PHOSPHORYLCHOLINE COATING OF EPTFE GRAFTS REDUCES NEOINTIMAL HYPERPLASIA IN CANINE MODEL

This study attempts to prevent neointimal hyperplasia by coating the g raft luminal surface with a derivative of phosphorylcholine (PC), ther eby providing a biocompatible surface with the assumption of limiting pannus tissue ingrowth from the graft anastomoses. Bilateral carotid a rtery bypass grafts were placed in six dogs using expanded polytetrafl uoroethylene (ePTFE). In each animal, one carotid arterial-arterial co nduit was constructed using a graft having a PC coating over the entir e luminal surface of the graft. On the contralateral side, uncoated gr aft served as a control. The processed specimens were analyzed for gra ft neointimal area and neointimal thickness. Cell proliferation was as sessed by staining for bromodeoxyuridine (BrdU) incorporation. All gra fts were patent except one control graft that was occluded at 4 weeks. There was a significant reduction in the anastomotic graft neointimal area between the treated and control groups (0.27 +/- 0.17 mm(2) vers us 0.53 +/- 0.13 mm(2), respectively; p = 0.008). Furthermore, the Brd U labeling index in the graft neointimal tissues was significantly sma ller (p < 0.001) in the treated group (2.64 +/- 0.77%) as compared wit h the control group (5.07 +/- 0.83%). These data demonstrate that PC c oating of ePTFE significantly reduces graft neointimal hyperplasia and cell proliferation in a canine carotid artery bypass model. The appli cation of PC within the ePTFE graft effectively blocks tissue ingrowth from the adjacent native vessel, thereby preserving the anastomosis l uminal diameter.