Nonthrombogenic small-caliber human umbilical vein vascular prosthesis

Area of Science:

• Biomaterials Science
• Vascular Surgery
• Biomedical Engineering

Background:

• Vascular grafts often face thrombotic complications, limiting their clinical success.
• Developing non-thrombogenic surfaces is crucial for small-caliber vascular prostheses.
• Heparin immobilization offers a promising strategy to enhance biocompatibility.

Purpose of the Study:

• To covalently immobilize heparin onto collagenous surfaces of human umbilical vein grafts (HUVG).
• To evaluate the heparin loading, stability, and antithrombotic properties of modified HUVGs.
• To assess the in vivo performance and patency rates of heparin-bound HUVGs.

Main Methods:

• Covalent binding of heparin using carbodiimide chemistry to ammonium hydroxide-treated HUVGs.
• Quantification of heparin loading via established assays.
• In vitro assessment of platelet adhesion and fibrin clot formation.
• In vivo implantation studies to evaluate thrombus formation and graft patency.

Main Results:

• Heparin loading on ammonium hydroxide-treated HUVGs (31.5 µg/cm²) surpassed that of untreated carotid arteries and HUVGs.
• Negligible heparin activity loss observed under both in vitro and in vivo conditions.
• Heparin-bound HUVGs significantly reduced platelet adhesion and fibrin clot formation in vitro.
• In vivo studies demonstrated a significant increase in thrombus-free surface and enhanced patency rates.

Conclusions:

• Covalent heparin immobilization on HUVGs creates a stable, non-thrombogenic surface.
• Heparin-bound HUVGs exhibit superior antithrombotic properties and improved in vivo patency.
• These findings highlight the potential of heparin-modified HUVGs as promising prostheses for small-caliber vascular applications.