[Objectives] The aim of this study was to evaluate graft patency and analyze factors related to graft survival and the effects of VAIVT (Vascular access intervention therapy) and surgical revisions. [Methods] Between January 2002 and March 2016, 540 polyurethane vascular access grafts (THORATEC^®) were performed at our hospital. We calculated the cumulative patency rates of these grafts, including the primary patency (problem-free), VAIVT-assisted primary patency (surgical revision-free), and secondary patency (functional) by the Kaplan-Meier method. Secondly, all grafts were classified into the following three groups according to the annual average of PTA times: 215 cases in the PTA-untreated group, 163 cases in the lower frequency group, and 162 cases in the higher frequency group. We analyzed the relationship between the PTA times and cumulative patency, and we examined factors related to graft survival by the COX proportional hazard model. [Results] Primary patency of all grafts was 35.7% at 1 year, 20.0% at 2 years and 7.5% at 5 years. VAIVT-assisted primary patency was 78.8% at 1 year, 70.4% at 2 years and 55.7% at 5 years. Secondary patency was 92.6% at 1 year, 86.0% at 2 years and 74.3% at 5 years. Among the three groups classified according the annual average PTA times, the lower frequency group showed significantly better results than the higher frequency group for secondary patency and VAIVT-assisted primary patency. On multivariate analysis, a larger diameter of the anastomotic vein was significantly correlated with a better secondary patency rate. [Conclusions] The results of graft patency varied according to the conditions. The development of more appropriate methods to obtain and manage a polyurethane vascular access graft is expected in the future.