S. Lepidi et al., THE DEGREE OF POROSITY INFLUENCES THE RELEASE OF GROWTH-FACTORS BY HEALING POLYTETRAFLUOROETHYLENE (PTFE) GRAFTS, European journal of vascular and endovascular surgery, 11(1), 1996, pp. 36-41
Objectives: The aim of this study was to determine the influence of th
e degree of porosity on the release of growth factors (PDGF AA, PDGF B
E, bFGF) by healing PTFE grafts. Design and setting: Laboratory animal
study. Materials: 1 cm long segments of non-reinforced PTFE grafts (3
0 microns fibril length, 2 mm internal diameter 0.39 mm thick) were pl
aced as an abdominal aortic interposition in Lewis rats. Fifteen graft
s served as control (Group A; porous grafts); in eight rats (Group B;
non porous grafts) the PTFE graft was completely wrapped by a non-poro
us plastic envelope. Animals were killed 4 weeks after surgery. Outcom
e measures: The release of PDGF AA, PDGF BE, and bFGF was assessed by
Enzyme Linked Immunosorbent Assay (ELISA). Results: The release of PDG
F AA, PDGF BE and bFGF was statistically higher in porous grafts. The
only histological difference between the two groups was that porous PT
FE grafts were invaded by many tufts of capillaries front the surround
ing tissue, whereas this phenomenon was absent in non porous PTFE graf
ts. Conclusions: The degree of porosity influences the release of grow
th factors by healing PTFE grafts. This fact may have implication in t
he endothelisation of PTFE grafts and in myointimal hyperplasia format
ion as well.