ThoraxCenter, Erasmus Medical Center, Rotterdam, the Netherlands.
Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
JACC Cardiovasc Interv. 2016 Apr 25;9(8):838-851. doi: 10.1016/j.jcin.2016.01.030.
The aim of the present study was to investigate the relationship between the integration process and luminal enlargement with the support of light intensity (LI) analysis on optical coherence tomography (OCT), echogenicity analysis on intravascular ultrasound, and histology up to 4 years in a porcine model.
In pre-clinical and clinical studies, late luminal enlargement has been demonstrated at long-term follow-up after everolimus-eluting poly-l-lactic acid coronary scaffold implantation. However, the time relationship and the mechanistic association with the integration process are still unclear.
Seventy-three nonatherosclerotic swine that received 112 Absorb scaffolds were evaluated in vivo by OCT, intravascular ultrasound, and post-mortem histomorphometry at 3, 6, 12, 18, 24, 30, 36, 42, and 48 months.
The normalized LI, which is the signal densitometry on OCT of a polymeric strut core normalized by the vicinal neointima, was able to differentiate the degree of connective tissue infiltration inside the strut cores. Luminal enlargement was a biphasic process at 6 to 18 months and at 30 to 42 months. The latter phase occurred with vessel wall thinning and coincided with the advance integration process demonstrated by the steep change in normalized LI (0.26 [interquartile range (IQR): 0.20 to 0.32] at 30 months versus 0.68 [IQR: 0.58 to 0.83] at 42 months, p < 0.001).
In this pre-clinical model, late luminal enlargement relates to strut integration into the arterial wall. Quantitative LI analysis on OCT could be used as a surrogate method for monitoring the integration process of poly-l-lactic acid scaffolds, which could provide insight and understanding on the imaging-related characteristics of the bioresorption process of polylactide scaffolds in human.
本研究旨在通过光密度（LI）分析光学相干断层扫描（OCT）、血管内超声回声分析以及组织学检查，研究整合过程与管腔扩大之间的关系，该研究在猪模型中进行，随访时间长达 4 年。
在临床前和临床研究中，在接受依维莫司洗脱聚 L-乳酸酸冠脉支架植入后长期随访中发现晚期管腔扩大。然而，时间关系及其与整合过程的机制关联仍不清楚。
对 73 只非动脉粥样硬化猪进行了体内评估，在 3、6、12、18、24、30、36、42 和 48 个月时分别通过 OCT、血管内超声和死后组织形态计量学进行评估。
归一化 LI（OCT 上聚合物支撑核心的信号密度，通过与相邻新生内膜进行归一化）能够区分支撑核心内结缔组织浸润的程度。管腔扩大是一个双相过程，发生在 6 至 18 个月和 30 至 42 个月。后一阶段伴随着血管壁变薄，与归一化 LI 的急剧变化一致（30 个月时为 0.26 [四分位距（IQR）：0.20 至 0.32]，42 个月时为 0.68 [IQR：0.58 至 0.83]，p < 0.001）。
在这个临床前模型中，晚期管腔扩大与支架整合到动脉壁有关。OCT 上的定量 LI 分析可以作为监测聚 L-乳酸酸支架整合过程的替代方法，这可以为理解和理解聚乳酸支架生物吸收过程的影像学特征提供帮助。
