Improving Outcomes in Vascular Access

The IMPROVA study is designed to identify novel predictors of vascular access success or failure. Clinical assessment complimented by Doppler ultrasound is the only currently employed methods of assessing suitability for placement of arteriovenous fistulae (AVF). These techniques are not capable of predicting vascular access outcomes suggesting that other potentially measurable factors may play a part. Despite efforts to improve placement of AVF in both the haemodialysis incident and prevalent population, many patients continue to dialyse through a central venous catheter (CVC), exposing them to higher risks of infection, co morbidity and mortality than dialysing via an AVF. Furthermore, AVF primary failure rates are reportedly as high in 20-50% in published series confirming that ultrasound cannot inform the clinician sufficiently to accurately predict success or failure. The aim of this study is to perform enhanced assessments of arterial health preoperatively and correlate these measurements with early AVF outcome. We intend to perform pulse wave analysis and velocity; measure advanced glycation end products and assess endothelial function using a vascular occlusion test. We also aim to assess whether patient reported symptoms of hand function can predict AVF outcome. These non-invasive measurements will provide a more accurate picture of overall vascular health prior to AVF formation with the ultimate intention of informing the clinician as to the likelihood of success or failure.