| Background:Randomized studies have shown that DESs reduce clinical restenosis rates significantly compared with BMSs due to inhibition of intimal neoproliferation. However this effect has proved to be associated with delayed or deficient re-endothelialization. Studies show that the neointimal coverage is closely related to the intrastent restenosis and thrombosis. Angiography can only display the vascular lumen, while IVUS imaging lacks sufficient resolution to reveal stent neointimal coverage accurately. optical coherence tomography (OCT) is a recently developed optical imaging technique that provides high resolution (around10μm) and particularly well adapted for the study of the most superficial layers of the stent new coverage.Objectives:(1) Comparison of neointimal coverage of sirolimus-eluting stents (SES) between OCT and histology:7,14and28days respectively after implantation;(2) Comparison of neointimal coverage of paclitaxel-eluting stents (PES) between OCT and histology:7,14and28days respectively after implantation;(3) Comparison of neointimal coverage of zotarolimus-eluting stents (ZES) between OCT and histology:7,14and28days respectively after implantation.Methods:54stents (18SESs;18PESs;18ZESs) were implanted in18minipig which were treated with asprin and clopidogrel and randomly divided into three groups. Every coronary artery contained only one stent. The porcines underwent OCT and were then euthanized at7days (n=6),14days (n=6) and 28days(n=6). All stent-implanted arteries in these animals were evaluated by histology. Corresponding OCT and histology images were selected with the distal and proximal radiopaque markers used as landmarks. Stent neointimal coverage at each strunt were evaluated. Neointimal hyperplasia (NIH) thickness, intrastent area, lumen area, NIH area and rate of strut coverage were measured calculated in each cross-section of OCT and pathological section.Results:11058struts were analysised with OCT. OCT image has no obvious difference with histology image7days after three kinds of DESs implantation. There are also no obvious difference between OCT and histology image14days after stent implantation by calculating NIH thickness, NIH area and rate of neointimal coverage.In28th day after implantation, there are also no obvious difference comparing OCT image with histology.Conclusions:This study showed that OCT image had good correlation with histology. The rate of neointimal coverage in three DESs groups were50%or over7days after implantation, and even more than90%28days after implantation, which showed that the neointimal coverage of DES were good in the early stage after implantation. ZES group showed best result in NIH thickness and neointimal coverage in three kinds of DESs. OCT is a high-resolution (around10μm) imaging technology that is10times of IVUS and particularly well adapted for the study of the most superficial layers of the vessel wall and for strut-by-strut stent analysis. Background:Coronary stenting is the standard strategy in percutaneous coronary intervention. The use of DESs reduce clinical restenosis rates significantly compared with BMSs due to inhibition of intimal neoproliferation. Howerve, it was reported that the rate of stent thrombosis especially the late stent thrombosis increased. Autopsy studies have shown this effect to be associated with delayed or deficient re-endothelialization. Optical coherence tomography (OCT) is an intracoronary imaging modality with a high-resolution of10to20, providing detailed information of stent strut malapposition and neointimal coverage. Different kind of stents have different characteristics which lead to different influence on the neointima hyperplasia. Most current studies concerned about the neointima by OCT more than3months after stent implantation.Objectives:(1) Comparison of neointimal coverage of sirolimus-eluting stents (SES) with bare-mental stent (BMS) by optical coherence tomography7,14and28days respectively after implantation;(2) Comparison of neointimal coverage of paclitaxel-eluting stents (PES) with BMS by optical coherence tomography7,14and28days respectively after implantation;(3) Comparison of neointimal coverage of zotarolimus-eluting stents (ZES) with BMS by optical coherence tomography7,14and28days respectively after implantation;(4) Comparison of neointimal coverage between SES and PES and ZES by optical coherence tomography7,14and28days respectively after implantation.Methods:72stents (18BMSs;18SESs;18PESs;18ZESs) were implanted in18minipig which were treated with asprin and clopidogrel and randomly divided into three groups. Every coronary artery contained only one drug-eluting stent and BMS was imlapnted in the proximal segment of DES of right coronary artery. The porcines underwent OCT and were then euthanized at7days (n=6),14days(n=6) and28days(n=6). All stent-implanted arteries in these animals were evaluated by OCT. Neointimal hyperplasia (NIH) thickness, intrastent area, lumen area, NIH area and rate of strut coverage were measured and calculated in each OCT cross-section.Results:There were15096struts analysized by OCT in this study. There were significant differences between SES group and BMS group7days,14days and28days after implantation in neointimal hyperplasia thichness, neointimal area and the rate of neointimal coverage (P<0.001). And the same result showed in the PES and ZES, except the rate of neointimal coverage in ZES group7days and28days after implantation (7days:53.62±2.49%vs55.40±3.55%, P=0.233;28days:94.88±2.93%vs97.64±2.51%, P=0.062). Conclusions:The neointimal coverage of struts were different between BMS and DESs in the first month after implantation. Better results showed in the BMS group comparing with DESs groups (especially the SES and PES groups). In addition, ZES had no significant different with BMS7days after implantation. There were also significant differents between different kinds of DESs. The result of ZES group was obviously better than SES and PES groups according to this study. Background:The use of DESs reduce clinical restenosis rates significantly compared with BMSs due to inhibition of intimal neoproliferation. Howerve, it was reported that the rate of stent thrombosis especially the late stent thrombosis increased. Studies have shown that the restenosis and intrastent thrombosis were associated with delayed or deficient re-endothelialization. Because of the limit of various conditions, coronary angiograpy (CAG) and intravascular ultrasound (IVUS) can not show the details of stents and neointima especially in the early stage after stent implantation. OCT is a high-resolution (around10μm) imaging technology that is10times of IVUS and particularly well adapted for the study of the most superficial layers of the vessel wall and for strut-by-strut stent analysis. There were many studies showed that the prognosis of zotarolimus-eluting stents (ZES) was good. But most of these studies cared about the neointimal coverage more than3months after implantation.Objective:Comparative analysis of neointimal coverage with ZES by optical coherence tomography (OCT) between7days and14days and28days after implantation. Comparison of neointimal coverage between OCT and histology and scanning electron microscope image.Method:Eighteen minipigs were randomly divided into three groups. Each animal was implanted with one zotarolimus-eluting stent in coronary artery randomly. Three groups of minipigs underwent OCT and were then euthanized at7days (n=6),14days (n=6) and28days (n=6) respectively after stent implantation. All stent-implanted arteries were observed by light microscope and scanning electron microscope after specimen disposal.Results:OCT image has good correlation with histology and scanning electron microscope. OCT results show that there were significant difference of neointimal hyperplasia thickness between7days,14days and28days groups (61.3±37.7μ m vs.132.6±103.3μm vs.244.3±282.3μm, P<0.001). The rate of neointimal coverage also had significant difference between the three groups (53.62%±2.49%vs.77.91%±4.84%vs.94.88%±2.93%, P<0.001). The distribution of variety of neointima were also different.Conclusion:Neointima can be clearly observed7days after stent implantation by OCT. Most of the struts were covered with neointima28days after ZES implantation. |
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