Reduction of carbon dioxide embolism for endoscopic saphenous vein harvesting

The endoscopic saphenous vein harvesting (EVH) introduced in coronary artery bypass surgery (CABG) is associated with less wound complication and postoperative pain. Carbon dioxide (CO2) insufflation is used during EVH to facilitate the procedure. The purpose of this study was to determine whether the incidence of CO2 embolism during EVH with CO2 insufflation could be reduced with lower CO2 insufflation pressure.

Four hundred and ninety-eight consecutive patients scheduled for elective off-pump CABG were prospectively studied. These patients were randomly assigned into high and low groups in which 15 and 12 mm Hg CO2 insufflation pressures were used during EVH, respectively. Multiplane transesophageal echocardiography (TEE) with transgastric inferior vena cava view was used to monitor the appearances of CO2 bubbles. If a burst of many CO2 bubbles were found by TEE, the CO2 insufflation would be stopped until detailed examination of the operative field.

The incidence of CO2 embolisms in the high group of patients (13.3%) was significantly higher than that in the low group (6.5%, p < 0.05). Two episodes of emergent cessation of CO2 insufflation occurred in the high group of patients. No massive CO2 embolism with significant hemodynamic alterations occurred in either group.

The incidence of CO2 embolisms during EVH could be reduced with lower CO2 insufflation pressure, which, in combination with increased surgical experience and continuous TEE monitoring of the inferior vena cava, helps to reduce the risks of massive CO2 embolism.