SINGLE-CLAMP TECHNIQUE - AN IMPORTANT ADJUNCT TO MYOCARDIAL AND CEREBRAL PROTECTION IN CORONARY OPERATIONS

To determine the myocardial and cerebral protective properties of the single cross-clamp (group I; n = 160) versus the partial occluding clamp (group II; n = 150) technique for construction of the proximal anastomoses, a retrospective analysis of 310 patients op erated on by the same surgeon was performed. Group I patients were older (median age, 70 versus 64 years; p less than or equal to 0.0001), with 83 (52%), versus 41 (27%) in group II, 70 years and older (p less than or equal to 0.0001). More group I patients were in New York Heart Association functional class IV (42 [26%] versus 22 [15%]; p = 0.008); more required preoperative balloon counterpulsation (35 [22%] versus 16 [11%]; p = 0.006); and more required emergent operation (20 [13%] versus 3 [2%]; p less than or equal to 0.0001). Antegrade crystalloid cardioplegia was used in both groups. The median cross-clamp time was 58 minutes for group I versus 44 minutes for group II (p less than or equal to 0.0001). However, there was no significant difference between the two groups in terms of the number of bypass grafts, the use of the mammary artery, or the bypass time. The operative mortality was 2.5% (n = 4) for group I versus 5.3% (n = 8) for group II (p = 0.16), and the perioperative myocardial infarction/low cardiac output state was seen in 6 patients (3.8%) in group I versus 18 patients (12%) in group II (p = 0.006). The median creatine kinase Mb release was 13 U/L for group I versus 19 U/L for group II (p = 0.0029). A major stroke occurred in 1 patient (0.6%) in group I and in 3 patients (2%) in group II (p = 0.3). Multivariate logistic regression analysis for an adverse outcome (operative mortality, myocardial output/low cardiac output state, and stroke), with 11 events (6.9%) occurring in 10 patients in group I and 29 events (19%) occurring in 24 patients in group II (p = 0.005), showed that use of the partial occluding clamp was a significant predictor for an adverse outcome (p = 0.002; odds ratio, 3.6; +/-95%, confidence intervals, 1.6 and 8.0), along with diabetes, nonelective coronary artery bypass grafting, and weight of 65 kg or less. The improved results associated with the single cross-clamp method suggest that this technique plays an integral part in ensuring myocardial and cerebral protection, possibly due to better cardioplegia delivery and distribution, more uniform rewarming and revascularization, and reduced manipulation of and trauma to the ascending aorta.