Photochemically Aided Arteriovenous Fistula Creation to Accelerate Fistula Maturation

Area of Science:

• Vascular biology
• Biomaterials science
• Surgical innovation

Background:

• High rates of arteriovenous fistula maturation failure necessitate improved pre-surgical strategies.
• Vein adaptation during maturation involves lumen dilatation and medial thickening, regulated by the vascular extracellular matrix.
• Targeting the extracellular matrix offers a potential approach to enhance fistula maturation.

Purpose of the Study:

• To investigate the efficacy of a device-enabled photochemical treatment in facilitating arteriovenous fistula maturation.
• To assess the impact of photochemical modification on vein wall properties and cellular response prior to fistula creation.

Main Methods:

• Sheep cephalic veins were treated with a photoactivatable molecule (10-8-10 Dimer) delivered via a balloon catheter with an internal light fiber.
• Photochemical reaction created new covalent bonds within the vein wall matrix proteins upon light activation.
• Histological analysis and cell proliferation assays were performed on treated and control veins.
• Isolated human veins underwent balloon over-dilatation to assess tolerance to mechanical stretch.

Main Results:

• Photochemical treatment resulted in significantly larger vein lumen diameter and media area at 1 week post-treatment compared to controls (p = 0.035 and p = 0.034).
• A higher percentage of proliferating smooth muscle cells was observed in treated veins (p = 0.029) without significant intimal hyperplasia.
• Human veins demonstrated tolerance to up to 66% overstretch during balloon angioplasty, indicating potential for clinical application.

Conclusions:

• Device-enabled photochemical vein treatment is a promising strategy to improve arteriovenous fistula maturation.
• The treatment promotes beneficial structural and cellular adaptations in the vein wall.
• Findings support the advancement of this technique towards clinical trials for hemodialysis access.