Introduction: The creation of a microvascular anastomosis is a complex procedure. A reduction of the operation time by a faster, safer, yet qualitative equal microvascular procedure would be advantageous. N-fibroin, one of the silk proteins, is biocompatible, proteolytically degradable and causes no foreign body reactions. Stents, made of n-fibroin are flexible, dimensionally stable and provide at the same time a high primary stability and surface quality. The aim of this study was to evaluate a new microvascular anastomosis technique, which is easy to handle and reduces the ischemic time of the transplant.
Material and methods: N-fibroin stents (diameter 0.9–1.15 mm) were implanted into the infrarenal aorta of Sprague–Dawley rats ( n = 30). After clamping and cutting the infrarenal aorta, the stents were inserted in both vessel ends, which were afterwards readapted again and fixed with a commercially available tissue adhesive. The animals were euthanized 16 weeks after implantation and the aortic anastomosis site was histologically (HE, EVG, van Kossa staining) examined.
Results: The n-fibroin stents showed high tissue compatibility. No foreign body reactions, rejection reactions or inflammatory reactions were seen. The vessel walls showed no pathologic reactions like aneurysm or stenosis. An inert degradation of the stents was observed.
Summary: In contrast to the established collagen scaffolds made of animal tissue, n-fibroin offers several advantages: individual adaptations in the production are possible, the risk of infection at the implantation site is low and the mechanical properties are excellent. The microvascular anastomosis technique using n-fibroin stents is a promising method, which could reduce operation time significantly and the rate of anastomosis closures. The biological as well as the mechanical properties of n-fibrion stents seem to be of great advantage for the presented indication.