Central and Peripheral Circulation Differ during Off-Pump Coronary Artery Bypass Grafting

Area of Science:

• Cardiovascular Surgery
• Physiology
• Medical Technology

Background:

• Off-pump coronary artery bypass grafting (OPCAB) is an alternative to on-pump CABG.
• Maintaining stable hemodynamics during OPCAB is crucial.
• Unexpected conversion to on-pump CABG may result from circulation instability.

Purpose of the Study:

• To investigate the impact of coronary artery ligation and shunt insertion during OPCAB on peripheral microcirculation.
• To evaluate the predictive value of cutaneous microcirculation for conversion to on-pump CABG.
• To assess changes in cutaneous laser Doppler perfusion (cLDP) and transcutaneous oxygen partial pressure (tcpO2) during OPCAB.

Main Methods:

• A pig model was used to evaluate peripheral circulation during OPCAB.
• Cutaneous laser Doppler perfusion (cLDP) and transcutaneous oxygen partial pressure (tcpO2) were monitored.
• Hemodynamic parameters (systolic, diastolic, mean arterial pressure) were recorded to ensure independence of perfusion measurements.

Main Results:

• Ligation of the left anterior descending coronary artery (LAD) significantly reduced cLDP and tcpO2.
• Insertion of a temporary shunt into the LAD significantly improved both cLDP and tcpO2 compared to ligation.
• Peripheral microcirculation (cLDP and tcpO2) was restored to near baseline levels after shunt insertion.
• Hemodynamic parameters remained stable throughout the OPCAB procedure.

Conclusions:

• Peripheral microcirculation is significantly affected during OPCAB, despite stable central hemodynamics.
• Temporary shunt insertion effectively normalizes peripheral microcirculation during OPCAB.
• Monitoring peripheral microcirculation may help predict the need for conversion to on-pump CABG.