Evaluation of right ventricular function during aortic operations
T. J. Vandermeer, B. S. Maini, T. H. Hendershott and F. D. Sottile
Department of Surgery, Saint Vincent Hospital, Worcester, MA 01604-4593.
The simultaneous measurements of mixed venous oxygen saturation (SvO2) and
right ventricular ejection fraction (RVEF) have now made it possible to
precisely define and correlate the various hemodynamic changes that occur
during abdominal aortic operations. Twenty-five patients undergoing
infrarenal abdominal aortic aneurysm repair were examined with a pulmonary
artery catheter capable of continuously measuring SvO2 and RVEF. With
aortic clamping, significant reductions in cardiac index, stroke volume
index, and right ventricular end-diastolic volume index (RVEDVI) were
noted, while RVEF remained unchanged. Following unclamping of the aorta, a
significant reduction in SvO2 occurred, accompanied by an increase in mean
pulmonary artery pressure and in pulmonary vascular resistance. Despite the
increase in afterload, RVEDVI and RVEF did not change after unclamping.
These preliminary data suggest that right ventricular function is preserved
during abdominal aortic aneurysm repair.