Perioperative Ultrasound Flow Evaluation in Grafts and Native Vessel during CABG

Abstract

New blood in the vascular bed after coronary artery bypass grafting (CABG) may represent a turning point between ischemia and normal tissue nutrition. Quality control during CABG preoperatively is essential because errors lead to immediate consequences. With an understanding of hemodynamics, we can now search for less invasive tools for quantification of coronary blood flow changes over time after CABG. Ultrasound is becoming a key player for that purpose and we will present its application. Perioperatively, quality control in CABG should include target selection of native coronary arteries, graft selection, anastomose checking, and long-term flow follow-up. Because some grafts are unreachable for ultrasound evaluation, we should examine both arterial venous sides of coronary circulation. We will present the use of classic, epicardial ultrasonography and TTFM probes by looking for stenoses and competitive flow. We will present our research for quantification of new blood in coronary vessels after CABG. There we found constant increase in flow over the early postoperative period (20% per graft). By increasing graft number, coronary flow increases first linearly and then stepwise. Measured data and trends can be used in ambulatory monitoring and screening of ischemic complications after CABG.