Influence of intracoronary shunt on myocardial ischemic injury during off-pump coronary artery bypass surgery.
The aim of the study was to evaluate the role of intracoronary shunt during off-pump coronary artery bypass surgery in patients with isolated left anterior descending coronary artery lesion. Forty patients undergoing off-pump coronary artery bypass using the left internal mammary artery to bypass the left anterior descending coronary artery were randomly assigned to have the bypass performed with intracoronary shunt or by occlusive snaring. Potential damage from the shunt or from snaring was monitored by clinical follow-up, monitoring of cardiac enzymes (cardiac troponin I, CK, CK-MB), electrocardiography, and echocardiography before and 24 h. after the surgery. Left ventricular myocardial biopsies were performed during surgery for histopathological analysis. None of the patients in this study died during or after the surgery. Duration of the anastomosis was significantly longer in the shunt group. No significant difference concerning the preoperative and postoperative CK levels between groups. The preoperative CK-MB levels of the groups were not significantly different, whereas postoperative levels was significantly lower in the shunt group. The preoperative troponin I levels of the groups were not significantly different, whereas postoperative levels was significantly higher in the snare group. Myocardial edema was significantly less in shunt group compared with snare group. There were no electrocardiographic abnormalities, severe CK-MB elevation, or hemodynamic deterioration after the operation in both groups. Intracoronary shunt may have beneficial effects due to the reduction of postoperative troponin I levels and myocardial edema during grafting of the left anterior descending coronary artery. However, further trials need to be performed for the documentation of their impacts precisely.