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Long-Term Functional Patency and Cost-Effectiveness of Arteriovenous Fistula Creation Under Regional Anaesthesia: A Randomised Controlled Trial

Background Regional anaesthesia improves short-term blood flow through arteriovenous fistulae (AVF). We previously demonstrated that regional anaesthesia (RA) compared to local anaesthesia (LA) improves primary AVF patency at three months. In this study, we report the effects of anaesthesia on longer-term AVF patency with corresponding cost-benefit analysis. an 126 patients undergoing primary radiocephalic or brachiocephalic AVF creation were randomised to receive RA (brachial plexus block; 0·5% L-bupivacaine and 1·5% lidocaine with epinephrine) or LA (0·5% L-bupivacaine and 1% lidocaine). Primary outcome measures have previously been reported. Primary, functional, and secondary patency at one year, re-interventions, and additional access procedures are reported here. Data were analysed by intention-to-treat. Cost effectiveness analyses were performed. The study was registered with ClinicalTrials.gov (NCT01706354). Results were analysed using SPSS Statistics v22 (Armonk, NY). Data were tested for normality. Assuming normal distribution, student’s t-test (2-tailed) was used to compare continuous data, and chi-squared test used to compare categorical data. Mann-Whitney U-tests were used for non-normally distributed data. Logistic regression analysis was carried out to examine the interaction between AVF site (RCF/ BCF) and anaesthesia on primary and functional patency. P<0·05 was considered significant. Results are presented as mean (95% CI), median (IQR), or as a percentage of the total population and odds ratio (OR). Missing data were limited and assumed to be missing at random. If a data point was missing, this case was removed from analysis of the specific variable of interest. A “last-forward” approach was taken towards fistula patency in patients who died. Data were analysed on an intention-to-treat basis. The study was powered according to the primary outcome 11 and no formal power calculation was performed for the secondary endpoints reported in this paper.