Fundamental study on safety of cavered retrieval ncetallic stent

带膜可回收可扩张金属支架的实验研究摘要：目的：评价裸露可回收可扩张金属支架(REMS)和带膜支架在犬下腔静脉中的应用效果。材料如下：11只成年犬接受了裸露的REMS，6只犬接受了带有聚尿管、涤纶和聚四氟乙烯的隐蔽式REMS。使用直径0.35 mm的圆形不锈钢、直径0.2 mm的加捻不锈钢线和尼龙外科线。不锈钢丝制成圆柱体，有12个之字形的发夹弯头，一侧的6个弯头拧成小圆环。这些环被不锈钢线环绕着。相邻物体的每两个弯头都用不锈钢线连接。回收装置由一个带旋转手柄的不锈钢挂钩、长护套和一根聚四氟乙烯棒组成。结果：放置1周后，裸露的REMS可从下腔静脉中取出，但超过2周后，裸露的REMS和覆盖的REMS不能被取出。所有裸露的REMS患者的下腔静脉管腔均通畅，而覆盖的REMS患者均闭塞。1周后病理检查显示裸露的REMS表面未完全复盖内膜，2周后内膜完全复盖。在被覆盖的RMS中，可见红色血栓和不完全被覆盖的内膜。对于闭塞性下腔静脉病变，不能尝试使用有遮盖的REMS。

Experimental Study on Covered Retrieval Expandable Metallic Stent.Summary : Purpose is to evaluate the efficasy of bared retrieval expandable metallic stent (REMS) and covered REMS in canine inferior vena cava. Meterials are as follows ; eleven adult dogs underwent the placement of bared REMS and six dogs underwent covered REMS with polyurethance, dacron and polytetrafuluoroethylene. Round stainless steel with diameter 0.35mm, twisted stainless steel thread with diameter 0.2mm and nylon surgical thread were used. The stainless steel wire was made into a cylindrical body with 12 zig zag hairpin bends, six bends of one side were twistcd to form small round loops. The loops were encircled by the stainless steel thread. Every two bends from neighboring bodies were connected by stainless steel thread. The retrieval set consists of a stainless steel hook with a rotating handle, long sheath and a Teflon rod. Results : After 1 week placemcnt, the bared REMS could be removed from IVC but over two weeks bared REMS and covered REMS could not be removed. Angiography showed the patency of the IVC lumen in all cases with bared REMS but occlusion in all cases with covered REMS.Pathological fidings showed incompletely covered intima on the surface of the bared REMS after 1 week placement and completely covered intima over 2 weeks. In covered REMS,the red thrombus and incompletely covered intima were noted. It is not acceptable for covered REMS to be tried to use for the obliterative IVC lesion.