Vann R D, Ritter E F, Plunkett M D, Wyble C W, Bensen C V, Gerth W A, Barwick W J, Klitzman B
F.G. Hall Hyperbaric Center, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710.
J Biomed Mater Res. 1993 Apr;27(4):493-8. doi: 10.1002/jbm.820270410.
Biomaterials exposed to blood often fail due to thrombosis. Gas nuclei (air) in the material are thrombogenic and a potential cause of failure. The effects of gas nuclei on patency and blood flow were studied in 4 mm diameter arterial grafts (Gore ePTFE; Johnson and Johnson Vitagraft ePTFE; Bard ACG EXS) in the femoropopliteal position of dogs. Control and denucleated (air-free) grafts were implanted bilaterally. Grafts were denucleated by immersion in degassed saline and exposure to 4 torr vacuum and 3,000-20,000 psig pressure. Graft patency was determined at harvest in 46 dogs. Blood flow was measured with acoustic flow probes in eight dogs. Denucleated graft patency was 60% after 2 days of implant while control patency was 22% (P < .05). Measured blood flow was higher in denucleated grafts than in control grafts (P < .02) in 4 of 5 dogs which had significantly different flows. Patency and flow decreased to zero for both control and denucleated grafts over periods of up to 80 days. Air in the control grafts may have been absorbed within several days, leading to late similarity with the denucleated grafts. Thus, removing the air from 4 mm ePTFE grafts decreased acute thrombosis and increased the patency.
暴露于血液中的生物材料常常因血栓形成而失效。材料中的气体核（空气）具有血栓形成倾向，是导致失效的一个潜在原因。在犬股腘动脉位置植入直径4毫米的动脉移植物（戈尔ePTFE；强生维塔移植物ePTFE；巴德ACG EXS），研究气体核对通畅性和血流的影响。双侧植入对照移植物和去核（无空气）移植物。通过将移植物浸入脱气盐水中，并暴露于4托真空和3000 - 20000磅力/平方英寸压力下来去除气体核。对46只犬在处死时测定移植物通畅性。用超声血流探头对8只犬测量血流。植入2天后，去核移植物的通畅率为60%，而对照移植物的通畅率为22%（P <.05）。在5只血流有显著差异的犬中，有4只犬的去核移植物的测量血流高于对照移植物（P <.02）。对照移植物和去核移植物的通畅性和血流在长达80天的时间内均降至零。对照移植物中的空气可能在数天内被吸收，导致后期与去核移植物相似。因此，从4毫米ePTFE移植物中去除空气可减少急性血栓形成并提高通畅率。
