Abstract
Anastomotic quality is directly associated with clinical outcomes of patients after coronary artery bypass grafting (CABG). Early and late graft failure are potentially fatal complications that can cause refractory angina, myocardial infarction, and arrhythmias. Hence, intraoperative graft assessment is of paramount importance in detecting stenotic anastomoses and ensuring the future graft function. Transit-time flow measurement (TTFM) is a less invasive and frequently used technique for intraoperative graft assessment during CABG. Previous studies have indicated that TTFM provides great benefits for patients in intraoperatively detecting stenotic anastomoses and in avoiding unnecessary postoperative complications. Accordingly, current clinical guidelines recommend routine intraoperative graft flow measurements during CABG. However, the interpretation of composite or sequential grafting by TTFM to predict the risk of graft failure remains controversial. Additionally, the TTFM prognostic value demonstrated lower accuracy in detecting anastomotic stenosis in patients with saphenous vein grafts than in patients with intrathoracic artery grafts. This clinically focused review of TTFM assessment of CABG revealed the clinical advances acquired with TTFM, which were diagnostically used in the detection of anastomotic stenosis in previously published studies. We provide a systematic overview of the evidence and considerations regarding the following topics: general principles of TTFM, intraoperative acquisition protocol, effects of TTFM on postoperative clinical outcomes, recommended cutoff values for each parameter, and the influence of graft type on the diagnostic value of TTFM.
