Evaluation of serial haemodynamic changes during coronary artery anastomoses in patients undergoing off-pump coronary artery bypass graft surgery: Initial experiences using two deep pericardial stay sutures and octopus tissue stabilizer

Abstract

OBJECTIVE: This study was designed to evaluate the serial haemodynamic changes during coronary artery anastomoses using two deep pericardial stay sutures and octopus tissue stabilizer in patients undergoing initial experiences of off-pump coronary artery bypass graft surgery (OPCAB) using continuous cardiac output and mixed venous oxygen saturation (SvO(2)) monitoring. METHODS: With IRB approval, thirty patients undergoing OPCAB were studied. Pulmonary artery catheter (PAC) for continuous cardiac output and SvO(2) monitoring was inserted before anaesthesia. Haemodynamic measurements were recorded after pericardiotomy for baseline value. During each coronary artery anastomosis, haemodynamic variables were measured at 1,3,5,10, and 15 min after the application of tissue stabilizer and after the removal. Vasopressors were used to maintain mean arterial pressure (MAP) higher than 60 mmHg. RESULTS: MAP and heart rate (HR) were maintained without significant change during the anastomoses of all three arteries. Cardiac index (CI), and SvO(2) decreased significantly after stabilizer application in all three arteries. CI was below 2.5 l/min/m(2) and SvO(2) was under 70% during left circumflex artery (LCX) anastomosis. The decrease in CI and SvO(2) were significantly greater during LCX anastomosis. The increase in mean pulmonary artery pressure (MPAP) and pulmonary capillary wedge pressure (PCWP) was significant only in left anterior descending artery (LAD). Central venous pressure (CVP) increased significantly during the anastomosis of all three coronary arteries. The differences in MPAP, PCWP and CVP among the three coronary arteries were not statistically significant. The highest dose of vasoconstrictor was used during LCX anastomosis. CONCLUSIONS: When the coronary anastomoses were performed with two deep pericardial stay sutures and octopus tissue stabilizer on the beating heart, CI and SvO(2) decreased significantly during all coronary artery anastomoses immediately after the stabilizer application and the degree of reduction in CI and SvO(2) increased with time, though MAP was maintained constantly. CI and SvO(2) during LCX anastomosis were consistently below normal values. Therefore close monitoring and proper managements are needed during graft anastomoses.