Tomizawa Y, Moon M R, DeAnda A, Castro L J, Kosek J, Miller D C
Department of Cardiothoracic Surgery, Stanford University School of Medicine, CA 94305.
Circulation. 1994 Nov;90(5 Pt 2):II160-6.
Poor patency rates have limited the success of biological vascular grafts in the coronary artery position. Recently, two bovine internal mammary arterial grafts have been developed for possible use as coronary artery bypass graft (CABG) conduits: (1) Denaflex grafts (Baxter Health-care Co, 3-mm ID) treated with polyepoxy compounds and with heparin ionically bound to the luminal surface and (2) Bioflow grafts (Bio-Vascular, Inc, 3-mm ID) treated with dialdehyde starch.
Thirty dogs underwent CABG with either a Denaflex (n = 20) or Bioflow (n = 10) graft to the left circumflex coronary artery (LCx). The left main coronary artery (n = 12) or proximal LCx (n = 18) was then ligated. Six-month patency (Kaplan-Meier) for Denaflex grafts was 44 +/- 13% (+/- SEM), compared with 12 +/- 11% for Bioflow grafts, but this difference did not reach statistical significance (P = .56). Among grafts open at 14 days, however, there were no occlusions among six Denaflex grafts versus five occlusions among seven Bioflow grafts. At 6 months, all six surviving Denaflex grafts appeared normal, while the only remaining patent Bioflow graft was angiographically dilated and had diffuse luminal irregularities. At 1 year, three Denaflex grafts angiographically had no dilation, stenosis, or luminal irregularities. Macroscopically, all explanted long-term (6 to 12 months) Denaflex grafts had a smooth, clean luminal surface, whereas the only patent Bioflow graft had multifocal thrombi. Microscopically, all Denaflex grafts had minimal degenerative changes, but the Bioflow graft had transmural linear cracks and medial deterioration.
These data suggest that long-term (> 6-month) patency is possible with small-caliber, low-flow biological grafts in the canine coronary position, although both types of grafts are prone to early occlusion. If these early failures are excluded, the Denaflex graft appears to be associated with better long-term patency and an absence of degenerative changes.
通畅率不佳限制了生物血管移植物在冠状动脉部位应用的成功率。最近，已研发出两种牛内乳动脉移植物，可能用作冠状动脉旁路移植术（CABG）的血管导管：（1）Denaflex移植物（百特医疗保健公司，内径3毫米），经聚环氧化合物处理，肝素以离子键形式结合于管腔表面；（2）Bioflow移植物（生物血管公司，内径3毫米），经二醛淀粉处理。
30只犬接受了将Denaflex移植物（n = 20）或Bioflow移植物（n = 10）移植至左旋冠状动脉（LCx）的CABG手术。然后结扎左冠状动脉主干（n = 12）或LCx近端（n = 18）。Denaflex移植物6个月的通畅率（Kaplan-Meier法）为44±13%（±标准误），Bioflow移植物为12±11%，但此差异无统计学意义（P = 0.56）。然而，在术后14天仍通畅的移植物中，6个Denaflex移植物均未发生闭塞，而7个Bioflow移植物中有5个发生闭塞。6个月时，所有存活的6个Denaflex移植物外观正常，而仅存的1个通畅的Bioflow移植物血管造影显示扩张，管腔弥漫性不规则。1年时，3个Denaflex移植物血管造影显示无扩张、狭窄或管腔不规则。大体观察，所有取出的长期（6至12个月）Denaflex移植物管腔表面光滑、洁净，而仅存的1个通畅的Bioflow移植物有多处血栓形成。显微镜下观察，所有Denaflex移植物仅有轻微退行性改变，而Bioflow移植物有透壁线性裂纹和中层退变。
这些数据表明，在犬冠状动脉部位，小口径、低流量生物移植物实现长期（>6个月）通畅是可能的，尽管两种移植物都易于早期闭塞。如果排除这些早期失败情况，Denaflex移植物似乎与更好的长期通畅率及无退行性改变相关。
