Comparison of parameters of blood flow of grafts of right or left internal mammary artery to the left anterior descending artery / 中华胸心血管外科杂志

ABSTRACT

Objective:To analyze and compare difference of ultrasonic blood flow of left internal mammary artery(LIMA) and right internal mammary artery(RIMA)as graft to left anterior descending artery(LAD) in patients undergoing off-pump coronary artery bypass grafting(OPCABG).Methods:From October 2017 to October 2019, a total of 363 patients who underwent OPCAB including 329 patients in LIMA-LAD group and 34 patients in RIMA-LAD group, were included in this study. Transthoracic ultrasound examination on IMA was performed before OPCABG. The blood flow , the value of PI(pulsation index) and diastolic flow(DF) of LIMA and RIMA to left anterior descending were measured and recorded by intraoperative TTFM. Patients underwent coronary artery CT examinations at 1 week after OPCABG to discover the patency of grafts.Results:The pre-operative diameter of RIMA was larger and the blood flow and pulsation index of RIMA was better than that of LIMA before OPCABG( P<0.001). But there was no significant difference in the flow, pulsation index and DF value of graft between the two groups after IMA were anastomosed to LAD( P>0.05). In situ skeletonized graft of RIMA did not show the advantage of increased blood flow. Compared with the preoperative parameters of flow of internal mammary artery, both the left and right grafts of IMA were significantly better in blood flow and pulsation index( P<0.001). Considering the remarkable difference in age between the two groups, Flow, PI and DF were compared again after propensity score matching, and there was still no statistical difference between the two groups( P>0.05). A total of 313 patients in LIMA-LAD group completed coronary CTA examination one week after surgery, among which 4 grafts had different degrees of problems. A total of 34 patients in RIMA-LAD group completed coronary CTA examination, one case indicated that the CTA imaging in distal segment was not clear, and the other results had no obvious abnormality. There was no significant difference in postoperative rate of coronary CTA completion( P=0.381) and rate of graft failure( P=0.405) between the two groups. Conclusion:Compared with the preoperative parameters of blood flow of internal mammary artery, both the left and right IMA grafts are significantly better in flow and pulsation index. The pre-operative diameter of RIMA is larger and the blood flow and pulsation index of RIMA is better than that of LIMA before OPCABG. But there is no significant difference in the flow, pulsation index and DF value of graft between the two groups after IMA are anastomosed to LAD. In situ skeletonized graft of RIMA do not show the advantage of increased blood flow.