Benson A E, Palmaz J C, Tio F O, Sprague E A, Encarnacion C E, Josephs S C
University of Texas Health Science Center at San Antonio, Department of Radiology, 78284-7800, USA.
J Vasc Interv Radiol. 1999 May;10(5):605-12. doi: 10.1016/s1051-0443(99)70091-6.
To evaluate expanded polytetrafluoroethylene (ePTFE) encapsulated stents for the treatment of aortic aneurysms with emphasis on the blood and tissue-material interactions.
Experimental aortic aneurysms were created in dogs by enlarging the aortic lumen with an abdominal fascial patch. Twenty animals underwent endoluminal repair after allowing the surgically created aneurysm to heal for 2 months prior to transluminal aneurysmal exclusion. The device used consisted of an 8-cm-long ePTFE encapsulated stent graft. The animals were killed in groups at 1 week and at 1, 2.25, 6, and 12 months. Specimens were processed for histologic and luminal surface studies.
Before the animals were killed, aortography demonstrated two thrombosed aortae in the 6-month group and two endoleaks in the 12-month group. Endothelialized neointima extended into the proximal and distal portions of the prosthetic lumen, with minimal cell coverage in the center of the graft. The overall percent surface area covered by endothelialized neointima was 22% +/- 6% at 6 months and 18% +/- 10% by 1 year (P = .75). Histologic examination demonstrated minimal tissue penetration into the ePTFE.
Transluminal exclusion of abdominal aortic aneurysms by encapsulated stent-graft is easily accomplished. With this device, tissue coverage and penetration of the stent graft is limited and does not tend to increase with time.
评估膨体聚四氟乙烯（ePTFE）封装支架治疗主动脉瘤的效果，重点关注血液与组织 - 材料的相互作用。
通过用腹部筋膜补片扩大主动脉管腔在犬体内制造实验性主动脉瘤。20只动物在手术制造的动脉瘤愈合2个月后进行腔内修复，然后经腔内排除动脉瘤。使用的装置由一个8厘米长的ePTFE封装支架移植物组成。动物在1周以及1、2.25、6和12个月时分组处死。对标本进行组织学和管腔表面研究。
在处死动物之前，主动脉造影显示6个月组有两个血栓形成的主动脉，12个月组有两个内漏。内皮化的新生内膜延伸到人工血管腔的近端和远端部分，移植物中心的细胞覆盖最少。6个月时内皮化新生内膜覆盖的总表面积百分比为22%±6%，1年时为18%±10%（P = 0.75）。组织学检查显示组织向ePTFE内的穿透极少。
通过封装支架移植物经腔内排除腹主动脉瘤很容易实现。使用这种装置，支架移植物的组织覆盖和穿透有限，且不会随时间增加。
