Background Self-expanding stents (SES) are reemerging as therapeutic alternatives to treat coronary artery disease. It has been proposed that SES can improve clinical outcomes by inducing less injury at implantation and achieving better vessel wall apposition. To date, little data exists comparing the vascular response to both methods of deployment in a controlled experimental setting. Objective To quantify differences in vascular injury and healing between second-generation SES and balloon-expandable stents (BES) and the effects of balloon postdilatation in a porcine coronary model. Methods Seventy-five bare SES (AXXESS or vProtect) and 42 BES (Vision) were implanted in porcine coronaries. A subset of these received balloon postdilatation (SES + D = 22, BES + D = 20). Follow-up was scheduled at 30 (BES = 10, BES + D = 6, SES = 19, SES + D = 8), 90 (BES = 6, BES + D = 8, SES = 19, SES + D = 8), and 180 days (BES = 6, BES + D = 6, SES = 15, SES + D = 6). Results In vivo imaging and histological analysis showed that neointimal formation peaks early (30 days) in BES. Conversely, for SES, the peak occurred later (90 days). However, the neointimal formation achieved in either group equalized at 180 days. For SES, postdilatation shortened the peak of neointimal formation to 30 days. Conversely, for BES, postdilatation delayed the peak of neointimal formation to 90 days. At 30 days, histology showed that SES had significantly less injury. However, at 90 days, injury scores tended to be higher for SES. By 180 days, injury scores were comparable between both groups. Conclusions The mechanism of stent expansion influences the degree of vascular injury and healing. The synergistic use of balloon postdilatation changes the dynamics of healing and may impact the potential beneficial effects inherent to SES technologies. © 2012 Wiley Periodicals, Inc.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine