Hydrogel-mediated release of basic fibroblast growth factor from a stent-graft accelerates biological fixation with the aortic wall in a porcine mode

目的：研究生物固定支架外表面明胶水凝胶释放的碱性成纤维细胞生长因子（bFGF）对主动脉壁局部反应的影响。方法：在6条猪主动脉内植入18个镍钛诺基聚酯覆盖支架，持续1个月。将植入的支架分为3组：对照组（未包被）、水凝胶组（包被含水的水凝胶）和bFGF组（包被含bFGF的水凝胶）。支架植入术后，比较各组血管内超声（IVUS）及显微镜定性、定量检查结果。结果：bFGF组在IVUS图像上可见薄的白色板层组织。与其他两组相比，bFGF组动物的新内膜组织形成明显增加，并且在新组织中检测到α平滑肌（SM）肌动蛋白阳性细胞（alphaSMCs）。紧密编织移植物织物中的alphasmc在bFGF组明显比其他组丰富。结论：支架内bFGF的局部控释可显著加速主动脉与支架间及支架材料内新生内膜组织的增殖。这些发现表明，移植物可以生物地固定在主动脉壁上，这可能有助于支架移植后动脉瘤的缩小。

PURPOSE: To evaluate the local reaction of the aortic wall induced by basic fibroblast growth factor (bFGF) released from a gelatin hydrogel coated on the outer surface of a stent-graft for the purpose of biological fixation.METHODS: A total of 18 nitinol-based, polyester-covered stent-grafts were implanted in 6 porcine aortas for 1 month. The implanted stent-grafts were divided into 3 groups: the control group (uncoated), the hydrogel group (coated with hydrogel containing water), and the bFGF group (coated with hydrogel containing bFGF). After stent-graft implantation, the results of intravascular ultrasound (IVUS) and qualitative and quantitative microscopic examinations were compared among the groups.RESULTS: In the bFGF group, a thin white lamellar tissue was observed on IVUS images. Significantly more new intimal tissue formation was observed in all the bFGF group animals than in the other 2 groups, and alpha smooth muscle (SM) actin-positive cells (alphaSMCs) were detected in this new tissue. The alphaSMCs within the fabric of tightly woven grafts were significantly more abundant in the bFGF group than in the other groups.CONCLUSION: The local controlled release of bFGF from the stent-graft significantly accelerated the proliferation of new intimal tissue between the aorta and the stent-graft and within the graft materials. These findings suggest that a graft can be fixed biologically to the aortic wall, which may contribute to the shrinkage of aneurysms following stent-grafting.