A. Pain and other disadvantages of AV fistula cannulation can be limited by using the so-called buttonhole technique. It was described for the first time as the contant site method by Twardowski et al. The authors report on a patient in whom the fistula was too short to use the rope ladder technique. As an alternative, the access was cannulated at a constant site. Later, in 1984, Krönung used the name buttonhole puncture technique. It was used primarily in patients treated with home hemodialysis, where cannulation was performed by one single person (often by the patient himself). In order to form a perfect buttonhole it is indeed essential that the fistula is cannulated at exactly the same site and using exactly the same angle every single time. The buttonhole technique has been adopted by the recent National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF K/DOQI) Guidelines for vascular access. Studies show that patient pain scores and bleeding time after dialysis are positively influenced when using this cannulation technique.~B. Till present in our center catheters with cylindrical points are used for cannulation of AV fistulas with the rope ladder technique. One can hypothesize that a catheter with a bevel point might have some advantages such as a larger entrance area and less traumatic cannulation. The latter may influence pain sensation of the patients.~The above background information gives rise to the following investigational questions:~A. Buttonhole vs rope ladder technique~Is pain sensation different when using buttonhole cannulation as compared to rope ladder cannulation technique?~Hypothesis:~AV fistula cannulation by buttonhole technique causes less pain than cannulation by rope ladder technique.~Is the level of anxiety different when using buttonhole cannulation as compared to rope ladder cannulation technique?~Hypothesis:~AV fistula cannulation by buttonhole technique causes less anxiety than cannulation by rope ladder technique.~Is bleeding time different when using buttonhole cannulation as compared to rope ladder cannulation technique?~Hypothesis:~Bleeding time is shorter when using buttonhole technique versus rope ladder technique.~Is the number and severity of complications related to AV fistula cannulation different between buttonhole and rope ladder technique?~Hypothesis:~When using the buttonhole technique for AV fistula cannulation the number and severity of complications is less than when using the rope ladder technique.~B. Ropeladder technique using catheters with cylindrical vs. bevel point~Is pain sensation different when using rope ladder cannulation catheters with cylindrical as compared to bevel point?~Hypothesis:~AV fistula cannulation using bevel point catheters causes less pain than cannulation using cylindrical point catheters.
A. Pain and other disadvantages of AV fistula cannulation can be limited by using the so-called buttonhole technique.~B. Till present in our center catheters with cylindrical points are used for cannulation of AV fistulas with the rope ladder technique. One can hypothesize that a catheter with a bevel point might have some advantages such as a larger entrance area and less traumatic cannulation. The latter may influence pain sensation of the patients.~The above background information gives rise to the following investigational questions:~A. Buttonhole vs rope ladder technique~Is pain sensation different when using buttonhole cannulation as compared to rope ladder cannulation technique?~Hypothesis:~AV fistula cannulation by buttonhole technique causes less pain than cannulation by rope ladder technique.~Is the level of anxiety different when using buttonhole cannulation as compared to rope ladder cannulation technique?~Hypothesis:~AV fistula cannulation by buttonhole technique causes less anxiety than cannulation by rope ladder technique.~Is bleeding time different when using buttonhole cannulation as compared to rope ladder cannulation technique?~Hypothesis:~Bleeding time is shorter when using buttonhole technique versus rope ladder technique.~Is the number and severity of complications related to AV fistula cannulation different between buttonhole and rope ladder technique?~Hypothesis:~When using the buttonhole technique for AV fistula cannulation the number and severity of complications is less than when using the rope ladder technique.~B. Rope ladder technique using catheters with cylindrical vs. bevel point~Is pain sensation different when using rope ladder cannulation catheters with cylindrical as compared to bevel point?~Hypothesis:~AV fistula cannulation using bevel point catheters causes less pain than cannulation using cylindrical point catheters.