High-output cardiac failure in fetuses with large sacrococcygeal teratoma: diagnosis by echocardiography and Doppler ultrasound.

With two-dimensional echocardiography and Doppler ultrasound, we demonstrated high-output cardiac failure in three fetuses with large sacrococcygeal teratomas. All fetuses had normal cardiac structure, dilated ventricles maintaining a normal fractional shortening index, a dilated inferior vena cava reflecting the increased venous return from the lower body, pericardial and pleural effusions as a manifestation of fetal hydrops, and a markedly thickened placenta. When fetal hydrops was present, the combined ventricular output was very high (mean 1280 ml/min/kg; normal 553 +/- 153 (SD)). Descending aortic flow was also sharply increased (mean 930 ml/min/kg; normal 184 +/- 20), as was placental flow (mean 480 ml/min/kg, normal 110 +/- 26). High-velocity arterial flow signals were also found within the tumor. In one fetus studied serially, placental thickness and tumor diameter increased rapidly; placental flow as a percentage of descending aortic flow decreased, indicating a further increase of flow to the tumor. These abnormal hemodynamic changes were reversed after the fetus's teratoma was surgically removed. We conclude that the sacrococcygeal teratoma acts as a large arteriovenous fistula, which causes high-output cardiac failure. Surgical removal of the teratoma in a previable fetus with such hemodynamic findings may prove to be the most effective treatment.