Histopathological Comparison among Biolimus, Zotarolimus and Everolimus-Eluting Stents in Porcine Coronary Restenosis Model.

Background And Objectives: The aim of this study was to examine the histolopathogical effects among the biolimus, zotarolimus, and everolimus eluting stent (EES) in the porcine coronary restenosis model.

Subjects And Methods: Pigs were randomized into three groups in which the coronary arteries (15 pigs, 10 coronaries in each group) had either a biolimus A9 eluting stent (BES, n=10), zotarolimus eluting stent (ZES, n=10) or an EES (n=10). Histopathologic analysis was performed at 28 days after stenting.

Results: There were no significant differences in the injury score among the three groups. There was a significant difference in the internal elastic lamina, lumen area, neointima area, percent area stenosis, and the fibrin and inflammation score among the three groups (4.3±0.53 mm(2), 2.5±0.93 mm(2), 1.8±1.03 mm(2), 40.7±20.80%, 1.7±0.41, 1.4±0.72 in the BES group vs. 5.1±0.55 mm(2), 2.3±1.14 mm(2), 2.8±1.00 mm(2), 55.4±21.23%, 2.0±0.39, 1.6±0.76 in the ZES group vs. 4.4±0.53 mm(2), 1.7±1.22 mm(2), 2.8±1.23 mm(2), 64.0±26.00%, 1.8±0.76, 2.1±0.90 in the EES group, respectively). BES is more effective in inhibiting neointimal hyperplasia compared to ZES and EES (p<0.0001). According to the fibrin and inflammation score, BES and EES are more effective in decreasing the fibrin deposition compared to ZES (p<0.001). Moreover, BES and ZES are more effective in reducing the inflammatory reaction compared to EES (p<0.001).

Conclusion: The result demonstrates that BES shows better histopathological characteristics than ZES and EES at one month after stenting in the porcine coronary restenosis model.