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Kidney Week

Abstract: PO1339

Longitudinal Geometry of Pig Arteriovenous Fistulas (AVFs)

Session Information

  • Vascular Access
    October 22, 2020 | Location: On-Demand
    Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

  • 704 Dialysis: Vascular Access

Authors

  • Cahoon, Savanna, University of Utah, Salt Lake City, Utah, United States
  • Falzon, Isabelle Dorothy, University of Utah, Salt Lake City, Utah, United States
  • Shiu, Yan-Ting Elizabeth, University of Utah, Salt Lake City, Utah, United States
  • Cheung, Alfred K., University of Utah, Salt Lake City, Utah, United States
Background

Hemodynamics has been postulated to be an important factor contributing to successful versus failed AVF maturation. Pigs, in general, have hemodynamic features that are similar to those in humans, and thus are an attractive animal model for investigating the mechanisms underlying and the interventions for promoting AVF maturation. A few earlier small clinical studies found associations between AVF geometry and maturation. Since geometry is a critical determinant of hemodynamics, we investigated the geometry of pig AVFs using magnetic resonance imaging (MRI) technology.

Methods

Carotid (side)-jugular (end) AVFs were created in female Yorkshire cross domestic pigs. Non-contrast black-blood MRIs were obtained at 1, 2, and 6-10 weeks (wks) post-AVF creation (n=3 per time point) and used to reconstruct AVF lumen geometries. Lumen area, anastomosis angle, venous tortuosity, and nonplanarity angle magnitude were quantified.

Results

The non-surgery lumen area of the external jugular vein was ~7 mm2. The AVF vein lumen area (mean ± standard deviation) significantly (p=0.0370) increased from 25.3 +/- 11.1 mm2 in wk 1, to 32.3 +/- 4.3 mm2 in wk 2, then to 62.7 +/- 21.3 mm2 in wks 6-10 suggesting that our pig AVF is a model for successful AVF maturation. Importantly, we also observed an increasing trend in the lumen areas from wk 1 to wks 6-10 of the proximal artery (24.0 +/- 17.3 mm2 vs. 28.0 +/- 8.60 mm2) and the distal artery (24.5 +/- 16.1 mm2 vs. 34.8 +/- 13.9 mm2). The anastomosis angles were similar in wk 1 and 2 (51.6 +/- 23.2° vs 50.2 +/- 21.0°) then decreased to 25.8 +/- 17.3° in wks 6-10. Venous tortuosity slightly increased from 0.13 +/- 0.05 in wk 1 to 0.15 +/- 0.05 in wk 2 then to 0.17 +/- 0.06 in wks 6-10. Non-planarity angle magnitude was 14.9 +/- 8.9° in wk 1 then decreased to 10.7 +/- 8.5 in wk 2 then increased to 24.6 +/- 9.4° in wks 6-10.

Conclusion

This is the first serial and detailed study of pig AVF geometric parameters. The anastomosis angles of our pig AVFs were in line with human radiocephalic AVFs in the literature (~30-60°). Our study sets the stage for examining the role of geometry in alterations in hemodynamic forces and in AVF maturation processes.

Funding

  • NIDDK Support