Objective Bare metal stent (BMS) implantation can resolve renal artery stenosis successfully, but in-stent restenosis does occur, especially in small diameter renal arteries (<5.0 mm). The aim of this study is to test whether a newly designed polymer-free sirolimus and probucol-eluting stent (SPES) can inhibit neointimal hyperplasia of renal artery in swine.
Methods 26 stents (18 SPES and 18 BMS) were implanted in 36 renal arteries of 18 animals. During every procedure, a SPES and a BMS were randomised to the right or left renal artery. Seven animals were sacrificed after 90 days, and 11 after 180 days.
Results Histomorphometric analysis was performed. After 90 days, minimal lumen area, neointimal area, score of inflammation and score of endothelialisation were not significantly different between BMS and SPES. After 180 days, minimal lumen area was not significantly different between BMS and SPES (6.55±2.91 mm2 vs 7.32±1.99 mm2, p=0.477), but neointimal area was significantly less in SPES vessels than in BMS vessels (3.07±0.83 mm2 vs 4.47±1.23 mm2, p=0.005). Score of inflammation and score of endothelialisation were not significantly different between BMS and SPES after 180 days.
Conclusion SPES can successfully inhibit neointimal hyperplasia of renal artery in swine. At the same time, inflammation and endothelialisation in SPES vessels were similar to BMS vessels.