Transit time flow measurement in coronary surgery / 中华胸心血管外科杂志

ABSTRACT

Objective: To review the experience of using the transit time flow measurement(TTFM) in coronary artery bypass grafting(CABG). Methods: From Sept.2001 to May, 2002,90 cases underwent CABG. Among them, 40 cases with off-pump beating heart (OPCAB) and 50 with conventional coronary bypass grafting. All graft patency were verified intraoperatinlly with TTFM. The flow value of left internal mammary artery (LIMA) in 30 cases was also detected by the same way before grafting to left anterior descending (LAD). Results: There was no operative death and severe complications. The mean flow value of LIMA in 30 cases was (42.9?33.0)ml/min. The actual blood flow value, measured simultaneously by exsanguination was (37.4?28.8)ml/min. Excellent correlation was demonstrated. The mean pulsatility index value (PI) was 1.00?0.04. The flow curve showed both diastolic and systolic filling. The mean flow value of LIMA to LAD, saphenous vein graft (SVG) or radial artery (RA) to circumflex coronary artery (LCX) or diagonal (D), SVG or RA to right coronary artery (RCA) or post anterior artery (PDA) were (29.9?9.5)ml/min, (33.7?17.5)ml/min and (31.5?19.2)ml/min. The PI values were 2.47?0.88, 4.00?1.90 and 2.60?1.30, respectively. The typical flow curve was shown in all LIMA to LAD, and SVG (or RA) to LCX (or D). Blood flow filling was mainly during diastole with minimal systolic peaks during the isovolumetric ventricular contraction. SVG or RA to RCA presents a particular flow pattern characterized by a dual filling. 6 grafts were revised basing on unsatisfied flow curves, PI, and the mean flow or all of them. Significant technical error such as conduit kinking, stenosis of distal anastomosis was found. Conclusion: The patency of graft in CABG can be verified in intraoperatively by use of TTFM. The decision of checking or revising a graft can be made basing on parameters acquired from the TTFM device. To correctly analyze the parameters warrants good clinical results.