Evaluation of graft flow between on-pump and off-pump coronary artery bypass grafting

Abstract

Background: Coronary artery bypass grafting (CABG) is an effective method to afford sufficient blood flow for that ischemic myocardium. Off-pump coronary bypass surgery (OPCAB) has been rediscovered and refined to avoid cardiopulmonary bypass. However, it’s a high technique demanding skill. And evaluation of the blood flow should be reliable. Transit time flow measurement (TTFM) is introduced to evaluate graft flow and anastomosis patency intraoperatively. The accuracy of graft flow depends on how to explain the parameters of TTFM. Here, we introduce our experiences on the explanation of TTFM parameters. Objective: We compared the graft patency of off-pump coronary artery bypass grafting with those of on-pump coronary artery bypass grafting by intraoperative transit time flow measurement (TTFM). Methods: Three hundred patients were divided into off-pump group and on-pump group. TTFM was routinely performed for assessment of graft patency during operation. Revision of the grafts depends on the TTFM findings. Results: One patient in OPCAB group was converted to conventional CABG group due to ventricular fibrillation. One patient died of multiple organ failure 21 days post-operation. Seven grafts were revised based on unsatisfactory TTFM findings. There was no statistical difference in the variables between the two groups except for anastmosis to right coronary artery. Conclusions: Off-pump surgery can provide the same flow of grafts as that of on-pump surgery. TTFM is an effective tool to decide if a well-function graft is or not, and it allows for revision of failure graft during operation. Keywords: Backward flow percentage, coronary artery bypass grafting, pulsatile index, revascularization, transit time flow measurement