PC228. A Magnetic Cannulation Approach Reduces Time and Radiation Exposure During Simulated Fenestrated Endograft Repair

The evolution of fenestrated endografts continues to expand endovascular options into challenging pelvic, visceral, and arch regions of the aorta. Enthusiasm of these new endografts is tempered, however, by increased procedural time, and more importantly, significantly increased radiation exposure to operators, staff, and patients. In particular, efficient cannulation of fenestrated endografts with customized branches in a three-dimensional space is limited by two-dimensional fluoroscopic imaging. The E-mag system was designed to expedite cannulation of endograft branches. Each fenestration is encircled by a copper coil that when energized attracts a magnetically tipped wire (Mag-wire; fluoroscopic image of Mag-wire cannulating an E-mag fenestration is shown in Figs 1 and 2). A custom stent was fabricated with laser welded 0.155 nitinol wire and polytetrafluroethilene with two renal artery fenestrations to mimic commercially available fenestrated endografts. The fenestrations of the stent graft were encircled with coils of copper wire, which were energized using a DC power supply to create a local electromagnetic field. Current was delivered at 4 amps to one fenestration at a time to magnetize each of the fenestrations. A Mag-wire was constructed from a neodymium magnet affixed to a standard 0.035 Glidewire. A mock aortoiliac system was created with the custom stent and bifurcated 3/8-inch tubing to represent tortuous iliac arteries. Imaging was completed on a GE Discovery fixed fluoroscopic unit. The magnetic field created at each fenestration averaged 1.5 Gauss. Within the aortic model, the Mag-wire was attracted only to the fenestration being energized. Five surgical clinicians of varying experience were each given 4 attempts with both a standard Glidewire and the E-mag system, with their time to completion recorded in seconds. The average time to cannulation with the Glidewire was 34.37 ± 39.91 seconds while the average time using the E-mag system was 5.73 ± 2.67 seconds (P < .01). There were no significant differences between vascular training levels using the E-mag system. This feasibility study suggests that an E-mag system significantly enhances cannulation of fenestrations in a model of complex endovascular aneurysm repair. This, in turn, reduced radiation time for these key steps. Further development of this approach may allow reduction of radiation exposure during complex branched endovascular procedures.Fig 2E-mag coils.View Large Image Figure ViewerDownload Hi-res image Download (PPT)