Department of Cardiac Sciences, LIBIN Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
Eur J Cardiothorac Surg. 2010 Aug;38(2):155-62. doi: 10.1016/j.ejcts.2010.01.026. Epub 2010 Feb 21.
This study was undertaken to evaluate transit-time flow (TTF) as a tool to detect technical errors in arterial bypass grafts intra-operatively and predict outcomes.
TTF's three parameters, pulsatility index (PI, index of resistance), flow (cc min(-1)) and diastolic filling (DF, proportion of diastole with coronary flow), were measured in 990/1000 (99%) of arterial grafts in 336 consecutive patients, prospectively enrolled in a database. Grafts were revised when TTF findings supported the otherwise suspected graft malfunction. If no other signs/suspicion of graft malfunction existed (normal electrocardiogram (EKG), stable haemodynamics and unchanged ventricular function on trans-oesophageal echocardiography (TEE)), and the PI was >5, grafts were not revised. Major adverse cardiac events (MACEs: recurrent angina, perioperative myocardial infarction, postoperative angioplasty, re-operation and/or perioperative death) were related to TTF measurements.
The average number of grafts per patient was 3.02, of which 99% were arterial. Satisfactory grafts were achieved in 916/990 (93%) of the grafts, with flows from 34 to 61 cc min(-1), PI < or =5 and DF of 62-85%. Fourteen conduits, 20 grafts (2%) suspected to be problematic, were revised. Patients were divided into two groups: 277 (82%) with at least one graft with PI < or =5 and 59 (18%) with a PI >5. MACE occurred in 25 (7.4%) patients--15/277 patients with a PI < or =5 (5.4%) and 10/59 with a PI >5 (17%, p=0.005). Mortality following non-emergent surgery was significantly higher in patients with a PI >5 (5/54, 9%) than in patients with a PI < or =5 (5/250, 2%, p=0.02). Flow and DF were not predictive of outcomes.
A high PI predicts technically inadequate arterial grafts during surgery--even if all other intra-operative assessments indicate good grafts; it also predicts outcomes, particularly mortality.
本研究旨在评估瞬时传输时间（TTF）作为一种工具，以检测术中动脉旁路移植术的技术误差并预测结果。
前瞻性地纳入了 336 例连续患者的数据库中，对 990/1000（99%）的动脉移植物测量了 TTF 的三个参数，即搏动指数（PI，阻力指数）、流量（cc min(-1)）和舒张充盈（DF，舒张期与冠脉血流的比例）。当 TTF 结果支持怀疑的移植物功能障碍时，对移植物进行修正。如果没有其他迹象/怀疑移植物功能障碍（正常心电图（EKG）、稳定的血液动力学和经食管超声心动图（TEE）上心室功能不变），且 PI>5，则不对移植物进行修正。主要心脏不良事件（MACE：复发性心绞痛、围术期心肌梗死、术后血管成形术、再次手术和/或围手术期死亡）与 TTF 测量相关。
每位患者的平均移植物数量为 3.02 个，其中 99%为动脉移植物。990 个移植物中有 916 个（93%）达到了满意的效果，流量为 34 至 61 cc min(-1)，PI<or=5，DF 为 62-85%。14 个导管，20 个（2%）疑似有问题的移植物被修正。患者被分为两组：277 名（82%）至少有一个 PI<or=5 的移植物，59 名（18%）PI>5。25 名（7.4%）患者发生了 MACE，其中 15 名/277 名 PI<or=5 患者（5.4%）和 10 名/59 名 PI>5 患者（17%，p=0.005）。PI>5 的患者非紧急手术后的死亡率明显高于 PI<or=5 的患者（5/54，9%vs.5/250，2%，p=0.02）。流量和 DF 都不能预测结果。
高 PI 预测术中动脉旁路移植术的技术不完善，即使所有其他术中评估都表明移植物良好；它也预测结果，特别是死亡率。
