Pseudointimal thrombogenicity changes in small arterial grafts.
Pseudointimal thrombogenicity changes in small arterial grafts.
复制标题
小动脉移植物中假性内膜血栓形成的变化。
作者：
J. Seeger;M. Borgeson;G. Lawson
假体植入后很快就会被血液蛋白覆盖。细胞向内生长和间质蛋白如胶原的积聚完成了移植物假性内膜的发育。为了探讨这些变化对移植物血小板反应性的影响，在犬颈动脉内植入聚四氟乙烯(PTFE)和涤纶(Dacron)两种不同孔隙度和凝血活性的移植物，分别于植入后第1、7和21d测定了铟111标记的血小板积聚。假内膜结构、重量和胶原含量也在每个测量间隔进行了测定。此外，还测定了自体移植颈动脉和解剖颈动脉上的血小板聚集量，以供比较。在1-7天内，所有移植物和动脉上的血小板聚集显著减少(p<0.05)。自体移植动脉和解剖动脉上的血小板积聚在7-21天间进一步减少，并接近基线。相比之下，涤纶移植物上的血小板积聚在第7天和第21天之间显著增加(p<0.05)，高于第1天的水平，而聚四氟乙烯移植物中的血小板积聚增加最小，并保持在显著低于第1天的水平。在这段时间，涤纶移植物中形成了厚厚的假内膜，含有大量的胶原，PTFE移植物上覆盖着薄薄的、不完整的假内膜，含有最少的胶原。假性内膜血小板反应性和成分的这些差异与涤纶移植物(78%)比聚四氟乙烯移植物(89%)的通畅率降低有关。
Prosthetic grafts are rapidly covered by blood proteins after implantation. Cellular ingrowth and accumulation of interstitial proteins such as collagen complete the development of graft pseudointima. To investigate the effect of these changes on graft platelet reactivity, indium 111-labeled platelet accumulation on two grafts of differing porosity and thrombogenicity (polytetrafluoroethylene [PTFE] and Dacron) was measured 1, 7, and 21 days after graft implantation in canine carotid arteries. Pseudointima structure, weight, and collagen content were also determined at each measurement interval. In addition, platelet accumulation on carotid autografts and dissected carotid arteries was determined for comparison. Platelet accumulation on all grafts and arteries diminished significantly (p less than 0.05) between 1 and 7 days. Platelet accumulation on autografts and dissected arteries decreased further between 7 and 21 days and approached baseline. In contrast, platelet accumulation on Dacron grafts increased significantly (p less than 0.05) between 7 and 21 days to levels above those measured at 1 day, whereas platelet accumulation in PTFE grafts increased minimally and remained significantly below 1-day levels. A thick pseudointima that contained significant amounts of collagen developed in Dacron grafts during this time period, and a thin, incomplete pseudointima containing minimal collagen covered PTFE grafts. These differences in pseudointimal platelet reactivity and composition were associated with decreased patency of Dacron grafts (78%) compared to PTFE grafts (89%).