Evaluation of in situ tissue-engineered arteriovenous grafts suitable for cannulation in a large animal model

Abstract

The sustainability of vascular access for hemodialysis is limited by frequent interventions and the inability of synthetic grafts to self-heal. Tissue engineering offers a solution through biodegradable grafts that remodel into autologous tissue. Here we assess electrospun polycarbonate-bis urea (PC-BU) vascular scaffolds (6mm-inner-Ø), reinforced with 3D-printed polycaprolactone coils, in a goat model, and compared them to expanded polytetrafluoroethylene (ePTFE) controls. The tissue-engineered grafts were repeatedly cannulated starting two weeks after implantation and were evaluated using computed tomography and histological analyses. By 12 weeks, the PC-BU grafts remodel into autologous tissue while maintaining structural integrity, maintaining integrity without dilations, ruptures, or aneurysms. Cannulation does not interfere with scaffold degradation or neo-tissue formation. Although the patency rate is lower for the PC-BU grafts (50%) compared to ePTFE (100%), the engineered grafts exhibit a self-healing response not seen in ePTFE. These findings demonstrate the potential of PC-BU tissue-engineered grafts as healing, functional vascular access solutions for hemodialysis, supporting cannulation during tissue transformation.