1st Department of Cardiac Surgery, Medical University of Silesia, Katowice, Poland.
Med Sci Monit. 2010 Mar;16(3):BR89-96.
Neointimal hyperplasia (NIH) in vein grafts implanted into the arterial system develops after re-endothelialization and is considered a significant risk factor of occlusion. Evidence suggests that VEGF-A expression with VEGFR-2 activation and/or VEGFR-1 down-regulation might be involved in inhibiting NIH formation. The aim was to assess whether a stented vein graft (SV) has an impact on VEGF-A and VEGFR-1 expression compared with non-stented vein grafts.
MATERIAL/METHODS: Twelve sheep received a radial vein with an outside stent (SV) and a radial vein (RV) transplanted into their carotid arteries. The covering of the luminal surface of the SV and RV grafts by endothelium was 98.3% and 96.3%, respectively, at 6 weeks. From the 6th to 12th weeks after transplantation, the time course of total VEGF-A expression and VEGFR-1 expression were evaluated separately for the intima and media.
VEGF-A and VEGFR-1 expression were significantly lower in the SV than in the RV group in the intima. In the media the SV grafts were associated with higher VEGF-A and VEGFR-1 expression at 6 and 8 weeks, but lower values were observed at weeks 10 and 12 compared with the RV grafts. Comparing the time courses of VEGF-A and VEGFR-1 expression in the intima and media with intimal/medial thickening in the SV and RV groups, negative correlations for the SV grafts were found.
These findings indicate that outside stenting of the vein graft decreases VEGF-A expression and induces significant down-regulation of VEGFR-1 in the intima and media after the re-endothelialization.
在动脉系统中植入静脉移植物后，新生内膜增生（NIH）会在再内皮化后发生，被认为是闭塞的一个重要危险因素。有证据表明，VEGF-A 的表达与 VEGFR-2 的激活和/或 VEGFR-1 的下调可能参与了抑制 NIH 形成。本研究旨在评估支架置入的静脉移植物（SV）与非支架置入的静脉移植物相比，对 VEGF-A 和 VEGFR-1 表达的影响。
材料/方法：12 只绵羊接受了带外支架的桡静脉（SV）和桡静脉（RV）移植到颈动脉。6 周时，SV 和 RV 移植物的内腔表面内皮覆盖率分别为 98.3%和 96.3%。移植后第 6 至 12 周，分别评估了 SV 和 RV 移植物内膜和中膜的总 VEGF-A 表达和 VEGFR-1 表达的时程。
SV 组的 VEGF-A 和 VEGFR-1 表达在内膜明显低于 RV 组。在中膜，SV 移植物在 6 周和 8 周时与 RV 移植物相比，VEGF-A 和 VEGFR-1 表达较高，但在 10 周和 12 周时表达较低。与 SV 和 RV 移植物的内膜和中膜 VEGF-A 和 VEGFR-1 表达的时间过程与内膜/中膜增厚进行比较，SV 移植物呈负相关。
这些发现表明，静脉移植物的外支架置入可降低 VEGF-A 的表达，并在再内皮化后诱导内膜和中膜 VEGFR-1 的显著下调。
