Results of long-term patency of small-diameter biodegradable vascular prostheses with atrombogenic drug coating of sheep model

Background. Preclinical tests of biodegradable small diameter vascular prostheses on a sheep model have been carried out. Aim. To assess the results of long-term patency and remodeling of biodegradable vascular prostheses based on polyhydroxybutyrate / valerate and polycaprolactone with an atrombogenic drug coating in a large laboratory animal model. Methods. We researched vascular prostheses made of polyhydroxybutyrate / valerate and polycaprolactone (PHBV/PCL) 4 mm in diameter with layer-by-layer vascular endothelial growth factor incorporated into the polymer framework, the main fibroblast growth factor, chemoattractant molecule containing SDF-1a (GFmix) surface, and additional modifying drug surface heparin and iloprost (PHBV/PCL/ GFmix/Heparin/Iloprost). Animals with implanted synthetic Gore-Tex vascular grafts with a diameter of 4 mm were included into a comparison group. Results. After one day of implantation it was revealed that the patency of biodegradable PHBV/PCL/GFmix/Heparin/Iloprost prostheses was 62.5%, while synthetic Gore-Tex prostheses were thrombosed in 100% of cases. At the same time, after 18 months of implantation, the patency of biodegradable vascular PHBV/PCL/ GFmix/Heparin/Iloprost prostheses decreased to 50%. Passable drug-eluting polymer grafts were completely resorbed after 18 months of implantation, and aneurysmically expanded newly formed vascular tissue was formed in their place. Conclusion. Vascular prostheses made of polyhydroxybutyrate/valerate and polycaprolactone showed better long-term patency results than synthetic prostheses used in the clinical practice. However, the strengthening of the external framework of the prostheses is required in order to prevent the formation of aneurysms.