Upper-Silesian Center of Cardiology, Medical University of Silesia, Katowice, Poland.
Med Sci Monit. 2010 Jan;16(1):BR40-4.
The high radial force and durability of cobalt-chromium alloy enable the construction of low-profile stents with thin struts, which improves their elasticity and may play a key role in reducing the incidence of neointimal hyperplasia as well as allow faster endothelialization. The aim of this study was to compare cobalt-chromium (CoCr) and stainless steel (SS) coronary stents in a pig model of neointimal hyperplasia.
MATERIAL/METHODS: Eighteen stents were implanted into the coronary arteries of nine pigs. Control coronarography was performed 28 days after stent implantation. The animals were then sacrificed, their hearts explanted, and the coronary arteries isolated for further histopathological analysis.
Quantitative coronary angiography and histomorphometric analysis revealed no statistically significant difference between the two groups of stents. However, there was a trend toward greater late lumen loss (p=0.09) and neointimal area in the CoCr stents (p=0.08). The qualitative histopathology of the CoCr stents revealed findings typical of bare metal stents reviewed in the literature and approved for use in clinical practice. No signs of stent thrombosis, necrosis, or fibrin deposits were observed nor signs of excessive inflammatory reaction. Endothelialization was complete within 28 days.
Despite thinner struts, CoCr stents have no advantage over stainless steel stents in terms of neointimal hyperplasia inhibition. However, their positive safety results together with their high radial strength, low profile, and excellent elasticity can ensure their usage, especially in lesions of complex morphology.
钴铬合金具有较高的径向力和耐用性，能够构建具有较薄支柱的低轮廓支架，从而提高其弹性，这可能在降低新生内膜增生的发生率方面发挥关键作用，并允许更快的内皮化。本研究旨在比较用于治疗新生内膜增生的钴铬（CoCr）和不锈钢（SS）冠状动脉支架。
材料/方法：将 18 个支架植入 9 只猪的冠状动脉内。支架植入 28 天后进行对照冠状动脉造影。然后处死动物，取出心脏，分离冠状动脉进行进一步的组织病理学分析。
定量冠状动脉造影和组织形态计量学分析显示两组支架之间无统计学差异。然而，CoCr 支架的晚期管腔丢失（p=0.09）和新生内膜面积有增加趋势（p=0.08）。CoCr 支架的定性组织病理学显示出与文献中回顾的裸金属支架相似的发现，并且已批准用于临床实践。未观察到支架血栓形成、坏死或纤维蛋白沉积的迹象，也未观察到过度炎症反应的迹象。内皮化在 28 天内完全完成。
尽管 CoCr 支架的支柱较薄，但在抑制新生内膜增生方面，与不锈钢支架相比没有优势。然而，其积极的安全性结果，加上其高径向强度、低轮廓和出色的弹性，能够确保其使用，尤其是在复杂形态的病变中。
