Coronary Artery Bypass Supplemented by Grafting of the Right Ventricular Branches—Case Reports

Abstract

Seventeen patients presented with angina pectoris class IV with or without dyspnea, or with dyspnea alone.

Cardiac catheterization revealed an elevated right atrial mean (6.5±3.2 mmHg), right ventricular systolic (31.3±10.3 mmHg) and diastolic (7.3±3.8 mmHg), pulmonary artery systolic (32.9±10.3 mmHg) and diastolic (15.4±5.8 mmHg), pulmonary capillary wedge (15.2±4.8 mmHg), and left ventricular end-diastolic (22.4±8.4 mmHg) pressures. The cardiac index was reduced (2.3±0.6 L/min/m²), as was the left ventricular ejection fraction (39.6±8.6%). Significant and diffuse coronary artery disease was present in 16 patients. In addition, their significant disease involved the proximal acute marginal (n = 6), or the anterior ventricular (n=5), or the anterior ventricular and acute marginal (n=1), or the conus and anterior ventricular (n=1) branches of the right coronary artery. In the remaining patients (n = 4), the latter artery had a significant lesion above or below the origin of those branches, which were free of disease per se. The right ventricular branches provided intercoronary or intracoronary collaterals, or both, in 12 patients.

Coronary artery bypass (4.6 grafts per patient) included vein grafts to the circumflex artery system (n = 22) ; the internal thoracic artery (n=8), or vein (n=6), or both (n=2) grafts to the left anterior descending artery; and vein grafts to the posterior descending artery (n = 8), diagonal branch (n = 7), ramus intermedius and right coronary artery (each, n = 3), and posterior left ventricular branch (n=1). It was supplemented by the vein grafts to the anterior ventricular (n=9), the acute marginal (n=7), or the acute marginal and conus (n=1) branches. One patient also had an aortic valve replacement.

Hemodynamics after the operation without pharmacologic support revealed significant decreases of the right atrial mean pressure to 4.7±2.5 mmHg (p < 0.01), pulmonary artery systolic pressure to 24±7.0 mmHg (p < 0.01), pulmonary artery diastolic pressure to 11.9±3.4 mmHg (p < 0.01), and pulmonary capillary wedge pressure to 9.6±2.9 (p < 0.01). There was a highly significant decrease of the left ventricular end-diastolic pressure as measured indirectly by pulmonary artery diastolic pressure to 11.9±3.4 mmHg (p < 0.001) and by pulmonary capillary wedge pressure to 9.6±2.9 mmHg (p < 0.001). Cardiac index increased significantly to 3.2±0.9 L/min/m² (p < 0.01).

All patients are alive and free of angina and dyspnea.

Did the revascularization of the right ventricular branches contribute to a functional improvement of the right and adjacent segments of the left ventricles and the septum?