Wilson G J, MacGregor D C, Klement P, Dereume J P, Weber B A, Binnington A G, Pinchuk L
Department of Surgery, Toronto General Hospital, Ontario, Canada.
ASAIO Trans. 1991 Jul-Sep;37(3):M475-6.
Polyurethane vascular prostheses offer the potential of superior thromboresistance and reduced anastomotic hyperplasia compared to existing Dacron and ePTFE alternatives, but have suffered from susceptibility to biodegradation, with resulting mechanical failure. To address this problem, the authors have developed and evaluated a composite prosthesis comprised of: 1) an inner blood interfacing elastomeric porous membrane made from Corethane, a proprietary Shore 80A polyurethane like material substantially devoid of ether/ester linkages, with superior biostability over conventional polyether urethanes, spun into a nonwoven structure with fiber diameters 10-15 microns and pore sizes 30-60 microns filled with gelatin +/- heparin; and 2) an outer soft, tissue interfacing, warp knitted Dacron mesh bonded to the inner layer to assure long-term dimensional stability. Twenty 4 mm ID x 5 cm L composite prostheses, half with heparinized gelatin (the remainder nonheparinized) were implanted as femoral interposition grafts in 10 dogs. Four of the 10 nonheparinized grafts occluded. All 10 with heparin remained widely patent, with two explanted at 6 months showing vascularized connective tissue growth through the graft, in contrast to the giant cell inflammatory response to the Dacron mesh, with a substantially endothelialized neointima and no Corethane biodegradation. Of the 10 patent grafts at 1 year follow-up, none showed aneurysm formation. This vascular prosthesis provides compliance superior to ePTFE and Dacron alternatives, with excellent suture retention and good kink resistance, while combining the superior thromboresistance and tissue ingrowth properties of polyurethanes with the proven biostability of Dacron.
与现有的涤纶和膨体聚四氟乙烯替代品相比，聚氨酯血管假体具有潜在的更高抗血栓性和减少吻合口增生的特性，但存在易生物降解的问题，从而导致机械故障。为了解决这个问题，作者开发并评估了一种复合假体，其组成如下：1）内部血液接触弹性体多孔膜，由Corethane制成，这是一种类似材料的专有邵氏80A聚氨酯，基本不含醚/酯键，与传统聚醚聚氨酯相比具有优异的生物稳定性，纺成纤维直径为10 - 15微米、孔径为30 - 60微米的非织造结构，并填充有明胶+/-肝素；2）外部柔软的、与组织接触的经编涤纶网，与内层粘合以确保长期尺寸稳定性。将20个内径4毫米×长5厘米的复合假体（其中一半填充肝素化明胶，其余未肝素化）作为股动脉间置移植物植入10只狗体内。10个未肝素化的移植物中有4个发生堵塞。所有10个肝素化的移植物仍保持广泛通畅，6个月时取出的2个显示有血管化结缔组织长入移植物，与对涤纶网的巨细胞炎症反应形成对比，有基本内皮化的新生内膜且无Corethane生物降解。在1年随访时的10个通畅移植物中，无一显示有动脉瘤形成。这种血管假体提供了优于膨体聚四氟乙烯和涤纶替代品的顺应性，具有出色的缝线保留能力和良好的抗扭结性，同时将聚氨酯的优异抗血栓性和组织长入特性与涤纶已证实的生物稳定性相结合。
