Initial experiences with rapid access, self-sealing, polycarbonate urethane nanofiber vascular grafts for hemodialysis

Hemodialysis is the leading renal replacement therapy worldwide and vascular access represents a critical issue for patients with terminal kidney failure. The superiority of fistulas and grafts over central venous lines is well recognized. However, there is a wide variation in vascular access preferences. Whether grafts should be considered as a secondary option compared to native fistulas is also a matter of debate. In the last decade, new arteriovenous vascular grafts have been developed with enhanced self-sealing properties and reduced thrombogenicity. Clinical trials in humans are currently available for the following devices: FlixeneTM, AcusealTM, VectraTM, RapidaxTM, and AVfloTM. Preliminary reports show better primary and secondary patency rates compared to standard polytetrafluoroethylene grafts with fewer complications. Our two-year experience with AVfloTM confirms these findings with primary and secondary patency rates as high as 56% and 82%, respectively. Cumulative thrombosis rate was 25% and 67% of grafts could be successfully rescued. There were no surgical site infections observed. Early cannulation grafts can be safely punctured within few days after placement and their self-sealing properties prevent formation of fluid collections around the prosthesis thus reducing puncture-related complications and infections. These extraordinary features allow to provide a more suitable vascular access to patients with difficult vascular anatomy, poor quality vessels, reduced life expectancy or in a need for urgent dialysis treatment. Reduction of incidental patients requiring temporary lines, increase of prevalent patients with permanent surgical access, and resource optimization are theoretical advantages offered by early cannulation grafts over standard grafts and poorly planned arteriovenous fistulas. Larger randomized clinical trials and costeffectiveness analysis are currently in progress.