVAR; Ferumoxytol; MRI.

Fig 1

Computed tomography angiography (CTA) with noncontrast (A), arterial (B), and venous (C) phases demonstrating a large abdominal aortic aneurysm (AAA) measuring approximately 7.5 × 9 cm (white arrow) with a bifurcated endovascular graft in place (red arrow). There was no clear evidence of endoleak.

Fig 2

Noncontrast surveillance computed tomography (CT) scan demonstrating sac expansion to 8.7 × 10.2 cm with a sac volume of 516 mL. In this study, there was increased focal outpouching of the right aspect of the aneurysm sac (red arrow) compared with the prior study, concerning for instability.

Fig 3

Magnetic resonance angiography (MRA) characterization of bilateral L2 lumbar endoleaks. (A) A maximum-intensity projection coronal time-resolved angiography with interleaved stochastic trajectories (TWIST) subtraction image demonstrating a patent bifurcated endograft with endoleaks just lateral to the flow divider; (B) A TWIST subtraction image reformatted in the axial plane; and (C) An axial postcontrast fast low angle shot (FLASH) three-dimensional (3D) image. White arrows indicate patent L2 lumbar arteries, whereas red arrows highlight evidence of perfusion to the aneurysm sac consistent with a type II endoleak.