Adaptation process of decellularized vascular grafts as hemodialysis access in vivo

Arteriovenous grafts (AVGs) have emerged as the preferred option for constructing hemodialysis access in numerous patients. Clinical trials have demonstrated that decellularized vascular graft exhibits superior patency and excellent biocompatibility compared to polymer materials; however, it still faces challenges such as intimal hyperplasia and luminal dilation. The absence of suitable animal models hinders our ability to describe and explain the pathological phenomena above and in vivo adaptation process of decellularized vascular graft at the molecular level. In this study, we first collected clinical samples from patients who underwent the construction of dialysis access using allogeneic decellularized vascular graft, and evaluated their histological features and immune cell infiltration status 5 years post-transplantation. Prior to the surgery, we assessed the patency and intimal hyperplasia of the decellularized vascular graft using non-invasive ultrasound. Subsequently, in order to investigate the in vivo adaptation of decellularized vascular grafts in an animal model, we attempted to construct an AVG model using decellularized vascular grafts in a small animal model. We employed a physical-chemical-biological approach to decellularize the rat carotid artery, and histological evaluation demonstrated the successful removal of cellular and antigenic components while preserving extracellular matrix constituents such as elastic fibers and collagen fibers. Based on these results, we designed and constructed the first allogeneic decellularized rat carotid artery AVG model, which exhibited excellent patency and closely resembled clinical characteristics. Using this animal model, we provided a preliminary description of the histological features and partial immune cell infiltration in decellularized vascular grafts at various time points, including Day 7, Day 21, Day 42, and up to one-year post-implantation. These findings establish a foundation for further investigation into the in vivo adaptation process of decellularized vascular grafts in small animal model.