Is intra-operative blood flow predictive for early failure of radiocephalic arteriovenous fistula?

Franois Saucy 2 Erik Haesler 1 Claude Haller 2 Sbastien Dglise 2 Daniel Teta 0 Jean-Marc Corpataux 2 0 Department of Nephrology, Lausanne University Hospital , Lausanne, Switzerland 1 Department of Vascular Medicine, Lausanne University Hospital , Lausanne, Switzerland 2 Department of Thoracic and Vascular Surgery, Lausanne University Hospital , Lausanne, Switzerland Background. For over 50 years, radiocephalic wrist arteriovenous fistulae (RCAVF) have been the primary and best vascular access for haemodialysis. Nevertheless, early failure due to thrombosis or non-maturation is a major complication resulting in their abandonment. This prospective study was designed to investigate the predictive value of intra-operative blood flow on early failure of primary RCAVF before the first effective dialysis. Methods. We enrolled patients undergoing creation of primary RCAVF for haemodialysis based on the preoperative ultrasound vascular mapping discussed in a multidisciplinary approach. Intra-operative blood flow measurement was systematically performed once the anastomosis had been completed using a transit-time ultrasonic flowmeter. During the follow-up, blood flow was estimated by colour flow ultrasound at various intervals. Any events related to the RCAVF were recorded. Results. Autogenous RCAVFs (n = 58) in 58 patients were constructed and followed up for an average of 30 days. Thrombosis and non-maturation occurred in eight (14%) and four (7%) patients, respectively. The intra-operative blood flow in functioning RCAVFs was significantly higher compared to non-functioning RCAVFs (230 vs 98 mL/ min; P = 0.007), as well as 1 week (753 vs 228 mL/min; P = 0.0008) and 4 weeks (915 vs 245 mL/min, P < 0.0001) later. Blood flow volume measurements with a cut-off value of 120 mL/min had a sensitivity of 67%, specificity of 75% and positive predictive value of 91%. Conclusions. Blood flow <120 mL has a good predictive value for early failure in RCAVF. During the procedure, this cut-off value may be used to select appropriately which RCAVF should be investigated in the operation theatre in order to correct in real time any abnormality. The Author 2009. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please e-mail: Introduction For over 50 years, radiocephalic arteriovenous f istula (RCAVF) has demonstrated unquestionable superiority over all other types of vascular access for haemodialysis [1]. The main benefits of arteriovenous fistula (AVF) are better long-term patency and lower complication rate. Nevertheless, failure within the first 4 months after surgery occurs in 20% to 50% of AVF [111]. Early failure of AVF is defined as occlusion or insufficient development to support haemodialysis within the first 3 months [12]. Maturation of an AVF depends on flow volume and diameter of the vein used for cannulation. In this regard, Robbin et al. showed that the likelihood of sufficient growth was 95% if flow volume was 500 mL/min or greater in association with a diameter of 4 mm [13]. In most successful AVF, these flow and size parameters are generally met within the first few weeks after construction [12]. Several pre-operative factors have been shown to predict the risk for early AVF failure. The main predictors are the diameters of the artery and vein. Pre-operative ultrasound (US) mapping is a useful tool for the accurate measurement of vessel diameter as a basis for planning operative strategy. Female gender and diabetes may also be risk factors for early AVF failure. In the scoring system proposed by Lok et al. to predict failure to mature of AVF, the four main clinical predictors were age over 65, peripheral or coronary artery disease and white race [14]. During surgical exploration, the operator should take into account the quality and size of the artery and the vein when deciding whether or not to create the fistula at the site chosen during pre-operative workup. Few studies have evaluated intra-operative factors to predict early failure immediately after construction of an AVF. Two previous studies evaluated the predictive value of intra-operative blood flow volume. Wong et al. were unable to demonstrate a link between intra-operative flow volume and the risk of early occlusion [10]. On the other hand, Johnson et al. showed that the failure risk was significantly higher if flow volume was less than 170 mL/min [15]. However, none of these studies were specif ically aimed to assess the value of intra-operative blood flow measurements for the outcome of RCAVF. The purpose of this study was thus to investigate the value of intraoperative blood flow measurements in the prediction for early failure and/or adequate function of RCAVF in a cohort of patients about to start a chronic haemodialysis program in our institution. Materials and methods Between January 2005 and December 2007, we performed 120 first-time AVF including 67 RCAV, i.e. 56% of the total number. The (...truncated)