Christensen LD, et al. - The frequency and type of bacterial colonization of the buttonhole tract over time and associated clinical infections were studied in this observational cohort study with 9 months of follow-up. Study participants included in-center hemodialysis patients using the buttonhole cannulation technique at 2 Danish dialysis centers. In hemodialysis patients, the buttonhole tract was commonly colonized with staphylococci and asymptomatic bacteremia, transiently or in a sustained manner. This finding indicates that the use of buttonhole cannulation technique confers substantial risk for access-related infections among patients. The possible value of surveillance of buttonhole colonization was suggested.