Multistage Preclinical Evaluation of MRI-Guided Stenting for Coarctation of the Aorta using in vitro and Porcine Models

PURPOSE: This study evaluated the technical and procedural feasibility of MRI-guided stent implantation for CoA using a structured multistage preclinical evaluation protocol. MATERIALS AND METHODS: A commercially available MR Conditional guidewire and dedicated research prototypes comprising nitinol stents, delivery systems, and balloon catheters were assessed in a three-stage protocol. Device visibility was evaluated in a standardized water phantom at 1.5 T and 3.0 T. In a polymer-based CoA vessel phantom, 10 stent implantations were performed by novices (n = 6) and experts (n = 4), with four separate expert-led balloon dilatations. MRI-guided stent implantation was subsequently performed in five porcine models. RESULTS: All devices were visible at both field strengths, with lateral artifact widths of 5.3-7.8 mm for the guidewire, 20.9-38.5 mm for the stent delivery system, 13.1-19.9 mm for the expanded stents, and 17.4-30.5 mm for the balloon catheter. Phantom stenting duration was 10.2 ± 7.2 mins for novices and 6.2 ± 2.7 mins for experts. MRI-guided stent implantation was successfully performed in all five animals, with a mean duration of 13.6 ± 7.5 mins. In one animal, balloon post-dilatation was additionally performed as a procedural proof of concept. CONCLUSION: MRI-guided stent implantation for CoA is feasible within a structured multistage preclinical evaluation protocol and supports further clinical translation of radiation-free endovascular treatment.