Long-term results of the "palliative" Mustard operation.

A long-term follow-up study after 41 palliative Mustard operations for transposition of the great arteries and pulmonary vascular obstructive disease is presented. The operations were performed from 1973 to 1980. Mean pulmonary arteriolar resistance was 13.96 +/- 6.7 Um2. A ventricular septal defect was not closed in 34 patients; in 7 it was created at operation. There were three hospital and two late deaths. Survivors were followed up for 3 to 10 years (mean 76.7 +/- 22.8 months). Before operation 4 children were in New York Heart Association functional class IV and 33 were in class III. Mean hemoglobin concentration was 19.43 +/- 3.14 g/dl and arterial oxygen saturation was 63.44 +/- 11.29%. After operation 18 patients were in functional class I, 17 in class II and only 1 in class III. Hemoglobin level decreased to 14.19 +/- 2.3 g/dl and arterial oxygen saturation improved to 89.12 +/- 7.25%. Cardiac catheterization in 21 survivors confirmed no change in pulmonary artery pressure and resistance. Effective pulmonary blood flow improved from 1.39 +/- 0.39 before to 2.6 +/- 0.78 liters/min per m2 after operation. The palliative Mustard operation carries a low risk and provides excellent symptomatic improvement up to 10 years in patients with transposition of the great arteries and pulmonary vascular disease.