Differential Effects of Single versus Double Aortic Clamping on Myocardial Protection during Coronary Bypass

Abstract

The effects of double (n = 60, group 1) versus single (n = 60, group 2) aortic clamping on myocardial function and protection were investigated during coronary artery bypass grafting using a heart-lung pump. In group 1, after opening the cross clamp, proximal anastomosis was completed using side clamps and, in group 2, distal and proximal anastomosis was completed with a single clamp. Cross clamping time in the single-clamp patients (group 2; 77.1 min) was significantly higher than in the double-clamp patients (group 1; 62.9 min). Troponin T was significantly higher in group 2 than in group 1 h and 24 h after surgery. Post-operative left ventricular ejection fraction decreased in both groups, but this was not statistically significant. Post-operative wall motion score index and myocardial performance index increased significantly in both groups compared with the pre-operative level. Overall, the double-clamp technique provided better myocardial protection than the single-clamp technique and neither technique seemed to have a negative impact on the early post-operative global functioning of the left ventricle, however the effect of these techniques on the global functioning of the left ventricle in the late postoperative period needs to be evaluated.

Surgical Risk Factors for Ischemic Stroke Following Coronary Artery Bypass Grafting. A Multi-Factor Multimodel Analysis

“…If a patient should require a CABG technique entailing the use of CPB, our findings suggest that there is no difference between performing proximal anastomoses with a side-biting clamp after releasing the total aortic cross-clamp or creating an anastomosis on full CPB with the aorta cross-clamped. Hence, our data recommend caution in choosing the single clamp technique and suggest carefully evaluating every individual patient for the potential advantages of the double-clamp technique, including better myocardial protection ( 38 ), compared to the disadvantages of the single-clamp method such as prolonging myocardial ischemic time and increasing the risk of cardiac and cerebral air embolism.…”