Introduction: The ability to successfully cannulate the arteriovenous fistula reliably is a critical step in the delivery of hemodialysis therapy. The av-Guardian vascular access system (Advent Access, Singapore) is designed to overcome the technical barrier to establishing reliable blunt needle access in patients with mature arteriovenous fistula. Methods: This was a first-in-man, prospective, non-randomized trial (registered on the Australian New Zealand Clinical Trial Registry (ACTRN12617000501347)) performed to assess the safety and feasibility of achieving repeatable successful cannulation via av-Guardian vascular access system to facilitate blunt needling in patients with mature arteriovenous fistula. The primary endpoints of the study included rate of successful hemodialysis sessions via av-Guardian vascular access system cannulation over 3 months and safety of the implants. Results: A total of six patients (four patients with brachiocephalic and two with radiocephalic arteriovenous fistula) were enrolled in the study. A pair of av-Guardian vascular access system were implanted, one each at the arterial and venous cannulation sites, under local anesthesia. Overall, the rate of successful cannulation through the av-Guardian vascular access system over 3 months in 216 hemodialysis sessions was 98.1% (212/216) at the arterial site and 94.4% (204/216) at the venous site. Significantly, 90% and 85.5% of the cannulations at the arterial and venous site, respectively, were successful at first attempt. Blood flow rates within the arteriovenous fistula were unaffected by the devices. Conclusion: The results demonstrated the safety and feasibility of a subcutaneously implanted, extravascular device in achieving repeatable successful cannulation via a constant site, to facilitate blunt needling in matured arteriovenous fistula in limited number of patients.
Blunt needle revision with viscoelastic materials via the anterior chamber for early failed filtering blebs after trabeculectomy
