Abstract: TH-PO756

Differences in Vascular Fibrosis Explain Sex Disparities in AVF Maturation Outcomes

Session Information

Category: Dialysis

  • 603 Hemodialysis: Vascular Access

Authors

  • Martinez, Laisel, University of Miami, Miller School of Medicine, Miami, Florida, United States
  • Duque Ballesteros, Juan Camilo, University of Miami, Miller School of Medicine, Miami, Florida, United States
  • Paez, Angela, University of Miami, Miller School of Medicine, Miami, Florida, United States
  • Tabbara, Marwan, University of Miami, Miller School of Medicine, Miami, Florida, United States
  • Hernandez, Diana Rosa, University of Miami, Miller School of Medicine, Miami, Florida, United States
  • Selman, Guillermo, Albany Medical College, Albany, New York, United States
  • Salman, Loay H., Albany Medical College, Albany, New York, United States
  • Velazquez, Omaida C, University of Miami, Miller School of Medicine, Miami, Florida, United States
  • Vazquez-Padron, Roberto I., University of Miami, Miller School of Medicine, Miami, Florida, United States
Background

Women have a higher risk of arteriovenous fistula (AVF) maturation failure than men, and the reason for this propensity is still unknown. Several studies have excluded sex-related differences in the diameter of native vessels as the explanation for this disparity, which suggests that the remodeling process in women is inferior. The purpose of this study was to compare two surrogate indicators of venous remodeling in females and males undergoing surgeries for two-stage AVF creation.

Methods

We measured intimal hyperplasia (IH) and medial fibrosis in native veins and AVF venous samples obtained during AVF creation (first-stage) and transposition (second-stage) surgeries, respectively. The analysis of native veins allowed the assessment of pre-existing sex-related differences in IH and medial fibrosis, whereas evaluation of AVFs allowed the comparison of postoperative remodeling between both sexes.

Results

Anatomical maturation failure (an AVF that never achieved an internal luminal diameter ≥ 6mm) occurred in 22/64 (34.4%) females and 18/97 (18.6%) males (p=0.027). The internal luminal diameter of the native basilic vein was similar between females and males (median 4.0 mm, interquartile range 4.0-4.0 in both, p=0.7). There were no significant sex-related differences in pre-existing IH and medial fibrosis between AVFs with successful maturation and maturation failure. Postoperative IH was also similar in AVFs with distinct maturation outcomes in both sexes. Interestingly, there was a significant increase in postoperative medial fibrosis in AVFs with maturation failure vs. successful maturation in females (55.0±2.7% vs. 44.0±2.2 [mean ± SEM], p=0.003), but not in males (51.2±2.9% vs. 48.0±1.6, p=0.4). Accordingly, logistic regression analyses demonstrated that the degree of medial fibrosis was associated with maturation failure in women (odds ratio [OR] 1.80 per 10% increase in medial fibrosis, p=0.034) but not in men (OR 1.03, p=0.4).

Conclusion

This study demonstrates for the first time the existence of sex-related differences in vascular remodeling after AVF creation, and that medial fibrosis is a major contributing factor to the increased risk of maturation failure in females.

Funding

  • NIDDK Support