[Intraoperative coronary flow measurement during bypass surgery: methods, clinical significance, and practical...

The success of coronary bypass surgery fundamentally depends on the proper function of the new conduits. The aim of intraoperative monitoring is to prevent early conduit occlusion and improve long-term outcomes. The 'Transit Time Flow Measurement' technique enables real-time, quantitative flow assessment, providing objective information about the hemodynamic status of the conduit. Based on the principle of ultrasonic transit time, this method allows for the determination of mean blood flow through the conduit and the pulsatility index. 'Transit Time Flow Measurement' reduces the risk of early conduit failure and supports surgical decisions, particularly with uncertain anastomoses. The most important parameters include mean flow, pulsatility index, and diastolic filling ratio, which are evaluated according to standardized thresholds. The advantages of the technique are its simplicity and rapid results, while its limitations include technical sensitivity, variability of measurement conditions, and dependence on operator experience. Comparison of the technique with other intraoperative techniques, such as angiography, highlights that although it does not replace visual inspection, it is an important adjunct tool for ensuring conduit quality. Overall, integration of 'Transit Time Flow Measurement' technique into routine surgical practice represents a significant advancement in the safety and efficacy of coronary bypass procedures. Orv Hetil. 2026; 167(6): 217-224.