Relative Efficacy of Left Ventricular Venting and Venous Drainage Techniques Commonly Used during Coronary Artery Bypass Graft Surgery

Abstract

Sixty patients with symptomatic coronary artery disease undergoing coronary artery bypass graft operation were prospectively randomized into one of six equal groups based on the intraoperative method of left ventricular venting and venous drainage. Group 1 had bicaval venous drainage without snaring and left ventricular venting through the superior pulmonary vein; Group 2, two-stage venous drainage and venting as in Group 1; Group 3, bicaval venous drainage without snaring and no left ventricular vent; Group 4, two-stage venous drainage and no left ventricular vent; Group 5, bicaval venous drainage without snaring and with ascending aortic venting through a catheter; and Group 6, two-stage venous drainage and venting as in Group 5. Left ventricular performance was determined by radionuclide ventriculography from which global ejection fraction and regional wall motion were determined. Cardiac output was obtained by the thermodilution technique. Myocardial temperature was assessed by a needle thermistor during aortic cross-clamping. Serial electrocardiograms and levels of myocardial-specific isoenzymes (serum CPK-MB) were also analyzed. Each of the techniques tested was equally effective as determined by an analysis of intraoperative myocardial cooling and postoperative hemodynamic profiles, radionuclide ventriculography, and ECG or enzymatic evidence of myocardial damage. However, we maintain that this conclusion is valid only if adequate ventricular decompression is provided intraoperatively.