光学相干断层成像评价药物洗脱支架置入术后极早期新生内膜的覆盖情况

Evaluation of very early neointimal coverage post drug-eluting stent implantation using opticalcoherence tomography

目的应用光学相干断层成像（OCT）评价药物洗脱支架置入术后极早期新生内膜的覆盖情况。方法入选行药物洗脱支架置入术的冠心病患者12例。支架释放后即刻和术后1周左右进行OCT检查，评价药物洗脱支架置入术后极早期新生内膜的覆盖情况。同时选取健康中华小型猪5只，置入雷帕霉素洗脱支架，1周后进行OCT和病理学检查。结果（1）12例患者共置入29枚药物洗脱支架，支架术后（7．7±2．6）d复查OCT。患者均未发生严重心血管不良事件。OCT检查显示大部分支架丝处于裸露状态，支架内膜覆盖率为（21．8±17．7）％，新生内膜厚度为（42．9±32．2）Ixm，贴壁不良率为（1．5±3．0）％，2例患者存在支架内附壁血栓（发生率为16．7％）。（2）在中华小型猪模型中，支架术后1周OCT检测的新生内膜覆盖率为（43．2．4-11．5）％，新生内膜厚度为（24．0±8．5）μm；病理学检查发现早期覆盖于支架上的组织主要包括蛋白聚糖、炎症细胞、纤维素和机化血栓，仅部分内膜有少量内皮细胞覆盖。结论OCT检查显示药物洗脱支架置入1周后即有新生内膜覆盖，但覆盖率较低，且新生内膜成分以蛋白聚糖、炎症细胞和机化血栓为主，再内皮化情况较差。

Objective To investigate the neointimal coverage at the very early phase after drug- eluting stent （DES） implantation using optical coherence tomography （OCT）. Methods OCT examination was performed immediately after stent deployment and about one week post stenting in 12 patients with coronary artery disease to detect neointimal coverage and stent thrombus. Sirolimus eluting stent implantation was also performed in 5 healthy Chinese minipigs, OCT and histopathology examination were made one week later in these minipigs. Results （ 1 ） Twenty-nine DES were implanted in 12 patients. There was no major cardiovascular event post stenting. The mean time of follow-up was （ 7.7 ± 2. 6 ） d, the mean percentage of stent coverage was （21.8 ±17.7）% , and neointimal hyperplasia thickness was （42. 9 ± 32. 2） p^m and the percentage of malapposition struts was （ 1.5 ±3.0） % , respectively. Mural stent thrombus was found in 2 of the 12 patients （the percentage is 16. 7% ）. （2） In the minipigs model, OCT evidenced that （43.2 ± 11.5 ） % struts were covered by neointima with a mean neointimal hyperplasia thickness of （24. 0 ± 8.5 ） p^m at one week. Histopathology examination illustrated that the neointima was mainly consisted of proteoglycan, inflammation cells, fibrin and organized thrombus at the very early phase after DES implantation, while endothelial ceils were barely found on the neointima. Conclusions Neointimal coverage is found as early as one week after DES implantation by OCT. The covered struts rate is very low and the main components of neointima are proteoglycan, inflammation cells, fibrin and organized thrombus. Re-endothelialization is rather poor at the very early phase post DES implantation.