Novel Nanocrystalline Diamond Coating of Coronary Stents Reduces Neointimal Hyperplasia in Pig Model
Abstract
Objectives: This study sought to study the performance of nanocrystalline diamond (NCD) coated stainless steel (SS) coronary stent in a pig coronary artery model. Background: Diamond is hard, biocompatible material which offers the possibility of functionalization by covalent carbon chemistry.
Methods: Unique microwave plasma enhanced chemical vapour deposition system enabled NCD coating of SS coronary stents. 26 coronary stents (13 NCD coated and 13 SS) were implanted in a randomized fashion into pig coronary arteries with balloon/artery ratio equal to 1.2. The area of neointimal hyperplasia, late loss and stent strut apposition was evaluated by optical coherence tomography at 6 weeks.
Results: All animals survived and all stents were patent at 6 weeks. There was a significantly larger lumen area in the NCD group (4.8+-0.97 versus 3.85+-0.87 mm2, p=0.02).
The neointimal hyperplasia area was smaller in the NCD group by 37% (1.57+-0.63 mm2 in NCD group versus 2.39+-0.87 mm2 in SS group, p=0.02). There was no difference in stent strut apposition and coverage between NCD and SS group.
Conclusion: Implantation of nanocrystalline diamond coated coronary stent significantly reduces neointimal hyperplasia by 37% in comparison to identical stainless steel stent and appears to be safe with very low incidence of non-apposed or uncovered struts.