Biodegradable polyglycolide endovascular coils promote wall thickening anddrug delivery in a rat aneurysm model

OBJECTIVE: We designed biodegradable polyglycolide coils (BPCs) and compare d the histopathological response to the coils with that to platinum Gugliel mi detachable coils (GDCs), after insertion into ligated common carotid art eries (CCAs) of adult rats. BPCs were also tested for use in local drug del ivery. METHODS: Segments (4-mm) of unmodified BPCs, unmodified GDCs, or BPCs coate d with Type I bovine collagen and recombinant human vascular endothelial gr owth factor-165 (500 mug/ml) were inserted into ligated CCAs of adult rats for 14 days, and specimens were compared with contralateral CCA control spe cimens. RESULTS: Arterial segments with BPCs exhibited substantially increased wall thickening, compared with GDCs (0.33 mm versus 0.10 mm, P < 0.005), which reduced the luminal diameter by 40%, relative to untreated contralateral co ntrol specimens (P < 0.05, n = 6). Arterial segments with BPCs also exhibit ed a marked reduction (P < 0.05, n = 6) in luminal area (0.72 <plus/minus> 0.93 mm(2)), with marked cellular proliferation within the coil diameter, i ndicating coil integration. Arterial segments with collagen/recombinant hum an vascular endothelial growth factor-coated BPCs also exhibited a marked 2 .9-fold increase (P < 0.005, n = 5) in wall thickness (0.29 +/- 0.11 mm) an d a 34% reduction in luminal diameter, compared with contralateral control vessels. There was marked proliferation of cells within the coil lumen of v essels treated with BPCs with collagen/recombinant human vascular endotheli al growth factor. CONCLUSION: In this feasibility study, BPCs enhanced the vascular response of CCA segments, compared with GDCs, and were also suitable for local prote in delivery to the vessel lumen, under conditions of stasis and arterial pr essurization of vascular cells.