The Difficult to Cannulate Hemodialysis Access

An access that is difficult to cannulate can prolong dialysis catheter exposure and cause access infiltration, dialysis access vessel injury, pain, and patient discomfort. The success of cannulation depends on a competent cannulator and favorable dialysis access characteristics. The development and optimization of formal training programs for cannulators including quality improvement, regular competency assessments and ultrasound training likely increases successful and safe cannulations. Fistula characteristics including depth, tortuosity, and vein caliber are also important factors. Several surgical and minimally invasive/endovascular techniques have been described to improve those relevant fistula characteristics. In addition, the advent of the endovascular fistula presents a new challenge for the cannulator needing education and in many cases surgical/endovascular interventions to improve the chances of successful cannulation.