Siebenmann R, Egloff L, Hirzel H, Rothlin M, Studer M, Tartini R
Herzzentrum Hirslanden, Zürich, Switzerland.
Eur J Cardiothorac Surg. 1993;7(5):235-8. doi: 10.1016/1010-7940(93)90210-3.
The internal mammary artery (IMA) string sign has been described as a narrowing of IMA grafts in the late course after coronary artery bypass grafting. It has been assumed that this phenomenon was due to competitive flow in grafts connected to only mildly stenosed coronary arteries. We analyzed 10 cases of IMA string sign operated on between March 1988 and June 1991. Bilateral IMA was used in six cases and unilateral IMA in four. The mean interval between operation and reangiography was 14 +/- 11 months. String sign of the whole length of the IMA was detected in nine cases, and of the distal part between two sequential anastomoses in one. In all cases, the stenosis of the vessel bypassed with the narrowed graft proved to be only mild (50% or less) at reangiography. In all six cases with bilateral IMA grafts, the contralateral IMA was widely patent. These were all connected to highly stenosed or occluded coronary arteries. With respect to this observation, there is a high index of suspicion that the string phenomenon occurs due to competitive flow in only mildly stenosed coronary arteries. We decided, for our strategy in coronary artery surgery, still to aim at complete revascularization using IMAs as much as possible, but to avoid connecting IMA grafts to only mildly or moderately stenosed coronary arteries.
乳内动脉（IMA）线样征被描述为冠状动脉旁路移植术后晚期IMA移植物的狭窄。据推测，这种现象是由于连接到仅轻度狭窄冠状动脉的移植物中存在竞争性血流所致。我们分析了1988年3月至1991年6月间接受手术的10例IMA线样征病例。6例使用双侧IMA，4例使用单侧IMA。手术与再次血管造影之间的平均间隔时间为14±11个月。9例检测到IMA全长的线样征，1例检测到两个连续吻合口之间远端部分的线样征。在所有病例中，再次血管造影显示，被狭窄移植物旁路的血管狭窄仅为轻度（50%或以下）。在所有6例双侧IMA移植物病例中，对侧IMA通畅良好。这些移植物均连接到高度狭窄或闭塞的冠状动脉。基于这一观察结果，高度怀疑线样征现象是由于仅轻度狭窄冠状动脉中的竞争性血流所致。对于我们的冠状动脉手术策略，我们决定仍尽可能以使用IMA实现完全血运重建为目标，但要避免将IMA移植物连接到仅轻度或中度狭窄的冠状动脉。
