Zanchetta M, Dalle Mule J, Di Mario C, Perelli R, Carlon R, De Lio U, Branchini B, Zingone B, Maiolino P
Divisione di Cardiologia, Ospedale Civile, Cittadella, Padova.
G Ital Cardiol. 1988 Nov;18(11):914-9.
The internal mammary artery, when used as a conduit for coronary artery bypass, offers a better long-term patency and survival rate than the saphenous vein. However, concern exists that the flow through the internal mammary artery may be inadequate during periods of peak myocardial demand. This flow was investigated in 18 consecutive patients who were selected for coronary bypass of the left anterior descending artery using the internal mammary artery. All patients were evaluated post-operatively within 12 months by means of graded maximal stress test, cardiac catheterization and exercise thallium-201 scintigraphy. Significant improvement in work capacity, maximal rate-pressure product, effort angina and ECG abnormalities during exercise stress testing were observed following internal mammary artery myocardial revascularization. The patency rate for internal mammary artery grafts was 100% (vs 85% for vein grafts); during the followup period, occlusion of a saphenous vein bypass or development of a new stenosis in a native coronary artery was noted in five patients, and two patients were classified as having partial revascularization. Ischemia, demonstrated by perfusion deficits at peak stress which disappeared in the 3-hour delayed film, was documented in 7.4% (4/54) of the areas supplied by internal mammary artery grafts, compared to 31% (13/42) of the regions revascularized using saphenous vein conduits. Although this result was not statistically significant, a definite trend is suggested. We conclude that ischemia demonstrated by stress thallium scintigraphy in the post-operative period is uncommon when an internal mammary artery graft has been used. This suggests that adequate coronary flow exists at peak myocardial demand during exercise.
当乳内动脉用作冠状动脉搭桥的管道时，其长期通畅率和生存率比大隐静脉更好。然而，有人担心在心肌需求高峰期，通过乳内动脉的血流量可能不足。对连续18例选择使用乳内动脉进行左前降支冠状动脉搭桥的患者的这种血流量进行了研究。所有患者在术后12个月内通过分级最大应力试验、心导管检查和运动铊-201闪烁扫描进行评估。乳内动脉心肌血运重建术后，运动应激试验期间的工作能力、最大心率血压乘积、劳力性心绞痛和心电图异常有显著改善。乳内动脉移植物的通畅率为100%（静脉移植物为85%）；在随访期间，5例患者出现大隐静脉搭桥闭塞或自身冠状动脉出现新的狭窄，2例患者被归类为部分血运重建。在乳内动脉移植物供血区域，7.4%（4/54）的区域在峰值应力时出现灌注缺损，在3小时延迟影像中消失，表现为缺血，而使用大隐静脉导管进行血运重建的区域中这一比例为31%（13/42）。虽然这一结果无统计学意义，但提示了一个明确的趋势。我们得出结论，术后用应力铊闪烁扫描显示的缺血情况在使用乳内动脉移植物时并不常见。这表明在运动时心肌需求高峰期存在足够的冠状动脉血流。
