Gender Differences in Arteriovenous Fistula Maturation

The National Kidney Foundation Dialysis Outcome Quality Initiative advocates for autologous arteriovenous fistula creation for patients who need hemodialysis. However, women continue to be less represented in this group, probably because of smaller vein diameters and decreased rates of maturation compared with men. The purpose of this study was to investigate the differences in maturation between women and men. A retrospective review of patients who underwent arteriovenous fistula creation between January 2014 and October 2019 at a tertiary academic medical center was performed; 672 patients were identified for analysis. Exclusion criteria included patients who failed to undergo preoperative vein mapping, patients who failed to follow up, and patients who were not on dialysis. A fistula was considered to be mature if it was successfully cannulated for dialysis. A χ2 analysis was performed to identify the relationship between sex and maturation status. A P value < .05 was considered significant. In the cohort, 38.7% of the patients were female, with an average age of 63.1 ± 13.8 years. There was no significant difference in preoperative vein size between women (2.89 ± 1.1 mm) and men (2.93 ± 1.1 mm; t [670] = −0.46; P = .77). The overall maturation rate was 82.4% (n = 554), of which 33.9% (n = 228) matured primarily and 48.5% (n = 326) required balloon-assisted maturation. There was a significant association between sex and maturation (χ24 = 24.70; P < .0001). Women were less likely than men to achieve primary maturation, 25.0% vs 39.6%, respectively. Women were more likely than men to experience dialysis access failure, 20.0% vs 10.0%, respectively. The frequency of secondary maturation was similar between sexes, 50.0% for women vs 47.6% for men. However, women were more likely than men to require more than one intervention, 24.6% vs 11.4%, respectively (P < .001). Based on multivariate analysis, vein size ≥2.5 mm (odds ratio, 2.1; confidence interval, 1.4-3.3; P < .001) and male sex (odds ratio, 2.3; confidence interval, 1.5-3.6; P < .001) were independent predictors of maturation. Women have a decreased frequency of primary maturation and a higher failure rate of dialysis access creation. In the current endovascular era, women may achieve secondary maturation at a frequency similar to their male counterparts, albeit with more interventions. Because preoperative vein sizes are similar, further investigation is necessary to study the inflow as an important determinant of fistula maturation.