Semi-blunt Needles: is Outcome Better?

The aim of this observational study in patients chronically hemodialyzed by a native arterio-venous fistula is to determine the impact of the use of semi-blunt needles on the quality of the punction. The investigators have observed that cannulation with blunt needles (button-hole method) is sometimes difficult and the use of a sharp needle may be necessary, with consequently more hematomes and infections. Our hypothesis is that canulation with semi-blunt needles would be easier than with classical blunt needles, and consequently the use of sharp needles would become less frequent. Inclusion criteria and study design are detailed below.