Biofabrication of small-diameter vascular graft with acellular human amniotic membrane: a proof-of-concept study in pig.

Expanded polytetrafluoroethylene (ePTFE) grafts are Food and Drug Administration approved and effective for large vessel surgeries but face challenges in smaller vessels (Inner Diameter, ID ⩽ 6 mm) due to reduced blood flow and higher risks of thrombosis, stenosis, and infection. This study developed a vascular graft with an ID of 6 mm from decellularized human amniotic membrane (DAM graft) and compared its performance to ePTFE grafts in a porcine carotid artery model for one month. DAM grafts retained key extracellular matrix structures and mechanical properties post-decellularization, with customizable layers and stiffness to meet specific clinical needs. DAM grafts demonstrated successful carotid artery replacement, showing good surgical feasibility, patency, and post-operative recovery in all animals. In contrast to ePTFE grafts, which exhibited significant neointimal hyperplasia (NIH), poor endothelialization, and inflammation, DAM grafts displayed organized endothelial coverage, smooth muscle alignment, and reduced inflammation, minimizing NIH, thrombosis, and graft failure. These findings position DAM grafts as a promising alternative to synthetic grafts, especially for small-diameter applications. Future research should focus on improving endothelialization, exploring molecular mechanisms, and assessing long-term outcomes to further optimize DAM grafts for clinical use.