In vivo evaluation of modified mandrel-grown vascular prostheses

The Omniflow(TM) Vascular Prosthesis (OVP) has been manufactured and extens ively tested in animal and human trials. It has mechanical and biological q ualities superior to synthetic and biological conduits, particularly in low flow conditions. For further development into the smaller diameter coronar y prostheses, the inner luminal surface is of paramount importance. In a pr evious study this inner surface was modified to produce a more uniformly th icker nonundulating surface. In this study the mandrels of these modified O VPs were treated with either collagen or heparin; the OVPs were evaluated f or patency, tissue integration and wound healing, and endothelialization us ing a dog model comparable to that used to evaluate the unmodified OVP. In all instances, each of the modified prostheses were fully patent and had no signs of any deleterious effects caused by these modifications; no thrombu s or aneurysms were visible. The tissue response was rapid with excellent n ew host collagen deposition within the vessel wall and minimal inflammatory and foreign body giant cells. Endothelialization was noted at the earliest explant time point in central regions of the prostheses, albeit that the h istological picture at this time point appeared to reflect a complex atypic al intimal layer. (C) 1999 John Wiley & Sons, Inc.