In an attempt to reduce platelet deposition and inhibit neointimal hyperplasia, we evaluated the effect of coating expanded polytetrafluoroethylene (ePTFE) grafts with phosphorylcholine (PC), a lipid found in animal cell membranes, in a dog model of femoral arteriovenous (AV) grafts. Eight mongrel dogs underwent placement of a PC-coated femoral AV graft on one side and an untreated control graft on the contralateral side. Platelet deposition was measured by autologous 111Indium-labeling and scintillation camera imaging analysis. Platelet deposition on the PC-coated grafts at 30 and 90 min. was 9.32 ± 4.35 x 109 and 10.00 ± 4.38 x 109, respectively, as compared with 10.26 ± 4.36 x 109 and 11.64 ± 5.08 x 109 platelet deposition on control grafts (P < 0.05). All grafts were patent at 4 weeks. There was a significant reduction of neointimal area at both arterial (0.07 ± 0.05 mm2) and venous (0.18 ± 0.09 mm2) anastomoses in the treated grafts as compared with arterial (0.15 ± 0.05 mm2) and venous (0.43 ± 0.22 mm2) anastomoses in the control grafts (P < 0.05). In addition, neointimal cell proliferation assayed by bromodeoxyuridine (BrdU) incorporation was reduced in both arterial (2.05 ± 0.81%) and venous (3.25 ± 0.17%) anastomoses of treated grafts compared with arterial (3.12 ± 1.23%) and venous (5.36 ± 1.18%) anastomoses of control grafts (P < 0.05). These data demonstrated that PC coating of ePTFE grafts significantly reduced platelet deposition, anastomotic neointimal hyperplasia, and neointimal cell proliferation in a dog model of AV grafts. This may represent a new strategy for prolonging hemodialysis graft patency.
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