A Novel Magnet Guided Cannulation (Magic) Hemodialysis Graft

Abstract

Introduction - Repeat needle cannulation to gain entry into a hemodialysis graft can be difficult for both trained in-center professionals and patients undergoing home hemodialysis. The high level of missed needle insertion attempts and cannulations can damage the integrity of the graft, cause pain and discomfort, lead to the formation of a hematoma, pseudoaneurysm, infection and potentially compromise the long term patency of the hemodialysis access. Methods - A standard wall polytetrafluoroethylene (PTFE) graft was modified with the application of stainless-steel rings on its outer surface. A device containing neodymium magnets was designed to locate the subcutaneously placed graft. Testing was performed in a porcine model. Ease of graft cannulation and proof of concept was evaluated. Results - The locator device was able to couple with the subcutaneously tunneled modified PTFE graft tested up to a distance of 1 cm below a porcine skin surface. Coupling was also accomplished with a graft in a curved and semi-curved configuration. Percutaneous access of the graft was readily achieved with the aide of the locator in each instance. Conclusion - This novel device incorporates a simple technology that allows easy location, target and cannulation of subcutaneously placed grafts. Its potential application for hemodialysis needs further study to determine whether it may facilitate and expedite access cannulation for treatment, decrease patient discomfort and expand the trend for home therapy.