BackgroundDirect access flow measurements are considered the most useful surveillance method for significant stenosis, and ultrasound dilution has become the most popular and validated technique. The goal of this study was to evaluate access flow (Qa) at the time of first cannulation and its relationship to the survival of vascular access in Korean hemodialysis patients. MethodsWe conducted a prospective observational study from May 2004 to June 2011. We enrolled 60 patients (36 men) who underwent the first access operation between January 2004 and December 2005 and were followed-up for surveillance. ResultsMaturation failure occurred in nine patients (15%). Mean time to first use was 1.8±1.2 months after surgery. The patients were followed-up for a mean of 50.5±25.9 months. There were 25 deaths and six kidney transplants in patients with a functioning access. The total percutaneous transluminal angioplasty incidence was 50 in 27 patients (0.14/access-year). The initial Qa was 757.5±476.4mL/minute. First cannulation time was not significantly correlated with initial Qa (r=0.234, P=0.075). A total of 22 of the 60 patients (36.7%) had an initial Qa<500mL/minute. Maturation failure, initial Qa<500mL/minute, and the use of antiplatelet agents were risk factors for poor primary patency. Diabetic status and use of a graft were risk factors for low cumulative patency. ConclusionAn initial Qa<500mL/minute is a risk factor for poor primary patency, while an initial Qa<500mL/minute is not a risk factor for low cumulative patency or mortality.