Multiple stent delivery system Multi-LOC, a new technology for spot-stenting of the femoropopliteal artery – proof of concept study in a preclinical large animal model

Abstract.Background: A new stent system was studied in a porcine model to evaluate its feasibility for spot-stenting of the femoropopliteal artery. Materials and methods: In a preliminary study in a single pig, handling and mechanical features of the novel multiple stent delivery system were tested. The Multi-LOC system demonstrated great feasibility regarding its pushability, trackability, and crossability. Excellent visibility of the individual stents allowed exact anatomically controlled implantation. In our main study, four to five short Multi-LOC stents (13 mm long) were implanted into the femoropopliteal arteries of six domestic pigs and long (60 to 100 mm) self-expandable nitinol stents were implanted into the same target vessel contralaterally to allow for intraindividual comparison. After four weeks survival under dual antiplatelet treatment, control angiography was performed. The animals were euthanized, stented vessels were explanted, and histologic sections were examined for the presence of neointimal formation. Results: Multi-LOC stents demonstrated no occlusion of the femoropopliteal axis (0 vs. 1 occlusion distal to a control stent), no stent fractures (0 out of 26 vs. 2 out of 6 control stents), and lower percentage diameter stenosis (0.564 ± 0.056 vs. 0.712 ± 0.089; p = 0.008) and length of stenosis (19.715 ± 5.225 vs. 39.397 ± 11.182; p = 0.007) compared to a standard control stent, which was similar in total length to the multiple stented artery segment. Histological examination confirmed myointimal hyperplasia underlying in-stent stenosis. Conclusions: The multiple stent delivery system was studied in a porcine model, which demonstrated its feasibility. Preclinical experience revealed favourable results concerning stent fracture, restenosis, and patency of spot-stented femoropopliteal arteries.