Stop posterior wall puncture of the arteriovenous graft (AVG). New findings of cannulation techniques from a prospective observational study with an AVG model and plastic cannula for dialysis.

Background: Posterior wall puncture of the AVG causes serious vascular access complications, but there is no concrete technical recommendation for AVG cannulation with plastic cannula. The purpose of this study is to identify cannulation techniques to reduce posterior wall puncture of the AVG using plastic cannula.

Methods: Sixty-three hemodialysis nurses' cannulations on experimental models were recorded and included in this study. Cannulations were conducted on AVG and AVF models with a plastic cannulation needle. We analyzed the angle of the needle, the motion of the needle, and the location of the needle in the graft lumen.

Results: The occurrence of posterior wall puncture of the AVG model was 22.2%. The cannulation angles in the AVG model were greater than those in the AVF model (p < 0.05). In the posterior wall puncture group of the AVG model, after the tip of the needle had reached into the graft lumen, the angle of the needle was not flattened (p < 0.05) and the outer sleeve of the needle was not inserted into the graft (p < 0.05). Furthermore, posterior wall puncture of the AVG model were observed in the group with less than 5 years of dialysis nursing experience (p < 0.05).

Conclusions: From this study, after the tip of the needle had reached into the graft lumen, flattening the angle of the needle and inserting the outer sleeve of the needle into the graft were suggested as specific cannulation techniques to reduce posterior wall puncture of the AVG. Furthermore, this study also suggests the importance of cannulation technique education for new dialysis nurses to reduce cannulation-caused complications.