BACKGROUND:The small-diameter blood vessel prosthesis faces the problem of lumen stenosis or even occlusion due to thrombogenesis and intimal hyperplasia after transplantation.The application of stem cells as seed cells to achieve endothelialization of blood vessel prosthesis helps to improve the long-term patency rate after vascular graft transplantation. OBJECTIVE:To summarize the research progress of the application of stem cells in the endothelialization of small-diameter blood vessel prosthesis. METHODS:The relevant articles published on PubMed and WanFang databases from 2013 to 2023 were retrieved by the first author.Chinese and English search terms included"vascular graft,tissue-engineered blood vessel/vascular tissue engineering,endothelialization,stem cells,endothelial progenitor cells,mesenchymal stem cells,induced pluripotent stem cells,embryonic stem cells."The relative articles in the domestic and overseas about the application of stem cells in the endothelialization of small-diameter blood vessel prosthesis in the past 10 years were retrieved.A total of 552 articles were initially found and we finally selected 81 articles to review according to inclusion and exclusion criteria. RESULTS AND CONCLUSION:(1)The low long-term patency rate restricts the application of small-diameter blood vessel prosthesis in clinic.The main causes of low long-term patency rate are thrombogenesis and intimal hyperplasia.The endothelium of native vessels has the function of anti-thrombogenesis and intimal hyperplasia.Endothelialization can simulate the function of native vessels,which is an effective way to improve long-term patency rate.(2)The small-diameter blood vessel prosthesis will undergo in vivo endothelialization after being implanted,but it is difficult to form complete endothelium.Stem cells have the potential to differentiate into endothelial cells.Recruiting stem cells in vivo or seeding them on the inner surface of blood vessel prosthesis in vitro is research strategy to achieve endothelialization.(3)The long-term patency rate of small-diameter blood vessel prosthesis has been improved to a certain extent through seeding endothelial progenitor cells,mesenchymal stem cells,induced pluripotent stem cells,and embryonic stem cells.Each has its own advantages.Endothelial progenitor cells are easy to obtain and can be directly used for seeding.Mesenchymal stem cells come from a wide range of sources and have the function of paracrine and immunological regulation.Induced pluripotent stem cells are rich in sources and the immunogenicity can be eliminated.Embryonic stem cells have a strong proliferative ability and can differentiate into many cells.(4)The application of stem cells in blood vessel prosthesis has not yet been transformed into clinic.Further researches are needed to promote clinical translation.