Perioperative study of blood flow of in-situ BIMA in coronary artery bypass grafting

Objective To observate the changing trend of flow of in-situ bilateral internal mammary artery as grafts during perioperative period in patients undergoing coronary artery bypass grafting(CABG), and to compare the parameters of flow between LIMA and RIMA. Methods A total of 57 patients , 50 males and 7 femails, mean aged(57.8±10.1) years, underwent bilateral IMA CABG in our hospital from August 2016 to January 2019. Transthoracic ultrasound of IMA examination was performed before CABG. The blood flow, the PI(pulsation index) and other parameters were measured and recorded by intraoperative TTFM. Results There was no significant difference of the average diameter and PI between LIMA and RIMA, but the preoperative flow of RIMA is higher(P=0.026) in our study. There was no significant difference of the average flow and PI between LIMA and RIMA recorded by TTFM(P>0.05), but the higher diastolic flow(DF) in LIMA grafts(P=0.022) compared with RIMA grafts may be associated with the different target sites(P<0.05). Compared with the preoperative flow and PI of IMA, the intraoperative flow and PI of both LIMA and RIMA grafts were better(P<0.001). Conclusion Compared with the preoperative flow of IMA, both flow of LIMA and RIMA are better. In spite of the targets exist difference , there are no significant difference of the average flow and PI between LIMA graft and RIMA graft recorded by TTFM. Key words: Internal mammary artery; Coronary artery bypass grafting; Transit-time flowmeter; Transthoracic arterial ultrasound