This study aimed to investigate the structural integrity and dynamic changes in chronically occluded residual arteries found in post–myocardial infarction (MI) scar. A transmural MI was induced in middle-aged, male Sprague-Dawley rats by left coronary artery ligation. The rats were euthanized 3 days and 1, 2, 4, 8, and 12 weeks after MI, and their hearts were processed into paraffin for histology, immunohistochemistry, and quantitative morphometry. It has been found that large- and medium-sized arteries were able to survive inside the transmural scars for 12 post-MI weeks. Furthermore, most residual arteries preserved their structural integrity for up to 2 weeks post-MI, but gradually all disused vessels had undergone neointimal hyperplasia and inward remodeling at later time periods. In addition, the replacement of vascular smooth muscle cells in the wall of residual arteries by extracellular matrix components led to a disruption of the vessel integrity and progressive obliteration of their lumen between 4 and 12 post-MI weeks. Taken together, this study demonstrate that residual arteries in post-infarcted region were capable of maintaining their structural integrity, including the patent lumen, during two post-MI weeks, suggesting that during this period they can be used as potential conduits for conceivable reflow of arterial blood within the scarred region of the heart

这项研究旨在调查在心肌梗死后（MI）疤痕中发现的慢性阻塞残余动脉的结构完整性和动态变化。通过左冠状动脉结扎术在中年雄性Sprague-Dawley大鼠中诱发透壁MI。在MI后第3天和第1、2、4、8和12周对大鼠实施安乐死，并将其心脏加工成石蜡进行组织学，免疫组织化学和定量形态学测定。已经发现大中型动脉能够在心肌梗死后12周内在透壁瘢痕内存活。此外，大多数残余动脉在心梗后最多可维持其结构完整性长达2周，但是逐渐地，所有废弃的血管都经历了新内膜增生并在随后的时间段内向内重塑。此外，在MI后4周到12周之间，细胞外基质成分置换残留动脉壁中的血管平滑肌细胞会导致血管完整性的破坏和其管腔的逐渐闭塞。综上所述，这项研究表明，梗塞后区域的残余动脉能够在心梗后的两个星期内维持其结构完整性，包括专利管腔，这表明在此期间它们可以用作潜在的可能的冠状动脉回流的导管。心脏疤痕区域内的动脉血