[Evaluation of cross circulation in conjoined twins].

This report describes the evaluation of cross circulation in conjoined twins. Female thoracoomphalopagus conjoined twins were delivered by cesarean section after 37 week's gestation. CT, MRI and echography were performed. A partial communication of pericardium and sternum, and a union of the liver were found. For the preoperative evaluation of cross circulation, a bolus of indigo carmine was injected, and the pigment appeared in the urine of the other twin. RI angiography showed that radionuclides in one twin were similar to those in the other after 5-10 minutes. During the operation, an injected bolus of SCC to one twin was not effective for the other twin. Inhaled isoflurane in one twin did not appear in the expired gas of the other twin. After the intentional hemorrhage for 3 minutes from one twin, the hemoglobin concentration of one of the twin was the same as that of the other. This demonstrates that acute hemorrhage from one twin seems to result in a significant and rapid decrease of hemoglobin in both babies equally. However, intravenous infusion of drugs to one of the twins requires a relatively long time to take effect in the other baby. We must be careful in anesthetic management of the surgical separation of conjoined twins.