Direct stenting limits sirolimus-eluting stent edge neointimal thickening

Area of Science:

• Cardiovascular Research
• Biomedical Engineering
• Interventional Cardiology

Background:

• In-stent restenosis remains a clinical challenge, particularly at the edges of stents.
• Sirolimus-eluting stents (SES) have shown efficacy in limiting in-stent restenosis.
• Understanding the impact of stent implantation techniques on neointimal hyperplasia is crucial.

Purpose of the Study:

• To analyze neointimal thickening after SES and bare metal stent (BMS) implantation.
• To assess the influence of stent implantation procedures (direct stenting vs. predilation) on neointimal thickening.
• To evaluate neointimal thickening in both the in-stent segment and at the stent edge.

Main Methods:

• Ex-vivo human mammary artery model.
• Comparison of balloon-expandable SES and BMS.
• Evaluation of direct stenting versus predilation techniques.
• Assessment of neointimal thickening via immunohistochemistry, western blotting, and histomorphometry at 28 days post-stenting.

Main Results:

• SES significantly inhibited in-stent neointimal thickening compared to BMS, irrespective of stenting technique.
• Direct stenting further reduced in-stent neointimal thickening in the SES group.
• Direct stenting significantly reduced neointimal thickness at the stent edge for SES, unlike with BMS.

Conclusions:

• Sirolimus elution from SES effectively inhibits neointimal hyperplasia by modulating RhoA and p27kip expression.
• Direct stenting is beneficial in minimizing edge restenosis when using SES.
• These findings support optimizing stent implantation techniques to enhance SES efficacy.