The abdominal aorta in spina bifida cystica.

The features of abdominal aortography in a small group of severely affected children with spina bifida cystica and kyphosis are presented. The examination was done to spinal fusion as earlier surgical reports had indicated a close relationship between the aorta and the vertebral bodies forming the apex of the kyphosis. The abdominal aorta was shown to bridge the apex of the kyphosis, thus it was outside the field of surgery and was not a potential hazard. Three vascular abnormalities emerged. First, the position of the aortic bifurcation, as judged by the vertebral level, was shown to be rather lower than usual, although lumbar kyphosis masked a relative aortic shortening. Second, the aorta was abnormally small in calibre with hypoplastic limb vessels. Third, abnormal segmentation of lumbar arteries was found in four of the eight in whom they were visualised, and correlates with the presence of vertebral body maldevelopment as opposed to neural arch maldevelopment. The possible pathogenic significance is discussed.