Optimized technique for intraoperative graft verification by ultrasonic flowmetry during coronary artery bypass surgery

Purpose. To determine the role of three-stage ultrasonic flowmetry of coronary bypass grafts for the purpose of early verification of technical errors during coronary bypass surgery.Material and Methods. A total of 214 grafts were analyzed. The first stage of flowmetry was performed on the arrested heart with and without proximal loop test; the second stage was performed after weaning patient from the heart-lung machine; the third was done after inactivation of heparin until the closure of the chest wound.Results. Among 214 grafts, flowmetry revealed insufficient blood flow in 4.2% (n = 9) of cases. Technical surgical errors in these shunts were confirmed during their revision. During the first measurement, non-optimal flowmetry parameters were observed in six cases (2.8%) including five cases (2.3%) where non-optimal blood flow was verified using a proximal loop test on the target coronary artery and one case (0.47%), which was not tested. Inadequate blood flow was found in one case (0.47%) during the second measurement, which confirmed technical errors in the proximal anastomoses. Low blood flow parameters were found in two cases (0.93%) during the third measurement, which was associated with bending of the shunts due to their excessive length. All surgical errors were corrected immediately at the stage of their verification.Conclusion. The strategy of three-stage flowmetry assessment makes it possible to ensure and document the adequate functionality of coronary bypass grafts at all stages of the operation. This allows for timely verification and immediate correction of any technical problems with coronary bypass grafts.