Imaging of Totally Blocked Arteries

Repairing totally occluded peripheral arteries remains challenging because they are not visualized using available imaging technologies. Contrast-enhanced magnetic resonance angiography (CE-MRA), X-ray computed tomography angiography (CTA), and invasive radiocontrast digital subtraction angiography (DSA) all rely on blood flow within arteries that are not totally occluded. Where the arterial lumen is totally occluded, contrast does not enter and the artery remains invisible. As a result, physicians have difficulty identifying a pathway or trajectory for catheter devices in order to improve blood flow using angioplasty.

Gadofosveset, an albumin-binding MRI contrast agent that is commercially available outside the United States, may accumulate in the walls of occluded arteries through a mechanism that is not known.

The goal of this protocol is to determine whether gadofosveset has value in planning catheter trajectories in totally occluded peripheral arteries. We propose to study the gadofosveset contrast enhancement patterns in occluded peripheral artery segments in up to 20 patients with known occluded iliac, femoral, and shoulder arteries being considered for catheter-based treatment.

This research may have value in planning and conducting minimally invasive treatments using conventional X-ray guidance and possibly in the future using investigational real-time MRI guidance.

• INCLUSION CRITERIA:

Subjects with known cardiovascular disease will be eligible for participation in this protocol. The subject is eligible under the following conditions:

• Subject's age is greater than 18 years of age.
• Known occlusion of iliac, femoral, or brachiocephalic arteries.

Exclusion criteria

Subjects with absolute contraindications to MRI scanning will be excluded. These contraindications include subjects with the following devices:

• Implanted cardiac pacemaker or defibrillator.
• Central nervous system aneurysm clips.
• Implanted neural stimulator.
• Cochlear implant.
• Ocular foreign body (e.g. metal shavings).
• Insulin pump.
• Metal shrapnel or bullet.

When subjects can provide evidence that their implanted device is labeled compatible with MRI, exceptions to the above exclusions can be made and recorded in the note.

Furthermore, certain subject groups will be excluded because of the administration of MRI contrast agents. The weight limit is related to availability of investigational contrast agents. Because of recent concerns about Nephrogenic Systemic Fibrosis/Nephrogenic Fibrosing Dermopathy after gadobenate exposure in patients with end-stage renal disease, renal excretory function will be determined and patients with severe renal excretory dysfunction are excluded from this research protocol.

• Pregnant women (subjects who are uncertain as to whether they are pregnant will be required to have a quantitative serum pregnancy test within 72 hours) or lactating women.
• Subjects who have experienced an allergic reaction to gadolinium-based contrast agents.
• Subjects with hemoglobinopathies.
• Weight greater than 120 kg.
• Subjects with renal disease (eGFR less than 30 ml/min/1.73m(2), or receiving renal replacement therapy).

The creatinine clearance will be estimated in all subjects as an estimated glomerular filtration rate (eGFR) using the abbreviated MDRD Formula.