In vivo evaluation of modified mandrel-grown vascular prostheses

Area of Science:

• Biomaterials Science
• Vascular Surgery
• Regenerative Medicine

Background:

• The Omniflow Vascular Prosthesis (OVP) exhibits superior properties compared to synthetic and biological grafts, especially in low-flow conditions.
• Development of smaller diameter coronary prostheses requires optimization of the inner luminal surface.
• Previous modifications created a uniformly thicker, non-undulating inner surface.

Purpose of the Study:

• To evaluate the efficacy of collagen or heparin surface treatments on modified OVPs.
• To assess patency, tissue integration, wound healing, and endothelialization in a canine model.
• To compare modified OVPs with previously studied unmodified versions.

Main Methods:

• Modified OVPs, with inner surfaces treated with either collagen or heparin, were implanted in a canine model.
• Evaluation included assessment of patency, tissue integration, wound healing, and endothelialization.
• Histological analysis was performed at various explant time points.

Main Results:

• All modified OVPs remained fully patent without thrombus or aneurysms.
• Rapid tissue response observed, with excellent host collagen deposition and minimal inflammatory cells.
• Endothelialization was present early in the central regions, though the intimal layer appeared atypical.

Conclusions:

• Collagen or heparin treatment of modified OVPs did not cause deleterious effects.
• The modified OVPs demonstrated excellent biocompatibility, tissue integration, and patency.
• These findings support the potential of modified OVPs for coronary artery applications.