Spotnitz W D, Keller M W, Watson D D, Nolan S P, Kaul S
Department of Surgery, University of Virginia School of Medicine, Charlottesville.
J Am Coll Cardiol. 1988 Jul;12(1):196-201. doi: 10.1016/0735-1097(88)90374-9.
To determine whether the success of internal mammary artery bypass grafting can be assessed intraoperatively using myocardial contrast echocardiography, sonicated Renografin-76 was injected into the aortic root of 11 dogs during the delivery of cardioplegic solution. Studies were performed with the left anterior descending coronary artery patent and totally occluded, and after internal mammary artery bypass grafting distal to the occluded vessel. Flow rate during cardioplegia was constant for all three stages in each experiment. Myocardial contrast echocardiography clearly demonstrated homogeneous myocardial perfusion with the left anterior descending coronary artery patent, lack of perfusion in the left anterior descending artery bed during its occlusion and excellent perfusion of the occluded bed after internal mammary artery bypass grafting distal to the occlusion in 10 of the 11 dogs. In one dog, the bypass graft was technically inadequate and contrast opacification was not noted in the left anterior descending artery bed after internal mammary artery bypass grafting. The exponential function C(t) = Ae-alpha t + Be-beta t was fitted to computer-derived time-intensity curves from the myocardium, where alpha denotes contrast washout and beta denotes contrast appearance. Respective values for alpha and beta (mean + 1 SD) were similar for the patent left anterior descending coronary artery and after internal mammary artery bypass grafting distal to the occluded artery (0.11 +/- 0.10 versus 0.10 +/- 0.10, and 2.5 +/- 2.4 versus 1.1 +/- 0.56). In conclusion, myocardial contrast echocardiography has potential for intraoperative assessment of the adequacy of coronary artery bypass grafting.
为了确定术中使用心肌对比超声心动图能否评估乳内动脉搭桥术的成功与否，在11只犬心脏停搏液灌注期间，将超声处理过的泛影葡胺-76注入主动脉根部。分别在左前降支冠状动脉通畅、完全闭塞以及闭塞血管远端进行乳内动脉搭桥术后开展研究。每个实验的三个阶段中心脏停搏期间的流速保持恒定。心肌对比超声心动图清晰显示，11只犬中有10只在左前降支冠状动脉通畅时心肌灌注均匀，左前降支动脉闭塞时该动脉供血区域无灌注，而在闭塞血管远端进行乳内动脉搭桥术后，该供血区域灌注良好。有1只犬的搭桥技术欠佳，在乳内动脉搭桥术后左前降支动脉供血区域未观察到造影剂显影。将指数函数C(t)=Ae-αt+Be-βt拟合到源自心肌的计算机生成的时间-强度曲线上，其中α表示造影剂洗脱，β表示造影剂出现。对于通畅的左前降支冠状动脉以及闭塞动脉远端进行乳内动脉搭桥术后，α和β的各自值（均值±1标准差）相似（分别为0.11±0.10与0.10±0.10，以及2.5±2.4与1.1±0.56）。总之，心肌对比超声心动图在术中评估冠状动脉搭桥术的充分性方面具有潜力。
