The Use of Glyceryl Trinitrate Patches in Arteriovenous Fistulas

Patients with end stage renal failure on haemodialysis must have a mechanism for achieving access to their vascular system for dialysis. Arteriovenous fistulas (surgically created connections between the artery and vein) are critical for the majority of patients. Not all the fistulas that are created work, a proportion fail early on and need to be revised or an alternative fistula created. A recent multicentre study demonstrated a 40% primary failure rate(1). In an attempt to increase the numbers of fistulae that reach maturation sufficient for dialysis access cannulation some renal centres apply GTN patches to the fistula at the time of surgery. It is thought that this works by increasing the size of the blood vessels and promoting blood flow through them and some preliminary work seems to support this(2). The evidence for the use of GTN patches in arteriovenous fistula creation is theoretical or based on preliminary work rather than robust evidence. Similarly no evidence exists within the literature to determine the safety and definite efficacy of this procedure in this population. We propose to conduct a double-blinded randomised control trial to answer the study question: does the application of a GTN patch increase the venous outflow diameter post fistula formation and does this result in improved fistula patency.