Pärsson H, Jundzill W, Hallberg E, Thörne J, Norgren L
Department of Surgery, University of Lund, Sweden.
Eur J Vasc Surg. 1993 Jan;7(1):63-70. doi: 10.1016/s0950-821x(05)80546-8.
Recently a new expanded polytetrafluoroethylene (ePTFE) graft with length compliant characteristics has been developed. The present study compared the acute thrombogenicity and 4 weeks healing characteristics of the stretch ePTFE graft to standard ePTFE grafts in vivo. Grafts of 6 cm length and 8 mm internal diameter were inserted end-to-side into the iliac arteries in pigs. Platelet adhesion was assessed by infusing indium-111-oxine (20 MBq) labelled autologous platelets and dynamically imaging the grafts. Explanted grafts (n = 14) were opened longitudinally and the thrombus-free surface (TFS) and segmental accumulation of platelets were determined. Stretch ePTFE grafts had significantly less platelet deposition when compared to standard ePTFE graft (p < 0.01). The dynamic increase of activity from 10 min after start of measurement was also significantly reduced (p < 0.05) for 170 min as compared to standard ePTFE grafts. TFS was 68 +/- 5% for stretch ePTFE and 37 +/- 5% for standard ePTFE grafts (p < 0.01). After explanation and fixation the grafts were investigated by light microscopy, scanning and transmission electron microscopy. At 1 week after surgery, both kind of grafts were covered by a fibrinous layer containing platelets and leukocytes. After 2 weeks a pseudoendothelial layer was found in the perianastomotic regions. After 4 weeks, two out of four standard ePTFE grafts were occluded due to intimal hyperplasia and subsequent thrombosis in the midportion of the grafts. All stretch ePTFE grafts were patent and covered by a smooth pseudointima. This study thus demonstrates a lower acute thrombogenicity in stretch ePTFE grafts compared to the standard graphs.
最近，一种具有长度顺应特性的新型膨体聚四氟乙烯（ePTFE）移植物已被研发出来。本研究在体内比较了可拉伸ePTFE移植物与标准ePTFE移植物的急性血栓形成性和4周愈合特性。将长度为6 cm、内径为8 mm的移植物端侧吻合植入猪的髂动脉。通过注入铟-111-氧嗪（20 MBq）标记的自体血小板并对移植物进行动态成像来评估血小板粘附情况。将取出的移植物（n = 14）纵向切开，测定无血栓表面（TFS）和血小板的节段性积聚情况。与标准ePTFE移植物相比，可拉伸ePTFE移植物的血小板沉积明显更少（p < 0.01）。与标准ePTFE移植物相比，测量开始后10分钟起活性的动态增加在170分钟内也显著降低（p < 0.05）。可拉伸ePTFE移植物的TFS为68 +/- 5%，标准ePTFE移植物为37 +/- 5%（p < 0.01）。在取出并固定后，通过光学显微镜、扫描和透射电子显微镜对移植物进行研究。术后第1周，两种移植物均被含有血小板和白细胞的纤维蛋白层覆盖。2周后，在吻合口周围区域发现假内膜层。4周后，4个标准ePTFE移植物中有2个因内膜增生及随后移植物中部的血栓形成而闭塞。所有可拉伸ePTFE移植物均保持通畅，并被光滑的假内膜覆盖。因此，本研究表明，与标准移植物相比，可拉伸ePTFE移植物的急性血栓形成性更低。
