A polyvinyl alcohol core coil containing basic fibroblast growth factor evaluated in rabbits with aneurysms induced by elastase

OBJECTIVE: The present study evaluates the effect of a novel coil with a polyvinyl alcohol (PVA) core that delivered basic fibroblast growth factor (bFGF) to aneurysms in rabbits induced by elastase. METHODS: PVA was processed to form small threads and inserted into the central core of a primary coil (PVA-core coil). After immersion in saline or bFGF (500 or 2000 mu g/ml), PVA-core coils were implanted into elastase-induced aneurysms in rabbits in vivo. Follow-up angiography was performed 4 and 8 weeks after embolization, and the effects were histologically semiquantified according to a grading scale. RESULTS: Follow-up angiography showed that the coils did not compact or protrude and that clots did not form in any group. The score of gross neck healing was significantly higher in the 8-week 2000 bFGF group than in the 8-week PVA coil group (2.7 +/- 0.6 versus 0.0 +/- 0.0, P < 0.05). The dome healing score was significantly higher in the 4-week 2000 bFGF group than that of the 4-week PVA coil group (4.0 +/- 0.0 versus 2.7 +/- 0.6, P < 0.05). Cells positive for (x-smooth muscle actin densely accumulated in the dome of the aneurysm embolized with PVA-core coils containing bFGF. CONCLUSION: Implantation of the PVA-core coil containing bFGF accelerated tissue growth at the neck as well as in the dome of aneurysms induced by elastase in rabbits. These results suggested that PVA-core coils could prevent the recanalization of embolized aneurysms.