Determination of timing for reoperation in patients after right ventricular outflow reconstruction

After right ventricular (RV) outflow reconstruction, patients often develop postoperative outflow tract stenosis or pulmonary regurgitation, or both. The aim of this study was to assess the relation between RV hypertrophy, volume, pressure, and function and to provide indications for repeat surgery. We performed magnetic resonance imaging to measure RV volume, wall mass, and the ratio of mass to volume in 31 patients after RV outflow reconstruction and in 12 controls. Patients were divided into 2 groups, New York Heart Association class I and the repeat surgery group. The RV stress index was defined as RV peak systolic pressure/(mass to volume); RV ejection fraction (EF) was calculated by ventriculography. The RV stress index for the repeat surgery group was significantly higher than for the remaining groups (p <0.01). In the New York Heart Association class I and control groups, a significant inverse correlation was observed between RVEF and the RV stress index (r = -0.59, p <0.01). All patients in reoperation group whose RVEF decreased to <95% confidence limit of regression had symptoms of RV failure. The RV stress index decreased substantially after reoperation, but RVEF remained at <95% limits. These findings suggest that excess RV wall stress contributes to impaired RV performance. The RV stress-RVEF relation may be useful in assessing RV function and in establishing a surgical indication.