EFFECT ON INTIMAL HYPERPLASIA OF DEXAMETHASONE RELEASED FROM COATED METAL STENTS COMPARED WITH NON-COATED STENTS IN CANINE FEMORAL ARTERIES

Purpose: Polymer-coated, dexamethasone (DXM)-releasing stents were tes ted in order to assess the efficacy of DXM released locally for the pr evention of stent restenosis due to intimal hyperplasia. Methods: Stre cker stents coated with a biodegradable membrane containing DXM were i mplanted percutaneously into the femoral artery in 14 dogs. The contra lateral artery received a conventional non-coated stent serving as con trol. The drugs are eluted by degradation of the carrier membrane. Fol low-up intraarterial digital subtraction angiography (DSA) was obtaine d at 3, 6, 9, 12, and 24 weeks with subsequent autopsy. Specimens for gross and microscopic pathology were obtained and histomorphometry was performed. Results: Four of 14 DXM-coated stents showed thrombotic oc clusion within the first 3 weeks; ten DXM-coated stents remained paten t. At follow-up DSA, DXM-coated stents showed a significantly wider lu men than the non-coated stents. At morphometry there was less intimal hyperplasia over DXM-coated stents than over non-coated stents (p < 0. 05). Conclusion: DXM-coated stents reduce neointimal hyperplasia in do gs when compared with non-coated stents.