Stefanadis C, Toutouzas K, Tsiamis E, Vlachopoulos C, Vaina S, Tsekoura D, Haldi L, Stefanadi E, Gravanis M, Toutouzas P
Department of Cardiology, University of Athens, Greece.
Cardiovasc Res. 1999 Feb;41(2):433-42. doi: 10.1016/s0008-6363(98)00211-9.
The use of stents has improved results after balloon coronary angioplasty. Several materials have been proposed for covering the metallic surface of the stent to reduce the rate of subacute thrombosis and restenosis. In our institution, an autologous arterial graft was used for covering the external surface of a conventional stent. The angiographic and histological response in a porcine coronary artery model was investigated.
An autologous arterial graft was removed from the femoral artery and carefully prepared. Subsequently, a conventional stent was covered externally by the arterial graft. Twenty-two covered stents and 22 uncovered regular stents were implanted alternatively in the coronary arteries of 22 pigs. One animal died immediately after the procedure, due to thrombus formation in the uncovered stent. Six animals were sacrificed at seven days and the remaining animals were sacrificed at two months. Before the sacrifice, coronary angiography was performed in all animals.
Thrombosis was detected in two control segments and in one covered stented segment. After seven days, the luminal surface of the covered stents was covered by a new endothelial layer in contrast to partial endothelial cell appearance in the control group. The angiographic parameters were similar between the two groups. Histologically, the covered stents were associated with less vascular injury compared to uncovered stents. In covered stents a trend towards reduction of maximal intimal hyperplasia was detected (covered: 116.6 +/- 47.75 vs uncovered: 150.25 +/- 46.81 microns, p = 0.08); also the thickness of the arterial media was reduced (covered: 21.34 +/- 10.28 vs uncovered: 102.63 +/- 18.71 microns, p = 0.02). The luminal and vessel areas were similar in the two groups.
The preparation and implantation of the autologous arterial graft-covered stent is technically safe and feasible. This type of covered stent results in accelerated endothelialization, less vascular injury, thinning of the arterial media and a trend to reduce the intimal hyperplasia in normal coronary arteries.
支架的应用改善了球囊冠状动脉成形术后的效果。已提出几种材料用于覆盖支架的金属表面，以降低亚急性血栓形成和再狭窄的发生率。在我们机构，使用自体动脉移植物覆盖传统支架的外表面。研究了猪冠状动脉模型中的血管造影和组织学反应。
从股动脉取出自体动脉移植物并仔细制备。随后，用动脉移植物在外部覆盖传统支架。将22个带覆盖物的支架和22个未覆盖的常规支架交替植入22头猪的冠状动脉中。1只动物在手术后立即死亡，原因是未覆盖的支架中形成血栓。6只动物在7天时处死，其余动物在2个月时处死。在处死前，对所有动物进行冠状动脉造影。
在两个对照节段和一个带覆盖物的支架节段中检测到血栓形成。7天后，与对照组部分内皮细胞出现相比，带覆盖物的支架的管腔表面被新的内皮层覆盖。两组之间的血管造影参数相似。组织学上，与未覆盖的支架相比，带覆盖物的支架与较少的血管损伤相关。在带覆盖物的支架中，检测到最大内膜增生有减少的趋势（带覆盖物：116.6±47.75 vs未覆盖：150.25±46.81微米，p = 0.08）；动脉中膜厚度也降低了（带覆盖物：21.34±10.28 vs未覆盖：102.63±18.71微米，p = 0.02）。两组的管腔和血管面积相似。
自体动脉移植物覆盖支架的制备和植入在技术上是安全可行的。这种类型的带覆盖物的支架可导致内皮化加速、血管损伤减少、动脉中膜变薄以及正常冠状动脉内膜增生有减少的趋势。
