Abstract
Juxtarenal aortic aneurysms present significant endovascular repair challenges due to short or absent infrarenal aortic necks, requiring precise alignment of fenestrations to maintain visceral organ perfusion. Conventional fenestrated endovascular aneurysm repair relies heavily on complex rotational catheter maneuvers, increasing procedural times and risks of branch vessel occlusion. This study introduces a novel, patient-specific Nitinol stent-graft equipped with embedded NdFeB micro-actuators that enable external magnetic positioning and post-deployment micro-alignment. Using patient-derived computed tomography angiography data, anatomical models and custom-shaped Nitinol frameworks were fabricated. The device was evaluated in a high-fidelity, pulsatile in vitro flow loop simulating physiological hemodynamic conditions. External electromagnetic actuation demonstrated sub-millimeter positional control, reducing mean fenestration rotational alignment error from 2.85 mm to 0.38 mm within 45 seconds of actuation. Target renal artery cannulation times were reduced by 68% compared to standard passive fenestrated grafts. Hydrodynamic assessment confirmed structural integrity under peak systolic pressures of 160 mmHg without evidence of Type I or Type III endoleaks. These results highlight the potential of magnetically actuated, patient-specific stent-grafts to streamline complex endovascular repair, minimize intraoperative fluoroscopy exposure, and improve technical success rates in patients with challenging aortic anatomies.
