[Influence of preoperative factors on off-pump coronary aortic bypass grafting success]

Heart displacement during off-pump CABG (OPCAB) might induce the hemodynamic instability. We attempted to show which preoperative factors would contribute to an increase in that incident during OPCAB. Between February 2000, and October 2000, 51 patients underwent CABG in Okamura Memorial Hospital. Of these patients, 42 patients (82.4%) underwent OPCAB and 9 patients (17.6%) were operated upon under cardiac arrest with cardiopulmonary bypass (NOPCAB). To expose target coronary arteries for OPCAB, 3 deep pericardial traction stitches were placed near the left lower pulmonary vein (LPV), the left of the inferior vena cava (IVC) and the mid portion between LPV and IVC. To further assist in providing good presentation, patients were placed in Trendelenburg position (30 degree head-down tilt) and the right decubitus (30 degree the right side-down tilt). There were no OPCAB patients to be converted to on-pump CABG during anastomosis. Mean number of grafts in OPCAB group was 2.5 +/- 0.1 per patient, while that in NOPCAB group was 3.4 +/- 0.2 (p < 0.01). The bypass patient rate were 97.1% (100/103) in OPCAB group and 100% (31/31) in NOPCAB group (p = NS). In both groups, bilateral internal thoracic arteries were actively used for reperfusion to the left coronary artery. In the preoperative catheterization findings, pulmonary capillary wedge pressure (PCW) and left ventricular end-diastolic pressure (LVEDP) were significantly higher in NOPCAB group than those in OPCAB group (PCW: 14.0 vs 7.9 mmHg, LVEDP: 14.0 vs 8.7 mmHg: p < 0.05), and there was a tendency of low preoperative ejection fraction (EF) and cardiac index (CI) in NOPCAB group compared with those in OPCAB group, although there were no differences in left ventricular end-diastolic and end-systolic volume index (LVEDVI and LVESVI) between both groups. These findings suggested that PCW and LVEDP within the normal limit could be credited for the success with OPCAB, while an increase of the left ventricular volume would not contribute to the actual success.