Risk Factors Associated with Patency Loss of Hemodialysis Vascular Access within 6 Months

BACKGROUND AND OBJECTIVES: Clinical guidelines support vascular access surveillance to detect access dysfunction and alter the clinical course by radiologic or surgical intervention. The objective of this study was to explore the association between loss of primary functional patency within 6 months of first use and demographic and clinical characteristics of patients receiving chronic renal replacement therapy with arteriovenous fistulas. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This was a retrospective study of all chronic hemodialysis patients followed by the Southern Alberta Renal Program from January 1, 2005 to June 30, 2008. Demographic and clinical variables and initial intra-access blood flow (IABF) were compared between those with and without loss of primary functional patency. To determine the contribution of independent variables to the dependant variable of loss of primary functional patency, a multivariable analysis using logistic regression was performed. RESULTS: The incidence of primary failure was 10% (81 of 831). Multivariable analysis found that older age (>65 years, odds ratio OR 3.6, P < 0.001), history of diabetes (OR 2.3, P = 0.007), history of smoking (OR 4.3, P < 0.001), presence of forearm fistulas (OR 4.0, P < 0.001), and low initial IABF (<500 ml/min, OR 29, P < 0.001) were independently associated with loss of primary patency. CONCLUSIONS: The set of patient risk factors identified in this study, particularly initial IABF, can be used to identify patients who are most at risk for developing vascular access failure and to guide a more directed approach for a vascular access screening protocol.