Hedeman Joosten P P, Verhagen H J, Heijnen-Snyder G J, van Vroonhoven T J, Sixma J J, de Groot P G, Eikelboom B C
Departments of Surgery and Haematology, University Hospital Utrecht, Utrecht, The Netherlands.
J Vasc Surg. 1998 Dec;28(6):1094-103. doi: 10.1016/s0741-5214(98)70036-9.
Small-diameter vascular grafts tend to have an early and high occlusion rate. Cell seeding on the luminal surfaces of small-diameter vascular prostheses may provide an antithrombotic lining and improve both the short-term and the long-term patency rates. We studied the net results of procoagulant and anticoagulant properties of seeded grafts under blood-flow conditions, and we compared the different available types of donor cells.
Monolayers of liposuction-derived cultured human microvascular endothelial cells (MVECs), human adult endothelial cells (HAECs), human umbilical vein endothelial cells (HUVECs), and human mesothelial cells (MCs) that had been seeded on expanded polytetrafluoroethylene (ePTFE) grafts were perfused with marginally anticoagulated blood (20 U/mL low molecular weight heparin; shear rate, 400/s, 10 minutes) or with non-anticoagulated blood (shear rate, 100/s, 5 minutes). The thrombin and fibrin generation in time was studied with the measurement of the plasma levels of prothrombin fragment 1 and 2 (F 1+2) and of fibrinopeptide A (FPA). The plain ePTFE graft was taken as a control.
When the seeded MCs were perfused with recirculating anticoagulated blood, a linear generation of F 1+2 in time was seen, with high levels of F 1+2 and FPA after 10 minutes (4.38 nmol/L and 362 ng/mL, respectively). Allopurinol was added, and the MCs generated less F 1+2 than the HAECs (0.7 nmol/L vs 1.86 nmol/L; P <.05). No fibrin formation was seen. The MVECs generated low amounts of F 1+2 (0.7 nmol/L; 10 minutes), and the HUVECs and the plain ePTFE graft generated the lowest amounts of F 1+2 (0.26 and 0.25 nmol/L, respectively). When the MCs were perfused with non-anticoagulated blood, high amounts of thrombin and fibrin were generated immediately and constantly and could not be decreased with allopurinol. The perfusion of the plain ePTFE graft showed a dramatic increase in F 1+2 and FPA levels towards the end of the experiments. The seeded HAECs, HUVECs, and MVECs inhibited this increase. These results were confirmed by means of scanning electron microscopy.
Vascular prostheses that are seeded with cultured MCs are highly procoagulant. Standard ePTFE graft prostheses also initiate coagulation, which supports the idea of cell seeding. The endothelial cells, of which the MVECs are the most readily available, seem to preserve their anticoagulant properties after being seeded on vascular grafts.
小口径血管移植物往往具有较高的早期闭塞率。在小口径人工血管的管腔内表面进行细胞接种，可能会形成抗血栓内膜，从而提高短期和长期通畅率。我们研究了在血流条件下接种细胞的移植物的促凝和抗凝特性的净结果，并比较了不同类型的可用供体细胞。
将抽脂来源的培养人微血管内皮细胞（MVECs）、成人内皮细胞（HAECs）、人脐静脉内皮细胞（HUVECs）和人间皮细胞（MCs）的单层细胞接种在膨体聚四氟乙烯（ePTFE）移植物上，然后用轻度抗凝血液（20 U/mL低分子量肝素；剪切速率，400/s，10分钟）或非抗凝血液（剪切速率，100/s，5分钟）进行灌注。通过测量血浆中凝血酶原片段1和2（F 1+2）以及纤维蛋白肽A（FPA）的水平，研究随时间变化的凝血酶和纤维蛋白生成情况。以普通ePTFE移植物作为对照。
当用循环抗凝血液灌注接种MCs的移植物时，随时间呈线性生成F 1+2，10分钟后F 1+2和FPA水平较高（分别为4.38 nmol/L和362 ng/mL）。加入别嘌呤醇后，MCs生成的F 1+2比HAECs少（0.7 nmol/L对1.86 nmol/L；P <.05）。未观察到纤维蛋白形成。MVECs生成少量F 1+2（0.7 nmol/L；10分钟），HUVECs和普通ePTFE移植物生成的F 1+2量最低（分别为0.26和0.25 nmol/L）。当用非抗凝血液灌注MCs时，立即持续生成大量凝血酶和纤维蛋白，且别嘌呤醇不能降低其生成量。普通ePTFE移植物的灌注在实验结束时F 1+2和FPA水平显著升高。接种的HAECs、HUVECs和MVECs可抑制这种升高。这些结果通过扫描电子显微镜得到证实。
接种培养MCs的血管移植物具有高度促凝性。标准ePTFE移植物假体也会引发凝血，这支持了细胞接种的观点。内皮细胞中MVECs最容易获得，接种到血管移植物上后似乎仍保留其抗凝特性。
