Bandyk D F, Towne J B, Schmitt D D, Seabrook G R, Bergamini T M
Surgical Service, Veterans Administration Medical Center, Milwaukee, WI.
J Vasc Surg. 1990 May;11(5):680-7.
Abnormalities of the conduit, outflow tract, and graft hemodynamics are important elements in the mechanism of vein graft thrombosis, and their role must be defined when planning reoperation. In a consecutive series of 353 in situ saphenous vein bypass graftings performed for occlusive or aneurysmal disease, graft thrombosis occurred in 18 (5%) patients during the perioperative period and unexpectedly in 14 (4%) patients after discharge from the hospital. Assessment of graft hemodynamics (calculation of blood flow velocity) before thrombosis was helpful in predicting success after graft revision. Five grafts with known low flow (systolic flow velocity less than 40 cm/sec) that thrombosed in the perioperative period did not have patency restored by thrombectomy or graft replacement unless the outflow tract was also modified. If poor quality vein or technical error was the mechanism of thrombosis, translocation of the distal anastomosis to a proximal arterial segment (n = 4), and graft replacement with normal autologous vein (n = 5) or prosthetic graft (n = 1) were successful in relieving limb ischemia. After discharge from the hospital, unexpected graft thrombosis was successfully treated by a variety of secondary procedures (thrombolysis/thrombectomy, autologous or prosthetic replacement) if prior surveillance with duplex scanning demonstrated low flow as a result of graft stenosis (n = 7) or normal graft hemodynamics (n = 5). Prosthetic replacement of two failed bypass grafts with low flow caused by diseased outflow did not remain patent. Scrutiny of graft hemodynamics and limb arterial anatomy for alternative outflow sites can identify patients likely to benefit from reoperation after in situ bypass thrombosis.
血管 conduit、流出道和移植物血流动力学异常是静脉移植物血栓形成机制中的重要因素，在计划再次手术时必须明确它们的作用。在一系列连续的353例因闭塞性或动脉瘤性疾病而进行的原位大隐静脉旁路移植手术中，18例（5%）患者在围手术期发生移植物血栓形成，14例（4%）患者在出院后意外发生移植物血栓形成。血栓形成前对移植物血流动力学（血流速度计算）的评估有助于预测移植物翻修后的成功率。5例围手术期发生血栓形成且已知血流较低（收缩期血流速度小于40 cm/秒）的移植物，除非同时对流出道进行修改，否则血栓切除术或移植物置换均无法恢复通畅。如果质量差的静脉或技术失误是血栓形成的机制，将远端吻合口移位至近端动脉段（n = 4），并用正常自体静脉（n = 5）或人工移植物（n = 1）置换移植物，成功缓解了肢体缺血。出院后，如果术前双功超声扫描监测显示由于移植物狭窄（n = 7）或移植物血流动力学正常（n = 5）导致血流较低，通过各种二次手术（溶栓/血栓切除术、自体或人工置换）成功治疗了意外的移植物血栓形成。因病变流出道导致血流较低的两个失败旁路移植物进行人工置换后未保持通畅。仔细检查移植物血流动力学和肢体动脉解剖结构以寻找替代流出部位，可以识别原位旁路血栓形成后可能从再次手术中获益的患者。
