Parapagus conjoined twins with unilateral mesenteric venous outflow.

This case presents a complication of attempted separation of parapagus conjoined twins, related to loss of an intact mesenteric-portal venous axis. Despite known lack of a superior mesenteric artery in the right twin, initial evaluation in the operating room suggested that separation was possible. After hepatic division, however, it became apparent that the mesenteric drainage was not separable; and the operation was aborted. Subsequently, significant growth failure and hypoglycemia were noted in the right twin. The situation was corrected by creating a shunt to reinstitute mesenteric flow to the right twin's liver and separating the twin's mesenteric drainage. One year postoperatively, both twins are independently nourishing themselves and have been free from hospitalization with stable glucoses.