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Abstract: TH-PO288

Morphometric Characterization of Arteriovenous Fistula (AVF) Explants Reveals Collagen and Versican as Dominant Components of Mature AVF Wall

Session Information

Category: Dialysis

  • 703 Dialysis: Vascular Access

Authors

  • Lotfollahzadeh, Saran, Boston University School of Medicine, Boston, Massachusetts, United States
  • El zinad, Nagla, Boston University Medical Campus, Boston, Massachusetts, United States
  • Zhang, Yichi, Computation Biology, Boston University School of Medicine, Boston, Massachusetts, United States
  • Elsadawi, Murad, Boston University Medical Campus, Boston, Massachusetts, United States
  • Balcells, Merche, Institute of Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
  • Kolachalama, Vijaya B., Computation Biology, Boston University School of Medicine, Boston, Massachusetts, United States
  • Chitalia, Vipul C., Boston University School of Medicine, Boston, Massachusetts, United States
Background

Arteriovenous Fistula (AVF) is the lifeline of patients with End-Stage Kidney Disease (ESKD) on hemodialysis. AVF undergoes profound remodeling to accommodate arterial pressure and flow, a process called arterialization of the vein. Despite the central importance of this process in functional AVF, there is a dearth of studies on humans characterizing the components of walls of the mature AVFs.

Methods

The morphology of AVF explants was probed with Masson Trichrome, Sirius Red, and Versican. This was followed by a color-based segmentation pipeline with a machine learning approach to quantify the components of AVF explants. Vascular smooth muscle cells were characterized using functional markers.

Results

Twenty-one patients had AVFs explanted for aneurysm (71.42%), pseudoaneurysm, stenosis, or aesthetic reasons (each in 9.52%). Neointimal hyperplasia characterized by intimal thickening was present in all AVFs. Other features included calcification, inflammatory infiltrate, needle track injury, and thrombus. Quantitative histological analysis of Masson Trichrome and Sirius red stains showed that in the AVF wall, collagen, vSMCs, and proteoglycan constituted 27.78%, 19.80%, and 31.45% of the wall, respectively. Compared to vSMC, the collagen and Versican were in the ECM by 1.40 fold and 2.76 fold, respectively. (p <0.001) Collagen was deposited in a concentric manner in the explanted AVFs with aneurysms and in an eccentric manner in the AVFs with pseudoaneurysms. vSMCs showed minimal staining of Ki67 and prominent staining of MYH11, α-smooth muscle actin, and Calponin, all markers of differentiated VSMCS with secretory phenotype.

Conclusion

This study confirms collagen and versican as prominent components of AVF walls and vSMCs with secretory features in the wall of AVF. This study now seeds future investigation to examine the regulation of the components of ECM in the arterialization of the vein.

Color and textile-based analysis

Funding

  • NIDDK Support