Background Vascular access (VA) dysfunction is a major clinical complication in the hemodialysis population and has a direct effect on dialysis outcome.This study was conducted to explore the role of microinflammation in the VA dysfunction in maintenance hemodialysis patients.Methods Forty-seven patients (male 35 and female 12) receiving maintenance hemodialysis were included for this study.They were divided into three groups:group 1 (n=15),patients with initial hemodialysis and new arteriovenous fistula (AVF);group 2 (n=18),patients treated with hemodialysis for long term with well-functional VA;group 3 (n=14),maintenance hemodialysis patients with VA dysfunction.Biochemical parameters and serum tumor necrosis factor-a (TNF-a),interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) were determined.High-sensitivity C-reactive protein (hs-CRP) was determined by latex-enhanced immuno-nephelometric method.Tissues of radial artery were taken from group 1 and group 3 for the histological study.Expression of CD68 and MCP-1 in the radial artery was determined by immunohistochemistry.Results Serum hs-CRP in group 3 was significantly higher than those in group 1 and group 2 ((7.40±2.42) mg/L vs (4.21±1.62) mg/L and (5.04±3.65) mg/L,P