Prognostic Factors for Arteriovenous Fistula Maturation

Abstract

Recent studies have reported successful arteriovenous (AV) fistula maturation rates between 40% and 80%, with older age, distal fistula location, and small vein diameter associated with greater failure rates. Our objective is to determine if these findings are consistent with the outcomes at our institution. A retrospective chart review was performed on patients who underwent upper extremity AV fistula creation at a single institution. Patient demographics and risk factors were analyzed, as well as fistula location and vein diameter based on preoperative ultrasound. Veins less than 2.5mm were not used for fistula creation. Successful fistula maturation was defined as the fistula serving as the primary access for hemodialysis for 3months or greater. Pearson Chi-Square, Fisher's Exact Test, and Mann-Whitney U-tests were used to determine significant associations. Between January 2012 and December 2013, 146 fistulas were created in 136 patients. The median age was 68. Median body mass index (BMI) was 27.8. Ninety-one fistulas were created in men and 55 in women. Ninety-two percent of patients had hypertension, 57% had diabetes, and 33% had coronary artery disease. Sixty percent of fistulas created were brachiocephalic, 24% were basilic vein transpositions, and 16% were radiocephalic. Median vein diameter was 3.7 (range 2.5-8.8). Eighty-four percent of patients were on hemodialysis at the time of fistula creation, and 21% had a prior fistula. One hundred five fistulas were accessed for 3months or more, resulting in a successful overall maturation rate of 72%. BMI greater than 29.5 (P=0.026) negatively impacted successful fistula maturation, whereas age, fistula location, and vein size did not. We noted a successful overall maturation rate of 72% at our institution when veins at least 2.5mm in diameter were used. Our sole negative significant predictor for fistula maturation was BMI greater than 29.5. Therefore, in our experience, age, sex, and fistula location should not be used to preclude patients with a vein diameter of at least 2.5 mm from consideration for AV fistula creation.