Abstract: FR-PO504
Retrograde Flow in Rat Arteriovenous Fistula
Session Information
- Dialysis Vascular Access
October 25, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 803 Dialysis: Vascular Access
Authors
- Northrup, Hannah M., University of Utah, Salt Lake City, Utah, United States
- Lee, Timmy C., University of Alabama at Birmingham, Birmingham, Alabama, United States
- Shiu, Yan-Ting Elizabeth, University of Utah, Salt Lake City, Utah, United States
Background
The arteriovenous fistula (AVF) is the preferred vascular access for patients on maintenance hemodialysis but has high maturation failure rates, due to insufficient increases in lumen diameter and flow of the venous limb. There is a paucity of studies investigating the role of the AVF’s distal artery in maturation failure. Retrograde flow in the AVF’s distal artery is sometimes seen in patients and is associated with conditions such as steal syndrome. However retrograde flow has been rarely studied in context of AVF remodeling. Both computational fluid dynamics (CFD) and animal models have become a popular research tool to analyze the hemodynamics of the AVF. We have reported that rat femoral AVFs have anastomosis angles and disturbed flow similar to those in human forearm AVFs. Here we present a novel CFD study analyzing retrograde flow in rats with AVF.
Methods
15 Sprague Dawley rats (12-16 week old males) underwent femoral artery (side) to femoral vein (end) AVF creation. 7 or 21 days after AVF creation rats underwent magnetic resonance imaging (MRI). MRI-based CFD was used to analyze the presence of retrograde flow in the distal artery 5 mm away from the anastomosis, and venous diameter and flow rate 5 mm away from the anastomosis. Spearman correlations were calculated to analyze association.
Results
14 out of 15 rats exhibited retrograde flow in the distal artery during the cardiac cycle. 2 rats had retrograde flow throughout 5-20% of the cardiac cycle. 7 rats exhibited retrograde flow over 70% of the cardiac cycle and 5 experienced 100% retrograde flow. Correlation between % retrograde flow and venous diameter was -0.140 with a p value of 0.614. Correlation between % retrograde flow and venous flow rate was 0.198 with a p value of 0.477.
Conclusion
Retrograde flow in the distal artery is present and prevalent in rat femoral AVF. Consequently, rat models may be a translational model for studying steal syndrome. There were no statistically significant associations between retrograde flow in the distal artery and AVF venous diameter and flow in rat models. Studies in human and other animal models of AVFs are needed.
Funding
- NIDDK Support